|
|
|
| Study on the hydro-mechanical coupling numerical model for layered rocks based on macro-meso structures |
| LIU Wu1，2，LU Qian1，GUO Shenlei1，ZHENG Liange3，YUAN Wenjun1 |
| (1. School of Civil Engineering，Hefei University of Technology，Hefei，Anhui 230009，China；2. Key Laboratory of Geological Hazards on Three Gorges Reservoir Area，Ministry of Education，China Three Gorges University，Yichang，Hubei 443002，China；3. Lawrence Berkeley National Laboratory，Berkeley 94701，America) |
|
|
|
|
Abstract Based on the macro-meso structures of layered rocks，the anisotropic multiscale damage model and deformation-dependent permeability evolution equation for saturated layered rocks were derived in the framework of thermodynamics. On this basis，the hydro-mechanical coupled numerical model of layered rocks was established in combination with TOUGHREACT，which is a well-designed open-source code for fluid flow simulation. The proposed model well considered the mechanisms of damage growth，sliding dilatancy and normal compression of small-scale arbitrary microcracks，and shear sliding of large-scale bedding planes. The influences of multi-scale structural changes(microcracks and bedding planes) on the characteristics of hydro-mechanical coupling in layered rocks were commendably reflected. Numerical validation and application of the proposed model were done on the simulations of water injection responses at laboratory and field scales. The simulation results demonstrated that the water injection-induced hydro-mechanical coupling responses，such as rock damage，water pressure enhancement，bedding plane opening and permeability evolution，were affected by the structural variations of microcracks and bedding planes as well as the spatial development characteristics of bedding planes. Better modeling the macroscopic hydro-mechanical responses of layered rocks depended on the accurate characterization of the internal macro-meso structures. The research may provide a good practical value for the evaluation of engineering disturbances in deeply layered surrounding rocks under coupled hydro-mechanical loading conditions.
|
|
|
|
|
|
|
|
|
2021, Vol. 40 
