the velocities of the nodes are regarded as unknown quantity
with the conditions of flow rule
velocity discontinuity
velocity boundary
the energy-work balance equation
the linear programming model of stability of slope subjected to pore water pressure are established. The pore water pressure is considered as an external force. Then the upper limit value of the safety coefficients of slopes
and the corresponding kinematically admissible velocity fields are obtained. Finally
using the proposed method,the stability of two classical soil slopes are calculated; and the results demonstrate the correctness of the method.