While some designs assume lateral loads are solely resisted by earth pressure against pile caps, research reveals that soil resistance along the pile length significantly contributes to lateral stability. Therefore, when analyzing pile lateral resistance, the earth pressure acting on the piles themselves must be considered.
Traditional analysis methods often employ a series of soil springs with either constant or depth-varying modulus of subgrade reaction. However, using a constant modulus oversimplifies soil behavior and leads to inaccurate results, typically overestimating the maximum reaction force and underestimating the maximum bending moment.
To obtain a more accurate soil response profile, pressuremeter tests are invaluable. Conducted within boreholes during site investigation, these tests measure the soil’s response to applied pressure, providing crucial data for determining the modulus of subgrade reaction at various depths. This data enables a more precise and reliable assessment of the pile’s lateral resistance, as highlighted by Bryan Leach in 1980.
By incorporating pressuremeter test results into the design process, engineers can better account for the complex interaction between the pile and surrounding soil, ensuring a more robust and resilient foundation system. This comprehensive approach not only enhances the accuracy of lateral resistance calculations but also leads to safer and more cost-effective pile designs.