圆形隧洞爆破荷载与瞬态卸荷作用围岩应变能效应研究

发布时间：2018-05-11 13:13

本文选题：岩石力学 + 深埋隧洞　；参考：《岩石力学与工程学报》2017年08期

【摘要】：深部岩体开挖过程中,能量的释放与耗散是导致围岩发生损伤破坏的重要诱因。针对深埋圆形隧洞爆破开挖,采用理论模型研究微差段间爆破荷载与地应力瞬态卸荷重复扰动及耦合作用下围岩应变能的变化规律,并基于弹性应变能判别准则计算围岩损伤范围。研究结果表明:在爆破荷载作用下,围岩应变能经历了先增大再减小最终趋于稳定的动态变化过程;在地应力的瞬态卸荷作用下,围岩应变能经历了先减小再增大最终趋于稳定的过程;二者耦合作用会进一步加剧围岩应变能动态调整过程,并且体现出更加明显的微差段间重复扰动效应,以开挖轮廓附近起爆的两圈崩落孔及周边孔最为明显。爆破荷载主要引起围岩张拉破坏,而地应力瞬态卸荷主要导致围岩压剪破坏,在二者耦合作用下地应力的存在会抑制爆破荷载引起的围岩张拉破坏,从而减小围岩的损伤范围。最后,采用锦屏二级水电站引水隧洞实测围岩损伤范围对理论计算方法的正确性进行了验证。
[Abstract]:During the excavation of deep rock mass, the energy release and dissipation are the important inducements for the damage and failure of surrounding rock mass. In view of blasting excavation of deep buried circular tunnel, a theoretical model is used to study the variation of strain energy of surrounding rock under the repeated disturbance and coupling action of blasting load and transient unloading of ground stress between millisecond sections. The damage range of surrounding rock is calculated based on the criterion of elastic strain energy. The results show that the strain energy of surrounding rock undergoes the dynamic process of first increasing and then decreasing to stability under the action of blasting load, and under the action of transient unloading of in-situ stress, The strain energy of surrounding rock experienced the process of decreasing and then increasing and finally becoming stable, and the coupling effect of the two will further aggravate the dynamic adjustment process of the strain energy of surrounding rock, and show a more obvious repeated disturbance effect between slightly different segments. The two-circle caving holes and the peripheral holes around the excavation profile are the most obvious. Blasting load mainly causes tensile failure of surrounding rock, while transient unloading of in-situ stress mainly results in compression and shear failure of surrounding rock. The existence of in-situ stress under the coupling of the two factors will restrain the tensile failure of surrounding rock caused by blasting load and reduce the damage range of surrounding rock. Finally, the correctness of the theoretical calculation method is verified by measuring the damage range of surrounding rock in the diversion tunnel of Jinping II Hydropower Station.
【作者单位】：三峡大学水利与环境学院;武汉大学水资源与水电工程科学国家重点实验室;
【基金】：国家自然科学基金资助项目(51609127) 湖北省自然科学基金项目(2016CFB238) 三峡大学研究生科研创新基金项目(SDYC2016002)~~
【分类号】：TV223

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