不同含水率断层宏微观破裂与强度折减损伤  

Macro and Micro Fractures and Strength Reduction Damage of Faults with Different Water Content

作　　者：高涛 陈云娟[3,4] 敬艺 刘建民 王津津[1,2] 杨传成 宋润钊[1,2] GAO Tao;CHEN Yun-juan;JING Yi;LIU Jian-min;WANG Jin-jin;YANG Chuan-cheng;SONG Run-zhao(Shandong Institute of Earthquake Engineering,Jinan 250014,China;Earthquake Administration of Shandong Province,Jinan 250021,China;School of Civil Engineering,Shandong Jianzhu University,Jinan 250101,China;Key Laboratory of Building Structural Retrofitting and Underground Space Engineering,Ministry of Education,Shandong Jianzhu University,Jinan 250101,China;School of Qilu Transportation,Shandong University,Jinan 250002,China)

机构地区：[1]山东省地震局,济南250014 [2]山东省地震工程研究院,济南250021 [3]山东建筑大学土木工程学院,济南250101 [4]山东建筑大学建筑结构加固改造与地下空间工程教育部重点实验室,济南250101 [5]山东大学齐鲁交通学院,济南250002

出　　处：《科学技术与工程》2024年第9期3773-3780,共8页Science Technology and Engineering

基　　金：国家自然科学基金面上项目(42172310);国家自然科学基金青年科学基金(51609130);山东省矿山灾害预防控制省部共建国家重点实验室开放基金(MDPC0909);山东省地震局科研项目(YB2304,YW2304,TD202303);山东建筑大学博士基金(XNBS1704)。

摘　　要：为探究深部地区断层花岗岩不同含水率的宏观与微观跨尺度性质,开展了轴压力学试验、扫描电镜(scanning electron microscope,SEM)试验和X射线衍射(X-ray diffraction,XRD)试验,分析其多尺度破裂与强度折减损伤关系。结果表明:无水状态下宏观以剪切破坏为主且破裂面平滑,而随着含水率提高,其破裂模式以张拉破坏为主,裂纹路径与主应力方向平行且整体松散;低含水率工况微观破裂为沿晶破裂,高含水率工况为沿晶破裂和穿晶破裂的复合型破坏;吸水中期峰值强度与弹性模量两指标衰减率为前期6倍,达到衰减幅度最大限并呈非线性指数下降,吸水后期两指标衰减率回弹至前期状态;劣化系数随含水率增长而降低,吸水前期水分子起润滑岩石内部矿物作用,中后期阶段水分子发生侵蚀软化导致强度大幅度折减。In order to explore the macroscopic and microscopic cross scale properties of granite with different water contents in deep areas,axial compression tests,scanning electron microscopy(SEM)tests,and X-ray diffraction(XRD)tests were conducted to analyze the relationship between multi-scale fracture and strength reduction damage.The results show that in the anhydrous state,the macroscopic failure is mainly shear failure and the fracture surface is smooth,while the macroscopic failure with an increase in water content is mainly tensile failure,and the crack path is parallel to the main stress direction and overall loose.The micro fracture under low water content condition is intergranular fracture,while the high water content condition is a composite failure of intergranular fracture and transgranular fracture.The attenuation rate of the peak strength and elastic modulus in the middle stage of water absorption is 6 times that in the early stage,reaching the maximum attenuation amplitude and showing a nonlinear exponential decrease.In the later stage of water absorption,the attenuation rate of the two indicators rebounds to the previous state.The deterioration coefficient decreases with the increase of water content.In the early stage of water absorption,water molecules play a role in lubricating the internal minerals of the rock,while in the later stage,water molecules undergo erosion and softening,leading to a significant reduction in strength.

关 键 词：深部断层 花岗岩 破裂模式 微观机制 强度折减 

分 类 号：TU452[建筑科学—岩土工程]