摘要
对于关闭煤矿硬岩巷道衬砌硐室储气空间而言,衬砌混凝土与围岩之间的良好黏结是保证储气空间承载层稳定与气密性的前提,但硐室内气压周期性的升高与下降会导致混凝土与围岩之间界面黏结力下降。为深入探究循环高内压交变荷载下围岩-衬砌组合结构界面强度疲劳劣化特性,开展了不同界面粗糙度岩石-混凝土组合体试样不同法向荷载的先疲劳后剪切试验,从岩石部分试验前后界面特征变化、应力-位移曲线、峰值强度和界面破坏模式等方面分析其强度特性。试验结果表明:变荷载作用后岩石-混凝土组合体试样在剪切过程中应力-应变曲线可分为裂缝闭合阶段(塑性-弹性变形阶段)、裂缝扩展阶段(弹性变形阶段)和脆性断裂阶段(破坏阶段)3个阶段,粗糙度越高,法向应力越大,各阶段发展越充分;界面刻槽处嵌入混凝土与砂岩岩柱相互挤压和交错,水平应变与主应变均呈现出明显的分区错动分布特征;在交变荷载作用下,颗粒之间发生断裂,并伴随着微裂纹延伸发展,岩屑与裂纹数量随上限应力增大而增多;组合结构强度特性与疲劳程度、界面粗糙程度、内压大小等密切相关。该研究可为压气储能条件下关闭煤矿硬岩巷道衬砌硐室稳定研究提供试验参考。
For gas storage in abandoned coal mine hard-rock tunnels,the bonding performance between concrete lining and surrounding rock is crucial for maintaining the bearing capacity and air-tightness of the containment structure.However,cyclic internal pressure variations can cause degradation of the interfacial bond.To study the fatigue deterioration characteristics of rock-lining interface strength under cyclic high pressure,direct shear tests were conducted on rock-concrete composite specimens with different interface roughnesses after fatigue loading under varying normal stresses.Strength characteristics were analyzed through interface morphology evolution,stress-displacement curves,peak strength and failure patterns.The results show that shear stress-strain curves can be divided into three stages:crack closure stage(plastic-elastic deformation),crack propagation stage(elastic deformation),and brittle fracture stage(failure).Higher interface roughness and normal stress facilitate more complete development of each stage.Concrete embedded in rock grooves and sandstone columns exhibit mutual extrusion and interlocking effects.Horizontal strain and principal strain display distinct zonal dislocation characteristics.Under cyclic loading,particle breakage occurs accompanied by microcrack propagation.Both rock debris and cracks increase with higher upper stress limits.This study demonstrates that the interface strength characteristics are closely related to fatigue degree,interface roughness and internal pressure magnitude.The findings can provide experimental basis for stability analysis of lined caverns in abandoned mines under compressed air energy storage conditions.
作者
付强
杨科
刘钦节
宋涛涛
吴犇牛
于鹏
FU Qiang;YANG Ke;LIU Qin-jie;SONG Tao-tao;WU Ben-niu;YU Peng(Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining,Anhui University of Science and Technology,Huainan,Anhui 232001,China;Key Laboratory of Geological Safety of Coastal Urban Underground Space,Ministry of Natural Resources,Qingdao Geo-Engineering Surveying Institute(Qingdao Geological Exploration Development Bureau),Qingdao,Shandong 266101,China;School of Mining Engineering,Anhui University of Technology,Huainan,Anhui 232001,China;State Key Laboratory for Safe Mining of Deep Coal and Environment Protection,Anhui University of Technology,Huainan,Anhui 232001,China)
出处
《岩土力学》
北大核心
2025年第S1期40-52,共13页
Rock and Soil Mechanics
基金
煤炭安全精准开采国家地方联合工程研究中心开放基金项目(No.EC2023030)
自然资源部滨海城市地下空间地质安全重点实验室开放基金项目(No.BHKF2023Z03)
安徽理工大学高层次引进人才科研启动基金(No.2024yjrc08)
关键词
关闭煤矿
压气储能
交变荷载
强度特性
岩石-混凝土组合体
abandoned coal mines
compressed air energy storage
cyclic loading
strength characteristics
rock-concrete composite specimens
