Being the factor of safety calculation device which calculates the

摘要

PROBLEM TO BE SOLVED: To provide equipment and a method for computing a safety factor of a surface failure of a slope, which enable a groundwater level of a surface layer to be obtained with accuracy, and which make the accuracy of the safety factor high.;SOLUTION: The safety factor computing equipments splits surface layer data into a plurality of area data, determines a hydraulic gradient for each of the area data, and determines the outflow direction of water from the positive and negative of the hydraulic gradient. In this case, when the outflow directions cross each other between the adjacent area data, a marsh is provided in the boundary of a crossing area. Subsequently, the inflow and outflow of the water are obtained for each of the area data from the hydraulic gradient, the outflow direction of the water, and the amount of rainfall; and an average degree of saturation is obtained from the inflow and the outflow. When the average degree of saturation exceeds a steady value, it is substituted into an approximate expression which indicates a relationship between the average degree of saturation and a groundwater level ratio, so that the groundwater level in the area data can be obtained. When the average degree of saturation is equal to/lower than the steady value, the groundwater level is set at 0. Finally, the safety factor in the area data is obtained from the obtained groundwater level.;COPYRIGHT: (C)2008,JPO&INPIT