Influence of Lateral Swelling Pressure on the Geotechnical Infrastructure in Expansive Soils

Lateral swelling pressure (LSP) can pose significant threats to the safety and stability of the geo-infrastructure. For this reason, it is necessary to take into account the influence of LSP in the design of geo-infrastructure such as basement walls, retaining walls, pile foundations, and pipelines built within or adjacent to expansive soils upon water infiltration. A relationship is developed to calculate the LSP upon free swelling from the vertical swelling pressure (VSP), which can be measured from conventional laboratory tests. This relationship is extended to calculate (1) the lateral earth pressure (LEP) behind a retaining structure with expansive soils as backfill material, and (2) the uplift friction along a single pile placed in expansive soils upon infiltration. Experimental results from large-scale tests and centrifuge tests from published literature are used to validate the proposed methods. The studies presented in this paper not only highlight the influence of LSP on the geo-infrastructure but also provide simple tools for taking account of it in the conventional geotechnical engineering practice for both saturated and unsaturated expansive soils.