Visco-elastic-plastic Stress And Deformation Analysis Of Jointed Rock Mass And Its Application To Engineering

Joninted rock mass is one of the most common engineering rock masses. Its strength, deformation and stability are mainly controlled by the structural planes in it. In this paper, the block element method is used to simulate the discontinuities. The structural planes in rock masses are simulated by the contacted elements between block elements while the rheological property of the structural planes are considered by the usage of a complex rheological model describing elastic-viscoelastic-viscoplasticity as the constitutive relation of contacted elements. The main contents are as followings:1. The theory of the block element method is systematically presented here and its relative theoretical formulas are deduced.2. By introducing the constant strain as another basic unknown quantity besides the rigid displacement at centroid of block elements, the elasticity of bock elements can be considered and the precision are improved.3. A complex rheological model describing elastic-viscoelastic-viscoplasticity is used as the constitutive relation of contacted elements. Its relative formulas are deduced and computation procedures are listed.4. To simulate the bolt in rock masses, it is considered as a special component through block elements. Bolt cooperates with bock elements and they form the integrate model. The stiffness of the bolts are added to the integer stiffness matrix.445. The above theories are applied in the stability analysis of the 5 machine set of PuBuGou hydropower underground cavity group. The results are analyzed and they are reasonable.