A modified Davis approach for geotechnical stability analysis involving non-associated soil plasticity

Abstract

For geotechnical stability analysis involving non-associated plasticity, the Davis approach with internal friction angle and dilatancy angle updated during the strength reduction process can lead to an improvement over the Davis approach without updating the two angles, according to recent studies. However, the Davis approach with internal friction angle and dilatancy angle updated may be overly conservative, especially for those geotechnical stability analyses involving large friction and small dilation, which provides the motivation to modify the Davis formula. In this work, a modified Davis approach is proposed by enhancing the original Davis formula. Based on the enhancing approach, two modified Davis formulas – a theoretically modified Davis formula derived from the geometric relation and an empirically modified Davis formula by multiplying the original Davis formula by an enhancement function – are investigated. The appropriate values of the parameters in two modified Davis formulas for practical use are studied. Numerical investigations disclose that the modified Davis formulas in conjunction with the appropriate parameters can lead to improved estimations of the geotechnical stability.