考虑受压侧岩体反力非线性作用的锚杆抗剪理论  

Shear resistance theory of bolt considering nonlinear behaviour of grout reaction force

作　　者：陈文强[1] 赵宇飞[2] 周纪军 CHEN Wen-qiang;ZHAO Yu-fei;ZHOU Ji-jun(School of Management, Tianjin University of Technology, Tianjin 300384, China;Geotechnical Engineering Department, China Institution of Water Resources and Hydropower Research, Beijing 100048, China;CNR Construction Engineering Co., Ltd., Beijing 100078, China)

机构地区：[1]天津理工大学管理学院,天津300384 [2]中国水利水电科学研究院岩土工程研究所,北京100048 [3]中车建设工程有限责任公司,北京100078

出　　处：《岩土力学》2018年第5期1662-1668,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51409283)~~

摘　　要：针对锚杆受压侧岩体或砂浆体反力非线性作用及结构面的剪胀效应问题,基于经典梁理论推导锚杆轴力与轴向变形及横向剪切力与横向变形的理论公式,建立了锚杆抗剪力计算公式。通过加锚结构面直剪试验验证理论计算有效性,并分析结构面剪胀系数、围岩强度、锚杆安装角(倾角)对锚杆变形和抗剪力的影响。结果表明:锚杆抗剪理论计算与室内试验结果吻合较好;结构面剪胀系数越大,越能较快调动锚杆抗剪作用,相反锚杆塑性强化特征越不明显,改善加锚结构面的阻滑抗剪作用,主要依靠结构面固有抗剪强度;随着围岩强度降低,锚杆需经一定变形才能发挥较大抗剪作用,而随着围岩强度增大,锚杆将迅速达到屈服状态,并且锚杆由轴向张拉破坏逐渐转为拉剪破坏;锚杆最优安装角随结构面内摩擦角增大而增大,依据实际工程中结构面内摩擦角取值范围,可估算锚杆最优安装角为30°～68°。This study aims to solve the problems on the nonlinear behaviour of rock mass or mortar against the pressure side of the bolt and the dilatancy effect of the structural surface. Theoretical formulas for the axial force and axial deformation, transverse shear force and transverse deformation of anchor bolts were derived, and the formula for the shear resistance of anchor bolts was also established based on the classical beam theory. The validity of the theoretical solutions was verified by the direct shear test on bolted structures. Furthermore, this study performed the effects of joint dilatancy coefficient, joint friction angle, surrounding rock strength and bolt installation angle on the deformation and Shear resistance of anchor rods. The results showed that the theoretical calculation results were in good agreement with the experimental results. The higher dilatancy coefficient led to the higher shear resistance of the bolt, but less significant of plastic behaviour. Thus, the shear resistance of bolted joint can be improved by the inherent shear strength of the structural surface. When the strength of surrounding rock decreased, the anchor bolt had to undergo specific deformation to exert a large shearing effect. The higher strength of rock resulted in the yield failure of the bolt within a shorter time, and the damage of the anchor bolt was gradually transformed from the axial tensile failure into tensile shear failure. The optimal installation angle of the bolt increased with the increase of the internal friction angle of the structure, The optimal installation angle of the bolt was estimated within the angle ranging from 300°to 68° in working joint conditions.

关 键 词：锚杆 岩体反力 抗剪力 轴向力 横向剪切力 

分 类 号：TU470[建筑科学—结构工程]