压力型与拉力型锚杆工作性状的室内足尺模型对比试验研究  

A comparative study of work characteristics of pressure-type and tensile-type anchors based on indoor full-sized model tests

作　　者：贺建清[1] 陈清[1] 陈秋南[1] 

机构地区：[1]湖南科技大学,湖南湘潭411201

出　　处：《水文地质工程地质》2013年第4期50-55,共6页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金资助项目(41172275);湖南省科技计划项目(2009SK3037)

摘　　要：基于室内足尺模型试验对比研究压力型和拉力型锚杆的工作性状,给出锚固体轴向应变的分布特点,验证基于Mindlin问题位移解推导出的压力型锚杆锚固段应力分布理论解的可行性,分析了在试验条件锚杆的极限承载力及破坏形式。试验结果表明,拉力型锚固段处于受拉状态,轴向应变值最大值发生在张拉端附近,距离张拉端越远应变值越小;压力型锚杆的锚固段处于受压状态,轴向应变值最大值发生在承载体附近,距离承载体越远应变值越小;拉力型锚杆破坏形式为锚固段注浆体与岩土层间的粘结滑移破坏,压力型锚杆的破坏形式为承载体附近锚杆周围土体剪胀破坏;压力型锚杆极限承载力较之拉力型锚杆在相同条件下有明显提高;实测值与基于Mindlin问题的位移解推导出的压力型锚杆锚固段应力分布理论解较吻合。Based on indoor full-sized model tests,the work characteristics of pressure-type anchor and tension-type anchor were examined and compared.The axial strain distribution characteristics of their anchorage segments were presented.The feasibility of the theoretical solution of stress distribution on anchorage segments of the pressure-type deduced by the Mindlin Displacement Solution was verified,and the ultimate bearing capacity and the failure form of anchors under test were also discussed.The experiment results show that the anchorage segments of tension-type anchor is in a state of tension under load,the maximum of axial strain value occurrs in the near of tension end,and the farther from the tension end,the axial strain value are smaller;while the anchorage segmen of pressure-type anchor is in a state of compression under load,the maximum of axial strain value occurrs in the near of bearing structure,and the farther from the bearing structure,the axial strain value are smaller.The failure form of tension-type anchor is bond-slip destruction between anchorage grouting body and geotechnical layer,while the faliure form of pressure-type anchor is shear dilatation of the soil mass around the anchorage end.Under the same condition,the ultimate bearing capacity of pressure-type anchor is obviously improved,compared with that of tension-type anchor.The measured axial strain values are in good agreement with the theoretical solution of the pressure-type anchorage derived from the Mindlin Displacement Solution.

关 键 词：压力型锚杆 拉力型锚杆 室内足尺模型试验 锚固段 轴向应变 

分 类 号：TU476[建筑科学—结构工程]