灌浆岩石锚杆拉拔变形和刚度的理论解析  

Theoretical analysis of pullout deformation and stiffness of grouted rockbolts

作　　者：许宏发[1] 王武[1] 江淼[1] 佟佺[1] 

机构地区：[1]解放军理工大学工程兵工程学院,江苏南京210007

出　　处：《岩土工程学报》2011年第10期1511-1516,共6页Chinese Journal of Geotechnical Engineering

基　　金：国家重点基础研究发展计划项目(973计划()2009CB724608)

摘　　要：岩石锚杆的变形计算是锚固工程设计中的一个关键因素。基于协调剪切变形段锚杆和岩体间剪切变形刚度的线性假定,不协调剪切变形段锚杆和岩体间剪应力沿杆长呈幂函数型分布的假定,通过荷载传递微分方程,对全灌浆锚杆和有自由端灌浆锚杆的拉拔变形和刚度进行了理论分析,推导出沿杆长剪应力分布函数、轴力分布函数和位移分布函数,进而可获得锚杆最大拉拔力和拉拔荷载–位移曲线。根据剪滞理论,由灌浆锚杆周围岩体单元应力平衡微分方程,推导出锚杆与岩体之间剪切弹性变形刚度的计算公式。与其它理论结果比较,表明本分析方法是合理的、可行的,对于灌浆锚杆变形、刚度及强度设计具有参考价值。The deformation calculation of rockbolts is one of key factors in anchor engineering design.In the segment of the shear deformation compatibility between the rockblots and the surrounding rockmass,the linear shear deformation stiffness is assumed.In the segment of the deformation incompatibility,the power function model of the shear stress distribution along the rockblots is presented.By means of the loading transfer differential equation,the pullout deformation and stiffness on the fully grouted and the grouted rockbolts with free end are analyzed.And the shear stress distribution function,the axial force distribution function and the displacement distribution function along the rockbolt are derived.Thus the maximum pullout force and pullout load-displacement curve on the grouted rockbolts can be obtained.Based on the shear-lag theory,from the equilibrium differential equation on an infinitesimal element of the rockmass around rockbolts,the calculation formulae for elastic deformation stiffness on the interface between the rockbolts and the rockmass are deduced.The comparison between the present results and other theoretical estimates shows that the proposed method is reasonable and feasible and has reference value for the design of deformation,stiffness and strength of grouted rockbolts.

关 键 词：灌浆岩石锚杆 拉拔变形 拉拔刚度 拉拔荷载-位移曲线 剪滞理论 

分 类 号：TU47[建筑科学—结构工程]