DEFORMATION STABILITY AND CONTROL THEORY OF STRUCTURES AND APPLICATION IN ROCK AND SOIL ENGINEERING

The conventional rigid body limit equilibrium method is not suitable to evaluate the stability and reinforcement of projects with large scale rock mass, such as arch dam abutment, high slope and large scale underground caverns. Stability and reinforcement analysis based on deformed configurations is needed, which is a key problem in rock and soil numerical analysis. Summarizing the characteristics and difficulties of deformation stability, a rigorous definition is presented for the instability analysis of complex multi-degree-of-freedom deformed structural system, as well as its logic expression and mathematical expression. Deformed structural stability criterion based on complementary energy norm and its variation was developed and stability criterion based on second variation of structural potential energy was unified. The minimum plastic complementary energy was improved and the general evolution trend was indicated, which establishes the strict theory basis for NATM contruction theory and pan’s principle of maximum and minimum. Finally, the deformation stability theory was applied in stability assessment of high arch dam abutment, high slope and large scale underground caverns.