902.2 MECHANICAL PROPERTIES - New Millennium Building

Transcription

Introduction
• High-Strength Low-Alloy Structural Steel with 50 ksi (345 MPa)
Minimum Yield Point to 4 inches (100 mm) thick, ASTM A588/
A588M
Special Profile Joists
This specification covers the design, manufacture and use of
Special Profile Steel Joists, SP-Series. Load and Resistance
Factor Design (LRFD) and Allowable Strength Design (ASD) are
included in this specification.
The term “Special Profile Steel Joists, SP-Series” as used
herein, refers to open web, load-carrying members utilizing hotrolled or cold-formed steel, including cold-formed steel whose
yield strength has been attained by cold working. SP-Series steel
joists are suitable for the direct support of roof decks in buildings.
SP-Series Design
The design of SP-Series joists’ chord and web sections shall be
based on a yield strength of at least 36 ksi (250 MPa), but not
greater than 50 ksi (345 MPa). Steel used for SP-Series joist
chord or web sections shall have a minimum yield strength
determined in accordance with one of the procedures specified
in Section 902.2, which is equal to the yield strength assumed
in the design. SP-Series joists shall be designed in accordance
with these specifications to support the loads specified in the
joist designation.
SP-Series Tables
The term “Yield Strength” as used herein shall designate the
yield level of a material as determined by the applicable method
outlined in paragraph 13.1 “Yield Point,” and in paragraph 13.2
“Yield Strength,” of ASTM A370, Standard Test Methods and
Definitions for Mechanical Testing of Steel Products, or as
specified in Section 902.2 of this specification.
902.1 STEEL
The steel used in the manufacture of chord and web sections
shall conform to one of the following ASTM specifications:
• Carbon Structural Steel, ASTM A36/A36M
• High-Strength Low-Alloy Structural Steel, ASTM A242/A242M
Standard Specification
• High-Strength Carbon-Manganese Steel of Structural Quality,
ASTM A529/A529M, Grade 50
• High-Strength Low-Alloy Columbium-Vanadium Structural
Steel, ASTM A572/A572M, Grade 42 and 50
88
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• Steel, Sheet and Strip, High-Strength, Low-Alloy, Hot-Rolled
and Cold-Rolled, with Improved Corrosion Resistance,
ASTM A606
• Steel, Sheet, Cold-Rolled, Carbon, Structural, High Strength
Low-Alloy and High-Strength Low-Alloy with Improved
Formability, ASTM A1008/A1008M
• Steel, Sheet and Strip, Hot-Rolled, Carbon, Structural,
High-Strength Low-Alloy and High-Strength Low-Alloy with
Improved Formability, and Ultra-High Strength, ASTM A1011/
A1011M
or shall be of suitable quality ordered or produced to other than
the listed specifications, provided that such material in the state
used for final assembly and manufacture is weldable and is proven
by tests performed by the producer or manufacturer to have the
properties specified in Section 902.2.
902.2 MECHANICAL PROPERTIES
The yield strength used as a basis for the design stresses
prescribed in Section 903 shall be either 36 ksi (250 MPa) or 50
ksi (345 MPa). Evidence that the steel furnished meets or exceeds
the design yield strength shall, if requested, be provided in the
form of an affidavit or by witnessed or certified test reports.
For material used without consideration of increase in yield
strength resulting from cold forming, the specimens shall be taken
from as-rolled material. In the case of material, the mechanical
properties of which conform to the requirements of one of the
listed specifications, the test specimens and procedures shall
conform to those of such specifications and to ASTM A370.
In the case of material, the mechanical properties of which do not
conform to the requirements of one of the listed specifications,
the test specimens and procedures shall conform to the applicable
requirements of ASTM A370, and the specimens shall exhibit a
yield strength equal to or exceeding the design yield strength
and an elongation of not less than (a) 20 percent in 2 inches (51
mm) for sheet and strip, or (b) 18 percent in 8 inches (203 mm)
for plates, shapes, and bars with adjustments for thickness for
plates, shapes, and bars as prescribed in ASTM A36/A36M, A242/
A242M, A529/A529M, A572/A572M, A588/A588M, whichever
specification is applicable on the basis of design yield strength.
The number of tests shall be as prescribed in ASTM A6/A6M for
plates, shapes, and bars; and ASTM A606, A1008/A1008M and
A1011/A1011M for sheet and strip.
STANDARD SPECIFICATION, SP-SERIES
a) The yield strength calculated from the test data shall equal or
exceed the design yield strength.
c) Where compression tests are used for acceptance and control
purposes, the specimen shall withstand a gross shortening of
2 percent of its original length without cracking. The length
of the specimen shall be not greater than 20 times the least
radius of gyration.
902.3 WELDING ELECTRODES
The following electrodes shall be used for arc welding:
b)For connected members both having a specified minimum yield
strength of 36 ksi (250 MPa) or one having a specified minimum
yield strength of 36 ksi (250 MPa), and the other having a
specified minimum yield strength greater than 36 ksi (250 MPa):
a) Steel Structures Painting Council Specification, SSPC No. 15
b) Shall be a shop paint which meets the minimum performance requirements of the above listed specification
903.1 METHOD
SP-Series joists shall be designed in accordance with these
specifications as simply supported, uniformly loaded trusses
supporting a roof deck so constructed as to brace the top
chord of the joists against lateral buckling. All joists are
designed as pinned at one end and roller bearing on the
opposite end to prevent horizontal thrust to the supporting
structure. The end fixity conditions of Scissor and Arch joists
require special consideration from the specifying professional
regarding end anchorage conditions. (See Sections 904.1 and 904.7)
Where any applicable design feature is not specifically covered
herein, the design shall be in accordance with the following
specifications:
a)Where the steel used consists of hot-rolled shapes, bars or
plates, use the American Institute of Steel Construction,
Specification for Structural Steel Buildings.
b)For members that are cold-formed from sheet or strip
steel, use the American Iron and Steel Institute, North
American Specification for the Design of Cold-Formed Steel
Structural Members.
SP-Series Tables
a) For connected members both having a specified minimum
yield strength greater than 36 ksi (250 MPa):
AWS A5.1:
E70XX
AWS A5.5: E70XX-X
AWS A5.17: F7XX-EXXX, F7XX-ECXXX flux-electrode
combination
AWS A5.18: ER70S-X, E70C-XC, E70C-XM
AWS A5.20: E7XT-X, E7XT-XM
AWS A5.23: F7XX-EXXX-XX, F7XX-ECXXX-XX
AWS A5.28: ER70S-XXX, E70C-XXX
AWS A5.29: E7XTX-X, E7XTX-XM
The standard shop paint is intended to protect the steel for
only a short period of exposure in ordinary atmospheric
conditions and shall be considered an impermanent and
provisional coating. When specified, the standard shop paint
shall conform to one of the following:
SP-Series Design
d) If any test specimen fails to pass the requirements of the
subparagraphs (a), (b), or (c) above, as applicable, two retests
shall be made of specimens from the same lot. Failure of
one of the retest specimens to meet such requirements
shall be the cause for rejection of the lot represented by
the specimens.
902.4 PAINT
b) Where tension tests are made for acceptance and control
purposes, the tensile strength shall be at least 6 percent
greater than the yield strength of the section.
Introduction
If as-formed strength is utilized, the test reports shall show the
results of tests performed on full section specimens in accordance
with the provisions of the AISI North American Specifications
for the Design of Cold-Formed Steel Structural Members. They
shall also indicate compliance with these provisions and with the
following additional requirements:
Design Basis:
Designs shall be made according to the provisions in this
Specification for either Load and Resistance Factor Design (LRFD)
or for Allowable Strength Design (ASD).
AWS A5.1: E60XX
AWS A5.17: F6XX-EXXX, F6XX-ECXXX flux-electrode
combination
AWS A5.20: E6XT-X, E6XT-XM
AWS A5.29: E6XTX-X, E6XTX-XM
or any of those listed in Section 902.3(a)
Load Combinations:
Other welding methods, providing equivalent strength as
demonstrated by tests, may be used.
1.4D
1.2D + 1.6 (L, or Lr, or S, or R)
LRFD:
When load combinations are not specified to NMBS, the required
stress shall be computed for the factored loads based on the
factors and load combinations as follows:
89
ASD:

 QFy



Introduction
F
ASD:
 QFy  
ASD:
Fcr  Q 0.658  e  F
When load combinations
are not specified to NMBS, the
y F 
ASD:
QF
 y  
e




 0.658

requiredWhen
stressload
shall
be computed
based
on theto load
F
Q
F

combinations
are not
specified
NMBS, the
cr
0.658  Fe  F
 y
(903.2-3)
F
Q

When
load
combinations
are
not
specified
to
NMBS,
the
When
load
combinations
are
not
specified
to
NMBS,
the
required
combinations
as
follows:
required
stress
shall
be
computed
based
on
the
load
cr
y
ASD:



    QFy  

requiredcombinations
stress
shall
be
computed
based
on
the loadas follows:
(903.2-3)
asbe
follows:
stress
shall
computed
based
on
the
load
combinations
F

e

D
(903.2-3)
Fcr  Q 0.658
Fy(903.2-3)
When load combinations are not specified to NMBS, the
combinations
as follows:


D + (L, or
S, or R)stress shall be computed based on the load
D Lr, or
required
D


D
D + (L,
or Lr, or S, or
For members with K  4.71 E
(903.2-3
combinations
asR)
follows:
r
QFy E
D +S,(L,ororR)
Lr, or S, or R)
K

D + (L, or Lr, or
Where:
For
members
with
For members with
 4.71
QFy
D
Where:
For members with K  4.71r E
D = dead
loadDdue
weight of the structural
r
QFy
Where:
+ (L, to
or Lthe
r, or S, or R)
Where:
elements
andload
the due
permanent
featuresof ofthethe
D = dead
to the weight
structural
For members with K  4.71 E
D=
dead
due
the
weight
the structural
r
QFy
Fcr  0.877 Fe
(903.2-4)
D = dead
load
dueload
toand
thetothe
weight
of ofthe
structural
structure
elements
permanent
features elements
of the Where:
Fcr = 0.877F
(903.2-4)
and
permanent
features
of theequipment
structure
and
the
permanent
features
of the
Fecr  0.877 Fe
(903.2-4)
L = elements
live
loadstructure
due
tothe
occupancy
and
movable
Dload
= due
dead
load
due and
to movable
the
weight
of the structural Fcr  0.877 Fe
(903.2-4)
Lr = structure
roof
load
L live
=L live
and
movable
equipment
=
live
load
duetotooccupancy
occupancy
equipment
elements
andmovable
the permanent
buckling stress determined in accordance
L
load
tolive
occupancy
and
equipment features of the FFe ==Elastic
S = live
snow
load
LrL
=
live
load
=due
load
rroof
roof
Elastic buckling
determined
in accordance
e
Fcr stress
 0.877
Fe
(903.2-4
structure
L
load
with
Equation
903.2-5
Rr = roof
load
due
to
initial
rainwater
or
ice
exclusive
of
the
S live
=S=
snow
load
with Equation
903.2-5
snow
load
buckling
stress
determined
in accordance
F
e = Elastic
L
=
live
load
due
to
occupancy
and
movable
equipment
S = snow
load
ponding
contribution
R = load
due to initial rainwater or ice exclusive of the
determined in accordance
Fe = Elastic
with buckling
Equationstress
903.2-5
R=to
load
due
to
initial
rainwater
or ice exclusive of the Lrinitial
=contribution
roof
live load
R = load dueponding
rainwater
or ice exclusive of the
with
Equation
903.2-5
2
ponding
contribution
 E
S = snow
load Loads for Buildings and
contribution
The currentponding
ASCE
7,
Minimum
Design
determined in accordan
(903.2-5)
F 
2Fe = Elastic buckling stress
2  E
R be=7,load
due
initial and
rainwater
orload
ice exclusive
of the e
Other Structures
used
for toDesign
LRFD
ASD
The currentshall
ASCE
Minimum
Loads
for Buildings
and
(903.2-5)
with Equation 903.2-5
2 
KF
(903.2-5)
ponding
contribution
The
current
ASCE
7, Minimum
Design
Loads
forLRFD
Buildings
The
current
ASCE
7,pertains
Loads
for
Buildings
combinations.
This
provision
exclusively
to and
the
Other
Structures
shall
beMinimum
used
forDesign
and
ASD
load
reE K 2
(903.2-5)
Fe 
2
Other
Structures
shall
bedoes
used
for
LRFD
ASD
load
combination
ofand
loads
and
notshall
imply
that
NMBS
verify
orASD
combinations.
This
provision
pertains
to load
the
r
Other
Structures
be
usedand
forexclusively
LRFD
and
2

E
For
hot-rolledKsections,
“Q” is the 
full
reduction factor for slender
Theofprovision
current
ASCE
7, Profile
Minimum
Design
Loads
for Buildings
and
combinations.
This
pertains
exclusively
to
the
generatecombination
load combinations.
development
for
Special
Joists.
r
loads
and
does
not
imply
that
NMBS
verify
or
(903.2-5
Fe 
This provision pertains exclusively to the
2
compression
elements.
Other
Structures
shall
be
used
for
LRFD
and
ASD
load
combination
of loads
does not for
imply
that Profile
NMBS Joists.
verify or
generate
load and
development
Special
For hot-rolled sections, “Q” K
is the full reduction factor for
combination
of
loads
and
does
not
imply
that
NMBS
generate
or
combinations.
This
provision
pertains exclusively to slender
the
generate
load development
for Special
Profile
Joists.
903.2 DESIGN
AND
ALLOWABLE
STRESSES
compression
For hot-rolledelements.
sections,r “Q” is the full reduction factor for
verify
load development
for SP-Series.
Design
Stress
= 0.9F
(LRFD)
combination
of loads
and STRESSES
does not imply that NMBS verify
or
crthe
903.2 DESIGN
AND ALLOWABLE
For
hot-rolled
sections,
“Q”
iselements.
full reduction (903.2-6)
factor for
slender compression
generate
load
development
for
Special
Profile
Joists.
Allowable
Stress
=
0.6F
(ASD)
(903.2-7)
903.2
DESIGN
AND ALLOWABLE
STRESSES
Design
Using Load
and Resistance
Factor Design (LRFD)
slender
compression
Design
Stress elements.
= 0.9Fcrcr(LRFD)
(903.2-6)
903.2
DESIGN
STRESSES
ForStress
hot-rolled
sections,
“Q” is(903.2-7)
the full(903.2-6)
reduction factor
Design
Using
LoadAND
and ALLOWABLE
Resistance Factor
Design (LRFD)
Allowable
Stress
= 0.6Fcr =(ASD)
Design
0.9Fcr (LRFD)
903.2
ANDso
ALLOWABLE
In theDesign
above equations,
ℓ is
taken
as
the
distance
in
inches
(mm)
Design
Using
Load
andDESIGN
Resistance
Factor
Design STRESSES
(LRFD)
slender
compression
elements.
Joists shall
have
their
components
proportioned
that the
Stress
=Stress
0.9F
(LRFD)
(903.2-6)
Allowable
=
0.6F
(ASD)
(903.2-7)
cr
cr
Design
Usingnot
Load
and Resistance
Factor Designthat
(LRFD)
between
panel points
for the
chord
andthe
the appropriate
shallfu, have
their
components
so proportioned
the
requiredJoists
stresses,
shall
exceed
Fn where,
Allowable
Stress
= 0.6F
(ASD)
(903.2-7) in
In the
above
equations,
 crismembers
taken as
distance
Design
Using
Load
and
Resistance
Factor
Joists shall
havestresses,
their components
proportioned
that
the Design (LRFD)
Stress
= 0.9F
(903.2-6
cr
required
fu, shall
notso
exceed
Fn where,
length
web
members,
and
r ispoints
the
corresponding
least
radius
In
the
above Design
equations,
foristhe
taken
as(LRFD)
the
distance in
inchesfor(mm)
between
panel
chord
members
Joistsfustress
their ksi
components
so proportioned that the
Allowable
Stress
=
0.6F
(ASD)
(903.2-7
required
,shall
shallhave
not exceed
F
cr
fu stresses,
= required
(MPa)
n where,
In
the
above
equations,

is
taken
as
the
distance
in
between
panel
points
for and
the
members
and
the inches
appropriate
length
forcomponent
web members,
requal
is the
of
gyration
of the (mm)
member
or any
thereof.
E ischord
shall
have
their
components
so proportioned thatinches
the (mm) between panel points for the chord members
stresses,
fu, shall
not
exceed
ΦFn where,
Fn = nominal
stress
ksi
(MPa)
furequired
=Joists
required
stress
ksi (MPa)
and
theleast
appropriate
length
for web
members,
corresponding
radius of
gyration
of the
memberand
or r is the
to
29,000
ksi
(200,000
MPa).
stresses,
fu, shall
not (MPa)
exceed Fn where,
In length
theleast
equations,
 ksi
isof(200,000
taken
as the or
distance
fu = required
stress
(MPa)
Fn =required
stress ksi
resistance
and
the corresponding
appropriate
web
members,
and
r is member
the
of 29,000
gyration
the
any component
thereof.
Eabove
isforradius
equal
to
funominal
stress
=factor
required
stress (MPa)
ksi ksi
(MPa)
F
inches
(mm)
between
panel
points
for
the
chord
nn =
 =stress
resistance
factor ksi
F
= nominal
design
ksi (MPa)
corresponding
least
radius
of
gyration
of
the
member
or
thereof.
E is equal
to 29,000web
ksi (200,000 memb
MPa).
Use
1.2 any
ℓ/rx component
for a crimped,
first primary
compression
Fn =factor
stress stress
ksi (MPa)
funominal
= required
 = resistance
and
the
appropriate
length
for
web
members,
and r is
Fn = design
stress
ksi (MPa) ksi (MPa)
any
component
thereof.
E
is
equal
to
29,000
ksi
(200,000
MPa).a moment-resistant weld group is not used for
member when
Allowable
Φstress
=Fresistance
factor
= nominal
stress
n Strength
= design
ksi
(MPa)
Fn Using
corresponding
least radius
of gyration
of the member
Design
Design
(ASD) ksi (MPa)
MPa).

r
for
a
crimped,
first
primary
compression
web
Use
1.2
this member; xwhere any
rx = member
radiusthereof.
of gyration
the plane
= resistance
factor
Using
ΦFn =Allowable
design
stress
ksi Design
(MPa) (ASD)
component
E isinequal
29,000web
ksi (200,0
Design
Strength
r x for
a crimped,
first primary
Use
1.2amoment-resistant
member
when
weld
group
iscompression
not to
used
Joists shall
have
theirFcomponents
so proportioned
that
the
of
the joist.
= design stress
(MPa)
n Strength
Design
Using
Allowable
Design
(ASD) ksi
MPa).

r
for
a
crimped,
first
primary
compression
web
Use
1.2
member
when
weld
group isinnot used
of gyration
for this member;
wherea rmoment-resistant
x
shallf, shall
have
their
components
so Design
proportioned
/  where,
requiredJoists
stresses,
not
exceed
FnStrength
x = member radius
Design
Using
Allowable
(ASD) that the
member
when
amember;
moment-resistant
weld
groupthe
is nominal
not of
used
rof
member
radius
gyration in
for
where
thecold-formed
plane
ofthis
the
joist.
Joists shall
havestresses,
their components
so proportioned
that the
required
f, shallAllowable
not exceed
Fn /  where,
x =calculating
For
sections
the
method
Design
Using
Strength
Design
(ASD)
first
primaryincompression w
Use
1.2
Joistsf, stress
shall not
haveexceed
their ksi
components
so proportioned that the
rx=r member
radius of
gyration
for this member;
where
x for a crimped,
the
plane
of
the
joist.
required
shall
Fn(MPa)
/  where,
fu stresses,
= required
column strength is given
in
the
AISI
North
American
Specification
member
a moment-resistant
shall
have
their
components
so proportioned thatthe
theplane
of the joist.
stresses,
f, shallksi
not(MPa)
exceed
Fn /Ὼ where,
For
sections when
the method
of calculatingweld
thegroup is not us
Fn = nominal
stress
fu required
=Joists
required
stress
ksi (MPa)
for
thecold-formed
Design of Cold-Formed
Steel
Structural
Members.
r
=
member
radius of
for
this
member;
where
required
stresses,
f,
shall
not
exceed
F
/

where,
x
f
= required
stress stress ksi (MPa)
nominal For
column
strengthsections
is given
the AISI
North
cold-formed
the inmethod
of calculating
thegyration
Fn =factor
(MPa) n
safety
u
funominal
stress
= required stress
ksiksi
(MPa)
the
plane
of
the
joist.
For
cold-formed
sections
the
method
of
calculating
the
F
=
nominal
ksi
(MPa)
American
Specification
for
the
Design
of
Cold-Formed
nominal
column
strength
is
given
in
the
AISI
North
n
 = safety
factor
Fn/ = allowable
stress
ksi (MPa)
(c)
Bending:
Φb = 0.90 (LRFD), Ὼb = 1.67 (ASD)
Fn fu= nominal
stress ksi (MPa)
= required
nominal
column
strength
is given
in Design
the AISIof North
Steel Structural
Members.
American
Specification
for the
Cold-Formed
 = safety
Stresses:
= allowable
stress stress ksi (MPa) ksi (MPa)
Fn/ factor
For cold-formed
sections
method of calculating
Ὼ stress
factor ksi
F=n safety
= nominal
stress
ksi (MPa)
American
Specification
for the Design
of the
Cold-Formed
Steel
Structural
Members.
Fn/Stresses:
= allowable
(MPa)
Bending
calculationsnominal
are to be
based strength
on using isthegiven
elasticin the AISI No
(a) Tension:
t = 1.67
(ASD)
column
t =0.90
= (LRFD),
safetystress
factor
Steel
StructuralMembers.
Fn/Ὼ=
allowable
ksi (MPa)
(c) Bending:
Stresses:
b = 0.90 (LRFD), b = 1.67 (ASD)
section
modulus.
American
Specification
for
the
Design of Cold-Form
(a) Tension:

=
0.90
(LRFD),

=
1.67
(ASD)
t
t
ksi (MPa)
Fn/ = allowable stress
(c) Bending: b = 0.90 (LRFD), b = 1.67 (ASD)
(a) Tension:
t = 0.90F(LRFD),
(ASD)
For Chords:
MPa)
Structural
t = 1.67
y = 50 ksi(345
Stresses:
Stresses:
(c)
Bending:
b =Steel
0.90
(LRFD),
Members.
(ASD)the elastic
Bending
calculations
are
to be based
on using
b = 1.67
section
For chords
and web members other than solid rounds:
For Webs:
Fy = 50 ksi
MPa),
For Chords:
Fy =(345
50 ksi
(345orMPa)
modulus.
Bending calculations are to be based on using the elastic
(a) For
Tension:
Ὼksi
= (LRFD),
1.67
(a) ΦTension:
=50
0.90
t =or1.67 (ASD)
tMPa)
For Chords:
Ft y===0.90
50
ksi
MPa)
36 (LRFD),
ksi
(250
F
ksi (345modulus.
MPa)
(345(ASD)
MPa),
Webs:
Fy=t(345
(c) are
Bending:
b = 0.90
(LRFD),
y = 50section
b = 1.67 (ASD)
Bending
calculations
to be based
on using
theelastic
For Webs:
Fy = 50 ksi
(345
MPa),
Fy =
36 ksi
(250orMPa)
section
Formodulus.
chords and web members other than solid
For chords:For
Fy =ksi
50(250
ksi (345
FyMPa)
= 50 (903.2-1)
ksi (345 MPa)
Fy ==Chords:
36
MPa)
Design Stress
0.9F
Design
Stress
calculations
are to be (903.2-8)
based than
on using
y (LRFD)
y (LRFD)
rounds:
For Bending
chords= 0.9F
and
web members
other
solidthe ela
= 50or
ksi (345(903.2-1)
MPa), or
For= Webs:
FyMPa)
ForStress
webs:
Fy = y50(ASD)
(345
Allowable
0.6F
(903.2-2)
Design
Stress
= ksi
0.9F
section
y (LRFD)
Allowable
Stress
=modulus.
0.6Fmembers
(903.2-9)
For chords
and web
other than
solid
y (ASD)
rounds:
Fy = 50 ksi (345 MPa)
FyMPa)
= 36(903.2-1)
ksi (250(903.2-2)
MPa)
Design
Stress
= 0.9F
(LRFD)
Allowable Stress
= ksi
0.6F
F
(250
y (ASD)
y = y36
rounds:
Fy = 50ofksi
(345
MPa)
Stressc = =
0.6F
y (ASD)c = 1.67(903.2-2)
(b) Allowable
Compression:
0.90
(LRFD),
(ASD)
For
chords
web members other than s
For web members
solid
round
crossand
section:
F
ksi (345 MPa)
Design
= 0.9Fy (LRFD)
(903.2-8)
DesigncStress
= 0.9F
y = 50 Stress
rounds:
(b) Compression:
= 0.90
(LRFD),
cy=(LRFD)
1.67 (ASD)
Design Stress
= 0.9F
(903.2-1)(903.2-1)
y (LRFD)
F
=
50
ksi
(345
MPa)
or
F
=
36
ksi
(250
MPa)
StressStress
=y 0.6Fy (ASD)
(903.2-9)(903.2-8)
Allowable
Stressc ==1.67
0.6F(ASD)
(903.2-2) yAllowable
Design
=
0.9F
y (ASD)
y (LRFD)
(b) Compression:

=
0.90
(LRFD),
c
E = 0.6Fy (ASD)
(903.2-2)
50 ksi
For membersAllowable
with K Stress
 4.71
y = 0.9F
Design Stress
AllowableFStress
=(345
0.6FMPa)
(903.2-9)
y (LRFD)
y (ASD) (903.2-8)
QFy E
r
StressStress of==solid
1.45F
(903.2-10)
y (LRFD)
K

For members
with
 4.71c = 0.90 (LRFD), c = 1.67 (ASD) Design
Allowable
0.6Fround
(903.2-9)
For web members
cross section:
y (ASD)
(b)
Compression:
QF
(b) Compression:
=r 0.90
c =y 1.67 (ASD)
E (LRFD), Ὼ
Allowable Stress
= 0.95F
(903.2-11)
yof(ASD)
For members
with K  4Φ.c71
Design
Stress
= 0.9F
(903.2-8
y (LRFD)
For web members
solid round
cross
section:
QFy
r
Fy =web
50 ksi
(345 MPa),
or Fround
= 36cross
ksi (250
MPa)
y Stress
Allowable
=section:
0.6F
(903.2-9
y (ASD)
For
members
of solid
Fy = 50 ksi (345 MPa), or Fy = 36 ksi (250 MPa)
For
with K  4.71 E
For members
members with
QFy
r
ksi (345 MPa),
or Fmembers
36 ksi of
(250
MPa)
F
Design
1.45F
(903.2-10)
y = 50 Stress
y y=(LRFD)
For= web
solid
round cross section:
Design Stress
= 1.45Fy (LRFD)
(903.2-10)
Fy == 1.45F
50 ksiy (345
MPa), or (903.2-10)
Fy = 36 ksi (250 MPa)
Design Stress
(LRFD)
 
SP-Series Tables
SP-Series Design
 
   
90
Design Stress
= 1.45Fy (LRFD)
85
(903.2-1
For bearing
plates:
Design
Stress
= 1.35Fy (LRFD) (903.2-12)
Stress
(ASD)
Fy = Allowable
50 ksi (345
MPa), or F=y 0.90F
= 36 yksi
(250 MPa) (903.2-13)
(d) Weld
Strength: = 1.35Fy (LRFD)
Design
Stress
Allowable Stress
= 0.90Fy (ASD)
(903.2-12)
(903.2-13)
Shear at throat of fillet welds:
(d) Weld Strength:
Nominal Shear Stress = Fnw = 0.6Fexx (903.2-14)
Nominal
LRFD: ΦwShear
= 0.75 Stress = Fnw = 0.6Fexx
(903.2-14)
= 0.75
LRFD:
wDesign
Shear Strength =
ΦRn Shear
= ΦwFnwStrength
A = 0.45F=exx A
Design
Rn = wFnw A = 0.45Fexx A
ASD: Ὼw = 2.0
(903.2-15)
(903.2-15)
ASD: w = 2.0
Allowable Shear Strength =
Allowable Shear Strength =
R /Ὼ = FnwA/Ὼw = 0.3Fexx A
Rn/wn = FwnwA/
w = 0.3Fexx A
(903.2-16)
(903.2-16)
Where
= effective
throat
area
Where
A =Aeffective
throat
area
flux-electrode combinations.
Fexx = 70 ksi (483 MPa)
Made with E60 series electrodes or F6XX-EXXX fluxelectrode
combinations.
Made with
E60 series electrodes or F6XX-EXXX flux-electrode combinations.
For
= 60 ksi (414 MPa)
Tension
on groove or butt welds shall be
exxcompression
the same as those specified for the connected material.
design element shall be accounted for in the design.

 (903.2-17)


(903.2-17)
= axial force required in the member
= distance from neutral axis to the extreme fiber
results
two stresses
for asymmetric sections such
Pr =axial
forceinrequired
in the member
as double angles
moment of inertia about axis perpendicular to radius
cIx ==distance
from neutral axis to the extreme fiber of divergence
results in two stress values for asymmetric sections R = radius of divergence from neutral axis. Usually the
such
as double
radius
of coldangles
rolling for Bowstring or Arch Joists
d = straight-line distance from node to node
Pr
c
Ix
= moment of inertia about axis perpendicular to 903.3
MAXIMUM
RATIOS
radius ofSLENDERNESS
divergence
The slenderness ratios, 1.0 /r and 1.0 s/r of members as a
R = radius of divergence from neutral axis. Usually the whole or any component part shall not exceed the values
radius of cold rolling for Bowstring or Arch Joists
given in Table 903.3-1, Parts A.
deffective
= straight-line
distance
fromK/r*
nodetotobe
node
The
slenderness
ratio,
used in calculating
the nominal stresses Fcr and Fe, is the largest value as
determined
from Table
903.3-1, Parts
B and C.
903.3 MAXIMUM
SLENDERNESS
RATIOS
Thecompression
slenderness ratios,
1.0 ℓ/rwhen
and 1.0
ℓs/rorof ties
members
as a they
In
members
fillers
are used,
whole
or
any
component
part
shall
not
exceed
the
values
given
shall be spaced so that the s/rz ratio of each component does
in Table
903.3-1,
Parts A. /r ratio of the member as a whole.
not
exceed
the governing
The
terms used
in Table ratio,
903.3-1
defined
ascalculating
follows:
The effective
slenderness
Kℓ/rare
to be
used in
nominal
Fcr and of
Fe,panel
is thepoints,
largestexcept
value as
the =
length stresses
center-to-center
= 36 in.
determined
from for
Table
903.3-1, /r
Parts
B and
C.member.
See P.N.
(914 mm)
calculating
chord
y of top
T.V. Galambos,
Chordsbetween
Without panel
Fillers point
=and
maximum
length Compression
center-to-center
Chod
s
and filler
or between
fillers
(ties).1975
in Longspan
Steel(tie),
Joists,
Research adjacent
Report No.
36, June
rStructural
= member
radius
gyration inDepartment,
the plane ofWashington
the joist.
x
Division,
CivilofEngineering
= member
radius
of
gyration
out
of
the
plane
of the joist.
rUniversity,
y
St. Louis, Mo.
rz = least radius of gyration of a member component.
In compression
members
or ties
are used, they
shall
* See P.N.
Chodwhen
andfillers
T. V.
Galambos,
Compression
be spaced
so thatWithout
the ℓs/rz Fillers
ratio of each
component does
Chords
in Longspan
SteelnotJoists,
Report
No.of36,
1975
exceed Research
the governing
ℓ/r ratio
theJune
member
as aStructural
whole. Division,
Civil Engineering Department, Washington University,
St. Louis, Mo.
The terms
used in Table 903.3-1 are defined as follows:
ℓ =length center-to-center of panel points, except ℓ =
36 inches (914 mm) for calculating ℓ/ry of top chord member.
ℓs =maximum length center-to-center between panel point
and filler (tie), or between adjacent fillers (ties).
rx =member radius of gyration in the plane of the joist.
ry =member radius of gyration out of the plane of the joist.
rz =least radius of gyration of a member component.
SP-Series Tables
Tension or
compression
on groove
butt welds
shallinto
be the
Divergence
Stress:
The design
of orchords
formed
same
as thosecold
specified
for shall
the connected
arches
through
rolling
include material.
a divergence
stress in the design. A secondary moment in the chord
resulting
from theStress:
divergence
of the ofactual
Divergence
The design
chordsmember
formed from
into arcs
the node-to-node linear design element shall be
through cold rolling shall include a divergence stress in the
accounted for in the design. In some cases the divergence
A secondary
moment
in the
chord
from
stressdesign.
may counter
act the
bending
stress
of resulting
the chord,
in the
divergence
of theofactual
memberstress
from the
node-to-node linear
this case
the effects
divergence
is ignored.
 divergence
Pr  c 
d2
2

 R R 
I x 
4
SP-Series Design
Made
withwith
E70E70
series
F7XX-EXXX flux Made
serieselectrodes
electrodes or
or F7XX-EXXX
electrode combinations.
shall be equal to:
Shear at throat of fillet welds:
For chords rolled to a radius, the secondary moment stress
shallFor
be equal
to: rolled to a radius the secondary moment stress
chords
Introduction
For bearing plates:
Fy = 50Stress
ksi (345 MPa)
or Fy y=(ASD)
36 ksi (250 MPa)
Allowable
= 0.95F
(903.2-11)
91
Introduction
TABLE 903.3-1
MAXIMUM AND EFFECTIVE SLENDERNESS RATIOS
kℓ/rx kℓ/ry kℓ/rz kℓs/rz
I TOP CHORD INTERIOR PANEL
A. The slenderness ratios, 1.0ℓ/r and 1.0ℓs/r , of members as a
whole or any component part shall not exceed 90.
B.
The effective slenderness ratio, kℓ/r, to determine Fcr where k is:
1. With fillers or ties 2. Without fillers or ties 3. Single component members 0.75
--- 0.75
1.0 --- 1.0
--- 0.75 ---
1.0
-----
C.
The effective slenderness ratio, kℓ/r, to determine Fe where k is:
1. With fillers or ties
2. Without fillers or ties
3. Single component members
0.75
0.75
0.75
---
---
---
---
--- ---
-------
II TOP CHORD END PANEL
SP-Series Design
A. The slenderness ratios, 1.0ℓ/r and 1.0ℓs/r , of members as a
whole or any component part shall not exceed 120.
B.
The effective slenderness ratio, kℓ/r, to determine Fcr where k is:
1. With fillers or ties
2. Without fillers or ties 3. Single component members 1.0
--- 1.0 1.0
--- 1.0 --- 1.0 --- 1.0
-----
C.
The effective sl enderness ratio, kℓ/r, to determine Fe where k is:
1. With fillers or ties 2. Without fillers or ties 3. Single component members 1.0 1.0 1.0 --- --- --- --- --- --- -------
0.75 --- 0.75* 1.0 --- 1.0 --- 1.0 --- 1.0
-----
III TENSION MEMBERS – CHORDS AND WEBS
SP-Series Tables
A. The slenderness ratios, 1.0ℓ/r and 1.0ℓs/r , of members as a whole
or any component part shall not exceed 240.
IV COMPRESSION MEMBERS
A. The slenderness ratios, 1.0 and 1.0ℓs/r , of members as a whole
or any component part shall not exceed 200.
B. The effective slenderness ratio, kℓ/r, to determine Fcr where k is:
1. With fillers or ties 2. Without fillers or ties 3. Single component members Standard Specification
* If moment-resistant weld groups are not used at the ends of a crimped, first primary compression web member, then 1.2ℓ/rx must be used.
92
σdiv = Divergence stress applied where applicable as
Introduction
defined in Section 903.2.17
STANDARD
SPECIFICATION,
SP-SERIES
Mu = required flexural strength
using LRFD
load
combinations,
kip-in
(N-mm)
903.4
MEMBERS
4 MEMBERS 903.4 MEMBERS
stress
applied
where
applicable
as
σdiv =σDivergence
stress
where
applicable
as where
div = Divergence
903.4
MEMBERS
=applied
Divergence
stress
applied
applicable
as
aded
divDivergence
σσdiv
=applied
Divergence
stress
applied
where
applicable
.4
MEMBERS903.4
σstress
=Section
stress
applied
where
applicable
as as
SMEMBERS
= elastic section modulus, in3 (mm3)
σdiv = Divergence
where
applicable
as
div
defined
in
903.2.17
903.4
MEMBERS
defined
in
Section
903.2.17
σ
=
divergence
stress
applied
where
applicable
as
div
defined
in
Section
903.2.17
STANDARD
SPECIFICATION
–
SP
SERIES
defined
in
Section
903.2.17
STANDARD
SPECIFICATION
––=div=SP
SERIES
(a)
Chords
903.4
MEMBERS
defined
in
Section
903.2.17
903.4
MEMBERS
903.4
MEMBERS
= nominal axial
compressive
stress
based on /r as
FcrChords
Chords
Section
903.2.17
STANDARD
SPECIFICATION
–inDivergence
SP
SERIES
σ
Divergence
stress
applied
where
applicable
σ
=
stress
applied
where
applicable
σdefined
Divergence
stress
applied
where
applicable
asas
div
required
flexural
strength
using
LRFD
load as
div
STANDARD
SPECIFICATION
SP
SERIES
Mu =M
required
flexural
strength
using
LRFD
load
u
(a)
Chords
defined
Equation
903.2-17
required
flexural
strength
using
LRFD
load
(a)(a)
Chords
Chords
MM
==kip-in
required
flexural
strength
using
LRFD
load
u=ustrength
Muin
required
flexural
strength
using
LRFD
load
defined in Section 903.2(b), ksi (MPa)
flexural
using
LRFD
load
Mu = required
(a)Chords
combinations,
(N-mm)
defined
in
Section
903.2.17
defined
in
Section
903.2.17
defined
in
Section
903.2.17
combinations,
kip-in
(N-mm)
shall
M
=
required
flexural
strength
using
LRFD
load
903.4
MEMBERS
combinations,
kip-in
(N-mm)
u
903.4
MEMBERS
3
3
σ
=
divergence
stress
applied
where
applicable
as
combinations,
kip-in
(N-mm)
3
3
div
σ
=
divergence
stress
applied
where
applicable
as
The
bottom
chord
shall
be
designed
as
an
axially
loaded
combinations,
kip-in
(N-mm)
(a)(a)bottom
Chords
903.4
MEMBERS
div
Chords
combinations,
kip-in
(N-mm)
(a)
Chords
The
chord
shall
be
designed
as
an
axially
loaded
= 1bottom
- 0.3 fauchord
/F’e for
endbepanels
CmThe
σ
=
divergence
stress
applied
where
applicable
as
903.4 MEMBERS
elastic
section
modulus,
in
(mm
) LRFD
=
required
flexural
strength
using
LRFD
load
M
σ
= div
divergence
stress
applicable
as
=
required
flexural
strength
using
load
M
required
flexural
strength
using
LRFD
load
S
=S
elastic
section
modulus,
in3 where
(mm
uuM
div
33 3 33
u=
shall
designed
asan
anaxially
axially
loaded
The
bottom
chord
shall
designed
loaded
3 ) modulus,
ction
S
=applied
elastic
section
modulus,
in
(mm
The
bottom
chord
shall
bebe
designed
as as
an
axially
loaded
The tension
bottom
chord
shall
be
designed
as
an
axially
loaded
combinations,
(N-mm)
Sin
=kip-in
elastic
section
(mm
))
defined
903.2-17
defined
inS
Equation
903.2-17
member.
=Equation
elastic
section
modulus,
in3in(mm
SF ==Felastic
section
modulus,
in
(mm
) based
tension
member.
C
defined
in
Equation
903.2-17
=
1
0.4
f
interior
panels
The
bottom
chord
shall
be
designed
as
an
axially
loaded
mtension
au/F’
e for
combinations,
kip-in
(N-mm)
combinations,
kip-in
(N-mm)
defined
in
Equation
903.2-17
combinations,
kip-in
(N-mm)
=
nominal
axial
compressive
stress
based
on
/r) as
member.
nominal
axial
compressive
stress
on
/r
as
cr
(a)
Chords
tension
member.
cr M
3axial
3 compressive
(a)
Chords
tension
member.
=
required
flexural
strength
using
LRFD
load
M
tension
member.
(a)
Chords
3
3
u
=
nominal
stress
based
on/r
/ra
F
=
required
flexural
strength
using
LRFD
load
3
3
S
=
elastic
section
modulus,
in
(mm
)
3
3
(a)bottom
Chords
=strength
nominal
axial
compressive
stress
based
F
The
bottom
as
anan
axially
loaded
The
bottom
shall
designed
as
axially
loaded
=
required
flexural
strength
using
LRFD
load
M
The
chord
bebe
designed
loaded
cr
=cr
nominal
axial
based
onon
/r
as
Ftension
= shall
specified
minimum
yield
strength,
ksi
(MPa) Fcr =
axial
compressive
stress
based
as
= u==
required
flexural
using
LRFD
load
MuS
cr
elastic
section
modulus,
in
(mm
) ) on
ychord
member.
unominal
S
=
elastic
section
modulus,
in
(mm
) /rstress
S
elastic
section
modulus,
incompressive
(mm
defined
in
Section
903.2(b),
ksi
(MPa)
defined
in F
Section
903.2(b),
ksi
(MPa)
combinations,
kip-in
(N-mm)
combinations,
kip-in
(N-mm)
defined
in
Section
903.2(b),
ksi
(MPa)
combinations,
kip-in
(N-mm)
tension
member.
Bottom
chords
that
are
rolled
for
arched
chord
joist
shall
defined
in
Section
903.2(b),
ksi
(MPa)
F
=
nominal
axial
compressive
stress
based
on
ℓ/r
as
σ
=
Divergence
stress
applied
where
applicable
as
tension
member.
tension
member.
Bottom
chords
that
are
rolled
arched
chord
joist
shall
combinations,
kip-in
(N-mm)
div
3(MPa)
3903.2(b),
2 for
defined
in ksi
Section
ksi
(MPa)
Section
903.2(b),
The
bottom
chord
shall
be
designed
as
an
axially
loaded
==
nominal
axial
stress
on
FFcrdefined
The
bottom
chord
shall
be
designed
as
an
axially
loaded
3 3(mm
3) based
Bottom
chords
that
are
rolled
for
arched
chord
joist
1=
-elastic
0.3
fau
/F’
for
end
nominal
axial
compressive
stress
based
on
/r
nominal
axial
compressive
based
on/r
/ras
asas
cr
S
=
section
in
1=F
0.3
fin
/F’
for
end
panels
Cshall
m
ecompressive
cr
Bottom
chords
that
rolled
for
arched
chord
joist
The
bottom
shall
be are
designed
as
an
axially
loaded
SS=C
section
modulus,
inin3 3panels
)3stress
mshall
au
e
chord
Efor
Bottom
chords
that
are
rolled
for
arched
chord
joist
shall
The
bottom
chord
shall
be
designed
as
an
axially
loaded
Bottom
that
are
rolled
arched
chord
joist
shall
S=-crelastic
=
elastic
section
modulus,
in
(mm
) end
=-1modulus,
1panels
-0.3
0.3
f(mm
/F’
for
end
panels
C
elastic
section
)(MPa)
be chords
designed
to
include
divergence
stress
per
Section
mmodulus,
au
efor
=Section
-903.2(b),
f(mm
/F’
panels
C
be
designed
to
include
divergence
stress
per
Section
defined
in
Section
ksi
m
au
e
tension
member.
defined
in
Section
903.2.17
=
1
0.3
f
/F’
for
end
panels
C
=
1
0.3
f
/F’
for
end
C
Bottom
chords
that
are
rolled
for
arched
chord
joist
shall
tension
member.
m
au
e
m
au
e
defined
in
Section
903.2(b),
ksi
(MPa)
=
,
ksi
(MPa)
F
be
designed
to
include
divergence
stress
per
Section
defined
in
903.2(b),
ksi
(MPa)
tension
member.
defined
in
Section
903.2(b),
ksi
(MPa)
e
=
nominal
axial
compressive
stress
based
on
/r
as
F
C
=
1
0.4
f
/F’
for
interior
panels
be
designed
to
include
divergence
stress
per
Section
cr
C
=
1
0.4
f
/F’
for
interior
panels
tension
member.
m
au
e compressive
=
nominal
axial
compressive
stress
based
on
/r
as
F
m
au
e
cr
be
designed
to
include
divergence
stress
per
Section
be
designed
to
include
divergence
stress
per
Section
2
=
nominal
axial
stress
based
on
/r
as
F
Bottom
chords
for
arched
chord
joist
shall
nominal
axial
on /r
as
Fcr1
903.2.17,
inchords
combination
with
tension
forces.
C
=-10.4
1end
-0.4
0.4
fau/F’
/F’
forinterior
interior
panels
Bottom
rolled
for
arched
chord
joist
shall
Bottom
chords
that
rolled
joist
shall
903.2.17,
in combination
with
tension
forces.
m
efor
Cfor
-end
fstress
panels
M
=that
flexural
strength
using
LRFD
load
m
au
ebased
crdefined
1
--10.3
0.3
fSection
//F’
Φ=compressive
FSection
panels
1=efor
fyield
/F’
for
interior
panels
CFm C
=
-=
0.4
/F’
interior
panels
u903.2.17,
(required
kare
inare
/combination
rin
)combination
e/F’
be903.2.17,
designed
to
include
divergence
stress
per
Equation
au
efau
au
e(MPa)
in
903.2(b),
ksi
(MPa)
=== 1
fmau
for
panels
C
with
tension
forces.
inC
ksi
specified
minimum
strength,
ksi (MPa)
=
-minimum
0.3
f/F’
end
panels
1f-defined
0.3
for
end
panels
Cm
in
with
tension
forces.
xcombination
=F
specified
yield
strength,
(MPa)
ym
au
e for
mCm
au
e903.2(b),
y
defined
in
Section
903.2(b),
ksiksi
(MPa)
903.2.17,
indesigned
combination
with
tension
forces.
903.2.17,
with
tension
forces.
defined
in
Section
903.2(b),
ksi
(MPa)
Bottom
that
are
rolled
for
arched
chord
joist
shall
bebedesigned
designed
to tochords
include
divergence
stress
per
Section
F
=
specified
minimum
yield
strength,
ksi(MPa)
(MPa)
Bottom
chords
that
are
rolled
for
arched
chord
joist
shall
include
divergence
stress
per
Section
be
Section
y
F
=
specified
minimum
yield
strength,
combinations,
kip-in
(N-mm)
y
Bottom
chords
that
are
rolled
for
arched
chord
joist
shall
F
=
specified
minimum
yield
strength,
ksi
(MPa)
F
=
specified
minimum
yield
strength,
ksiksi
(MPa)
C
=
1
0.4
f
/
Φ
F
for
interior
panels
=
1
0.3
f
/
F
for
end
panels
C
y
y
BottomWhere
chordsthat
are panel
rolled length,
for
arched
chord
joist
shallas defined in
m
m
903.2-17,
in
combination
with
tension
forces.
=C
1==
-21
0.3
fau
/0.4
/fau
F
end
CCmC
-1-10.4
/F’
for
interior
panels
2-f0.3
m
eeeend
=
ffor
/F’
for
interior
panels
C
10.3
fauau
/F’
for
interior
panels
=
-0.4
fFeau
/au
eF
end
panels
m
epanels
m
efor
m
au
3per Equation
3 Equation
is
the
in
inches
(mm),
=
1
for
panels
be
designed
to
include
divergence
stress
per
m
au
e
aded 903.2.17,
be
designed
to
include
divergence
stress
903.2.17,
forces.
2

E
903.2.17,
in
combination
with
tension
forces.
in
combination
with
tension
2

E
beSdesigned
to include
divergence
stress
per
= to
elastic
section
modulus,
in
(mm
) Equation
2interior
be designed
include
divergence
stress
per
Equation
1
--fau
0.4
//F
panels
e for
CCmF
1=
0.4
//FffFeau
for
interior
panels
F
C
=2-=specified
specified
minimum
yield
strength,
ksi (MPa)
minimum
strength,
ksi
(MPa)
yield
yy =
=
minimum
strength,
(MPa)
C
=
1specified
for
panels
specified
yield
strength,
ksiksi
(MPa)
interior
EEyield
m
au
einterior
903.2-17,
combination
with
forces.
For
LRFD:
f aucombination
in
9with
Ffytension
(903.4-1)
==
, Fksi
(MPa)
=ym
1
-E
0.4
f0.4
for
panels
903.2(b)
and
r
is
the
of gyration
aboutFethe

E
903.2-17,
forces.
For LRFD:
f auSection
in

0div.LRFD:
9F0y .with
(903.4-1)
=FF
, ksi
(MPa)
meyF
au
eminimum
x tension
903.2-17,
in
combination
with
tension
forces.
div
2F
903.2-17,
in
combination
tension
forces.
F
=
specified
minimum
yield
strength,
ksi
(MPa)
For

90F
0.radius
.9FF
(903.4-1)
=
,
ksi
(MPa)
22,Fminimum
yspecified
F=
=
yield
strength,
ksi
(MPa)
e
For
LRFD:
=div
nominal
axial
compressive
stress
based
on
/r
as
Fcr
f



9
(903.4-1)
=
,
ksi
(MPa)
F
y
For
LRFD:
au
div
y
e
For LRFD:
f auaxis


0
.
9
F
(903.4-1)
(903.4-1)
ksi
(MPa)
F
For
LRFD:
f



0
.
(903.4-1)
F
=
specified
minimum
yield
strength,
ksi
(MPa)
=
,
ksi
(MPa)
au
div
y
e
2
y
2
e
2
Fy ( k=specified
minimum
yield strength,
ksi (MPa)
(rkx2

rE
)
y au
div
y
2
/
)
of bending.
2/
2
x
E (k(k(/kr/ /)rrx x))
defined
903.2(b),
ksi (MPa)
k =/=r=x )2E 22EE
rtical
For
LRFD:
0div
.60in
.
90Section
(903.4-1)
,,ksi
(MPa)
FF(e
FWhere
x
eeFe=
For
LRFD:
F
.F9.9yyFFy0(903.4-2)
(903.4-1)
E
For
, ksi
(MPa)
(MPa)
f adivfauauLRFD:

(903.4-2)
For
ASD:
div
shallFor ASD:
fFor
LRFD:
For
f1au
.60.3
F0fdiv

Epanel
div
22length,
y0
.
9
F
(903.4-1)

is
the
panel
in inches
(mm),
as defined
in
=
,2, ksi
ksi
(MPa)
F
a C
y auf 
Where

is
the
in
inches
(mm),
as defined
in (mm),
e
f

(903.4-1)
=
,
ksi
F
f



0
.
6
F
(903.4-2)
For
ASD:
div
y
e
=
/F’
for
end
panels
For
LRFD:
f



0
.
9
F
(903.4-1)
f



0
.
6
F
(903.4-2)
For
ASD:
au
div
y
=
ksilength,
(MPa)
F
m
au 
2)(MPa)
e ((k
f



0
.
6
F
(903.4-2)
For
ASD:
a .e9 F
div
y
ng
in
For
LRFD:
f



0
(903.4-1)

/
r
)
Where

is
the
panel
length,
inches
asdefin
defin


0
.
6
F
(903.4-2)
For
ASD:
=
,
ksi
(MPa)
F
2
auf
div
y
a
div
y
e
Where

is
the
panel
length,
inininches
(mm),
For
ASD:
(
k

/
r
k

/
r
)
Q
=
form
factor
defined
in
Section
903.2(b)
a
div
y
(903.4-2)
au
div
y
2
Where

is
the
panel
length,
in
inches
(mm),
in
a
div
y
 isthe
panel
length,
indefined
inches
(mm),
defined
ction
((/rkkrx))/Where
2xrxx )x rand
((kk/903.2(b)
Section
rx the
isradius
the
radius
of as
gyration
about
theas as
is
of
gyration
about
the
Section
903.2(b)
and
/
r
)
x
2
2
C
=
1
0.4
f
/F’
for
interior
panels
x
m
au
e
ed in
Section
903.2(b)
and
r
is
the
radius
of
gyration
abot
x and
x
Section
903.2(b)
and
r
is
the
radius
of
gyration
abou
(903.4-2)
For
ASD:
A
=
area
of
the
top
chord,
in.
(mm
)
Section
903.2(b)
r
is
the
radius
of
gyration
about
the
x
Section
903.2(b)
and
r
is
the
radius
of
gyration
about
x
f



0
.
6
F
(903.4-2)
For
ASD:
f



0
.
6
F
(903.4-2)
For
ASD:
x (mm),
div 
ff adiv
(903.4-2)
For
Where
the
is
the
panel
length,
in inches
(mm),
as
defined
6yy.6
(903.4-2)
For
axis
of
a f adiv
div
y0
aa ASD:
Where
is
the
panel
length,
in
inches
(mm),
defined
div
Where
the
panel
length,
inches
(mm),
asas
axisWhere
of
bending.
Where
is
the
panel
in
as
in inin in

0minimum
FF
0y y..66 F
Fyy yield
(903.4-2)
For
isbending.
panel
length,
in
inches
(mm),
as
defined
indefined
FASD:
=ASD:
specified
strength,
ksi (MPa) axis
f aof
atop
0.top
(903.4-2)
For
ASD:
div
ygyration
Where
isis
the
panel
length,
inininches
inches
(mm),
as defined
defined
axis
ofrlength,
bending.
div
Where
isis
the
panel
length,
in
inches
(mm),
as
defined
in in the
axis
of
bending.
of
bending.
The radius
the
chord
about
its vertical
axis
of
bending.
The radius
of gyration
of
the
chord
about
its
vertical
ofThe
radius
of
gyration
of
the
top
chord
about
its
vertical
axis
Where
ℓ
the
panel
length,
in
inches
(mm),
as
defined
in
Section
903.2(b)
and
is
the
radius
of
gyration
about
the
radius
of
gyration
about
the
Section
903.2(b),
Section
903.2(b)
risradius
is
of
gyration
about
thethe
radius
gyration
about
Section
903.2(b)
rxrthe
xx is
ofofradius
gyration
about
the
Section
903.2(b),
and
rand
Theof
radius
ofgyration
gyration
ofthe
the
top
chord
about
itsvertical
vertical
x and
The
radius
of
of
chord
about
2 top
the
radius
of of
gyration
about
the thethe
Section
903.2(b),
and
The radius of gyration
theof
chord
about
its top
vertical
x isx radius
The
gyration
of
the
chord
about
its its
vertical
gyration
about
the
Section
903.2(b),
andand
rxisisthe
axis shall
not
be radius
less
than
/120
where
 istop
spacing

E
axis
of
bending.
axis
of
bending.
axis shall
not be
less
than
/120
where
 iswhere
the
spacing
in in
shall
notshall
be
less
than
ℓ/120
ℓthe
is the
spacing
inisinches
axis
of
bending.
Section
903.2(b),
and
r
is
the
radius
of
gyration
about
the
Q
=
form
factor
defined
in
Section
903.2(b)
axis
of
bending.
axis
of
bending.
x
Q
=
form
factor
defined
in
Section
903.2(b)
axis
of
bending.
axis
not
be
less
than
/120
where
the
spacing
in
axis
of
bending.
axis
shall
not
be
less
than
/120
where
is
the
spacing
lyaxis
by inches
=form
form
factor
defined
in Section
903.2(b)
shall
not
beradius
less
than
/120
where
chord
ischord
the
spacing
in
The
radius
of
gyration
of
the
top
chord
about
its
=oflines
,the
ksi
(MPa)
Fbetween
The
radius
of
gyration
of
the
top
about
its
vertical
axis
shall
not
less
than
/120
where
vertical
is vertical
the
spacing
2 2defined
2 in Section
QQ=top
=in
903.2(b)
The
of
gyration
of
the
top
chord
about
its
vertical
egyration
Q in =in
form= factor
defined
Section
903.2(b)
2factor
For
ASD:
The
radius
of
gyration
of
about
its
vertical
Q
form
factor
903.2(b)
The
radius
of
of
the
top
chord
about
its
vertical
The
radius
of
gyration
of
the
top
chord
about
its
(mm)
lines
of
bridging
as
specified
inSection
inches
(mm)
between
ofbe
bridging
as
specified
in
The
radius
gyration
of
top
chord
about
its
2the
area
the
chord,
in.defined
) in Section
(mm)
between
lines
oftop
bridging
as
specified
invertical
A in
=A
area
of theof
top
chord,
in.
(mm
) top chord,
axis
bending.
22 2 22
2 of
2 (mm
inches
(mm)
between
lines
of
bridging
as
specified
in
2in.
inches
(mm)
between
lines
of
bridging
as
specified
inches
(mm)
between
lines
of
bridging
as
specified
in
ction
A
=
area
the
in.
(mm
(
k

/
r
)
axis
shall
not
be
less
than
/120
where
 is
the
spacing
in
inches
(mm)
between
lines
of
bridging
as
specified
in
axis
shall
not
be
less
than
/120
where

is
the
spacing
in
A
=
area
of
the
top
chord,
(mm
))
A
=
area
of
the
top
chord,
in.
(mm
)
Q
=
form
factor
defined
in
Section
903.2(b)
axis
shall
not
be
less
than
/120
where

is
the
spacing
in
A
=
area
of
the
top
chord,
in.
(mm
)
x
Q
=
form
factor
defined
in
Section
903.2(b)
axis
shall
not
be
less
than
/120
where
is
the
spacing
in
Section
904.5(d).
Q
=
form
factor
defined
in
Section
903.2(b)
axis
shall
not
be
less
than
/120
where
 is
the
spacing
axis
shall
be
less
/120
where
 is
the
spacing
in
Section
904.5(d).
axisnot
shall
not
be than
less
than
/120
where
the
spacing
in in
factor
defined
in
Section
903.2(b)
=form
form
factor
defined
903.2(b)
= =form
factor
defined
Section
QQ Q
= form
factor
defined
in Section
2 Section
2 903.2(b)
904.5(d).
2in in
2903.2(b)
Section
904.5(d).
inches
(mm)
between
lines
of
bridging
as
specified
in
Section
904.5(d).
(903.4-6)
at
the
panel
point:
f

f

0
.
6
F
2
2
Section
904.5(d).
2
2
inches
(mm)
between
lines
of
bridging
as
specified
in
A
=
area
of
the
top
chord,
in.
(mm
)
Section
904.5(d).
2(mm
2 )2
ofofthe
top
chord,
in.
)2(mm
2
abridging
bof bridging
yspecified
inches
(mm)
between
lines
of
in
inches
(mm)
as
specified
inches
(mm)
between
lines
of
bridging
as
specified
inas
A=area
=
the
toptop
chord,
in.
(mm
=area
of
top
chord,
in.
) ) 2)
AAA
QA=A
form
factor
defined
in
903.2(b)
inches
(mm)
between
lines
of
bridging
as
specified
in indefined in
inches
(mm)
between
lines
oflines
bridging
asinches
specified
in
Where
 isbetween
the
panel
length,
inas
(mm),
the
top
chord,
in.Section
(mm
)(mm
=area
area
of
the
chord,
(mm
== area
area
ofofthe
the
top
chord,
in.in.
Section
904.5(d).
Section
904.5(d).
Section
904.5(d).
Section
904.5(d).
2
2
904.5(d).
The
topSection
chord
shall
be
considered
as
stayed
laterally
by
Section
904.5(d).
Section
904.5(d).
The top
chord
shall
be
considered
as
stayed
laterally
by
is
the
radius
of
gyration
about
the
Section
903.2(b)
and
r
A
=
area
of
the
top
chord,
in.
(mm
)
x
For
ASD:
shall
The
toptop
chord
shall shall
be
considered
as stayedby
laterally
by the
For by
ASD:
The
top
chord
beconsidered
considered
asstayed
stayed
laterally
by
The
chord
be
as
laterally
The the
top chord
be
considered
as
laterally
mber
For
ASD:
The
top
chord
shallshall
bestayed
considered
asSection
stayed
laterally
byASD:
ASD:
For
ForFor
ASD:
at
the
mid
panel:
roof
deck
provided
the
requirements
ofSection
the roof
deck
provided
the
requirements
ofthe
Section
axis
ofchord
bending.
The
top
shall
be
considered
as
stayed
laterally
by
The
top
chord
shall
be
considered
as
stayed
laterally
by
roof
deck
provided
the
requirements
of
904.9(c)
For
ASD:
the
roof
deck
provided
requirements
of
Section
For
ASD:
The
top
chord
shall
be
considered
as
stayed
laterally
by
the
roof
deck
provided
the
requirements
of
Section
the
roof
deck
provided
the
requirements
of
Section
shall
The
top
chord
shall
be
considered
as
stayed
laterally
by
For
ASD:
the
roof
deck
provided
the
requirements
of
Section
ertical
The
top
chord
shall
be
considered
as
stayed
laterally
by
For
ASD:
(903.4-6)
at
the
panel
point:
0
904.9(c)
of
this
specification
are
met.
For
ASD:
(903.4-6)
at
the
panel
point:
f

f
panel
0f .6Fpoint:
The
top
chord
shall
be
considered
as
stayed
laterally
by
The
chord
shall
be
considered
as
stayed
laterally
by
the
roof
deck
provided
the
requirements
of
Section
904.9(c)
oftop
this
specification
are
met.
fprovided
the
roof
deck
provided
the
requirements
ofof Section
For
ASD:
aat
ba panel
y .6 Fyf f f f 
For
ASD:
For
ASD:
the
roof
deck
provided
the
requirements
of Section
(903.
athis
904.9(c)
of
this
specification
are
met.
this
specification
are
met.
at the
panel
point:
(903.4
at
the specification
roof
deck
the
requirements
Section
the
fthe
0f.b6
Fpoint:
6.y6FFy y
904.9(c)
ofroof
this
are
met.
904.9(c)
of
this
specification
are
met.
(903.4-6)
atfpoint:
panel
point:
fay a afb b b(903.4-6)
0(903.4-6)
.600
F.(903.4-6)
904.9(c)
of
specification
are
met.
athe
bf 
y0.6 F
the
deck
provided
the
requirements
of
Section
for

0
.
2
,defined
ng
in the
at
the
panel


904.9(c)
of
this
specification
are
met.
at
the
panel
point:
f


0
.
6
F
theroof
roof
deck
provided
the
requirements
of
Section
deck
provided
the
requirements
of
Section
904.9(c)
of
this
specification
are
met.
Q
=
form
factor
in
Section
903.2(b)
a
b
(903.4-6)
at panel
the panel
point:

af fbfa  f0
y0.6 Fy
904.9(c)
of this
specification
are met.
(903.4-6)
at
the
point:
.
6
F
904.9(c)
of
this
specification
are
met.
b
F
a f b f  0
2
2
(903.4-6)
at
the
panel
point:
904.9(c)
of
this
specification
areare
ed
The
top chord
shall
be adesigned
as
a continuous
member
(903.4-6)
at
panel
point:
0F.Fy6yFy
(903.4-6)
atmid
thethe
panel
point:
faa fa bfb fb y0.6
.6
904.9(c)
of
this
met.
904.9(c)
of
this
specification
are
met.
Theintop
chord
shall
be
designed
as
amet.
continuous
member
A
=specification
area
ofshall
the
top
chord,
in.
(mm
) a continuous
at
at
the
panel
point:
(903.4-6)
the
mid
panel:
at the
panel:
top
The
top
chord
be
designed
as
a continuous
member
The
top
chord
shall
be
designed
ascontinuous
member
The top
chord
shall
be
designed
as
adesigned
continuous
member
The
top
chord
shall
be
designed
as
a continuous
member
The
top
chord
shall
be
as
a
continuous
member
The
top
chord
shall
be
designed
as
a
member
at
the
mid
panel:
The
chord
shall
be
designed
as
a
continuous
member
at
the
mid
panel:
at
the
mid
panel:
subject
to
combined
axial
and
bending
stresses
and
shall
at
the
mid
panel:
The
top
chord
shall
be
designed
as
a
continuous
member
at
the
mid
panel:
subject to combined
axial
and
bending
stresses
and
shall
at
the
mid
panel:
The
top
chord
shall
be
designed
as
a
continuous
member
at
the
mid
panel:
subject
to
combined
axial
and
bending
stresses
and
shall
at thefamid panel:
fa
subject
to
combined
axial
and
bending
stresses
and
shall
beand
subject
to top
combined
axial
and
bending
stresses
and
shall
subject
to
combined
axial
and
bending
stresses
shall
subject
to
combined
axial
and
bending
stresses
and
shall
subject
tothat:
combined
axial
and
bending
stresses
and
shall
subject
to
combined
axial
and
bending
stresses
and
shall
The
chord
shall
be
designed
as
a
continuous
member
subject
tothat:
combined
and
stresses
and
sotop
proportioned
The
top
chord
shall
be
designed
as
a continuous
member
for
mid
The
chord
designed
as
a bending
continuous
member
fafor
be sobe
proportioned
subject
toshall
combined
axialaxial
and
bending
stresses
and
shallshall
at
the
mid
0.2 , for
0mid
0panel:
.panel:
2,panel:
f fafa
at
the
-3)
at the
the
mid
panel:
be
sobe
proportioned
that:
be
so
proportioned
that:
sosubject
proportioned
that:
be
so
proportioned
that:
be
so
proportioned
that:
so
proportioned
that:
for

be
so
proportioned
that:
to
combined
axial
and
bending
stresses
and
shall


be
so
proportioned
that:
forfora  0.200.,2.2, ,
lybeby
F
be
proportioned
that:
fffa.a2 ,
F
subject
to
combined
axial
and
bending
stresses
and
shall
subject
toso
combined
and
bending
stresses
and
shall
f
For ASD:axial
a
a
fa  0afa.a2
F for
fa, ,000..22.2,, , Fa FF
a
for


bebe
so
proportioned
that:
for

ction
for Fafor
Fa0.2
For
LRFD:
so
proportioned
that:
be
so
proportioned
that:
For LRFD:
0.,2 , a
forfor
 0.2
For
LRFD:
LRFD:
For
LRFD:


F
a
For LRFD: For



f
C
f

8


LRFD:
For
LRFD:
For
LRFD:
F
F
a
ForFor
LRFD:
For
LRFD:
a
m
(903.4-6)
at
panel point:
a Fa F
fba  fbdiv  0.6 F
 
 the
.0
(903.4-7)
a a
 y1(903.4-3)
at
the
panel
point:
For
LRFD:
ffau
fau
f0
0
..67
9ff0bu
F.fy9F00y
at
the
panel
point:
f

..9
F
(903.4-3)
at
the
panel
point:
f

.
9
F
(903.4-3)
9
F
at
the
panel
point:

f
(903.4-3)

bu
au
y

For
LRFD:
au
bu
y
For
LRFD:
 
1
at
the
panel
point:
f

9
F
(903.4-3)
bu
a



  
at
the
panel
point:
f

0
.
9
F
(903.4-3)
at the panel at
point:
fthe
panel
fbupanel
fpoint:
0
.
9
(903.4-3)
the
panel
point:
F
fbu
bu
0au
.au
9
F
(903.4-3)
at
the
point:
f
f

0
.
9
F
(903.4-3)
au
y0
a f


bu
y
at
point:
au
y
f


.
9
F
(903.4-3)
au
y
(903.4-3)
at
the
panel
bu
y

QFb

y
1   au bu
   
 
mber



at
the
mid
panel:




at
the
panel
point:
f

f

0
.
9
F
(903.4-3)
F










au
bu
y
e
at
panel
point:
fau
0.F9yFy
(903.4-3)
at the
thethe
panel
point:
fau
 fbufbu
 0.9
  Cm 88CfC
 
shall
div
ffbdiv
 (903.4-3)
at
the
mid
panel:
  f     


mfC
at
panel:
at
mid
bdiv

Cfbffm
at
atmid
the
mid
panel:
bm
C.C
 ffaa ff8aa8f affaa88C
atthe
the
mid
panel:
8div




f
8mf bC


m
panel:
at
the
mid
panel:
(903.4-7)

f1.b011div
f
8

b
div
(903.4-7)
(903.4-7)
at
the
mid
panel:

m
at the
the mid
mid panel:
panel:
..00div(903.4-7)

1
(903.4-7)
ab
div
div
f
C
a
8
div

 (903.4-7)
at
the
mid
panel:
11
a
at thefor
mid panel:
 F F9F9 9 a   1m.00fmbm
(903.
,
(903.4-7)
.0.b0
(903.4
(903.4-7)
011.0.0
(903.4-7)
mf1F
fau 0.f2
1.
1.aF
.f67





a 

991

F


1
..f67
ffa  

.
67
f
au



a 

f
C
8

67
f

a

a
9
F
9
9
F





a

f
f
at
the
mid
panel:
F
f
1
67

a
b
div

9
F
f


a


1
.
67
f


f
1
.
67


for,

0
.
2
,


a


af



f
C
f

a    f a
fau


8



C

1
.
67
f




8



9
F
au
au
for,


0
.
2
,

a
1
.
67
f
1
QF

a
f
au


a
a







1
QF

au
a
1
QF

a
f
mid
panel:


at at
thethe
mid
panel:
1
.
67
f

1
.
0
(903.4-7)


a
m
b
div



a
m
b
div


a
a


1
QF




a

f for,
for,au  0.200,.2.2, ,
0
for
, 0
a .0
, .2 ,for,for,
bQF
 b b (903.4-7)
 b1
for
au
QF
b1 bQF
1.0QF
(903.4-7)
 1 1 FF
 F 1
bQF
forau for
F..22cr0,, .c2
for
00.2
.
2
fF
a999FF
1bFb FFeQF
ffaFFbeef1
cc,0F
67
cFFcrccF
e1ee.67
F
 Faa F
e11.67
aucr
 

Fcr
cr fau
fau  0.2, cF
cF
F



e
cF
crcr
.


cr afor,






e




cr




1
QF



c
cr
a


 1 1  a QF
b   e
-4)
.2
0.,2 ,
 
for,for, F  0
 QF
faf ffaa    FFeF   bb 
c cr
-3)



0
.
2
,
for




e
e

0
.
2
,
for


a


f



   cFccrFcr
    

fafor F0a .2 ,0.2 ,
 

   
  
afor
.2, , 0.2 , for
forforfF

fa fafa 00.2.2, ,
F0aa.2
Faa0
for


for







0
.
2
,
for
F






F


f
C
f


8


 ffau  au 88   C
f8
    
 8div88CCm8divC

ffaa f
1fC.bfff0bu
1f.div
fCCbu
a
f au
Fafor
mmffffbubuaau
mm 
fdiv
f
a
fm
div
div(903.4-4)
C
.1(903.4-4)
mC
 au    C
au8budiv
div
m
..22
, Fa FF
(903.4-7)
0div
a0
a 
..00 1(903.4-4)
au
bubu
(903.4-4)
 faufau
bu
div
fau

f mbubu
88 mC
11.0.01(903.4-4)


.
0
(903.4-4)
10
(903.4-4)


0
.,2 , a  
for

0
for

a
mm1b.0
div div (903.4-4)

1
.
0
(903.4-4)



(903.4-4)





9

F
1
.
0
(903.4-4)




 c F
9
9
F
F
















1
.
0
(903.4-8)
f





F

9
c f cr9 8







C
f


f



1
.
67
f






cr
F
9
a
a



f



F



au
9

F


f






c
cr


au
m
bu
div
cr9mcrfQbu9f9
FaFa 
faf1au.0QQF
cr12cfcF
91
auauFC
 F   (903.4-4)
 c cr f auf au 1 8
cc8
cC

1div
 
Q

fbdiv
F

F
au
FcrccrF
 (903.4-4)
 yffau
m
11bubbF
au
Fcr

bFy y(903.4-4)
yyb F
  F  1 
0
1Q
0QF
bbQ
Fy.
 f   ffa  Cm fCCm ffb  div 
FaufQaQau1b.FQ
1.67
F  1yy1111au
FbF
9 FaQ

yQ
 
SP-Series Design
 
 
 
SP-Series Tables
consideration, ksi (MPa)
defined
in Section 903.2.17
consideration,
(MPa)
consideration,
ksiksi
(MPa)
M = required flexural strength using ASD load
combinations, kip-in (N-mm)
3
3
88
a a
defined in Section 903.2(b), ksi (MPa) 89
89
8989
Discover
the easiest
way
to specify
special
profile joists:
defined
Section
903.2(b),
(MPa)
defined
in in
Section
903.2(b),
ksiksi
(MPa)
  divdiv   1.0  (903.4-8)
F
c
c crF
eFe
ebe bb y   
cF
ec F
ccFFF
eecff auauefauQ
cr 9 91cc F
 afa a  C m bfbm  bdiv
e

ccr 
ceF
c F


  11.0.0 1.0 (903.4-8)




F
(903.4-8)

e


(903.4-8)
c
e






b
y







 (903.4-8)
Qb 
m1.
Fby Fy 
fbfdivf11

mffC
 ff a 22fFaFa22FFCaC

..67
ffa 
 1 1c FeQ



67
div

b
67


a





C
f
a

 (903.4-8)
1
.
67
f




f   f c F






C
f
a




1
.
0
a 
m 1
bf1 fdiv



a







QF

F



1
.
0
(903.4-8)
a
m
b
div




C
f

a





QF
a
m
b
div



.e2,fau  
b1m.QF
2F  1 1a  F
QF
  fau
(903.
fa,ceff0au
0bbb  div (903.4-8)
for

(903.4
au
f

1
011.0.0
(903.4-8)



au
2
F
f

b





1
.
67
f

0
.
2
for
au


F




f
C
f
f
au


a


0
.
2
,
for,


1
.
67
f


aF
, for,fau auau stress,
for,
11.67
ksi
(MPa) 2 Faa faf 1.67
fa  =
eediv
.20, .2 0,0..22 ,compressive
for
2C
fmFaC
2FfFbeFaeaQF
  .(903.4-8)
a
crP/A,
0.
2 ,0Required
for for


2
for,


.
67
f

f

0
.
2
,


F


f
1
QF



1
.
0



0
.
2
,
for,
F






1
a




1
.
67
f

a
m
b
div
c
a
m
b
div
a

F

0
.
2
,
for,




a
c F
crc Fcr
Fcr caxial
FaccF
a .0
P
f cr strengthusing
 2F1  F F
 bb111b  1
 b b (903.4-8)
QF
0QF
(903.4-8)
required
bQF
c cr =
cF
F ASD load
1.QF
fcompressive
 F
P/A,
 stress,
 stress,
a 
for,cr faufau  0.2, c F
== P/A,
e 11..67
F
-4)
67
required
ksi
(MPa)
ffaF
a 
 
crc crcr
e.67
Feksi

2
required
faf  =



2


e compressive
F



e (MPa)


1
f
P/A,
required
compressive
stress,
ksi
(MPa)

f


F
a

0
.
2
,
a





0
.
2
,
for,for, au



1
QF
a
combinations,
kips
(N)




=
P/A,
required
compressive
stress,
ksi
(MPa)





a

e
F
 ksiload
b  stress,
fa a P ==P/A,
(MPa)
ausing
 
QF
Fcompressive

using
ASD
QF
 Required
 stress
1required
ASD
axial
strength
load
1axial
 strength
ccFccr
b
busing
= required
required
axial
ASD
-5)
required
strength
loadload
e strength
crFcrbending
fb = M/S,
at the location underPPfP =P=required
using
axial
ASD
ASD
Required



F
F
=
P/A,
compressive
stress,
ksi (MPa)
combinations,
kips
(N)


=
required
axial
strength
using
load


=
P/A,
Required
compressive
stress,
ksi
(MPa)
f
a


combinations,
kips
(N)
e
e





a



(N)
Required
stress,
ksi
(MPa)
fa = P/A,combinations,
combinations,
kips
 fa fafcompressive
  compressive
P/A,
Required
compressive
stress,
ksi(MPa)
(MPa)
(N)
 C  fCCm ff ksi
  
a=kips
==strength
P/A,
Required
compressive
stress,
(MPa)


P/A,
Required
stress,
ksiksi
(MPa)
 ffau consideration,

 f au
=
M/S,
required
bending
stress
at
the
location
under

b M/S,
P
=
required
axial
using
ASD
load
fb=
=ff=
required
bending
stress
at
the
location
under




bu
div

P
=
required
axial
strength
using
ASD
load
m




combinations,
kips
(N)
bu
div




C
f
=
M/S,
required
bending
stress
at
the
location
under


f
b
m
P
required
axial
strength
using
ASD
load


f
M/S,
required
bending
stress
at
the
location
under
au
bu
div
au

 f =Divergence

bfa
m
P
=
required
axial
strength
using
ASD
load


1
.
0
(903.4-5)



=
P/A,
Required
compressive
stress,
ksi
(MPa)
 σ
bu
div

1
.
0
(903.4-5)
P
=
required
axial
strength
using
ASD
load


P
=
required
axial
strength
using
ASD
load
1.0(903.4-5)
consideration,
ksi
(MPa)
applicable
 divapplied
  1.01where
(903.4-5)as
 (903.4-5)
ksi
(MPa)
combinations,
kips
(N)stress atstress,
mffstress
=
P/A,
Required
compressive
stress,
(MPa)
==required
P/A,
Required
compressive
ksiksi
(MPa)
combinations,
kips
(N)
consideration,
ksi
(MPa)
b
ksi(N)
(MPa)
22div
cffa C
F
fa consideration,
M/S,
required
bending
the
location
under
kips
ffbudivdivCfau
buFcr
 f  
 ffau f au 22cC
m

combinations,
kips
(N)
.0 
(903.4-8) fPfbacombinations,
cFFcr
=consideration,
axial
strength
using
ASD
load
combinations,
kips
(N)
C
C
au
m
f

combinations,
kips
(N)


C
σ
=
divergence
stress
applied
where
applicable
as
c
cr
fdiv
m
bu



div

f
C
f




1
.
0
(903.4-5)
σ
=
divergence
stress
applied
where
applicable
as

au
 au  

cr
defined
in
Section
903.2.17
f

=
M/S,
Required
bending
stress
at
the
location
under




div

1

Q
F

1
.
0
(903.4-5)
au
m
bu
div
P
=
required
axial
strength
using
ASD
load



f
f

P
=
required
axial
strength
using
ASD
load

f
=
M/S,
Required
bending
stress
at
the
location
under

b


au


σ
=
divergence
stress
applied
where
applicable
as

1

Q
F
au
m
bu
div
b
2
F
div


1
.
0
(903.4-5)


fb =
M/S,
Required
stress
at the
location
under
σdiv
= divergence
applied
where
applicable
asstress
consideration,
(MPa)

(903.4-5)
fbending
M/S,
Required
bending
stress
the
location
u
Fyy using
 aCau ff11F1.67
Fyybbdiv
b Q
combinations,
kips
(N)
mFfQbuabstrength
(903.4-5)
b= M/S,
fbstress
==ksi
M/S,
Required
bending
atatthe
location
un
 fF   M
1.ASD
011.0.0 load
(903.4-5)
Required
bending
stress
at the
location
unde
bEquation
defined
in
Equation
903.2-17
crcr2
defined
infin
903.2-17
F
f

=
required
flexural


consideration,
ksi
(MPa)



1
QF
 22cc F


c
e
m
bu
div
combinations,
kips
(N)




combinations,
kips
(N)
consideration,
ksi
(MPa)


au

F


2

F


f
defined
in
Equation
903.2-17






c
e


au


b




F
2
F

consideration,
ksi
(MPa)






defined
Equation
903.2-17

cf auaucrfau1 
f


c
e


c
cr


au

C
f








C
f










2

F

1
.
0
(903.4-5)





f
consideration,
ksi
(MPa)

1
Q

F


f
=
M/S,
Required
bending
stress
at
the
location
under
σ
=
divergence
stress
applied
where
applicable
as




c
cr
c
e




Q

F
au

div
b
consideration,
ksi
(MPa)




f

m
bu
div



m
bu
div
c
cr





au
b
y
=
required
flexural
strength
using
load
au 1.01(N-mm)
consideration,
ksi ASD
(MPa)

MMσ
=fM
required
flexural
strength
using
ASD
load
bbyy111Fekip-in
0Q
b Fy(903.4-5)
 2c Fcr   Fcombinations,
M
=
required
flexural
strength
using
ASD
load
=
M/S,
Required
bending
stress
at
the
location
under
bQ
=
M/S,
Required
bending
stress
at
the
location
b=
Divergence
stress
applied
where
applicable
asunder
y (903.4-5)
=
required
flexural
strength
using
ASD
load
Fyb F
σdiv
Divergence
stress
where
applicable
as
div
 stress,
fFaue compressive
Q
div
compressive
 F=fauPu/A,
crequired
σ
==fbDivergence
stress
where
applicable
as
 .stress,
consideration,
ksi
(MPa)
3(MPa)
3
1PP
defined
inσdiv
Equation
903.2-17
combinations,
kip-in
(N-mm)
c F
FF
=applied
Divergence
stress
applied
where
applicable
as
=
ksi
  (MPa)
cc required
ee
combinations,
kip-in
(N-mm)
divDivergence
u/A,

σ
=applied
Divergence
stress
applied
where
applicable
ksi

F







σ
=
stress
applied
where
applicable
as as
e 
combinations,
kip-in
(N-mm)
f

f


Q

=
/A,
required
compressive
stress,
ksi
(MPa)
f
S
=
elastic
Section
Modulus,
in
(mm
)
c
cr
cr


div

 2f2caufF


c
e
au
u
consideration,
ksi
(MPa)
combinations,
kip-in
(N-mm)
consideration,
ksi
(MPa)


3
3
=
P
/A,
required
compressive
stress,
ksi
(MPa)



au

f
=
P
/A,
required
compressive
stress,
ksi
(MPa)
b
y
au
c e 
au
3
3
required

strength

auu= 1
u  axial
defined
in
Section
903.2.17
Q
 load
3where
3) applicable as
defined
inSection
Section
903.2.17


S
=
elastic
Section
Modulus,
in
(mm
1
Q
F
P
using
LRFD



F
3(mm
3 ASD
defined
in
Section
903.2.17
S
=
elastic
Modulus,
in
)

urequired
σ
=
Divergence
stress
applied
P
axial
strength
using
LRFD
load



F
M
=
required
flexural
strength
using
load
div
u =
b
y
b
y
defined
in
Section
903.2.17
S
=
elastic
Section
Modulus,
in
(mm
)
P
=
required
axial
strength
using
LRFD
load

=
P/A,
Required
compressive
stress,
ksi
(MPa)
f
c
e
defined
in
Section
903.2.17
compressive
  kips
allowable
= div
elastic
Section
Modulus,
inapplied
(mm
) where
=uRequired
required
strength
using
LRFD
load
a  =
nder f
defined
in
Section
903.2.17
axial
stress based on /rMas S=M
ksi
compressive
σ
=
Divergence
stress
applicable
σrequired
=
Divergence
stress
applied
where
applicable
asas
 F
P
required
axial
strength
using
LRFD
load
axial
required
flexural
strength
using
ASD
load
div
= PPuu/A,
ksi
(MPa)
uFa=
required
flexural
strength
using
ASD
load
(N)
(MPa)
fau
Required
=
allowable
axial
compressive
stress
based
on
/r
as
F=
e
combinations,
c Fce kips
Required
kips
M flexural
strength
using
ASD
load
axial
compressive
stress
based
on
as
F=
compressive
stress,
ksi
(MPa)
 =defined
(N)
au =auPuu/A, Required
combinations,
kips
(N)
=combinations,
compressive
faufau
stress,
defined
in
903.2.17
required
flexural
strength
using
ASD
load
=combinations,
allowable
axial
compressive
stress
based
on
/rASD
asASD
(N-mm)
=
Pu/A,
/A,
compressive
stress,
ksi(MPa)
(MPa)
combinations,
(N)
P
=
required
axial
strength
using
ASD
load
MM=Section
==kip-in
required
flexural
strength
using
load
uRequired
allowable
axial
compressive
stress
based
on/r
/r
as
Fa a =F=aaallowable
Prequired
stress,
ksi
M
required
flexural
strength
using
load
in
Section
903.2(b),
ksi
(MPa)
P
/A,
compressive
stress,
ksi
(MPa)
f
au
u
f
=
M
/S,
bending
stress
at
the
location
under
combinations,
kip-in
(N-mm)
P
=
required
axial
strength
using
LRFD
load
defined
in
Section
903.2(b),
ksi
(MPa)
bu
u
defined
in
Section
903.2.17
combinations,
kips
(N)
defined
in
Section
903.2.17
fbu
=
MMu/S,
required
bending
stress
atatthe
location
under
combinations,
kip-in
(N-mm)
Puu =f urequired
axial
strength
load
defined
ininSection
903.2(b),
ksi
(MPa)
combinations,
kip-in
(N-mm)
using
LRFD
load
f=
=
M
/S,
required
bending
stress
at
the
location
under
3using
3(MPa)
defined
in
Section
903.2(b),
ksi
buRequired
urequired
fbuu/A,
/S,
bending
stress
the
location
under
M
=
required
flexural
strength
ASD
load
combinations,
kip-in
(N-mm)
compressive
stress,
ksi
(MPa)
=
required
axial
strength
using
LRFD
load
defined
Section
903.2(b),
ksi
(MPa)
uP
3
3
combinations,
kips
(N)
combinations,
kip-in
(N-mm)
S
=
elastic
Section
Modulus,
in
(mm
)
au = P
u
P
=
required
axial
strength
using
LRFD
load
3
3
u
combinations,
kip-in
(N-mm)
3
3
P
=
required
axial
strength
using
LRFD
load
consideration,
ksi
(MPa)
u=
consideration,
ksi
Section
Modulus,
inusing
(mm
)ASD
kips
(N)
M== elastic
=
required
flexural
strength
load
required
flexural
strength
ASD
load
elastic
Section
Modulus,
in
(mm
) Modulus,
=
Required
compressive
stress,
fau= combinations,
PuP
/A,
Required
compressive
stress,
ksi
(MPa)
combinations,
kips
(N)
consideration,
ksi
(MPa)
f
MuM/S,
/S,
required
bending
stress
atksi
the(MPa)
location
under under
u/A,
SS ==SMelastic
Section
Modulus,
in
(mm
)using
au
bu
3 3)3)
ksi(MPa)
(MPa)
(N-mm)
elastic
Section
in3 3(mm
(mm
strength
using
LRFD
load
combinations,
kips
(N)
-5) fP
fconsideration,
=
Required
bending
stress
at the location
u = required
==kip-in
elastic
Section
Modulus,
combinations,
kips
(N)
b axial
FFa == combinations,
combinations,
allowable
axial
compressive
stress
based
ℓ/r
as
S SS=
elastic
Section
inon3in(mm
) as
combinations,
kips
(N)
3 Modulus,
3 based
f
=
M
/S,
Required
bending
stress
at
the
location
under
combinations,
kip-in
(N-mm)
kip-in
(N-mm)
P
=
required
axial
strength
using
LRFD
load
allowable
axial
compressive
stress
on
/r
P
=
required
axial
strength
using
LRFD
load
fbu
=
M
/S,
Required
the
location
under
bu
u
u
=
allowable
axial
compressive
stress
based
on
/r
as
F
a
u
u
bending
stress
at
the
location
under
consideration,
ksi
(MPa)
a =Sallowable
axial
stress
based
Funder
bu
u
= elastic
Section
Modulus,
in
(mm
)3 3on /r as
aunder
combinations,
kips
(N)
fbu
=uM
Mu/S,
/S,
Required
bending
stress
atthe
the
location
consideration,
ksi
(MPa)
=allowable
allowable
axial
compressive
stress
based
on/
Facompressive
uRequired
3compressive
f
=
Required
bending
stress
at
location
3compressive
a allowable
=
axial
stress
based
F
bu
f
=
M
/S,
bending
stress
at
the
location
under
defined
in
Section
903.2(b),
ksi
(MPa)
=
axial
stress
based
onon
/r
a
F
bu
a
ksi
(MPa)
S = defined
=
elastic
Modulus,
inksi
(mm
Sdefined
elastic
Section
Modulus,
in
(mm
) )
kips
inSection
Section
903.2(b),
(MPa)
combinations,
kips
(N)(N)stressksi
consideration,
defined
inSection
Section
903.2(b),
ksi
(MPa)
ksi (MPa)
in
903.2(b),
ksi
(MPa)
fbu
= consideration,
Mucombinations,
/S, σ
Required
bending
at
the
location
under
consideration,
(MPa)
=
allowable
axial
compressive
stress
based
on
/r
as
F
defined
in
Section
903.2(b),
ksi
(MPa)
a
consideration,
ksi
(MPa)
defined
in
Section
903.2(b),
ksi
(MPa)
=
Divergence
stress
applied
where
applicable
as
consideration,
ksi
(MPa)
div
defined
in Sectionstress
903.2(b),
ksion
(MPa)
Required
bending
stress
location
under
fbufbu= =
MuM
/S,
Required
bending
stress
at at
thethe
location
under
allowable
axial
compressive
stress
based
on
allowable
axial
compressive
based
/r/r
asas
u/S,
FF ==
93
Introduction
Fb = 0.6 Fy, allowable bending stress, ksi (MPa)
Cm = 1 - 0.5 fa/Fe for end panels
Cm = 1 - 0.67 fa/Fe for interior panels
(b)Web
The vertical shears to be used in the design of the web members
shall be determined from full uniform loading, but such vertical
shears shall be not less than 25 percent of the end reaction.
Interior vertical web members used in modified Warren-type
web systems shall be designed to resist the gravity loads
supported by the member plus an additional axial load of 1/2 of
1 percent of the top chord axial force.
(c) Eccentricity
Members connected at a joint shall have their center-of-gravity
lines meet at a point, if practical. Eccentricity on either side of
the neutral axis of chord members may be neglected when it
does not exceed the distance between the neutral axis and the
back of the chord. Otherwise, provision shall be made for the
stresses due to eccentricity. Ends of joists shall be proportioned
to resist bending produced by eccentricity at the support.
SP-Series Design
(d) Extended Ends
Extended top chords or full depth cantilever ends require the
special attention and coordination between the specifying
professional and NMBS. The magnitude and location of the
loads to be supported, deflection requirements, and proper
bracing shall be clearly indicated in the contract documents
and joist erection plans.
903.5 CONNECTIONS
(a) Methods
SP-Series Tables
Joist connections and splices shall be made by attaching the
members to one another by arc or resistance welding or other
accredited methods.
(1) Welded Connections
a)Selected welds shall be inspected visually by the manufacturer.
Prior to this inspection, weld slag shall be removed.
b) Cracks are not acceptable and shall be repaired.
c) Thorough fusion shall exist between weld and base metal
for the required design length of the weld; such fusion
shall be verified by visual inspection.
d) Unfilled weld craters shall not be included in the design
length of the weld.
e) Undercut shall not exceed 1/16 inch (2 mm) for welds
oriented parallel to the principal stress.
f) The sum of surface (piping) porosity diameters shall not
exceed 1/16 inch (2 mm) in any 1 inch (25 mm) of design
weld length.
g) Weld spatter that does not interfere with paint coverage
is acceptable.
94
(2) Welding Program
NMBS shall have a program for establishing weld
procedures and operator qualification, and for weld
sampling and testing. (Refer to Steel Joist Institute
Technical Digest #8, Welding of Open Web Steel Joists.)
(3) Weld Inspection by Outside Agencies (See Section 904.13
of this specification).
The agency shall arrange for visual inspection to determine
that welds meet the acceptance standards of Section
903.5(a)(1). Ultrasonic, X-ray, and magnetic particle testing
are inappropriate for joists due to the configurations of the
components and welds.
(b) Strength
(1) Joint Connections shall develop the maximum force due
to any of the design loads, but not less than 50 percent
of the strength of the member in tension or compression,
whichever force is the controlling factor in the selection of
the member.
(2) Shop Splices may occur at any point in chord or web
members. Splices shall be designed for the member force
but not less than 50 percent of the member strength.
Members containing a butt weld splice shall develop an
ultimate tensile force of at least 2 x 0.6 Fy times the full
design area of the chord or web. The term “member” shall
be defined as all component parts comprising the chord or
web, at the point of splice.
(c) Field Splices
Field Splices shall be designed by NMBS in accordance
with the AISC Steel Construction Manual. Splices shall be
designed for the member forces, but not less than 50 percent
of the member strength.
Top chord splices may be designed as “compression only”
when the joist is not subject to an in-service net uplift. Most
all joists are subject to negative bending moment during
hoisting at erection and “compression only” splices shall be
designed for these tension forces.
903.6 CAMBER
SP-Series joists are furnished with no camber. NMBS can provide
special camber as required by the contract documents. The
specifying professional shall give consideration to coordinating
joist elevation with adjacent framing. Technical performance
requirements shall be coordinated between NMBS and the
specifying professional.
903.7 VERIFICATION OF DESIGN & MANUFACTURE
(a) Design Calculations
Design calculations prepared by a professional engineer
registered in the state of the NMBS manufacturing plant are
available for NMBS SP-Series joists upon request.
Introduction
904.1 USAGE
This specification shall apply to any type of structure where roof
904.1 USAGE
decks are to be supported directly by SP-Series joists installed
This specification
applyWhere
to any
type of joists
structure
where
as hereinaftershall
specified.
SP-Series
are used
other
roof decks
aresimple
to bespans
supported
directly bydistributed
SP-Series
joists as
than on
under uniformly
loading
installed as hereinafter specified. Where SP-Series joists are
prescribed in Section 903.1, they shall be investigated and
used other than on simple spans under uniformly distributed
if necessaryinto Section
limit the 903.1,
requiredthey
stresses
to those
loadingmodified
as prescribed
shall
be
listed inand
Section
903.2. if necessary to limit the required
investigated
modified
stresses to those listed in Section 903.2.
CAUTION: If a rigid connection of the bottom chord is to be
CAUTION:
connection
of the bottom
chord
to be
made Ifto atherigid
column
or other support,
it shall be
madeisonly
after
made the
to the
column oforthe
other
it shall
made
application
deadsupport,
loads. The
joist be
is then
no only
longer
after the application of the dead loads. The joist is then no
simply supported, and the system must be investigated for
longer simply supported, and the system must be investigated
continuous
frame
actionbybythe
thespecifying
specifyingprofessional.
professional.
for continuous
frame
action
The designed
a rigid-type
connection
moment
The designed
detaildetail
of a of
rigid-type
connection
andand
moment
plates plates
shall shall
be shown
on inthe
drawings and
by on
thethe
be shown
the structural
contract documents
specifying
professional.
moment
plates
shall be The
furnished
structural
drawingsThe
by the
specifying
professional.
moment
by other
thanshall
NMBS.
plates
be furnished by other than NMBS.
904.2 SPAN
904.2 SPAN
SP-Series Design
The “span”
term “span”
as used
herein
is defined
as shown
The term
as used
herein
is defined
as shown
on on
thethe
diagram
at theatright.
On beams,
thethe
span
diagram
the right.
On beams,
spanisistotothe
thecenter
center line of
of the the
supporting
steel
span isisdefined
definedasas
supporting
steeland
andon
on aa wall,
wall, span
6” 6”
(152
(152 mm) over the support. In each case, the vertical location
mm)
over
the
support.
In
each
case,
the
vertical
location
of
of the point for determining span is at the top of the joist topthe
chord. point for determining span is at the top of the joist top chord.
the bearing
a SP-Series
different
When When
the bearing
pointspoints
of a of
SP-Series
joistjoist
areare
at at
different
elevations,
the span
of the
shallshall
be determined
by by
thethe
elevations,
the span
of joist
the joist
be determined
length length
along along
the slope.
the slope.
In all cases,
the design
length
of the
is equal
to the
span
In all cases,
the design
length
of joist
the joist
is equal
to the
span
less 4” (102 mm).
less 4” (102 mm).
904.3 DEPTH
SP-Series Tables
904.3 DEPTH
The nominal
depth as
specified
in the designation
of SP-Series
The nominal
depth
as specified
in the designation
of SPjoists shall
the maximum
depth
of the depth
joist as
Seriesbejoists
shall be the
maximum
of measured
the joist as
between the top and bottom chords. When joist geometry
measured between the top and bottom chords. When joist
consists of parallel chords, (e.g. Scissor or Arch), the
geometryshall
consists
of parallel
chords, (e.g.to Scissor
Arch),
measurement
be made
perpendicular
the topor and
measurement
shallnot
be prescribing
made perpendicular
and
bottomthe
chord.
If a profile
to one to
of the
thetop
four
types or
variations
catalog
is used, to
the
depth
bottom
chord. Ifinathis
profile
not conforming
onenominal
of the four
types
shall be
measuredin this
perpendicular
to athe
chord
tangent,
at abe
or variations
catalog is used,
nominal
depth shall
discontinuous panel point, (i.e. top or bottom chord ridge), or at
measured perpendicular to a chord tangent, at a discontinuous
the greatest nominal depth along the span. In any case,
panel to
point,
bottomshall
chordberidge),
or at the in
greatest
dimensions
be (i.e.
usedtopinordesign
as specified
the
nominal
depth along the span. In any case, dimensions to be
contract
documents.
used in design shall be as specified in the contract documents.
SP-Series joists may have various chord configurations and
may have
bearing
conditions
thatvarious
cause the
pitch in
SP-Series
joists
may have
chordexcessive
configurations
and
the chords.
Thebearing
designconditions
of the joist
all the
cases
shall be
may have
that in
cause
excessive
pitch
comprehensive to meet all design requirements set forth in the
in documents.
the chords. The design of the joist in all cases shall be
contract
comprehensive to meet all SP-Series design requirements set
forth in the contract documents.
91
95
Introduction
904.4 END SUPPORTS
(a) Masonry and Concrete
SP-Series joists supported by masonry or concrete are to
bear on steel bearing plates and shall be designed as steel
bearing. Due consideration of the end reactions and all other
vertical or lateral forces shall be taken by the specifying
professional in the design of the steel bearing plate and
the masonry or concrete. The ends of SP-Series joists shall
extend a distance of not less than 6 inches (152 mm) over the
masonry or concrete support and be anchored to the steel
bearing plate. The plate shall be located not more than 1/2
inch (13 mm) from the face of the wall and shall not be less
than 9 inches (229 mm) wide perpendicular to the length
of the joist. The plate is to be designed by the specifying
professional and shall be furnished by other than NMBS.
(c) Bridging Types
For spans less than or equal to 20 feet (6.096 m), welded
horizontal bridging may be used. If the joist center of gravity
is above the supports, the row of bridging nearest the center
is required to be bolted diagonal bridging.
For spans more than 20 feet (6.096 m) all rows shall be bolted
diagonal bridging. Where the joist spacing is less than 2/3
times the joist depth at the bridging row, both bolted diagonal
bridging and bolted horizontal bridging shall be used.
(d) Quantity and Spacing
The maximum spacing of lines of bridging shall not exceed
the values in Table 904.5-1.
TABLE 904.5-1
Where it is deemed necessary to bear less than 6 inches
(152 mm) over the masonry or concrete support, special
consideration is to be given to the design of the steel
bearing plate and the masonry or concrete by the specifying
professional. The joists must bear a minimum of 4 inches
(102 mm) on the steel bearing plate.
SP-Series Design
(b) Steel
Due consideration of the end reactions and all other
vertical and lateral forces shall be taken by the specifying
professional in the design of the steel support. The ends of
SP-Series joists shall extend a distance of not less than 4
inches (102 mm) over the steel supports for top chords less
than angle size L5” x 5” x ½”, otherwise 6 inches (153mm).
904.5 BRIDGING
SP-Series Tables
Top and bottom chord bridging is required and shall consist
of one or both of the following types.
(a) Horizontal
Horizontal bridging shall consist of continuous horizontal
steel members with a ℓ/r ratio of the bridging member of
not more than 300, where ℓ is the distance in inches (mm)
between attachments and r is the least radius of gyration of
the bridging member.
(b) Diagonal
Diagonal bridging shall consist of cross-bracing with a
ℓ/r ratio of not more than 200, where ℓ is the distance in
inches (mm) between connections and r is the least radius
of gyration of the bridging member. Where cross-bracing
members are connected at their point of intersection, the
ℓ distance shall be taken as the distance in inches (mm)
between connections at the point of intersection of the
bridging members and the connections to the chord of
the joists.
96
BRIDGING SPACING AND FORCES
TOP CHORD
MAXIMUM
NOMINAL
LEG SIZE BRIDGING
FORCE
SPACING
REQUIRED
< 2” 11’-0” 400 lbs.
2” 12’-0”
550 lbs.
2½”
13’-0”
750 lbs.
3” 16’-0” 950 lbs.
3½” 16’-0” 1300 lbs.
4” 21’-0” 1850 lbs.
5” 21’-0” 2300 lbs.
6” x 6” x 0.500” 26’-0” 2800 lbs.
6” x 6” x 0.625” 30’-0” 3450 lbs.
6” x 6” x 0.75” 30’-0” 4050 lbs.
Nominal bracing force is unfactored. 8” chords – contact NMBS
(e) Connections
Connections to the chords of the steel joists shall be made
by positive mechanical means or by welding, and capable
of resisting a horizontal force not less than that specified in
Table 904.5-1.
(f) Bottom Chord Bearing Joists
Where bottom chord bearing joists are utilized, a row of
diagonal bridging shall be provided near the support(s).
This bridging shall be installed and anchored before hoisting
cables are released.
Bridging shall support the top and bottom chords against lateral
movement
during the OF
construction
period and shall hold the
904.6
INSTALLATION
BRIDGING
steel joists in the approximate position as shown on the joist
Bridging
shall
support the top and bottom chords against
placement
plans.
lateral movement during the construction period and shall hold
the steel joists in the approximate position as shown on the
Theplacement
ends of all plans.
bridging lines terminating at walls or beams shall
joist
be anchored to resist the nominal force shown in Table 904.5-1.
The ends of all bridging lines terminating at walls or beams
shall be anchored to resist the nominal force shown in Table
904.7 BEARING SEAT ATTACHMENT
904.5-1.
with fixed anchorage
conditions may induce a horizontal thrust to the supporting
CAUTION:
Scissor
and Arch
joists with
anchorage
structure. The
specifying
professional
shallwelded
give consideration
conditions
mayat induce
horizontal
to the supporting
to this thrust
the fixeda ends
of the thrust
joist. Alternatively,
roller
structure. The specifying professional shall give consideration
(slip)
end
supports
result
in
lateral
displacement
of
the
reaction
to this thrust at the fixed ends of the joist. Alternatively, roller
at theend
roller
(slip) end
ofinthe
joist.displacement
Anchorage conditions
must
(slip)
supports
result
lateral
of the reaction
atberoller
(slip) end
thespecifying
joist. Anchorage
conditions
be
investigated
byofthe
professional
and themust
design
investigated
by the specifying
professional
and theappropriate
design of
of the supporting
structure shall
accommodate
the supporting structure shall accommodate appropriate
anchorage conditions.
anchorage conditions.
the specifying professional on the contract documents.
904.8 JOIST
SPACING
Where
uplift forces
are a design consideration, SP-Series
joists shall be anchored to resist such forces (Refer to Section
Joists shall be spaced so that the loading on each joist does
904.12
Uplift).
not exceed the design load (LRFD or ASD) for the particular
joist as designated in the contract documents.
904.8 JOIST SPACING
904.9 ROOF DECKS
Joists shall be spaced so that the loading on each joist does not
(a) the
Material
exceed
design load (LRFD or ASD) for the particular joist as
designated in the contract documents.
Roof decks may consist of gypsum, formed steel, wood, or
other suitable material capable of supporting the required
loadDECKS
at the specified joist spacing.
904.9 ROOF
(a) Material
(b) Bearing
Roof Decks
decks may
of gypsum,along
formed
wood, orof the
shallconsist
bear uniformly
thesteel,
top chords
otherjoists.
suitable material capable of supporting the required
load at the specified joist spacing.
(c) Attachments
(b) Bearing
The spacing of attachments along the joist top chord shall
not exceed 36 inches (914 mm). Such attachments of the
Decksdeck
shalltobear
the shall
top chords
of the of
joists.
the uniformly
top chordalong
of joists
be capable
resisting
the forces given in Table 904.9-1.
(c) Attachments
TABLE 904.9-1
SP-Series Design
For
For applicable
applicable conditions,
conditions, horizontal
horizontal thrust
thrust force
force to
to be
be resisted
resisted
by
bythe
the joist
joistoror allowable
allowablelateral
lateralslip
slipatatthe
thesupport
support and
and design
design
details of end anchorage conditions shall be clearly indicated
details
of
end
anchorage
conditions
shall
be
clearly
indicated
by
by the specifying professional in the contract documents.
joists shall be anchored to resist such forces (Refer to
(c) UpliftSection 904.12 Uplift).
CAUTION:
Scissor
Arch joists
904.7
BEARING
SEATand
ATTACHMENT
thereto with minimum of two 1/4 inch fillet welds, 4 inches
long, or two 3/4 inch ASTM A325 bolts or equivalent. When
SP-Series joists are used to provide lateral stability to the
Uplift
supporting
member, the final connection shall be made by
welding
or
as
designated
by the
specifying
professional.SP-Series
Where uplift
forces are
a design
consideration,
Introduction
904.6 INSTALLATION OF BRIDGING
The spacing of attachments along the joist top chord shall
DECK
FORCES of the
not exceed 36 inches
(914ATTACHMENT
mm). Such attachments
deck toTOP
the top
chordLEG
of joists NOMINAL
shall be capable
of REQUIRED
resisting
CHORD
FORCE
the forces given in Table 904.9-1.
≤2”
100 PLF
TABLE 904.9-1 2½”
150 PLF
3”
Ends
joists resting on steel bearing plates on
Ends of SP-Series
SP-Series joists
on
masonry
structuralconcrete
concrete
shall
be attached
thereto
masonry ororstructural
shall
be attached
thereto
with
with a minimum of two 1/4 inch (6 mm) fillet welds 2
a minimum
of two
1/4orinch
(6 two
mm)3/4
fillet
welds
inches
(51
inches
(51 mm)
long,
with
inch
(19 2mm)
ASTM
mm)
long,
or
with
two
3/4
inch
(19
mm)
ASTM
A307
bolts
A307 bolts (minimum), or the equivalent.
(minimum), or the equivalent. Top chords of angle size L5” x
(b) Steel
5” x 1/2” or greater shall be attached thereto with minimum
of twoof1/4
inch fillet
welds,
4 inches
long,supports
or two 3/4
Ends
SP-Series
joists
resting
on steel
shallinch
be
ASTM
A325
bolts
or
equivalent.
attached thereto with a minimum of two 1/4 inch (6 mm)
welds 2 inches (51 mm) long, or with two 3/4 inch (19 mm)
ASTM A307 bolts (minimum), or the equivalent. Top chords
of angle size L5” x 5” x 1/2” or greater shall be attached
≤2” 5”
6” x 6” x 0.500”
2½” 6” x 6” x 0.625”
3”6” x 6” x 0.75”
3½” 4” 5” 400
PLF
NOMINAL FORCE
REQUIRED
500 PLF
100 PLF
600 PLF
150 PLF
750 PLF
200 PLF
850 PLF
Nominal bracing force
unfactored.
200isPLF
8” chords – contact NMBS
(d) Wood Nailers
300 PLF
400 PLF
Where wood nailers are used, such nailers in conjunction
6” xwith
6” x deck
0.500”shall
be firmly attached
500toPLF
the top chords of the
joists in conformance with Section 904.9(c).
6” x 6” x 0.625” 600 PLF
6” x 6” x 0.75” 700 PLF
Nominal bracing force is unfactored. 8” chords – contact NMBS
93
97
fillet welds 2 inches (51 mm) long, or with two 3/4 inch (19
(b) mm)
Steel ASTM A307 bolts (minimum), or the equivalent.
When SP-Series joists are used to provide lateral stability
to
theofsupporting
the on
final
connection
Ends
SP-Series member,
joists resting
steel
supports shall
shall be
be
made by welding or as designated by the specifying
attached
thereto
with
a
minimum
of
two
1/4
inch
(6
mm)
fillet
professional.
4”
TOP CHORD LEG
SP-Series Tables
(a)
(a) Masonry
Masonry and
and Concrete
Concrete
200 PLF
DECK
3½” ATTACHMENT FORCES
250 PLF
Introduction
(d) Wood Nailers
Where wood nailers are used, such nailers in conjunction
with deck shall be firmly attached to the top chords of the
joists in conformance with Section 904.9(c).
904.10 DEFLECTION
905.1 STABILITY
The deflection due to the design live or snow load shall
not exceed the following:
• 1/360 of span where a plaster ceiling is attached
or suspended
When it is necessary for the erector to climb on the SP-Series
joists, extreme caution must be exercised since unbridged
joists may exhibit some degree of instability under the
erector’s weight. The degree of instability increases for
geometries common with SP-Series joists due to their higher
center-of-gravity.
• 1/240 of span for all other cases
(a) Stability Requirements
Roofs:
(1) Before an employee is allowed on the SP-Series joists:
BOTH ends of joists at columns (or joists designated
as column joists) shall be attached to its supports.
For all other joists a minimum of one end shall be
attached before the employee is allowed on the joist.
The attachment shall be in accordance with Section
904.7.
The specifying professional shall give consideration to the
effects of deflection.
904.11 PONDING
The ponding investigation shall be performed by the specifying
professional. Refer to Steel Joist Institute Technical Digest #3,
Structural Design of Steel Joist Roofs to Resist Ponding Loads
and AISC Steel Construction Manual.
When a bolted seat connection is used for erection
purposes, as a minimum, the bolts must be snug
tightened. The snug tight condition is defined as the
tightness that exists when all plies of a joint are in firm
contact. This may be attained by a few impacts of an
impact wrench or the full effort of an employee using
an ordinary spud wrench.
SP-Series Design
904.12 UPLIFT
Where uplift forces due to wind are a design requirement, these
forces must be indicated in the contract documents in terms
of NET uplift in pounds per square foot (Pascals). The contract
documents shall indicate if the net uplift is based upon LRFD or
ASD. When these forces are specified, they must be considered in
the design of joists and/or bridging. A single line of bottom chord
bridging must be provided near the first bottom chord panel points
whenever uplift due to wind forces is a design consideration.
Refer to Steel Joist Institute Technical Digest #6, Structural
Design of Steel Joist Roofs to Resist Uplift Loads.
(2) For SP-Series joists with spans less than or equal to 20
feet (6.096 mm) that are permitted to have horizontal
bridging per the restrictions of Section 904.5.(c), only one
employee shall be allowed on the joists unless all bridging
is installed and anchored.
SP-Series Tables
904.13 INSPECTION
Joists shall be inspected by NMBS before shipment to verify
compliance of materials and workmanship with the requirements
of these specifications. If the buyer wishes an inspection of the
steel joists by someone other than NMBS, they may reserve the
right to do so in their “Invitation to Bid” or the accompanying
“Job Specifications.”
Arrangements shall be made with NMBS for such inspection of
the joists at the manufacturing facility by the buyer’s inspectors
at buyer’s expense.
(3) For SP-Series joists with spans more than 20 feet (6.096m),
the following shall apply:
a) All rows of bridging shall be bolted diagonal bridging.
Where the joist spacing is less than 2/3 times the
joist depth at the bridging row, both bolted diagonal
bridging and bolted horizontal bridging shall be used.
b) Hoisting cables shall not be released until all bolted
bridging is installed and anchored, unless an alternate
method of stabilizing the joist has been provided.
c) No more than one employee shall be allowed on these
spans until all bridging is installed and anchored.
(4) When permanent bridging terminus points cannot be
used during erection, additional temporary bridging
terminus points are required to provide lateral stability.
98
(6) After the joist is straightened and plumbed, and all bridging
is completely installed and anchored, the ends of the joists
shall be fully connected to the supports in accordance with
Section 904.7.
(b) (b)
Landing
and
Placing
Loads
Landing
and
Placing
Loads
bearing seats are attached.
(2)
During the construction period, loads placed on the
SP-Series joists shall be distributed so as not to
(2) During
the construction period, loads placed on
exceed the capacity of the joists.
(3)
the
SP-Series joists shall be distributed so as not to exceed
the
joists. of joist bridging shall not
Thecapacity
weight of
ofthe
a bundle
exceed a total of 1000 pounds (454 kilograms). The
bundle of joist bridging shall be placed on a
(3) The
weightofof 3a bundle
of joist
bridging
shall notatexceed
minimum
steel joists
that
are secured
one a
total
1000edge
pounds
kilograms).bundle
The bundle
end. ofThe
of (454
the bridging
shall of
bejoist
positioned
within
1 foot on
(0.30
m) of theofsecured
end.joists
bridging
shall
be placed
a minimum
three steel
A copy of the OSHA Steel Erection Standard §1926.757,
Open Web Steel Joists, may be found at www.newmill.com for
reference. Qualified person is defined therein as “one who, by
possession of a recognized degree, certificate, or professional
standing, or who by extensive knowledge, training, and
experience, has successfully demonstrated the ability to solve
or resolve problems relating to the subject matter, the work, or
the project.”
(2)
(c) Field
FieldWelding
Welding
(c)
All field
welding
be performed
in accordance
(1)(1)All field
welding
shallshall
be performed
in accordance
with
with the contract documents. Field welding shall not
the contract
documents.
Field
welding
shall
not
damage
damage the joists.
the joists.
(2)
On cold-formed members whose yield strength has
been attained by cold working, and whose as(2) On cold-formed
members whose yield strength has been
formed strength is used in the design, the total
attained
by
cold
working,
as-formed
strength
length of weld
at any and
one whose
point shall
not exceed
50
is used
in theofdesign,
the totaldeveloped
length of weld
at any
percent
the overall
width
of one
the
section.
pointcold-formed
shall not exceed
50 percent of the overall developed
width
of
the
cold-formed
section.
(d) Handling
Particular attention should be paid to the erection of SP(d) Handling
Series joists. Care shall be exercised at all times to avoid
(4)a)
No The
bundlecontractor
of deck may
be placed
on SP-Seriesfrom
joistsauntil
has
first determined
(2)
“qualifiedhas
person”
and documented
a siteall bridging
been installed
and anchoredin and
all joist
specific erection plan that the structure or portion
bearing
ends
attached,
unless
the
following
conditions
of the structure is capable of supporting the load.
are met:
paragraphs
2 and
3, must be braced
anchored
to prevent
lateral
Each
joist shall
be adequately
laterally
before
any
movement.
loads are applied. If lateral support is provided by bridging, the
lines,Systems
as defined in Section 905.1(a)(2) and 905.1(a)
(e) bridging
Fall Arrest
(3), must be anchored to prevent lateral movement.
the following conditions are met:
b) The bundle of decking is placed on a minimum of
3 steel
joists. has first determined from a “qualified
a) The
contractor
(2)
and
documented
a site specific
erection
c) person”
The joists
supporting
theinbundle
of decking
areplan
attached
at both or
ends.
that
the structure
portion of the structure is capable of
d) supporting
All rows ofthe
bridging
load. are installed and anchored.
e)b) The
The total weight of the decking does not exceed
bundle of decking is placed on a minimum of three
4000 pounds (1816 kilograms).
bridging
lines,
as
defined
in
Section
905(a),
SP-Series joists shall not be used as anchorage points for
a fall arrest system unless written direction to do so is
(e) Fall
Arrestfrom
Systems
obtained
a “qualified person.”(2)
SP-Series joists shall not be used as anchorage points for a
fall arrest system unless written direction to do so is obtained
from a “qualified person.”(2)
steel joists.
The edge of the bundle of decking shall be
SP-Series Tables
f)
the
SP-Series Design
that are secured at one end. The edge of the bridging
No bundle of deck may be placed on SP-Series
bundle
shall be
within
1 foot
(0.30 m)and
of the
joists until
all positioned
bridging has
been
installed
secured
end.
anchored
and all joist bearing ends attached, unless
damage toattention
the joists should
and accessories.
Particular
be paid to the erection of
SP-Series joists. Care shall be exercised at all times to
Each joist shall be adequately braced laterally before any
avoid
damage
to theIfjoists
and
accessories.
loads
are applied.
lateral
support
is provided by bridging,
(4)
stated
in paragraph
905(b)(3)
of this section,
(1)(1) Except
Exceptasas
stated
in paragraph
905(b)(3)
of this no
(1)
section, no "construction
allowed
on the
“construction
loads”(1) are loads”
allowed are
on the
SP-Series
joists
SP-Series joists until all bridging is installed and
until
all
bridging
is
installed
and
anchored,
and
all
joist
anchored, and all joist bearing seats are attached.
Introduction
(5) In the case of bottom chord bearing joists, the ends of
the joist must be restrained laterally per Section 904.5(f)
before releasing the hoisting cables.
placed
one foot
(0.30 of
m)decking
of the are
bearing
c) The
joistswithin
supporting
the bundle
attached
surface
of the joist end.
at
both ends.
g) The edge of the construction load shall be placed
d) All
rowsone
of bridging
arem)
installed
anchored.
within
foot (0.30
of the and
bearing
surface of
(1)
the joist end.
e) The
total weight of the decking does not exceed 4000
poundsof(1816
A copy
the kilograms).
OSHA Steel Erection Standard
§1926.757, Open Web Steel Joists, is included at
f) The edge of the bundle of decking shall be placed within
www.newmil.com for reference. Construction loads are
one footfor
(0.30
of the bearing
surface
the joist
defined therein
joistm)purposes
as “any
loadofother
thanend.
the weight of the employee(s), the joists and the bridging.”
(5) The edge of the construction load shall be placed within one
A copy of the OSHA Steel Erection Standard
foot (0.30
m) ofWeb
the bearing
the be
joistfound
end. at
§1926.757,
Open
Steel surface
Joists, of
may
(2)
(1)www.newmil.com
for reference.
Qualified
person
is
A copy of the OSHA
Steel Erection
Standard
§1926.757,
defined therein as “one who, by possession of a
Open
Web Steel
Joists,
is included
at www.newmill.com
recognized
degree,
certificate,
or professional
standing, or for
reference.
Construction
loads are
defined
for joist
who by extensive
knowledge,
training,
andtherein
experience,
has successfully
demonstrated
abilityof the
to solve
or
purposes
as “any load
other than thetheweight
employee(s),
resolve problems relating to the subject matter, the work,
the
joists and the bridging.”
or the project.”
99
SP-Series Design
Introduction
The following abbreviated design examples demonstrate the
selection of an SP-Series joist from the Weight Tables given all
necessary geometry and loading information. The information
found in the SP-Series Weight Tables includes the uniform
self-weight of the joist as well as bridging and seat-depth
requirements. For Scissor (SPSC) and Arch (SPAC) Joists, the
table
will noteprofile
if the horizontal
is greater than
This and
The following examples serve as brief examples of going from
a special
geometrydeflection
to the SP-Series
load2”.
tables
allowance
is
for
a
pin-roller
bearing
anchorage
condition.
The and
determining the uniform self weight of the joist, the bridging requirements, the seat depth, and for Scissor (SPSC)
horizontal
deflection,
or
slip,
is
at
the
roller
end.
Arch (SPAC) Joists, the table will note if the horizontal deflection is greater than 2”. This allowance is for a pin-roller
906.1 GABLE EXAMPLE
anchorage condition and the horizontal deflection, or slip, is at the roller end.
ALL TABLES ARE BASED ON ASD
Gable Joist Example
GABLE
JOIST
(SPGB)
From the above diagram, the following information
is used
to enter
the Gable Joists (SPGB) Weight Tables on page 19.
Span:
40’-0”
Depth:
46” is used to enter
End
6”
Top Chord
Pitch:
From the
above diagram, theCenter
following
information
theDepth:
Gable Joists
(SPGB) Tables
on page
24. 2” / foot
Total Load: 300 plf
The weight tables are based on a 0.75 Live to Total Load ratio (300 x 0.75 = 225 plf) and check
Total Load: 300 plf Uplift
Load: 160 plf
Total Load is the result of worst-case equivalent uniform load, WeqM-TL, based on investigation of
This
load
is not shown in the above diagram but is called out on the contract drawings in the NET
all
load
cases.
SP-Series Tables
Span: 40’-0” Center Depth:
46”
End Depth:
2” / foot
for a Live
Load Deflection
not 6”
to exceed L/240,Top
orChord
40’ x Pitch:
12 / 240
= 2” maximum deflection for 225
plf.
UPLIFT plan and calculated for the given joist spacing.
Live Load: 120 plf SP-Series tables are based on a 0.75 Live to Total Load ratio (300 x 0.75 = 225 plf) and check for a Live Load
deflection not to exceed L/240, or 40’ x 12 / 240 = 2” maximum deflection for 225 plf. The Live Load in this
example,
120 plf, isgeometry
less than is
75found
percentonofpage
the total
From the information above,
the correct
23.load, 225 plf, therefore deflection is within limits.
Joist Designation: 46 SPGB 300 / 225 / 160
From
the table:
Uplift Load:
160 plf JoistUplift
Self-Weight:
PLF
Net
is not shown in23the
above diagram but is called out in the contract documents in the
Bridging
Required:
3
Rows
of Bolted X-Bridging
NET UPLIFT plan.
Seat Depth:
5” Deep Seats
Joist Designation:
46 SPGB
300 / 120 /should
160 be noted on the contract documents and reflected in the section details.
Bridging
and seat depth
information
From the information above, the correct geometry is found on page 28.
From the table: Joist Self-Weight: Bridging Required: Seat Depth: 8 PLF
3 Rows of Bolted X-Bridging
5” Deep Seats
Bridging and seat depth information should be noted in the contract documents and reflected in the section details.
100 www.newmill.com/digital-tools
95
Introduction
906.2 BOWSTRING EXAMPLE
STANDARD SPECIFICATION – SP SERIES
906.2 BOWSTRING EXAMPLE
EXAMPLES BASED ON ASD
BOWSTRING JOIST (SPBW)
From the above diagram, the following information is used to enter the Bowstring Joists (SPBW) Weight Tables on page
From
35. the above diagram, the following information is used to enter the Bowstring Joists (SPBW) Tables on page 40.
Center
46” End Depth: 6” End Depth: 6”
Top 62’-0”
Chord Radius: 62’-0”
Center Depth:
46”Depth:
Top Chord Radius:
Total Load:
800 plf
Total Load is the result of worst-case equivalent uniform load, WeqM-TL, based on investigation of
Live Load:
400 plf
SP-Series tables are based on a 0.75 Live to Total Load ratio (800 x 0.75 = 600 plf) and check for
Uplift Load:
220 plf
Net Uplift is not shown in the above diagram but is called out in the contract documents in the
Total Load: 800 plf Live Load: 400 plf Uplift Load: 220 plf TotalallLoad
the result of worst-case equivalent uniform load, WeqM-TL, based on investigation of
load iscases.
all load cases.
SP-Series Design
Span:
40’-0”
Span:
40’-0”
a Livetables
Loadare
Deflection
to Live
exceed
L/240,
40’(800
x 12
/ 240= 600
= 2”plf)
maximum
for 600
SP-Series
based on not
a 0.75
to Total
Loador
ratio
x 0.75
and checkdeflection
for a Live Load
plf.
The Live
Load
in this
example,
400
plf,=is2”less
than 75
percentforof600
theplf.
total
600 in
plf,
therefore
deflection
not to
exceed
L/240,
or 40’ x 12
/ 240
maximum
deflection
Theload,
Live Load
this
deflection
is iswithin
limits.
example,
400 plf,
less than
75 percent of the total load, 600 plf, therefore deflection is within limits.
Net NET
UpliftUPLIFT
is not shown
plan. in the above diagram but is called out in the contract documents in the NET
UPLIFT plan.
Joist Designation: 46 SPBW 800 / 400 / 220
SP-Series Tables
Joist Designation: 46 SPBW 800 / 400 / 220
From
thethe
information
correct
geometry is found17onPLF
page 44.
From
table: above, the
Joist
Self-Weight:
Bridging Required:
From the table: Joist Self-Weight:
17 PLF 5” Deep Seats
Seat Depth:
Bridging Required: 3 Rows of Bolted X-Bridging
Bridging and seat
depth
information
noted
in the contract documents and reflected in the section details.
Seat
Depth:
should5”beDeep
Seats
97
101
Introduction
906.3 SCISSOR EXAMPLE
Scissor Joist Example
SCISSOR JOIST (SPSC)
From the above diagram, the following information is used to enter the Scissor Joists (SPSC) Weight Tables on page 51.
From the above diagram, the following information is used to enter the Scissor Joists (SPSC) Tables on page 56.
SP-Series Design
Span: 40’-0”
Chord Depth: 36”
Ridge Depth: 37.1”
Shape Depth: 97”
Top Chord Pitch: 3 / 12
Span: 40’-0” Chord Depth: 36” Shape Depth: 97” Top Chord Pitch: 3” / foot
Ridge Depth:
Total Load: 600 plf
The 37.1”
weight tables are based on a 0.75 Live to Total Load ratio (600 x 0.75 = 450 plf) and check
Total Load: 600 plf Uplift Load: 110 plf
for a Live Load Deflection not to exceed L/240, or 40’ x 12 / 240 = 2” maximum deflection for 450
plf.Load is the result of worst-case equivalent uniform load, WeqM-TL, based on investigation of
Total
all load cases.
This load is not shown in the above diagram but is called out on the contract drawings in the NET
UPLIFT plan.
Live Load: 370 plf SP-Series tables are based on a 0.75 Live to Total Load ratio (600 x 0.75 = 450 plf) and check for a Live Load Joist Designation: 36
deflection
not to
exceed
L/240, or 40’ x 12 / 240 = 2” maximum deflection for 450 plf. The Live Load in this SPSC 800
/ 600
/ 110
example, 370 plf, is less than 75 percent of the total load, 450 plf, therefore deflection is within limits.
SP-Series Tables
Uplift Load: 110 plf From the table:
Self-Weight:
18 PLF
NETJoist
UPLIFT
plan.
Bridging Required:
Seat Depth:
Joist Designation: 36 SPSC
600 / 370 Deflection:
/ 110
Horizontal
5 Deep Seats
≤2”; as the note for x>2 is not shown in the cell
Bridging
and seat depth
should is
befound
noted
the60.
contract documents and reflected in the section details.
From
the information
above, information
the correct geometry
onon
page
From the table: Joist Self-Weight: Bridging Required: Seat Depth: Horizontal Deflection: 18 PLF
5 Deep Seats
≤2”; as the note for бx>2 is not shown in the cell
97
Introduction
STANDARD SPECIFICATION – SP SERIES
906.4 ARCH EXAMPLE
906.4 ARCH EXAMPLE
EXAMPLES BASED ON ASD
ARCH JOIST (SPAC)
From the above diagram, the following information is used to enter the Arch Joists (SPAC) Weight Tables on page 67.
From the above diagram, the following information is used to enter the Arch Joists (SPAC) Tables on page 72.
Chord Depth: 36”
Total Load:
Chord Depth: 36” Total Load is the result of worst-case equivalent uniform load, WeqM-TL, based on investigation of
loadiscases.
Total all
Load
the result of worst-case equivalent uniform load, WeqM-TL, based on investigation of
all load cases.
315 plf
Live Load: 315 plf Uplift Load:
Top Chord Radius: 43’-0”
Top Chord Radius: 43’-0”
450 plf
Total Load: 450 plf Live Load:
Shape Depth: 96”
Shape Depth: 96” SP-Series tables are based on a 0.75 Live to Total Load ratio (450 x 0.75 = 338 plf) and check for
a Live Load Deflection not to exceed L/240, or 40’ x 12 / 240 = 2” maximum deflection for 338 plf.
SP-Series
are based
onexample,
a 0.75 Live315
to Total
ratio
(45075
x 0.75
= 338ofplf)
and
check
for a338
Liveplf,
Load
The tables
Live Load
in this
plf, Load
is less
than
percent
the
total
load,
therefore
deflection
not to is
exceed
L/240,
or 40’ x 12 / 240 = 2” maximum deflection for 338 plf. The Live Load in this deflection
within
limits.
SP-Series Design
Span: 40’-0”
Span: 40’-0” example, 315 plf, is less than 75 percent of the total load, 338 plf, therefore deflection is within limits.
200 plf
NET UPLIFT plan.
Uplift Load: 200 plf Net Uplift is not shown in the above diagram but is called out in the contract documents in the
Joist Designation: NET
UPLIFT plan.
36 SPAC 450 / 315 / 200
SP-Series Tables
Joist
Designation:
36 SPAC
450 the
/ 315correct
/ 200 geometry is found on page 71.
From
the information
above,
From
table: above, the
Joist
Self-Weight:
From
thethe
information
correct
geometry is found17
onPLF
page 76.
Bridging Required:
Seat Depth:
5” Deep Seats
Joist Self-Weight:
Deflection:
17 PLF ≤2”; as the note for  >2 is not shown in the cell
Horizontal
x
From the table: Bridging Required: 2 Rows of Bolted X-Bridging
Seat
Depth:
should5 be
Deep
Seatsin the contract documents and reflected in the section details.
Bridging and seat
depth
information
noted
Horizontal Deflection: ≤2”; as the note for x>2 is not shown in the cell
99
103
SP-Series Tables
SP-Series Design
Introduction
NOTES:
Building a better steel experience...
New Millennium is your nationwide resource for reliable, structural steel roof-and-floor systems.
Our dynamic manufacturing facilities are strategically located across North America for all your
standard and special profile steel joists, plus steel roof and floor decking.
Indiana Manufacturing Facility
6115 County Road 42
Butler, IN 46721
Phone: (260) 868-6000
Fax: (260) 868-6001
Nevada Manufacturing Facility
8200 Woolery Way
Fallon, NV 89406
Phone: (775) 867-2130
Fax: (775) 867-2169
Virginia Manufacturing Facility
100 Diuguids Lane
Post Office Box 3400
Salem, VA 24153
Phone: (540) 389-0211
Fax: (540) 389-0378
Mexico Manufacturing Facility
Carr. Panamericana 9920
Col. Puente Alto
C.P. 32695
Cuidad Juarez Chihuahua
Mexico
Phone: (915) 298-5050
Fax: (915) 298-4040
Florida Manufacturing Facility
1992 NW Bascom Norris Drive
Lake City, FL 32055
Phone: (386) 466-1300
Fax: (386) 466-1301
Corporate Office
7575 W. Jefferson Blvd.
Fort Wayne, IN 46804
Phone: (260) 969-3500
Arkansas Manufacturing Facility
3565 Highway 32 North
Hope, AR 71801
Phone: (870) 722-4100
Fax: (870) 722-4245
© 2014 New Millennium Building Systems, LLC All rights reserved.
New Millennium Building Systems is a wholly owned subsidiary of Steel Dynamics Inc.

902.2 MECHANICAL PROPERTIES - New Millennium Building

Transcription

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