抽水蓄能电站云母石英片岩各向异性特性试验研究  

Experimental Study on Anisotropic Characteristics of Mica Quartz Schist in Pumped Storage Power Stations

作　　者：石盼 刘志伟 樊柱军 王明伟 杨亚军 SHI Pan;LIU Zhiwei;FAN Zhujun;WANG Mingwei;YANG Yajun(Northwest Electric Power Design Institute Co.,LTD.,China Power Engineering Consulting Group,Xi'an 710075,China)

机构地区：[1]中国电力工程顾问集团西北电力设计院有限公司,西安710075

出　　处：《西北水电》2024年第4期45-49,61,共6页Northwest Hydropower

基　　金：中国电力工程顾问集团西北电力设计院有限公司科技项目(NW-RD032-2023).

摘　　要：云母石英片岩的各向异性特征对抽水蓄能电站地下洞室围岩稳定性影响较大。通过岩矿鉴定、室内压缩实验、直剪试验、点荷载现场试验等手段,分析了云母石英片岩强度、变形的变化规律,研究了不同风化程度的云母石英片岩在不同加载方向上的各向异性特性。结果表明:在漫长地质历史过程中经历各种地质作用,云母石英片岩的矿物形成了强烈的定向排列结构,使云母石英片岩具有明显的片状构造,从而导致云母石英片岩在力学性质上具有明显的各向异性;在不同方向荷载作用下,云母石英片岩的抗压强度、变形模量、弹性模量均表现出一定的各向异性,随着水平与片理面夹角的增大,云母石英片岩的单轴抗压强度、变形模量、弹性模量先减小后增大,均呈现出“U”型的变化规律;水平与片理面夹角α为0°时,岩石破坏为压密剪切破坏,α为40°时,岩石破坏为复合剪切破坏,α为70°时,岩石破坏为典型层面剪切破坏,α为90°时,岩石破坏为劈裂张拉破坏;直剪试验指出片理面间的粘结强度较低,在荷载方向与片理方向平行时易产生错动,反应了云母石英片岩的各项异性;通过点荷载试验,不同风化程度不同加载方向的云母石英片岩点荷载强度呈现出明显的各向异性,平行片理面的强度主要由片理层间的胶结强度提供,而非云母石英片岩本身的力学强度特性,同时云母石英片岩的各向异性程度随着风化程度减弱而稍有减弱。The anisotropic characteristics of mica quartz schist have significant impact on the stability of the surrounding rock of the underground cavern of the pumped storage power station.Through rock and mineral identification,indoor compression test,direct shear test,point load field test and other means,the variation law of strength and deformation of mica quartz schist is analyzed,and the anisotropic characteristics of mica quartz schist with different weathering degrees in different loading directions are studied.The results show that during the long geological history,the minerals of mica quartz schist have formed a strong directional arrangement structure after various geological actions,which makes mica quartz schist have obvious lamellae,resulting in obvious anisotropy in mechanical properties.Under the action of loads in different directions,the compressive strength,deformation modulus and elastic modulus of mica quartz schist all show certain anisotropy.With the increase of the angle between the horizontal and the schistosity plane,the uniaxial compressive strength,deformation modulus and elastic modulus of mica quartz schist first decrease and then increase,showing a“U”-shaped variation law.When the angle between the horizontal and the schistosity plane a is 0°,the rock failure is compression shear failure,and whenαis 40°,the rock failure is compression shear failure.Whenαis 70°,the rock failure is compound shear failure,and whenαis 90°,the rock failure is splitting tensile failure.The direct shear test indicates that the bonding strength between schistosity planes is low,and dislocation is prone to occur when the load direction is parallel to the schistosity direction,reflecting the anisotropy of mica quartz schist.Through the point load test,the point load strength of mica quartz schist with different weathering degrees and different loading directions shows obvious anisotropy.The strength of parallel schistosity planes is mainly provided by the bonding strength between schistosity layers,rather

关 键 词：云母石英片岩 抽水蓄能电站 各向异性 室内岩石试验 点荷载试验 

分 类 号：TV743[水利工程—水利水电工程]