抽水蓄能电站蚀变岩力学特征及工程性能研究  

Study on Mechanical Characteristics and Engineering Performance of Altered Rock in Pumped Storage Power Station

作　　者：樊柱军 刘志伟 贺鸣 冯超越 FAN Zhujun;LIU Zhiwei;HE Ming;FENG Chaoyue(Northwest Electric Power Design Institute Co.,Ltd.,China Electric 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38-44,共7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重大科技项目(NW-RD032-2023).

摘　　要：蚀变岩体的存在对抽水蓄能电站工程岩体的稳定性有重要影响。通过室内压缩试验、剪切试验、蠕变试验、渗透试验及现场饱和剪切试验、干湿循环剪切试验等手段,分析了不同蚀变程度岩体力学特征。试验结果表明:强蚀变、弱蚀变、微蚀变岩体饱和抗压强度平均值分别为为0.2、37.9、71.8 MPa,其工程性状分别和残坡积风化物、强风化、弱风化等岩体相似;弱蚀变岩体由于矿物颗粒较粗,其内摩擦角43.10°~46.55°,比微蚀变内摩擦角39.2°~42.8°,有一定程度的增加;在抗渗透变形破坏方面,强蚀变岩体重塑样的临界渗透破坏坡降在5.356~9.773,具有碎石、砂土等渗透变形破坏特征;强蚀变岩体具有蠕变效应,强度随时间存在降低;强蚀变岩体水理化特征较明显,干湿循环后,抗剪强度出现降低0%~6%。基于蚀变岩体工程力学性能特征,建立了蚀变岩体的工程性能分级量化指标,研究成果对工程处置具有较好的指导意义。The existence of altered rock mass has significant impact on the stability of the rock mass in pumped storage power station engineering.The mechanical characteristics of rock mass with different alteration degrees are analyzed by indoor compression test,shear test,creep test,permeability test,field saturated shear test,dry-wet cycle shear test and other means.The test results show that the average saturated compressive strength of strongly altered,weakly altered,and slightly altered rock masses are 0.2,37.9,and 71.8 MPa,respectively,and their engineering properties are similar to those of residual slope weathering,strongly weathered,and weakly weathered rock masses,respectively;due to the coarse mineral particles,the internal friction angle of weakly altered rock mass is 43.10°~46.55°,which is higher than the internal friction angle of slightly altered rock mass of 39.2°~42.8°;in terms of resistance to permeability deformation and damage,the critical permeability failure slope of the reshaped sample of strongly altered rock mass is 5.356~9.773,with the same permeability deformation and damage characteristics as gravel and sand;strongly altered rock mass has a creep effect,and its strength decreases with time;the water physicochemical characteristics of strongly altered rock mass are more obvious,and after dry-wet cycles,the shear strength decreases by 0%~6%.Based on the engineering mechanical properties of altered rock mass,a quantitative index for the engineering performance classification of altered rock mass is established,and the study results have guiding significance for engineering treatment.

关 键 词：蚀变岩体 饱和抗压强度 渗透变形破坏 蠕变效应 水理化 量化指标 

分 类 号：P642[天文地球—工程地质学]