construcción con guadua

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sunday, may 25th
We started the day off with a consultation with our professor, Gabriel.
He gave us the constraints of our design including the following:
our foundation could not be larger than 7x5 meters (aprox. 21x15
ft) we would have 3 trusses & we needed to only use about 60%
of our gaudau (about 35 beams). Our structure would become a
replacement pavilion for university-community member gatherings.
As a design team we began sketching ideas, exploring the various
truss (or sercha) designs we had observed previously. We decided
because the length of our gaubau was only 19.5’ at most, our trusses
would need to be composed of two trusses place together. For this
reason we began to design an inverted pez. Originally we wanted to
use this as we liked the curved truss design, but Gabriel then told us
after the length was too short to achieve the curves in our design. In
addition to using two serchas we wanted to use an asymmetrical design
that would incorporate two serchas of different lengths and slopes.
By lunch we had a near finished initial design. Later we split into a
group for model building and another for the CAD drawing of our
structure. In the evening we received significant feedback from
Andres and Greta. From this, we modified our design, adding
a horizontal beam to add structural support and removing a
vertical post as we we overstructuring our design in this aspect.
lessons learned
- curves cannot be achieved in smaller structures.
- be cautious to not over-structure by adding extra poles for aesthetics.
- we needed help to make our design structurally-sound.
monday, may 26th
The morning of Monday the 26th, course participants traveled to the
Javeriana to start work on the structure. There, we met with the builders
from the NGO Escuela Para La Vida, as well as faculty members from the
University who would be assisting us with the project. Checho, Michael, and
Greta from Escuela Para la Vida taught us guadua construction terminology
we would need to know, and further discussed with us the feasibility of
our model. A short pole from the eve to a diagonal beam was added to
the design for structural support, and a few measurements were changed.
After lunch, a few course participants, faculty members, and our instructors
visited the Vice President of Javeriana University to present our designs and
decide on a site orientation. The plans were so well received that we were
asked to build four trusses instead of the original three, thus expanding our
footprint. After splitting into two groups, we began building. Meanwhile, Julie
and Greta looked over the plan’s measurements and disseminated them. We
had almost completed 2 trusses when we realized that the same diagonal
pole on the two trusses wasn’t meeting its adjacent pole at the right spot. We
went home confused and had no solution for this problem until the following
day when we realized we needed to put the roof at more of an incline.
terminology and best practices
llave: wrench
pulidora: grinder
tuerca and arandela: nut and washer
varilla roscada: threaded steel rod
disco de corte: cutting disk
disco de lija: sanding disk
martillo: hammer
cercha: truss
esterilla: bamboo mat
broca: drill bit
cepa: the part of the guadua pole that
grew closest to the ground
cola: part of the guadua pole that grew
away from the ground
-when compressive strength is needed,
put the cepa at the bottom with the cola
facing up
-when tensile strength is needed, put two
guadua poles together with cepas and
colas not matching
-bolts can’t be farther than 5 cm away
from nodes
-for compressive strength put bolts above
nodes, for tensile strength put bolts below
nodes
-tightening bolts should be the last
thing you do, as you may need to make
adjustments
tuesday, may 27th
The day began significantly slower than Monday. After repeatedly
remeasuring guadua poles and finding that our measurements were
a little off, Bahia began working on the AutoCAD to fit the actual
structure. This consumed most of her day as she had to remeasure
most of the guadua and figure out where the problem intervened.
Part-way through building, we ran into another design issue. One
of our trusses cut too much into the interior space of the building.
In strictly architectural terms, the area where the pole met the post
was smaller than one Karina in height. This cutting into the building
could potentially cause a fire hazard, as people could hit their
heads on the pole. Rather quickly, we had to come up with a design
decision. In the end, we decided to cut the pole where it intersected
a cross beam. This solution opened up the space and reduce the
potential for accidents, as well as allowing keep the right angle.
Gabriel explained to us that often what looks good on paper does
not translate to construction as easily. The graceful, downward
lines that looked so beautiful in the plan turned out to be both a fire
hazard and a space restriction. Artists who practice architecture
must often change their aesthetic and their goals in order to
account for what is a reasonable achievement. Architecture must be
functional. However, we were able to keep the essence of our plan.
lessons learned
-guadua, being a unique material, tends to vary more in construction.
Therefore, not all measurements can be exact, which is difficult to then
translate into an AutoCAD file.
-design and build is a non-sequential process; design occurs, but is often
changed on site, as the design must be changed to accomodate for reality
-design decisions on site must be made quickly and efficiently
-measurements must be done from the same point on the guadua
tuesday, may 27th continued
Another problem we ran into was the lack of labor. Julie was sick at home,
Bahia was on AutoCAD, and Ande was still weak from being ill. This left
only Maya, Karina, and Erika to work on finishing the trusses. Furthermore,
we did not split up into groups, which led us to a congested workflow.
By the end of the day, we had cut pieces to fit our new design,
drilled though where we would put the varillas and cut off
the ends. One truss was finished and moved into the shade.
lessons learned
-make sure many eyes check over final drawings and measurements before
sending them out
-be aware of what gets lost in translation (visual and verbal)
-when you draw Guadua on CAD, everything must be drawn on the x-axis
-begin drawing in the “right” units. in this case, meters
wednesday, may 28th
On Wednesday, we put together the columns and diagonals of
the second truss with alicate joints. The tools needed to do so
included: a drill, a drill bit, a grinder, wrenches, a chop saw, rope,
and an extension chord. When it was complete, we proceeded
to flip the first and second truss up and rest it against a tree close
to the Javeriana’s architecture department building. It took more
than 10 people to do the flipping and moving of the trusses.
lessons learned
Drafting a structure of guadua proved challenging for me as someone still new
to AutoCAD. Simple rules - measuring from the center of each pole, averaging
the diameters to 12 cm - were helpful, but were difficult to apply consistently
across a variety of joints and cuts. A clear understanding of the structure and the
way poles overlapped was necessary to keep the plans organized and accurate.
thursday, may 29th
We arose from our beds and approached the day with enthusiasm.
Sandro picked us up from La Casa Cafe and we headed to javerinana
with Michael and Greta but without ande and Gabriel. enthusiasm
decreased when we saw the rain clouds drift into our horizon. they
broke into a million pieces and fell upon the guadua. dramatic it was.
actually this is all a lie, it was raining when we woke up. all this to say,
the weather reflected our mood: we all needed a little bit of alone time.
Nevertheless, we started working on different things on the second floor
of the academic building, looking out over the site. most of us started
on the reflection booklet, others on the banco [bench], and the rest on
he CAD files. fortunately, like the end of a war at sea, the sun broke
through between the clouds brighting the day. cheery we became.
Michael, Maya, Julie and Bahia continued working on the already cut
pieces for truss #3 while Checho, Karina and Erika worked on truss #4
from scratch. after many hours of laborious effort an iguana strutted
towards truss number 3 with the intent to kill. Michael yelled, “Bahia!
QUE PASA? IGUANA?! AH!” in that moment the iguana, defeated in
it’s attempt, scurried up the tree never to be seen again. the afternoon
continued in sweat and laughter until 5pm when both trusses were
completed. as soon as the final varilla was cut off the rain broke out again.
perhaps all the forces of the earth worked towards us finishing the trusses.
lessons learned
-attitude matters when working in groups. when one person isn’t too happy,
that unhappiness is infectious and is unpleasant.
-working in groups of 2 increased our pace and we were able to complete 2
trusses in the rough span of 4 hours.
-we were able to work fast because we had the right measurements needed
and were not making them up anymore.
-we could have asked for assistance from others when we needed to.
friday, may 30th
We entered the work site for the last time Friday morning, the four
trusses or cerchas complete. The previous afternoon Greta and
Gabriel devised a supplementary project in the form of a bench.
The construction of this bench emphasized the Boca de Pez or
“fish mouth” method of joinery and the concrete injection process
for bamboo. Once we arrived at the University, Greta presented the
group with a set of rough sketches including dimensions so we could
get a quick start. After a week of working together, group dynamics
were recognized and utilized for efficiency. Erika, Maya, Juan Manuel,
and Checho measured and marked guadua while Julie, Karina, and
Bahia started making cuts at the chop saw under the supervision of
Michael. They cut close to the nodes for the greatest structural stability.
Meanwhile, Ande drew up a more detailed sketch of the project based
on the schematic drawings by Greta. Once everything was cut straight
Checho showed the group how to cut a Boca de Pez using a large circular
drill bit with a diameter roughly the same as the guadua. He taught us
that the cut must be made four centimeters from the measured edge.
He was able to eyeball the cut without marking the four cm line because
of persistent practice. The cut is then cleaned up using a cutting disk
to round off sharp fibrous edges. As we worked it became apparent
that Checho and Micheal have slightly different styles when it comes to
cutting the Boca; Checho cut one side of the guadua then turned it to cut
the other whereas Micheal went through the guadua from the same side.
Next these pieces were laid out with the vertical posts showing that
some of the guadua have larger diameters so Checho and Micheal
marked this and then went back into the cuts to increase the diameter of
the “mouth”. Once the pieces fit together snugly we drilled through the
posts and chiseled out nodes to bolt the bench together. Some of the
bolts have washers welded to the end to provide a sort of loop to thread
another bolt through, creating a connected system inside the guadua.
people involved
5 College Students
Anderson Clemens
Karina Rosenstein
Bahia Marks
Erika Linenfelser
Julie Pedtke
Maya Sause
5 College Instructor
Gabriel Arboleda
Universidad Javeriana
Juan Manuel
Maria Claudia
Escuela Para La Vida
Andres Bappler
Greta Tresserra
Checho
Maicol Herrera