Active Earth Thrust Considering Tension Crack, Pore-water Pressure and Soil Nonlinearity

The presences of tension cracks and pore-water pressure will reduce the stability of a soil-wall system. This study develops a kinematical approach to analyze how the active earth thrust is influenced by tension cracks and pore-water pressure, using the powerlaw nonlinear yield criterion. Although many cracks may be present in the backfill, this paper only involves one crack which leads to the most unfavorable effect. The influence of pore-water pressure is also considered using the concept of pore-water pressure coefficient. The power-law yield criterion is adopted characterize the soil strength, and the generalized tangential technique is introduced to realize the transition to the conventional linear problem. An objective function for the active earth thrust is derived from the equilibrium of rates of work and energy. Numerical results are determined from a maximization programming. By comparing with the available solution, the presented solution is validated. The results show that the presence of cracks has an unfavorable influence of increasing the active earth thrust, and this effect is even more obvious when the impact of seepage pressure is considered.