The effects of soil spatial variability on the reliability of rigid buried pipes

The dysfunctions and failures of buried pipes such as sewer pipes result, in large part, from the heterogeneity of the geotechnical conditions and the soil spatial variability. Soil defects induce stresses, counter-slopes and joint openings, leading to violations of the serviceability limit state (SLS). A model has been developed that includes a description of the soil spatial variability within the framework of geostatistics, where the correlation length of soil properties is the main parameter. It is based on a mechanical description of the soil–structure interaction between a set of segmented buried pipes and the soil support, represented by a modified Vlassov model. The results show that the magnitude of the induced effects depends primarily on the following four factors: the magnitude of the soil variability, the soil–structure stiffness ratio, the structure–connection stiffness ratio (relative flexibility) and the soil–structure length ratio.