Performance of Buried Small Pipes

An analytical and experimental program was conducted to study the deflection and loadcarrying capacity of smalldiameter corrugated plastic drain pipes. The pipe samples were buried in different soils with various compaction conditions around the pipe. Measurements were taken of the vertical deflection and the pressure around the pipe under a wide range of surface loads. It was found that the most important parameters governing the pipe deformation are the pipe stiffness and the type and degree of compaction of the soil around the pipe. The variation of the modulus of elasticity of the pipe with deformation should be taken into account in pipe deflection prediction. This factor is particularly important in the case of smalldiameter pipes buried in loose soil. The pipe stiffness was found to deteriorate under cyclic loading and unloading. The measured lateral pressure distribution was found to be almost uniform, which departed from the simplified parabolic assumption.