岩体变形破坏过程的能量机制

 叙述岩体单元变形破坏过程中能量耗散与强度、能量释放与整体破坏等概念。在循环压缩载荷下，实测岩石的能量耗散及损伤，数据拟合表明，基于能量耗散分析建立的岩石损伤演化方程可以较好地描述岩石的损伤演化过程。在循环压缩载荷下同时实测不同加载速度及不同载荷水平下岩体内可释放应变能、耗散能、卸荷弹性模量及卸荷泊松比的变化规律，给出复杂应力条件下卸荷弹性模量的变化公式。基于可释放应变能建立岩体单元的整体破坏准则，该准则与大理岩的双压试验结果符合得比较好。对工程中常见的层状岩体，提出基于畸变能与广义体积膨胀势能而建立的层状岩体破坏准则，该准则与层状岩的双压试验也符合得比较好。

ENERGY MECHANISM OF DEFORMATION AND FAILURE OF ROCK MASSES

The relationships between energy dissipation and strength，energy release and global failure during the deformation and failure of rock mass element are discussed. Under the condition of cyclic compressive load，the energy dissipation and damage variable are calculated and used to fit the damage evolution equation based on the analysis of energy dissipation. The releasable strain energy，dissipated energy，unloading elastic modulus and unloading Poisson¢s ratio are calculated at different loading levels and different loading speeds so that an equation about unloading elastic modulus under complex stress condition is obtained. The global failure criterion of rock mass element is proposed based on the analysis of releasable strain energy and is well accordance with the result of biaxial compressive test on marble. The failure criterion of layered rock mass is proposed based on the analysis of distortion energy and general potential energy of volume；and it is well accordant with the result of biaxial compressive test on layered rock.