30 Feet Long Model and Anchor Study
The Origin of Our 30 Feet Long Model
During the last week of February, the 30 feet long model group decided to build a real life model. It was time to do something representative of everything we have been researching– but at a life size scale. This time the material had to be real too. No more basswood, but structural wood. After much research with fir, timber, white pine wood, and yellow pine wood – we decided for the yellow pine wood. We bought everything at a wood store in the South side of San Antonio called MG Building Materials located at 2561 S.W. Military Drive. The dimension we chose was 1 by 4 inch by 12 feet. We purchased about seventeen pieces. These pieces were cut in half using the table saw. Before we cut it, we were sent to training with Sam Cerda in order to learn how to manage the table saw safely. So, after cutting these pieces we had about 34 wood members. After cutting them, the wood members size changed to 1 inch by 2 inch by 12 inch. We cut any additional extra spaces in the mightier saw to make every member even. We also placed each piece on the power drill and drilled holes every 3 inches. The joints in the center were cut a blue table that had (a router). It made a very flexible horizontally long drilled hole for flexibility. We alternated some of the members in a diagonal orientation where we had 4 pieces drilled, in line and attached with numerous screws, bolts and washers. Some examples were assembled and pinned by the edge of the curbside, and then our group lifted the center of the structure, while the others classmates kept the other ends in the ground. The structure bent easily and it was not necessary to moisten it. In February 28, we did another test, – but this time we added two more thirds of the model completing it We chose the rock garden located in the back of UTSA College of Architecture as our test site. We lifted the center and the rest of the classmates pushed from either end, but we made a mistake – we pressed inwards too much and some of the joints snapped. When we reported this to our professor on Monday, March 3 2014, we realized we had placed the joining members in the wrong position. They were overlapping and they needed to be end butted. On March 5, we created a new group to research the Roof skin structure. Andres volunteered to help them with this group. We also researched and worked with the anchors. After much discussion, a decision was made to make the anchors of rebar. Aleks suggested they should be welded. After he welded them, he suggested we place them in cast concrete. This gave the anchors more weight. The anchors have a place where the wood members can be inserted and attached to the anchor. There is also a handle to transport the anchor to another location when needed.
Our structure will be light, easy to transport and easy to fabricate. We think it will be safe. It will be safe enough to be stretched and anchored. A person could possibly walk on top of it. It is economical, as long as we choose a lumberyard that can give us good pricing for yellow pine. Since we are using a fabric structure, it could be attached when the grid shell is still in the floor. Then, later when we lift the grid shell, the flexible fabric will adjust by itself. We can build it on site, and anchored it safely. Then later after three months – we can dismantle it and move it to the Travis Park. It would still be respectful to nature for it will not require a slab, leaving the landscape untouched. The appearance of our model would still organic and nature-like, still resembling a mountain, a valley, or a flock of birds.
Our Old Grid Shell vs. Our New Grid Shell
Before, we were interested in a four-point grid shell. But, it looked very structural and not so artistic. So, we would like a three one, or a linear one with two points. Something that would look stunning. By Monday, we had a third of the model done a grid shell with only two points, and single layer, and it bent without much effort. On Friday, we double layered it – but it snapped. So, we documented our findings and went back to the to the drawing table for a solution.
These week’s structures were be made of:
The Evolution of Our Minimum Surface construction throughout the semester
The Tents or membrane structures of yesterday gave us the concept of using diagonal masts or columns. We will incorporate the diagonal masts or columns along with our anchors for support This will make our anchors transportable, and the grid shell structural because we would be able to generate the proper tension and compression.
The shapes for this week were mostly one third of a grid shell, in the shape of a semi circle.
Our objective is still to design a minimal grid shell structure, but it would not connect the old Mc Nay to its new wing, instead it will become a gathering place – a place for the museum patrons to relax or take a break. It will be at a back lot – next to the McNay’s new wing. It will be structural, but also artistic. There will be no clear roof, but made from a white weather, stretchy fabric.
A Minimum structure can be built using tension and compression, wood, fabric, and anchor support. We experimented this week by going to a real life scale.
This week we focused on our model larger and human scale. We tested how to join the pieces by double layering, the wood with screws, bolts and washers. We made fallacies, but we learned from them. Initially, we thought the model would bend easily because we did from single layer. But, by Friday, we had it entirely of wood members that crossed each other and had some redundancy. Unfortunately, it snapped in the afternoon when we tried to bend it. We forgot to imagine that it needed to be end-butted. We still are able to experiment with symmetry, hierarchy (we went from large to small shapes), and a datum line, an axis. It also gave us some repetition, transformation (for we did change the size of the shapes). We put aside the idea of the approach for the structure or to design a configuration for the path. One would enter instead through the outside garden of the new wing, and instead of a walkway – it would be an outdoor gathering place. Its shape provides enough volume to visually guide people in one or two directions, but is a place for the patrons to have a pleasant perhaps a reflection area (a place to contemplate the city, the property, the museum).
Jesus Baray Troy O’Connor Juan Carlos Dominguez Barry Reina
Aleksandr Mikhailov Andres Mulet
(The 30 Feet Model Group).