不同渗压下岩石-混凝土界面剪切渗流耦合初探  

Experimental investigation on rock-concrete interface shear permeability properties under different pore pressures

作　　者：贾朝军 庞锐锋 张升[1] 郑艳妮 雷明锋[1] 施成华[1,2] JIA Chaojun;PANG Ruifeng;ZHANG Sheng;ZHENG Yanni;LEI Mingfeng;SHI Chenhua(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Research Center of High-speed Railway Construction Technology,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]高速铁路建造技术国家工程研究中心,湖南长沙410075

出　　处：《铁道科学与工程学报》2025年第3期1100-1111,共12页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(52378421,52178402);中国中铁股份有限公司科技研究开发计划项目(2022-重点-10)。

摘　　要：为揭示重力坝和高水压隧洞等工程支护结构在剪切渗流耦合作用下与原岩界面之间的相互作用及其对剪切力学特性和渗流性质的影响,利用三维激光扫描技术重构隧道开挖边界,在此基础上制备具有自然粗糙面的半圆柱形花岗岩试样,浇筑混凝土形成岩石-混凝土圆柱样,进行标准养护。利用设计的新型岩石-混凝土界面剪切渗流测试方法开展不同渗压条件下的剪切渗流耦合试验,探讨了渗压对岩石-混凝土界面在渗流应力耦合作用下剪切破坏的影响。研究结果表明,岩石-混凝土界面在剪切渗流耦合过程中会经历裂纹闭合、弹性变形、裂纹非稳定扩展、错动断裂及峰后破坏阶段。断裂强度、峰值强度和残余强度均随渗压增加而线性降低;渗透率随剪切应变增加先降低后增加,且最大渗透率滞后于峰值强度。剪切渗流耦合作用下渗透率受界面开度、界面粗糙特征及填充特征影响,但岩石-混凝土界面破坏前、后均表现为随开度的增加而线性增加。花岗岩和混凝土的力学性质影响界面的抗剪强度,随着渗压的增加,花岗岩界面磨损改善;分析破坏前后试样界面粗糙特征,界面磨损主要由花岗岩界面几何特征决定,并集中在剪切起始位置。研究成果可为特高坝坝基稳定性计算、高水压隧洞初期支护设计等提供理论支撑和现实依据。The interaction between support structures such as gravity dams and high-pressure water tunnels with the original rock interface under shear seepage coupling,and its impact on shear mechanical properties and seepage characteristics,was explored.Three-dimensional laser scanning technology was used to reconstruct the tunnel excavation boundary.Subsequently,semi-cylindrical granite specimens with natural rough surfaces were fabricated.The concrete was cast to form a rock-concrete cylindrical sample,which undergo standard curing.A novel rock-concrete interface shear seepage testing method designed for this research was employed to conduct shear seepage coupling experiments under various seepage pressures,examining the influence of seepage pressure on shear failure of the rock-concrete interface under stress coupling from seepage.The results reveal that the rock-concrete interface experiences stages of crack closure,elastic deformation,unstable crack propagation,dislocation fracture,and post-peak failure during the shear seepage coupling process.Fracture strength,peak strength,and residual strength all exhibit a linear decrease with increasing seepage pressure.The permeability initially decreases and then increases with shear strain,with maximum permeability lagging behind peak strength.Under shear seepage coupling,permeability is affected by interface aperture,roughness characteristics,and filling features,yet it linearly increases with aperture both before and after interface failure.The mechanical properties of granite and concrete influence the interface’s shear resistance.As the seepage pressure rises,the granite interface wear improves.An analysis of the roughness characteristics of the sample interfaces before and after failure reveals that interface wear,primarily determined by the geometric characteristics of the granite interface,is concentrated at the shearing initiation point.The research results can provide a theoretical support and practical basis for the calculation of the stability of the foundation

关 键 词：岩石-混凝土界面 剪切 渗流 渗压 渗透率 

分 类 号：TU45[建筑科学—岩土工程]