Meso Statistic Damage Model Of Rock And Its Application In The Underground Engineering

With the development of rock mechanics, physics mechanics characters of rock are not only unlike with other engineering materials, but also different from soil and concrete distinctly, which has been realized gradually by people. In recent years, the development of damage mechanics provides a referenced explaining mode for inelastic character and failure mechanism of rock material. People has already named rock with initialized damage material and adopted some character parameter to describe the distribution state of defects in rock with reason. Rock material belongs to the inelastic problem even in elastic state because of its particularity. Many researches indicate that inelastic distortion of rock are the reason of great deal of micro-crack in rock. At present, the problems of macro-damage and fracture of rock have been studied in meso scale internationally. With the rapid development of electronic-computer and gradual perfection of calculation technique, there are more advanced desire for intensity theories and constitutive relation of rock, so that rock mechanics characters are described more turely and complicated engineering problems of rock mechanics are solved.This paper is based on the mathematic model of Weibull distribution in statistic theories, which describes the random distribution of rock intensity. In the paper, the parameters of model are solved by means of differential coefficient of mathematics and the influence of parameters to the damage model are analysized. The curve of stress-strain of damage model are compaired to the curve of rock experiment, the rationality of damage model is be validated. On this base, the Drucker-Prager criterion of intensity is be replaced by theory of unite intensity, and meso statistic damage model of rock based on the theory of unite intensity is be founded, which enlarges application range of the damage model. Moveover, the constitutive relation of statistic damage is set in ABAQUS through the platform of secondary exploiture of ABAQUS, for the sake of numerical simulation of rock material. In order to validate its feasibility, there are numerical simulation of uniaxial and triaxial compress studies for the rock specimen. The results indicate that more better precision in numerical simulation of rock. Finally, combined with a certain engineering example, the numerical simulation of tunnel digging is performed using the model, and better effect has been obtained, which validate the rationality of numerical simulation method.