Investigation of the excavation of stony soil slopes using the virtual element method

This study improved two parts of the virtual element method (VEM) to ensure that the stability of a stony soil slope, especially under excavation conditions, could be better studied. One of the improvements was the specific realization of the excavation algorithm, including the determination of how to identify polygonal elements that needed to be excavated, and the deactivate and reactivate polygonal elements used to calculate the excavation load during the slope excavation process. The second improvement was the calculation of the factor of safety (FOS) of a slope by combining shear strength reduction and the phi-nu inequality so that the stability of the stony soil slope could be better evaluated. The principal goal was to extend the latest developed virtual element method to the analysis and calculation of the excavation of a stony soil slope. Because the VEM was shape independent, it also allowed the number of nodes in an element to be chosen flexibly and fluidly, so the number of nodes could be changed easily during a simulated procedure. Two numerical examples of the one-step excavation of a homogeneous slope and the two-step excavation of a stony soil slope were solved with the improved VEM. The numerical results showed that the VEM could accurately simulate the excavation process of the slope.