Mechanical Method to Evaluate Safety Factors in Buried Pipes

Abstract

The method presented studies the real behavior of a buried pipes system and its interaction with the surrounding soil. A mechanical system is used to apply a nondestructive loading from the inside of the structure, allowing a parametric model of the complex soil-pipe structural behavior to be developed. The principle of the first inspection step is to apply a cyclic loading to the pipe and to measure produced displacements. Data obtained are investigated with a finite-element theoretical model, which provides the pipe's real behavior in its real state. The resulting model allows a theoretical analysis. By this analysis, we refine and explain deteriorations and stress distribution in each tested section of the network. This theoretical model can be used for installations in trench, embankment, or tunnel. In this paper, we present different assumptions and steps used to analyze the real structural behavior of buried pipes in operating conditions and the method to determine the safety factor. Upon this factor, we can distinguish areas with high risks and normal risks. This evaluation permits one to optimize investments of buried pipe rehabilitation.