Thanks for the response.
Depending on alignment chosen, length varies between 3000' and 10000'
The structure is really that large, width is fixed, height varies from about 8' to 30', it's for combined sewage (dry- and wet-weather)
Struts are 2'x2' reinforced concrete, for structural support...
I'm doing some research for a new project, and would like to get some input.
The project is calling for a 36" sewer force main to be constructed INSIDE a large underground transport/storage structure (~17'w x 30'h). Tentative plans are to place the new FM atop the 2'x2' struts that run at 12'...