Verrazano Narrows Storm Surge Barrier

Verrazano Narrows Storm Surge Barrier
ASCE Met Section Infrastructure Group Seminar 2009
Conference “Against the Deluge: Storm Surge Barriers to
Protect New York City, March 31st 2009
Peter Jansen, Principal Engineer Hydraulic Structures, ARCADIS
Piet Dircke, Program Director Water, ARCADIS
Contents
•
•
•
•
•
•
•
•
•
•
Introduction
Location Verrazano Narrows
• inhoudsopgave
Passage of ships
Tide reduction and wet cross section
Conceptual design
Height and overtopping
Details
Reliability
Estimate of Costs
Concluding remarks
• Questions and discussion
The Netherlands
1
2
3
5
4
Comparison of New York / New Jersey and the Netherlands
•
•
•
•
•
Complex sea, tidal and river water systems
Urban area with high property values & densities
Large urban areas below or just above sea level vulnerable to
floods
Environmental impact as a major issue
Large ports with intense shipping
New York
Rotterdam
Location Verrazano Narrows
New York Harbor Bay
North of Bridge
Not too far
Depth
Alignment half
a mile north of
Verrazano Bridge
The Narrows
Staten Island
Long Island
Verrazano bridge
Present Cross section Verrazano Narrows
Cross section
60
Cross section
Cross section
40
Width: 6000 feet
Width: 6000 feet
Depth: 60 feet (max)
Depth: 60 feet (max)
20
0
-20
Wet cross section:
Wet surface:
310.000 ft2
310.000 ft2
-40
-60
6600
R1
6270
5940
5610
5280
4950
4620
4290
3960
3300
3630
width (ft)
2970
2640
2310
1980
1650
1300
990
660
330
0
-330
-80
depth (ft)
Embankement above
Embankement above
50 feet within
50 feet within
300-600 feet
300-600 feet
Impeding water only
n
o
i
t
p
o
c
i
t
s
i
l
a
e
r
o
N
Passing ships
Tidal flow
Passage of ships
Biggest ship
afloat must be
able to pass
Emma Maesk
Length: 1300 feet
Beam: 185 feet
Draft: 53 feet
Heigth: 251 feet
Cross section for biggest ships
Requirements for
Requirements for
passage of ships
passage of ships
Width: 860 feet
Width: 860 feet
Sill: - 66 feet
Sill: - 66 feet
Clearance: unlimited
Clearance: unlimited
= blue area
Wet surface:
Wet cross section: 2
57.000 ft
19 %
Additional cross section for smaller ships
Additional cross section for smaller ships
2 gates
2 gates
Width: 165 feet
Width: 165 feet
Sill: - 40 feet
Sill: - 40 feet
Clearance: 80 feet
Clearance: 80 feet
Total wet cross
Total wet surface:
Section
70.000 ft2
23 %
Reduction tide in New York Harbor Bay (1)
Limited wet cross section
= limited tide
Tides
Present tide NYHB
4,0
3,0
2,0
W aterlevel (ft)
1,0
0,0
20,0
30,0
40,0
50,0
60,0
70,0
80,0
-1,0
-2,0
-3,0
-4,0
Tide NYHB,
limited cross section
90,0
Reduction tide in New York Harbor Bay (2)
Limited wet cross section
= limited tide
Tide in relation to wet cross section
100
90
Reduction to 23%
= tide reduction to 85-90 %
80
T i d e (% )
70
Tide; basis model
with safety margin
60
..
50
40
30
20
10
0
0
10
20
30
Cross section (%)
40
50
60
Reduction tide in New York Harbor Bay (3)
Limited wet cross section
= limited tide
8
Maximum velocity
during mean tide
7
Velocity (knots)
6
Reduction to 70.000 sq ft2
= tide reduction to 85-90 %
5
4
.. and higher peak velocities
up to 6-8 knots
3
2
1
0
0
10
20
30
Cross section (%)
40
50
60
Additional wet cross
section for
• higher tidal range
• lower velocities
Additional cross section tidal flow
16 gates
Width:
130 feet
Sill:
- 40 feet
Clearance: 5 feet
Total wet cross section
155.000 ft2
= 50 % of present wet
cross section
Combination of three existing Dutch barriers …(1)
Maeslant storm
surge barrier
1997
Combination of three existing Dutch barriers …(2)
Hartel Canal
storm surge barrier
1997
Combination of three existing Dutch barriers …(1)
Easter Scheldt
storm surge barrier
1986
… used in the right places (1)
Sector gate for large opening:
Maeslant
… used in the right places (2)
Sector gate for large opening:
Lifting gates, high clearance for smaller openings:
Maeslant
Hartelkering
… used in the right places (3)
Sector gate for large opening:
Maeslant
Lifting gates, high clearance for smaller openings: Hartelkering
Lifting gates, fixed beam for extra wet cross section: Easter Scheldt
Technical overview
Closed
Open
Artist impression
Requirements impeding water
- Structural reliability
- Reliability closure
- Limit overtopping and leakage
Water level outside
30,0
Water level
water level (ft)
25,0
Desig
n
Cate storm
gory
3 hur
Surg
rican
e of 2
e
2 fe e
t
20,0
Storm surge
15,0
Normal tide
10,0
Sea level rise
5,0
0,0
-5,0
1
7
13
19
25
time (hr)
31
37
43
49
Height: allowing overtopping and some leakage
Allowing overtopping is reducing height and reducing costs
30,0
25,0
20,0
Outside
15,0
10,0
Inside
5,0
49
46
43
40
37
34
31
28
25
22
19
16
13
10
7
4
0,0
1
water level (ft)
•
-5,0
Opentime (hr)
Closed
Open
Allowing overtopping and some leakage
Allowing overtopping is reducing height and reducing costs
Inside water level will rise - allowable below safe water level
8,0
Safe level
7,0
With overtopping
6,0
5,0
water level (ft)
•
•
4,0
With river discharge
3,0
2,0
1,0
No river, no overtopping
0,0
20,0
25,0
30,0
35,0
40,0
45,0
50,0
-1,0
time (hr)
Open
Closed
Open
Details sector gate
Enormous gates
640 feet long
Sliding over sill
Height -66 to + 30 feet
Detail sector gate
Large Foundation
Locomobiel
Details 130-feet lifting gate
Fixed beam between
+ 5 and + 36 feet
Sill at -40 feet
Gate between -40 and + 5 feet
Gate hanging on cylinders
Maintenance road
Details 130-feet lifting gate
Some leakage between gate
and fixed beam
Operating mechanism 130-feet lifting gates
Cylinders able to lift heavy gates
Fail-safe solution:
If operating system fails automatic
closure of gates by local system,
battery controlled, using gravity
Applicable up to lifts of 80 feet
Reliable if used / tested monthly
Details 165-feet lifting gate
No fixed beam
Sill at -40 feet
Clearance of 80 feet
No cylinders but winches in towers
Height up to + 28 feet
Large lifting gate 1,000 kips
(= 1 meps?)
Reliability
Reliability is a key issue; meassures taken include
•
•
•
•
•
Use proven concepts
Operating mechanism above water
Fail save design
Simple movement (horizontal or vertical only)
Easy accessible for maintenance
Operations is vital
• Early warning system
• Dicision making (who en when)
• Stopping of ships
Maintaining reliability is essential
How to keep a structure reliable
when you use it only one every 10 years
•
•
•
•
Maintenance driven design
Thoughtful construction
Risk based management
Learning and cooperating with other
storm surge barrier managers
• Strong organization with sufficient
budget
Costs
Rough estimate
Sector gate
16 + 2 lifting gates
Tie-in structures
Total
O&M Budget estimated
US$ 75mln annually
Much lower costs with
less lifting gates
Many additional studies
required
US$ 2.5 bln
US$ 3.5 bln
US$ 0.5 bln
US$ 6.5 bln
Concluding remarks
Storm surge barrier possible
Reliability is key issue
Barrier includes all state of the art
knowledge of barrier design
and operation
Requirements and dimensions will
determine costs => additional studies
An extra landmark for New York …
Conclusion
bringing safety when required
Questions
Questions