Determination of soil properties for sandy soils and road base at Riverside Campus using laboratory testing and numerical simulation

This study evaluated the soil properties of clean sand, a silty sand, and a road base that are extensively used as a backfill for full-scale testing at Riverside Campus at Texas A&M University. The three soils were collected at the Riverside Campus and the testing schedule included grain size analysis, hydrometer test, specific gravity, maximum dry density, Atterberg limit, stiffness, direct shear test, triaxial test, and a simple procedure to estimate the maximum and minimum void ratio of the clean sand. Relation between strength/deformation, vertical displacement/shear displacement, and physical properties were evaluated to estimate the frictional resistance and angle of dilation of the clean sand and the silty sand. Numerical simulations of the Direct Shear Test (DST) were conducted on the clean sand using Finite Element Model in the computer program LS-DYNA. The simulations were intended to reproduce the Direct Shear Test (DST) to estimate the frictional resistance and dilatancy effects of the clean sand under different compressive stresses. Field tests were also conducted on the clean sand and the road base. These tests included the in-situ density determination, in-situ water content, and the soil modulus using the Briaud Compaction Device (BCD).