In practice of soil slope engineering,most research work on earth pressures employs the same assumption that the failure surface in the backfilled clay is a plane.

<ABSTRACT> Twenty-seven geogrid-reinforced steep slope model tests designed through orthogonal principle have been performed to search for the variable law of failure surface location and its pattern, which is affected by multi-factors.

This paper researches the failure surface modes of displaced soil mass in front of anchor plate by tests, meanwhile analyses the earth resistance.

The principle and execution of this method in detail are described,which is based on FEM and combined optimization and the most dangerous latent rupture plane in slope is determined.

Through computing their focal mechanism solutions it is found that most rupture planes show horizontal strike-slip feature but one or two show obvious dip-slip feature, which indicates the diversification of the focal mechanism sol.

A new method is presented for silo classification using the rupture plane in the storage.

This paper applies the Dijkstra shortest route algorithm in search of the most dangerous underlying fracture plane and works out its displacement and stress to evaluate the reliability of a foundation pit via simulating the course of foundation pit excavation by using the elastic-plastic finite element method.

In order to make the foundation safe,this paper analyzes the distributing of the loading and the effect on foundation during bad management in backfill of pit by deducing the calculation formula of soil pressure based on the rupture surface.

Relationship between micro-structural characters of fracture surface and strength of soft clay;

A method of locating the fracture surface of slope under earthquake through several ways is provided,which is an accurate foundation for dynamic stability analysis of slopes.