## Robbie FordARCH 2700 Structures Portfolio

Project 1: Structural Equilibrium

Project 1 - For this project, I worked with a partner (Cameron Gambrell) to make a model that uses tensile and compression elements to hold up a one pound cube in the air, raised above a simple platform. We used three wooden dowels, two the same length and a third shorter one, and fishline to suspend the cube. The fishline was tied at points on the corners of the cube to suspend it from the dowels and they were pulled tight to hold it in place. We positioned the shortest dowel as a point for the cube to rest against on one side with the other two longer dowels were used as the main supports for the string to hold up the cube. The dowels were positioned at opposite corners of the platform and facing inward towards the cube.

Project 1
Project 1
Project 1
Project 2: Structural Live Load Test

For this second Project, I worked by myself to design and construct a model of a horizontal freespan structure. My design for it was inspired by cantilever bridges I have seen like the old Charleston Cooper River bridges as well as some smaller swing bridges. Its design consists of a simple arc that moves upwards from the base towards its center which comes to a point in the middle of its span before sloping back downward towards the other end of the span. I made my model out of only 1/8 inch square wood dowels and Tacky glue. The length of the structure was 24 inches and it weighed in at 0.105 pounds. It was tested by placing the model so that it rested on two surfaces with 1.5 inches of each end of the model on each surface and a 21 inch span resting in equilibrium above an open gap of space. Then weights were hung from points that were at 7 inches and 14 inches of its span until it failed. It held up to 9 weights when it failed, each weight being approximately 3.4 pounds. To find its structural efficiency, I took the live load of the bridge (its weight before testing it) and divided that by the dead load of the weights. This means that its structural efficiency was 291.4; in other words, the model held 291 times its total weight.

Project 2
Project 2
Project 2
Project 2
Project 2
Project 2
Project 2
Project 3: Design of Trusses

For this Final Project, I made several different truss designs that fit within a certain set of parameters. The first design was perfectly symmetrical, and for this I utilized a simple triangle form that is common in house roof truss designs. The second design has variable pitch, and for this one I chose to do a simplified version of my bridge truss design from Project 2. For the third model, I had to do an asymmetrical design, so I chose to make a right triangle form for the trusses. And for the fourth and final model, I made a curved truss design that resembles other bridges I have seen. I made all of these models using simple square wood dowels and glue, just like I used in Project 2. All were made at 3/32"=1' scale and they all proportionally equal 80 feet spans.

Project 3

Top to Bottom: Perfectly Symmetrical, Variable Pitch, Asymmetrical, and Curved

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