According to bifurcation specificities of displacement for compound rockmass slope affected by groundwater, the displacement formulas for rockmass slope in the process of progressive failure are derived, and the sufficient condition for the sudden instability of rockmass is given.

Also, this model indicates that groundwater softens the rock mass of slide surface by the physicochemical effect and reduces rigidity ratio of the rock mass, and leads to sudden instability.

Study on catastrophic theory model of instability of coal pillar and roof system;

Study of the Hole Wall Instability for Method of Drilling Bits;

Discussion on the application of boundary theory in determination of instability of mined-out area and damage control;

Analysis of buckling during sheet′s springback;

Study on the method of evaluating fatigue and buckling in traversing pipeline;

General buckling and test analysis of composite stiffened cylindrical panel;

Study on the Unstability Stretching of Stainless Steel Sheet;

In allusion to penetrative cranny distributing characteristics of underground rock-mass, the effect laws of the penetrative cranny distribution on underground roadway unstability were analyzed, and the correctness to the theoretical analysis by example calculation of roadway observation data in Wuyang coalmine of Lu'an mining district was proved.

The article describes molten urea unstability from the outlet pipe by checkink the abnormal urea production.