锦屏二级水电站深埋完整大理岩基本破坏方式及其发生机制  

PRIMARY FAILURE TYPES AND THEIR FAILURE MECHANISMS OF DEEP BURIED AND INTACT MARBLE AT JINPING II HYDROPOWER STATION

作　　者：侯哲生[1] 龚秋明[2] 孙卓恒[1] 

机构地区：[1]烟台大学土木工程学院,山东烟台264005 [2]北京工业大学城市防灾与减灾教育部重点实验室,北京100124

出　　处：《岩石力学与工程学报》2011年第4期727-732,共6页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(50878009);山东省优秀中青年科学家科研奖励基金资助项目(BS2010SF028)

摘　　要：通过对锦屏二级水电站隧洞工程的现场调查,针对深埋完整大理岩,归纳并分析其在隧洞开挖后的4种基本破坏方式及其发生的机制:(1)拉张型板裂化岩爆:洞壁围岩因开挖卸荷发生拉张型板裂化,同时岩板积聚弹性应变能,当应变能积聚到一定程度时,岩板由于受扰动突然失稳释放应变能形成岩爆。(2)拉张型板裂化片帮:洞壁围岩发生拉张型板裂化,岩板向洞内发生内鼓弯折,最后岩板失去支撑,在重力作用下垮塌脱离母岩。(3)剪切型岩爆:洞壁围岩首先形成潜在剪切楔形体,楔形体积聚弹性应变能,当潜在剪切面上的剪应力超过岩体的抗剪强度时楔形体被突然抛出形成岩爆。(4)剪切型片帮:先形成剪切楔形体,楔形体逐渐与母岩分离,并在重力作用下垮塌脱离母岩。实际工程中,4种基本破坏方式可单独发生也可组合发生,且拉张型破坏的发生频率高于剪切型破坏。锦屏二级水电站深埋完整大理岩基本破坏方式的归纳,对深入认识深埋完整硬岩的力学行为具有重要的工程实际意义。Based on field investigation for tunnels at Jinping II Hydropower Station,four primary failure types of deep buried marble are classified and their failure mechanisms are analyzed：（1） The first one is tensile slabbing rockburst.The rock mass near tunnel wall is slabbed due to unloading of excavation;at the same time,the elastic strain energy is stored in the slabs.Then,when the strain energy is stored sufficiently,the energy is released suddenly and the rockburst occurs.（2） The second one is tensile slabbing spalling.The rock mass near tunnel wall is slabbed due to unloading of excavation.Then,the slabs bend to inner of the tunnel and break.At last,the instabilities of slabs appear and they collapse down from the tunnel wall.（3） The third one is shear rock burst.A potential wedge of rock is formed in the rock mass near the tunnel wall because of the shearing action;and at the same time,the elastic strain energy is stored in the wedge.Then,the wedge is pushed out from the tunnel wall and the rockburst occurs when the shear stress on the potential shear surface exceeds the shear strength of the rock mass.（4） The last one is shear spalling.A wedge of rock is formed in the rock mass near the tunnel wall.Then,the wedge is detaching gradually from the tunnel wall,and at last,the wedge collapse down from the bottom of the tunnel.The four failure types may occur separately or combinatorially.The occurrence frequency of tensile failure is higher than that of shear failure.The failure classification of deep buried marble is useful for understanding the failure mechanisms of depth buried and intact hard rock mass and tunnel support design.

关 键 词：岩石力学 锦屏二级水电站 完整大理岩 岩爆 片帮 

分 类 号：TU45[建筑科学—岩土工程]