不同应力水平与初始水化损伤下软岩锚固剂耦合结构剪切力学特性  

Shear mechanical properties of soft rock-grout structures under different stress levels and initial hydration damage conditions

作　　者：荣浩宇 李桂臣[3] 赵光明[4] 许嘉徽 梁东旭 RONG Haoyu;LI Guichen;ZHAO Guangming;XU Jiahui;LIANG Dongxu(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing,Jiangsu 210098,China;College of Civil and Transportation Engineering,Hohai University,Nanjing,Jiangsu 210098,China;School of Mines,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;School of Mining Engineering,Anhui University of Science and Technology,Huainan,Anhui 232001,China;School of Civil Engineering,Xuzhou University of Technology,Xuzhou,Jiangsu 221116,China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [2]河海大学土木与交通学院,江苏南京210098 [3]中国矿业大学矿业工程学院,江苏徐州221116 [4]安徽理工大学矿业工程学院,安徽淮南232001 [5]徐州工程学院土木工程学院,江苏徐州221116

出　　处：《岩石力学与工程学报》2024年第8期1936-1951,共16页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(U22A20165,52174089);国家自然科学基金青年基金资助项目(52304082)。

摘　　要：以砂岩锚固剂组合试样为研究对象,基于不同法向应力与浸水时间下三轴剪切试验,分析应力水平与初始水化损伤影响下软岩锚固剂耦合结构承载特性。研究表明,水化损伤加剧会显著削弱岩石与胶结面的抗剪能力,增大试样变形量并使其承载能力发生劣化,法向应力相同时,浸水30 d条件下试样剪切强度分别降低23.14%~35.46%。法向应力增大会约束试样内微裂隙的聚结贯通,提升其承载能力,浸水时间相同时,试样剪切强度随法向应力增大分别增加97.15%~137.12%。组合试样剪切破坏模式受应力水平与初始水化损伤共同制约,呈沿胶结面剪切滑动、混合剪切破坏与沿岩石部分破坏3种类型。随浸水时间增加,试样总应变能、弹性应变能与耗散能均不断降低,试样破坏所需能量减少。浸水时间相同时,试样耗散比随法向应力的增大分别降低54.38%~57.56%,法向应力增加会提升试样的能量存储能力,裂隙发育所需外部输入的能量提升,进而增强结构的承载能力。根据组合试样剪切力学响应,建立不同浸水时间与法向应力下软岩锚固剂耦合结构剪切模型。In this research,triaxial shear tests under different stress levels and initial hydration damages were carried out on sandstone-grout composite specimens under different normal stresses and immersion times to investigate the shear mechanical properties of rock-grout composite structures.The results showed that the increased damage induced by hydration significantly reduced the shear resistances of the rock and the bonding surface,increased the deformation amount of the specimen and degraded its bearing capacity.The shear strength of the specimens decreased by 23.14%-35.46%under the condition of 30 d of immersion,while maintaining the same normal stress level.The increase of normal stress restricted the development of micro-fractures in the specimen and improved the bearing ability.The shear strength of the specimens increased by 97.15%-137.12%with increasing normal stress,while maintaining the same immersion time.The shear failure mode of the composite specimens is limited by the stress level and initial hydration damage.There were three typical failure modes,including shear slip along the rockgrout interface,mixed shear failure and partial rock failure.With increasing immersion time,the total strain energy,the elastic strain energy and the dissipated strain energy of the specimen decreased,and the energy required for specimen failure reduced.The dissipation ratio of the specimens decreased by 54.38%-57.56%with increasing normal stress at the same immersion time.The increase of normal stress raised the energy storage capacity in the specimen,as well as the input external energy required for fracture development,thus enhancing the bearing performance of the structure.According to the shear mechanical behaviors of the composite specimens,a shear model of soft rock-grout structures under different immersion times and normal stresses was established.

关 键 词：岩石力学 应力水平 软岩 岩石锚固剂耦合结构 三轴剪切 能量演化 

分 类 号：TU45[建筑科学—岩土工程]