Earth Pressure Distribution on Buried Pipes Installed with Geofoam Inclusion and Subjected to Cyclic Loading

摘要

Buried pipes and culverts installed under embankments supporting transport infrastructure are often designed to carry both static and cyclic loading. Earth pressures acting on these structures are affected by the installation conditions. The induced trench approach is used to reduce the contact pressure on rigid culvert's walls under heavy embankments by utilizing the shear strength within the backfill. A compressible material, such as the EPS geofoam blocks, is generally placed above the buried structure and the overlying prism of soil is allowed to move downward. In this work, the distribution of the contact pressure on a pipe buried within granular material and experiencing cyclic loading is investigated. Results are presented at key locations on the pipe circumference and the changes in contact pressure during cyclic loading are examined. Results show that the installation of EPS geofoam block over the pipe resulted in overall enhanced performance of the soil-geofoam-pipe system with significant reduction in the measured radial pressure, particularly at the crown and invert locations. Less pronounced effect was found at the sides of the pipe. These results confirmed that the inclusion of EPS geofoam within the backfill material can significantly enhance the response of buried structures particularly for shallow-buried pipes under repeated loading.