ABSTRACT
If the pipe cross section is not circular, "ring" analysis must be modified. For most buried pipes, a circular cross section is the most effic ient shape. But even flexible circular rings deflect out-of-round during installation. Morever, a demand exists for non-circular cross sections. Some typical examples are shown in Figure 9-1. A standing demand exists in highway departments for culverts with reduced height of cross section. Each inch of height of the culvert requires an enormous amount of soil to raise the highway by that amount. The pipe arch and low profile arch are examples of efforts to serve highway demands for reduced heights of culverts. Multiple culverts serve to reduce heights, but also increase costs, spread stream beds, and trap trash.
