ABSTRACT
As Eduardo Torroja explained, “The process of visualizing or conceiving a structure is an art. Building codes dictate design standards for loads based on structural systems, materials used, building occupancy and location. Then one load is stacked atop another, structural elements are pushed down, or compressed. Common alternative poses broaden the base and spread out the load between more supporters–as either a body pyramid or a modified tower. Pyramidal shapes make sense as a way to share loading across more “supports” and to create a wider base for added resistance against instability. Theoretically more and more bodies can be added to the pose to complete a full circle. Free-body diagrams can evaluate or calculate forces. In the double-cantilever, the horizontal thrust force at the feet are counteracted at the same point, but when the feet are separated to make an arch, the horizontal thrust has to be resisted from outside.
