Impact of Earthquake Characteristics on Seismic Slope Stability Using Modified Pseudodynamic Method

Abstract

Seismic slope stability analysis is often limited by the ability to encompass specific earthquake characteristics, such as shaking amplitude, frequency, and time as well as varying soil properties, such as cohesion and friction angle across the depth with consideration of damping and amplification. In this paper, a simple procedure that combines the discretization-based kinematic analysis and modified pseudodynamic method is presented to offer a more holistic analysis considering earthquake and soil characteristics more appropriately. This is achieved by the implementation of the discretization-based kinematic analysis along with a modified pseudodynamic method. The discretization technique aids to generate a kinematically admissible failure surface with considerations to varied soil strength parameters. Its significance lies in the preprocessing to generate a unique failure mechanism dependent on the varied soil properties of the slope while also facilitating the work rate calculations. The use of the modified pseudodynamic method is adopted in this study to overcome the shortcomings of the pseudostatic and simple pseudodynamic method, enabling one to consider the complete time history of earthquake-induced ground movement, having also considered the amplification effect when shaking approaches the soil’s natural frequency. Equating the external and internal rates of work by integration of elementary rates yields the closed-form solution in yield seismic acceleration and/or slope-bearing capacity. A parametric study with a range of independent variables, accompanied with detailed discussion, is also presented to offer a more pragmatic perspective on the performance of nonuniform stratified slopes subjected to earthquakes.