In the case of two-dimensional plane stress condition, the cyclic stress induced by earthquake in earth includes horizontal tangential cyclic shearing stress, τvh, vertical cyclic normal stress, σy, and horizontal cyclic normal stress, σh.

The cyclic shearing stress induced by earthquake in earth includes cyclic normal stress difference, [σvd - σhd]/2, and horizontal tangential cyclic shearing stress, τhd These two componentS of cyclic shearing stress are the main factors complicating procedures for assessing the deformation or stability of earth and earth structures during earthquake.

,relationship between horizontal shear stress and horizontal displacement,horizontal shear stress and normal stress,normal stress and residual shear resistance ,normal stress and frictional shear resistanee,frictional horizontal stress and horizontal displacement.

So,sets up reservoir formed patterns of hidden concea] fractured systems and interprets the zones affected by considerable horzontal shear are good.

In order to study the influence of principal stress axis cyclic rotation at low shear stress level on clay′s behavior,a series of experiments of Hangzhou typical intact soft clay were conducted.

The calculating method of horizontal sheer was given by using the model.

The relations between the inclined crack character values under service loads and shear stresses of the T-shape beam sections are developed herein based on a variable angle truss model using which shear level of sections can be predicted, and the basis of assessing the shear strength of existing buildings is provided.