Seismic passive pressures of earth structures by nonlinear optimization

Conventional seismic passive pressures of earth structures are based on a linear failure criterion in earthquake zones. However, experimental evidence shows that the strength envelopes are nonlinear over a wide range of normal stresses. In this paper, the analytical expressions of seismic passive pressures acting on inclined rigid walls are derived with nonlinear failure criterion. Quasi-static representation of earthquake effects using a seismic coefficient is adopted for seismic estimations. Instead of using the nonlinear criterion, a linear failure criterion, which is tangential to the nonlinear criterion, is used to formulate the seismic passive pressure problems as nonlinear programming problems. Analytical results are presented and compared with the previously published solutions using numerical technique. The influences of the parameters in the nonlinear failure criterion on seismic pressures and failure mechanisms are discussed.