摘要
针对锦屏二级水电站深埋完整大理岩拉张型板裂化破坏和剪切型破坏,从断裂力学的角度对其发生机制予以解释。断裂力学理论表明,岩石在足够大轴向力作用下,其内部微裂纹在发生摩擦滑动或剪切滑移和自相似扩展后进一步弯折扩展。隧洞开挖后洞壁围岩径向应力降低,切向应力增大。当径向应力为零时,弯折裂纹继续发展,围岩产生平行于洞壁的破裂面,即产生拉张型板裂化破坏;当洞壁围岩存在一定径向应力时,弯折裂纹停止扩展转化为剪切裂纹扩展,即围岩产生剪切型破坏。对锦屏二级水电站深埋完整大理岩破坏机制的分析,为类似深埋隧道工程围岩失稳破坏机理的解释具有一定借鉴作用。
From the perspective of fracture mechanics,the occurrence mechanism of tensile slabbing failure and shear failure of the deep-buried and intact marble in Jinping Ⅱ Hydropower Station is explained.The theory of fracture mechanics shows that under large enough axial force,the kinking of the closed microcracks inside a rock would appear after shear slipping and self-similar growth.After tunnel excavation,the radial stress would be reduced,and the tangential stress would be increased.When the radial stress closes to zero,the closed microcracks would keep kinking,then the fracture plane parallel to the tunnel wall would appear to make the rock produce tensile slabbing failure.When there is some degree of tangential stress,the closed microcracks would stop kinking,and the shear cracks would appear to make the rock produce shear failure.The analyses for the failure mechanism of deep-buried and intact marble in Jinping Ⅱ Hydropower Station would have a certain reference value in explanation of failure mechanism for surrounding rock of similar deep-buried tunnels.
出处
《水利与建筑工程学报》
2012年第1期36-38,42,共4页
Journal of Water Resources and Architectural Engineering
基金
山东省优秀中青年科学家科研奖励基金(BS2010SF028)
