STUDY OF CRITICAL SLOPE DEGREE OF CHANNEL EXCAVATION BASED ON FINITE ARC AND STRENGTH REDUCTION METHOD

Stress,strain and displacement in slope are calculated using the finite difference method.The finite arc method is presented based on the limit equilibrium theory and strength reduction method with deformation′s change trend as a standard of failure.The presented method is applied to search critical slip surface and the minimum safety coefficient of slip,and the case studies with verification and parameters′ discussion demonstrates the accuracy in the application of slope engineering.The presented method and the limit equilibrium method are applied to study critical slope of one large channel excavation in South-to-North Water Diversion Project.In the study three typical channel′s slope modes including high slope,reclaimed slope and deep excavation slope mode are selected to get the safety coefficients′ change with slope degrees of excavation,then the critical excavated slope of channel can be determined.The computed results show that high slope and reclaimed slope in the large channel require a high level for excavated slope degree.Compared to the excavation,the filling load owes more effect on the slope′s stability.It′s found that the presented methods in this paper more accurate and rational,which could complement the insufficiency of existing methods.The methods not only solve the design problems of large channel′s slope,but also provide a good reference for the similar slope engineering.