摘要
锦屏一级水电站枢纽区发育多处危岩,2012年7月22日猴子坡危岩区发生了约8 000 m3的局部崩塌,造成缆机平台破坏与一桥梁损毁,对工程的施工与永久运营构成重大威胁。因此在详细地质调查的基础上,分析了该区危岩体经主动网治理后以滑移-拉裂为主要变形特征的失稳破坏模式。运用极限平衡理论建立了快捷、有效的岩体稳定性判别公式;并在反演危岩体的失稳破坏过程中,针对滚石运动采用恢复系数法计算滚石速度,以及滚石击毁桥梁的最小等效半径。研究表明,主动网上滞留的岩块与降雨是诱发岩体失稳破坏的主导因素。当主动网上滞留岩块重力达到一定程度时(G2/G1=0.11),在暴雨工况下危岩体失稳破坏的概率将会急剧上升;反算出滚石运动到桥面的速度为48.05 m/s,从而推算出滚石击毁桥梁的最小等效半径为1.45 m,为后续防护提供借鉴参考。
At project complex area of JinpingⅠ Hydropower Station many unstable rock mass were found and they seriously threaten the engineering safety.A rockfall with volume of 8 000 m3 occurred at monkey slope of the right bank and caused significant damage to the construction on July 22,2012.Based on the detailed onsite geological investigation and measurement of dangerous rock,the sliding-tension failure mode and the stability of dangerous rock body are analyzed while inversion the failure process of the dangerous rock masses,taking restitution coefficient aiming at the rolling rocks movement to calculate the velocity and analysis the minimum equivalent radius of the stones which was wrecked the bridge.Research shows that the stranded rock on active network and rainfall are the leading factors causing the rockfall;while the gravity of stranded rocks reaches a certain level( G2/G1= 0.11),the probability of dangerous rock mass destruction will rise sharply in heavy rain condiontion,obtained by calculating the speed of rolling stones when arrival to the deck is about 48.05 m /s,so if the equivalent dius of the dangerous rock is about 1.45 m,it will breakdown the brige,providing references for subsequent protection.
出处
《科学技术与工程》
北大核心
2014年第30期91-96,共6页
Science Technology and Engineering
基金
国家自然科学基金项目(40972195)
国土资源部公益性行业专项(201211055)资助
关键词
危岩体
稳定性
破坏模式
极限平衡
碰撞恢复系数
等效半径
dangerous rock body stability failure mode limit equilibrium theory restitution coefficient equivalent radius
