高应力岩体动力扰动下发生岩爆的试验研究进展报告

李夕兵 宫凤强 杜坤 李地元

摘要：深部岩石工程在开挖卸荷过程中，储存在高应力岩体内的应变能力会被释放，从而导致围岩破裂并有可能诱发岩爆等动力灾害。为了研究三维受力的高应力岩体在卸荷条件的力学特性和破坏模式，从高地应力受力环境出发，利用自行研制的岩石真三轴电液伺服诱变 （扰动）试验系统，深入研究真三轴卸荷状态下高应力岩石的力学特性及动载荷诱发岩爆的可能性，揭示深部岩爆灾害的扰动诱发机理。获得研究成果：利用真三轴电液伺服诱变 （扰动）试验系统对不同应力状态下花岗岩、红砂岩及水泥砂浆的立方试件进行了真三轴卸载压缩破坏试验。研究结果表明卸载后二维受力下岩石的抗压强度随中间主应力的增大而增大，但增大的幅度逐渐降低。当单轴压缩或中间主应力较小时，岩石破坏模式为剪切破坏；随着中间主应力的增大，花岗岩和红砂岩的破坏模式逐渐由剪切破坏转变为板裂破坏，水泥砂浆在高应力卸载下仍然发生塑性大变形剪切破坏。

关键词：深部岩体；高应力；岩爆；动力扰动

Abstract：For deep rock engineerings， the high strain energy stored in deep rock mass may be induced to release in the process of excavation unloading and rockburst and slabbing failure of rock can be resulted. In order to understand the influence of rock types and stress paths on the occurrence of mechanical properties and failure mode， experimental studies were carried out on granite， red sandstone and cement mortar cubic specimens under true triaxial unloading condition. The tests were completed by using a self-developed triaxial electro-hydraulic servo controlled testing system. At first， three dimensional stresses were applied on a cubic rock specimen until the magnitude of stress reaching to a predefined geostress level. Afterwards， the force along the minimum principal stress direction was unloaded， and then the force along the maximum principal stress direction was loaded until the rock specimen got final failure. Testing results showed that the peak strength was increased with the increase of the intermediate principal stress. Meanwhile， the failure modes of granite and red sandstone specimen were changed from shear to slabbing with certain intermediate principal stress. In contrast， the failure mode of cement mortar specimen under triaxial unloading condition was still shear and large plastic deformation was observed.

Keywords：Deep rock mass； high stress； rock burst； dynamic disturbance

閱读全文链接（需实名注册）：http：//www.nstrs.cn/xiangxiBG.aspx？id=49236&flag=1