剪切荷载下贯通结构面应变能演化机制研究

 开展贯通结构面剪切荷载下应变能演化规律研究，有利于更好地理解岩体复杂的力学行为。以重庆武隆鸡尾山滑坡岩体结构面为例，综合利用三维激光扫描、红外热成像以及离散元数值模拟等技术，开展岩体结构面室内与数值试验，获取剪切破坏全过程应变能演化规律。研究结果显示：(1) 贯通结构面剪切破坏时，能量集聚发生在岩体结构面表面，其中面向剪切方向的部位，能量集聚相对较多，证明这些部位在剪切破坏过程中起到主要抗剪作用；(2) 贯通结构面上下盘接触部位在剪切破坏前，发生能量集聚现象，弹性应变能增加，当增加到能量极限时，接触部位岩体被剪断破坏，能量释放，应变能减小。并且不同部位的应变能演化规律不一样，结构面中部位置剪切破坏时上下盘可能发生多次摩擦，能量演化也交替出现集聚与释放现象；(3) 红外热成像试验温度分布结果与数值模拟弹性应变能结果具有较好的一致性，说明数值模拟数据真实可靠。该研究成果对完善岩体不同荷载下的能量演化机制做出了一定贡献。

Strain energy evolution of penetrative rock joints under shear loading

The strain energy evolution of penetrative rock joints under shear loading was investigated to better understand the mechanical behavior of rock mass. To effectively investigate the stability of rock mass，laboratory direct shear tests and numerical simulation on rock joint samples collected from the Jiweishan landslide at Wulong in Chongqing were conducted to obtain the strain energy evolution during the shear failure. Energy accumulation was found to mainly occur on the surface of penetrative rock joints，wherein the areas within rock joints facing the shear direction had higher strain energy and contributed more to the resistance of shear failure. Energy absorption happened with the increasing of elastic strain energy before the shear stress reaching the peak value. When the peak shear stress was reached，those tiny contacting places were damaged and the energy accumulated was translated into the energy liberation associated with the decreasing of the elastic strain energy. Additionally，the energy evolution varied from places to places. The friction may occur repeatedly in the center of the rock joint，accordingly，the energy absorption and liberation may take place alternately. Numerical simulated results matched well with the temperature distribution obtained through infrared thermal imaging，which indicated that the numerical simulation method used to estimate the energy evolution in this paper was accurate and reliable.