Lateral Force Induced by Rectangular Surcharge Loads on a Cross-Anisotropic Backfill

This article presents approximate but analytical-based solutions for computing the lateral force (force per unit length) and centroid location induced by horizontal and vertical surcharge surface loads resting on a cross-anisotropic backfill. The surcharge loading types include: point load, finite line load, and uniform rectangular area load. The planes of cross-anisotropy are assumed to be parallel to the ground surface of the backfill. Although the presented solutions have never been proposed in existing literature, they can be derived by integrating the lateral stress solutions recently addressed by the author. It is clear that the type and degree of geomaterial anisotropy, loading distances from the retaining wall, and loading types significantly influence the derived solutions. An example is given for practical applications to illustrate the type and degree of soil anisotropy, as well as the loading types on the lateral force and centroid location in the isotropic/cross-anisotropic backfills caused by the horizontal and vertical uniform rectangular area loads. The results show that both the lateral force and centroid location in a cross-anisotropic backfill are quite different from those in an isotropic one. The derived solutions can be added to other lateral pressures, such as earth or water pressure, which are necessary in the stability and structural analysis of a retaining wall. In addition, they can be utilized to simulate more realistic conditions than the surcharge strip loading in geotechnical engineering for the backfill geomaterials are cross-anisotropic.