Parametric study of the unified strength theory for a loess foundation supporting a strip footing

摘要

The unified strength theory is one of the most suitable theories to study the influence of the intermediate principle stress, of which the influence could be considered using a parameter b. A physical model experiment and numerical simulation were conducted to comparatively study such influences for a loess foundation supporting a strip footing, and the proper value of b for the foundation was determined. The value of b has a significant influence on the calculation of the stress distribution, bearing capacity, and failure characteristics of the foundation. The calculated bearing capacity increased linearly with increasing b, and an improvement factor of 60-100% could be obtained by using b=1.0 over using b=0.0. Based on the comparison, the authors found that b=0.17-0.20 resulted in a valid fit for the studied loess foundation, which provided an improvement in the bearing capacity of 15-18% over what was calculated using the Mohr-Coulomb failure law.