Abstract
The seismic or static undrained slip line field theory and Cauchy, Riemann, mixed boundary value problems for undrained soil slopes are derived. A new failure mechanism is proposed to determine the undrained bearing capacity adjacent to slopes. The effects of geometric or strength parameters and seismic forces on static and seismic undrained bearing capacity are investigated. The convergence of the proposed method is proved. The static and seismic undrained bearing capacities predicted by the proposed method are close to those of the currently existing methods. The proposed method does not need to assume or search the failure modes, and a new limit state evaluation index is given.