循环荷载对充填结构面岩体剪切特性的影响  

Influence of cyclic loading on shear properties of rock at filled structural face

作　　者：许旭堂 陈翔龙 杨枫 鲜振兴 徐祥 XU Xu-tang;CHEN Xiang-long;YANG Feng;XIAN Zhen-xing;XU Xiang(College of Transportation and Civil Engineering,Fujian Agriculture and Forestry University,Fuzhou 350108,Fujian,China)

机构地区：[1]福建农林大学交通与土木工程学院,福建福州350108

出　　处：《长安大学学报(自然科学版)》2025年第1期24-37,共14页Journal of Chang’an University(Natural Science Edition)

基　　金：国家自然科学基金项目(41702288);福建省自然科学基金项目(2022J01157);福建农林大学杰出青年科研人才计划项目(XJQ202014);福建农林大学科技创新专项基金项目(KFb22103XA)。

摘　　要：针对山区道路岩质边坡在动荷载作用下的疲劳劣化特性,开展循环荷载作用下充填结构面岩体的剪切特性研究。基于自制的岩石直剪仪以及自动化采集系统,设计并使用天然岩样进行直剪试验,分析不同起伏角和充填度下结构面岩体的应力-应变曲线发展和强度演化特性,并利用平均剪胀角来表征起伏角和充填度对充填结构面岩体剪切特性的影响。研究结果表明:小起伏角结构面岩体以无峰型应力-位移曲线为主,而大起伏角的无充填、充填结构面岩体分别以陡峰型、缓峰型曲线为主,上扬型曲线主要出现于高起伏角及高充填度的结构面;随着起伏角的增加,结构面岩体剪切强度峰值因剪断破坏加剧而逐渐增强,并呈现强剪缩、弱剪胀特点;随着充填度的增加,结构面岩体剪切强度峰值及其差值均减小,且循环剪切过程中因充填层的压密效应显著,导致其剪胀特性不明显;结构面岩体剪切应力峰值和平均剪胀角均随循环剪切次数的增加而减小,并渐趋于稳定,且结构面的磨损程度也逐渐降低;当充填度大于1时,平均剪胀角的下降主要由结构面磨损、充填物部分挤出导致;当充填度小于1时,平均剪胀角的降低由结构面剪断、滑移磨损所引起。研究成果可为循环荷载作用下的山区道路岩坡长期安全、稳定及耐久性评价提供参考。Aiming at the fatigue degradation characteristics of rock slopes on mountainous roads under dynamic loads,a study was conducted on the shear characteristics of rock masses with filled structural planes under cyclic loads,a self-made rock direct shear instrument and an automated collection system were used to design and conduct direct shear tests on the rock mass.The stress-strain curve developments and strength evolution characteristics of rock masses filled with structural planes under different undulation angles and filling degrees were analyzed,and the average shear expansion angle was used to characterize the impacts of undulation angle and filling degree on the shear properties of rock mass filled with structural planes.The results show that thestress displacement curves are mainly peakless at small undulation angles,while the unfilled and filled structural faces with large undulation angle is dominated by steep-peak curve and slow peak-curve,respectively,and the uplifted curves mainly appear at high undulation angles and high filling degrees.As the fluctuation angle increases,the peak shear strength of the structural face gradually increases due to the increase in shear damage,and shows the characteristics of strong shear contraction and weak shear expansion.With the increase in the filling degree,the peak shear strength of the rock at structural face and its difference both decrease,and the shear expansion characteristics are not obvious due to the significant compression-density effect of the filling layer during the cyclic shear process.Both the peak shear stress and the average shear expansion angle of the rock at structural face decrease with the increase in the number of cyclic shears and gradually stabilize,and the wear of the structural face also gradually decreases.When the filling degree is greater than 1,the decrease in the average shear expansion angle is mainly caused by the wear of the structural face and the extrusion of the filling material.When the filling degree is less than 1,the decrease

关 键 词：道路工程 充填结构面 循环荷载 起伏角 充填度 循环剪切次数 

分 类 号：U411[交通运输工程—道路与铁道工程]