Structural Performance of Cast-in-Place Pipe

Results of studies of the structural behavior of cast-in-place pipe under typical loads and field conditions are presented. Analyses include a simplified method along with studies based on the theory of elasticity and the finite element method. The effects of the variable elastic properties of in-situ soil, backfill, and concrete are studied, along with variable surface pressure. Stresses at crown, invert, and spring line are presented for the various conditions considered. The study indicates that in-situ and backfill soil strength properties have a significant influence on the stress conditions in the pipe. High-strength soils result in lower stresses in the pipe. Low soil strengths result in linear increase in pipe stresses with an increase in surface pressure. High soil strength result in a leveling off of pipe tensile stresses with an increase in surface pressure.