循环荷载下白云岩渐进损伤试验研究  

Experimental study on progressive damage of dolomite under cyclic loading

作　　者：黄颖异 陈世万 余波 郑克勋 左双英[1,2] HUANG Yingyi;CHEN Shiwan;YU Bo;ZHENG Kexun;ZUO Shuangying(The College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,Guizhou,China;Key Laboratory of Karst Geological Resources and Environment of Guizhou University,Guiyang 550025,Guizhou,China;China Electric Power Construction Group Guiyang Survey and Design Institute Company Ltd.,Guiyang 550081,Guizhou,China)

机构地区：[1]贵州大学资源与环境工程学院,贵州贵阳550025 [2]贵州大学喀斯特地质资源与环境教育部重点实验室,贵州贵阳550025 [3]中国电建集团贵阳勘测设计研究院有限公司,贵州贵阳550081

出　　处：《水利水电技术(中英文)》2025年第1期231-243,共13页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金项目(41902301,42162027);贵州省科技支撑计划(黔科合支撑[2022]212)。

摘　　要：【目的】为揭示岩溶区抽水蓄能电站的典型碳酸盐岩基岩在抽水蓄能运行过程中循环荷载作用下的损伤发展及破坏机制,【方法】对岩溶区的典型地层白云岩开展了分级循环加载试验和大循环加载试验。【结果】结果表明:(1)分级循环加载过程中,低应力循环时[(0.15~0.35)σ_(ucs),(0.35~0.55)σ_(ucs)],以孔隙压密为主;高应力循环时[(0.75~0.95)σ_(ucs)],各循环均产生不可逆应变,损伤持续积累,变形模量出现降低而泊松比持续增大。(2)应力超过“疲劳应力门槛值”时[(0.85~0.90)σ_(ucs)],声发射信号在循环加卸载过程中持续产生,损伤开始积累至岩样破坏。(3)对于大循环加载试验,应力范围为(0.30~0.85)σ_(ucs)时,试样未破坏;应力范围为(0.30~0.90)σ_(ucs)损伤可分为:初始压密塑性变形段、损伤稳定累积段、损伤加速累积段;应力范围为(0.30~0.95)σ_(ucs)时,试样损伤快速加剧至破坏,损伤阶段性不明显。【结论】认识了白云岩加、卸过程中能量演化规律及力学性质劣化机制,研究成果可为岩溶洼地抽水蓄能水库设计和工程监测提供支撑。[Objective]To study the damage development and failure mechanism of the bedrock of pumped storage power station in karst area under cyclic loading,[Methods]the incremental cyclic loading-unloading test and cyclic loading-unloading test with large stress amplitude are carried out on the typical dolomite rock.[Results]The result show that:(1)For the incremental cyclic loading-unloading tesy,pore compaction dominates under low stress cycles[(0.15~0.35)σ_(ucs),(0.35~0.55)σ_(ucs)],and irreversible strain appears under high stress[(0.75~0.95)σ_(ucs)],indicating damage accumulates with loading and the elastic modulus decreases while the Poisson’s ratio increases with cyclic loading.(2)When the stress exceeds the‘fatigue stress threshold’[(0.85~0.90)σ_(ucs)],the acoustic emission signal generates continuously during the cyclic loading and unloading process,and the damage accumulates until the rock failure.(3)For the cyclic loading-unloading test with large stress amplitude,for the test with the stress range of(0.30~0.85)σ_(ucs),the sample is not damaged.For the test with the stress range of(0.30~0.90)σ_(ucs),the damage process could be divided into three parts:the initial compaction stage,the stable damage accumulation stage,the damage accelerated accumulation stage.For the test with the stress range of(0.30~0.95)σ_(ucs),the damage of rock sample is rapidly accumulating to failure.[Conclusion]The energy evolution law and mechanical property degradation mechanism of dolomite during loading and unloading were studied,which could provide support for the design and engineering monitoring of pumped storage reservoirs.

关 键 词：循环加卸载 声发射 疲劳特性 B值 损伤变量 影响因素 力学性能 

分 类 号：TV223.1[水利工程—水工结构工程]