Numerical modelling of three-dimensional sinkhole stability using finite different method

The stability of a cavity underlying homogeneous clay in an unsupported greenfield condition is examined in this paper using the finite difference program, FLAC. Shear strength reduction method (SSRM) is utilised to study two- and three-dimensional failure mechanisms of a horizontal trapdoor. Stability results are presented in the forms of factors of safety (FoS) and failure extent ratios for various dimensionless ratios. Numerical results are compared with the finite element limit analysis technique with upper and lower bound theorems, and a good agreement is found between the solutions. Several practical examples are provided to demonstrate the use of design charts and tables.