中等蚀变结构面剪切变形破坏特性及统计损伤模型  

Shear deformation characteristics and statistical damage model of moderately altered structural planes

作　　者：丁秀丽[1] 刘通灵 黄书岭[1] 张雨霆[1] DING Xiuli;LIU Tongling;HUANG Shuling;ZHANG Yuting(Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources,Changjiang River Scientific Research Institute,Wuhan,Hubei 430010,China)

机构地区：[1]长江科学院水利部岩土力学与工程重点实验室,湖北武汉430010

出　　处：《岩石力学与工程学报》2022年第11期2161-2172,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51979008);长江科学院创新团队项目(CKSF2021715/YT);云南省重大科技专项计划项目(202102AF080001)。

摘　　要：岩体蚀变往往导致其物理力学性能的显著劣化,蚀变沿结构面的伴生分布是蚀变岩地层常见的地质现象,对地下工程围岩稳定性将产生重要影响。针对河北丰宁抽水蓄能电站地下厂房洞室群围岩普遍存在的蚀变结构面,选取蚀变程度、充填厚度及岩壁粗糙度基本一致的天然蚀变结构面,通过开展结构面剪切特性试验、声发射(AE)监测等研究工作,分析天然中等蚀变结构面剪切变形和强度特征、破坏模式、AE能量演化规律等,构建基于天然结构面声发射能量规律的剪切统计损伤模型,并分析模型参数对结构面剪切变形和强度的影响规律。结果表明:(1)剪切应力对法向和切向变形均有影响,在剪切后期试样即将破坏前会有剪胀效应;结构面破坏模式主要表现为沿着蚀变充填物破坏,伴随块状颗粒裂解、破碎,最终沿结构面剪切滑移破坏;(2)剪切全过程均伴随AE能量释放,AE信号在应力变化时突增并在应力平衡后趋于平静,在试样剪切破坏前突然活跃,可将整个试验过程分为压密阶段、裂解阶段、破碎阶段及滑移阶段;(3)基于天然结构面剪切过程AE能量定义了损伤变量,假设结构面微元强度服从Weibull分布,推导天然结构面的剪切统计损伤模型,由试验结果验证了所建立模型的合理性和适应性。Altered rock masses often lead to deterioration of physical and mechanical properties obviously.The associated distribution of alteration along the structural plane is a common geological phenomenon in altered rock strata,which will have an important impact on the stability of surrounding rock of underground engineering.The natural altered structural planes with the same degree of alteration,filling thickness and rock disk roughness,existing in the surrounding rocks of the underground powerhouse cavern groups of Fengning Pumped Storage Power Station in Hebei Province China,were selected to carry out the shear characteristics test and acoustic emission(AE)monitoring.The shear deformation and strength characteristics,failure mode and AE energy evolution law of natural moderate altered structural planes were analyzed.A shear statistical damage model based on the AE energy law of the natural structural planes was established,and the effects of model parameters on shear deformation and strength were analyzed.The results show that:(1)Shear stress has an effect on both normal and tangential deformation,and dilatancy effect occurs at the late shear stage before the specimen is about to fail;the failure mode of the structural planes is mainly manifested as failure along the filling material,dissociating and crushing of massive particles,and finally shear sliding;(2)AE is released in the whole shear process of natural altered structural planes,it bursts when stress changes and tends to be calm after stress balanced,and active suddenly before shear failure.The whole test process can be divided into compaction stage,dissociation stage,crushing stage and slip stage;(3)With the AE energy sequence of natural structural planes’s hear process to define the damage variable and assuming the micro elements among the structural plane obey Weibull distribution,a shear statistical damage model of natural structural planes was derived,which is in good rationality and adaptability with the experimental results.

关 键 词：岩石力学 天然蚀变结构面 剪切变形特征 破坏模式 声发射演化规律 剪切统计损伤模型 

分 类 号：TU45[建筑科学—岩土工程]