加锚岩体结构面抗剪强度尺寸效应试验及机理研究  

Experimental and mechanism study on the size effect of shear strength of anchored rock joints

作　　者：刘广建 王志成 罗战友 杜时贵 王康宇 裘伟奇 周浩 陈曦 LIU Guangjian;WANG Zhicheng;LUO Zhanyou;DU Shigui;WANG Kangyu;QIU Weiqi;ZHOU Hao;CHEN Xi(Institute of Rock Mechanics,Ningbo University,Ningbo 315211,China;School of Civil Engineering,Shaoxing University,Shaoxing 312000,China)

机构地区：[1]宁波大学岩石力学研究所,浙江宁波315211 [2]绍兴文理学院土木工程学院,浙江绍兴312000

出　　处：《采矿与岩层控制工程学报》2024年第4期87-97,共11页Journal of Mining and Strata Control Engineering

基　　金：国家自然科学基金资助项目(42107177,42277147);浙江省自然科学基金资助项目(LQ20E040002)。

摘　　要：为揭示加锚岩体结构面抗剪强度尺寸效应机理,开展了系列尺寸(100~400 mm)加锚结构面室内剪切试验,对比分析结构面锚固前后抗剪强度及锚杆抗剪力的变化规律,研究了锚杆和结构面的变形破坏特征。研究结果表明:(1)结构面锚固前后抗剪强度均呈负尺寸效应,且尺寸效应随着法向应力增加而逐渐减弱;锚杆抗剪力随着结构面尺寸增加呈非线性增加。(2)锚杆呈“S”形变形特征,变形角度、剪切变形量和轴向变形量随着结构面尺寸增加呈非线性增加;结构面受锚杆挤压发生破裂的程度随着结构面尺寸增加而减弱。(3)引用“锚杆作用面积”概念,结构面尺寸较小时,锚杆作用面积超出结构面产生“边缘效应”,导致锚杆未充分发挥抗剪性能;随着结构面尺寸增大,锚杆性能得到充分发挥,锚杆抗剪力先迅速增加后保持稳定。The shear tests were carried out on anchored joints of a series of size(100-400 mm)to reveal the size effect mechanism of shear strength of anchored rock joints.The changes in shear strength before and after joint anchoring and the shear resistance of anchor bolt were compared and analyzed,and the deformation and damage characteristics of anchors and joints were studied.The results show that the rock joint shear strength before and after anchoring exhibits a negative size effect,and this size effect gradually weakens with the increase of normal stress.The shear resistance of rock bolt increases nonlinearly with the increase of joint size.The rock bolt exhibits a"S"shaped deformation feature,and the deformation angle,shear deformation,and axial deformation increase nonlinearly with the increase of joint size.The degree of joint squeezing caused by bolting decreases with the increase of joint size.Introducting the concept of"anchor bolt action area",the action area of the anchor bolt exceeds the joint when the joint size is small,resulting in"edge effect",which leads to the anchor bolt not fully exerting its shear resistance performance.As the rock joint size increases,the performance of the anchor bolt is fully utilized,and the shear resistance of the anchor bolt rapidly increases.

关 键 词：锚固结构面 抗剪强度 尺寸效应 锚杆变形 锚杆作用面积 

分 类 号：TU458[建筑科学—岩土工程]