Determination of Critical Height of Cut Slope of Red-Bed Soft Rock under Seismic Loading

Abstract

The widespread red-bed soft rock, characterized by its poor engineering properties as road building materials, plus the frequent large intensity earthquakes necessitates growing attention on the seismic design of cut slope in the west region of Yunnan province, China. To calculate the critical heights of the slope under seismic loading, a slope model is established and its dynamic response under seismic loading is analyzed by using Fast Lagrangian Analysis of Continua (FLAC3D)based on three-dimensional finite difference method .The reliability of the model is verified by comparing the analytical results with other relevant research results. The stability factors at different slope heights and ratios are gained; accordingly, back calculate the critical heights of the slope at different slope ratios under either the gravity loading only or combined with seismic loading, when the stability factor is equal or greater than 1.1. The above analysis helps provide seismic design guidance for the cut slopes of red soft rock in Yunnan province.