METHOD FOR ULTIMATE BEARING CAPACITY OF FOUNDATION BASED ON 3D FAILURE SURFACE

In order to find the ultimate bearing capacity of a foundation with given size, grids the foundation soil and supposes a uniform load act on the foundation, then uses calculus answers of Holl's formula and corner-points method to estimate extra stress of every mesh knots by program with MATLAB. Based on the extra stress, the principal stress can be obtained. According to the failure criterion, the program can search out the coordinate of points which are destroyed. Using the function of dealing with graph by MATLAB, takes the failure points together in the coordinate graphs. Then enlarge the uniform load and find the failure points until these points can form a failure surface. Therefore this uniform load is the ultimate bearing capacity of the foundation. This method can avoid errors bring by unreasonable hypothesizes of the experience forums, and we can get the three-dimensional failure surface of the foundation soil. The results demonstrate that this method is an efficient method to find out the ultimate bearing capacity.