A method for automatically identifying the shape of locking sections in slopes

Intermittent joints are widely found in slopes and the rock section (locking section) in intermittent joints is an important structure that prevents joints from interconnecting and maintains slope stability, but the exact shape of the locking section is not yet known. In this paper, based on the finite difference method (FDM), k-means algorithm, and alpha shape algorithm, a method is proposed to calculate the shape of locking sections and to quantitatively analyze the controlling effect of locking sections and non-locking sections areas on the stability of slopes. In addition, for slopes with high accuracy in the shape of the locking section, the original mesh in the FDM is reconstructed and a network of discrete points is arranged at the locking section at customised intervals and the maximum principal stresses at each discrete point are calculated by the inverse transformation method of the isoparametric elements. This method greatly reduces the influence of grid size on the shape of the locking section. Finally, eight working conditions were designed to investigate the effect of the position of the weak interlayer on the shape and area of the locking section. The results show that the shape of the locking section does not change much as the angle of the line connecting the end points of the weak interlayer increases, and the shape basically remains elliptical, while the area of the locking section changes by increasing and then decreasing.