The3D Damage Rheology Model Analysis Of The Jointed Rock And Engineering Application

The study on the mechanics and time-dependent feature of fractured rock mass is always an important subject of rock mechanics and engineering. Based on the theoretical method of rock damage mechanics, rock rheological mechanics and numerical calculation, this paper makes a preliminary study on the damage and rheology coupled model of fractured rock mass and damage evolution.First, according to the structural characteristics of fractured rock mass and the geometric damage theory, we cite a second—order damage tensor to describe the deterioration of rock mass due to cracks. Taking the crack area, direction, space and density as the major influencing factors of the damage variable, we stack the damage contribution of groups of cracks on each section to describe the anisotropic damage approximatively. The Nishihara model is taken as the basic model to study the time-dependent characteristics of rock mass. And its one-dimensional constitutive equation is transformed into three—dimensional form. Eventually, by introducing the second-order damage tensor into the rheological constitutive equation on the basis of the equivalent strain hypothesis, the three-dimensional viscoelastic-plastic damage constitutive equation is deduced.Second, taking advantage of FLAC3D,we compile the above constitutive equation model on the Microsoft Visual C++environment, and realize the secondary further development of FLAC3D. The operation principles of secondary development program is also described.Third, the surrounding rock stability of the underground cavern group of Jinping I hydropower station is analysed by using the development program. And the results are compared with the ones obtained from the computation with elastic-plastic model and monitoring results. According to the comparative results, the model is basically reasonable.Finally, using the criterion of damage evolution to judge the law of the damage evolution zone.