锦屏大理岩原位应力环境水软化特性分析  

Analysis of Water Softening Characteristics in the In-situ Stress Environment of Jinping Marble

作　　者：张龙 张茹[2,3] 任利[3] 张泽天[2,3] 张建海[2,3] 谢晶[2,3] 张安林 任海 罗浩 ZHANG Long;ZHANG Ru;REN Li;ZHANG Zetian;ZHANG Jianhai;XIE Jing;ZHANG Anlin;REN Hai;LUO Hao(School of Resource&Safety Eng.,Wuhan Inst.of Technol.,Wuhan 430074,China;School of Water Resources&Hydropower,Sichuan Univ.,Chengdu 610065,China;State Key Lab.of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Eng.,Sichuan Univ.,Chengdu 610065,China;Yalong River Hydropower Development Co.,Ltd.,Chengdu 610051,China)

机构地区：[1]武汉工程大学资源与安全工程学院,湖北武汉430074 [2]四川大学水利水电学院,四川成都610065 [3]四川大学深地工程智能建造与健康运维全国重点实验室,四川成都610065 [4]雅砻江流域水电开发有限公司,四川成都610051

出　　处：《工程科学与技术》2024年第3期1-10,共10页Advanced Engineering Sciences

基　　金：国家自然科学基金重点基金项目(U23B20146);武汉工程大学科研启动项目(23QD82)。

摘　　要：中国水电资源主要集中在西部高山峡谷地区,将水电站建筑物布置在极深洞室群常常是经济且较优的选择。受典型河谷地貌特征和区域强烈高地应力、高渗透压环境影响,极深洞室围岩力学特性演化规律和长期稳定性是亟需解决的关键科学问题。不同赋存深度应力环境下,水岩耦合作用对岩石力学性质的影响尚不明确,导致深部岩体工程面临一定的风险性和低效性。基于自主设计并研制的深部原位应力环境岩石饱水试验系统,开展锦屏大理岩原位应力环境与无压环境下饱水时长为1、23、60和100 d的水软化试验,并进行5组不同围压下的三轴压缩试验。研究发现:深部原位应力环境下锦屏大理岩饱水100 d后峰值强度劣化程度约为无压饱水100 d的3倍,其余力学参数(如内聚力、内摩擦角等)劣化度也远大于无压饱水条件;锦屏大理岩峰值强度劣化度随水岩耦合环境深度的增加(100、1000、1400、1800和2400 m)均呈现先减小后增大的非线性变化特征;通过探索锦屏大理岩水软化机理,发现摩擦弱化效应与孔隙水压力作用共同造就了锦屏大理岩峰值强度非线性变化规律。结果表明,原位应力环境下的水软化效应及其对围岩力学性质的影响更加突出,在对深部地下工程进行稳定性分析时必须考虑围岩水软化特性,该结论对锦屏地下工程的建设和维护具有重要的指导意义。Objective China’s hydropower resources are primarily concentrated in the western mountains and valleys,characterized by narrow ground space and significant altitude differences.Consequently,it is often more economical and efficient to locate hydropower station buildings within ex-tremely deep caverns.However,the region’s typical geomorphic features,coupled with the strong environmental impact of“high geostress”and“high permeability”,pose numerous safety challenges during both construction and operation phases for these extremely deep caverns.Under-standing the evolutionary patterns and long-term stability of the mechanical properties of surrounding rock is of paramount importance.A critical scientific challenge lies in elucidating the influence of water-rock coupling on the mechanical properties of rock under varying depths of stress,which currently leads to certain risks and inefficiencies in deep rock mass engineering.Methods To realistically simulate the coupled environment of water and rock at different depths,our research group independently developed a rock saturation test system under deep in-situ stress conditions.This system comprises five reactors,collectively named the deep environment simulation cavity,capable of replicating the in-situ stress environment of underground engineering at five distinct depths.Through a servo motor,rotary motion is converted into linear motion,facilitating the transfer of water pressure from the motor cavity to the kettle cavity for pressuriza-tion.Additionally,the pump transmission rate allows for adjustment of pressurization speed.Leveraging this self-designed and developed rock saturation test system under deep in-situ stress conditions,we conducted water softening tests on Jinping marble with saturation durations of 1,23,60,and 100 days.To provide comparative insights,we also conducted water softening tests on Jinping marble without pressure saturation for dur-ations of 0,1,23,60,and 100 days.Each group underwent five sets of triaxial compression tests at v

关 键 词：锦屏大理岩 原位应力环境 水软化特性 水软化机理 

分 类 号：TU45[建筑科学—岩土工程]