Case Study and Design Build 

As its name suggests, the basis of this structural type is the mutual support of its elements. In other words, reciprocal frames are self-supporting, where each member equally bears the weight of the one next to it. In its simplest form the system is made of three members in a closed circuit. This concept persists even through the most complex reciprocal structures.

Below is the process of building a reciprocal structure and the steps taken to achieve it.

Figure 1. A 100mm diameter circle was set up and divided into 12 equal parts, marking 50mm, where base members will meet. 

Scaled at 1:100m.

Figure 2. The clockwise configuration of the base members was drawn.

Figure 3. The counter-clockwise configuration of the top members was drawn.

Figure 4. The transfer of loads from the upper reciprocal to the base

Figure 5. Top View of the Load path along the upper reciprocal structure

Challenges arose in the construction of the interwoven frame as the structure is not stable until all members are in place, extra supports (helping hands from family members) were needed.  Figure 8 illustrates the top view of the load path. Loads are distributed through the members down to the ground. In the case of this structure, the loads distribute themselves along the top members, then transfer to the base members.

See below the finished reciprocal structure.

There are several benefits of building reciprocally, primarily, the ease of construction. Members in a reciprocal frame are relatively small in comparison to the span of which they must support. There is a degree of built-in repetition in these structures. Not to mention in symmetrical systems, every member and every joint are identical. Moreover, reciprocal roofs, for instance, do not require a center support, many even leave the opening in the center to create an oculus or skylight.