2017年1月上施工技术 第46卷第1期CONSTRUCTIONTECHNOLOGY85 DOI:10. 7672/sgjs2017010085 对称型节理发育岩体隧道锚喷支护形式分析*
杨忠峰',郭吉平23,朱文轩4 (1.上海同岩土木工程科技股份有限公司,上海200092;2.贵州路桥集团有限公司,贵州贵阳550001; 3.贵州独平高速公路有限公司,贵州贵阳550001;4.同济大学土木工程学院地下建筑工程系,上海200092) 【摘要】针对近对称型节理发育的Ⅳ级围岩区段,建立二维离散元计算模型,分析公路隧道开挖时不同支护参数下 围岩深部位移、锚杆轴力及初支内力的分布特征及变化规律,探究该类地质条件下错喷支护的必要性,明确合理的 支护形式及设计参数。
分析表明:施作格栅拱架后,必须设置锁脚锚杆,以减小围岩受扰动程度,确保落底安全;设 置锁脚锚杆后,再增设系统锚杆、局部锚杆,支护效果提升不明显,建议原设计方案优化为“喷射混凝土+格栅拱 架+锁脚锚杆”,现场监测数据验证了该方案的可行性。
【关键词】隧道工程;支护;对称节理;离散元;锚杆 [中图分类号】U451*.2[文献标识码】A【文章编号】1002-8498(2017)01-0085-04 The Bolt-shotcrete Support Research of Rock Tunnel withSymmetricalJoint Yang Zhongfeng',Guo Jiping²”,Zhu Wenxuan* (1.Shanghai Tongyan Civil Engineering Technology Co.,Ltd., Shanghai 200092, China; 2.Guizhou Road & Bridge Group Co.,Lid.,Guiyang,Guizhou 550001,China; 3.Guizhou Duping Highway Co.,Ltd.,Guiyang,Guizhou 550001,China;4.Department of Geotechnical Engineering, College of Civil Engineering,Tongji University,Shanghai 200092,China) Abstract;A two-dimensional discrete clement model of tunnel is established, located in IV rock with symmetrical joint nearly.Thedisplacement of therock,thebolt axial force and the intemal forc of the concrete are researched under different support parameters, so that we can determine the reasonable support designing parameters.The results show that the lock pin bolt should be set when the steel grid is installed to reduce rock loose range and ensure tunnel safety, the supporting effect of the additional bolt systems, local bolt is not obvious when the foot bolt lock is set. It is remended that the original design change as ‘shotcrete + steel grid + bolt lock pin',the feasibility of the scheme is verified by the monitoring data from the field. Key words:tunnels; supports; symmetric joint; DEM; bolts 0引言伟力探讨了节理间距对隧道围岩压力的影响,分 随着国家高速公路的建设,需要穿越山岭的路析了不同节理间距下隧道围岩压力的分布规律。
段也随之增多。
而大部分岩体都是沉积形成具有结合数值模拟和实际工程,有学者["分析了节理 层理,加上节理裂隙的存在",极大降低了隧道结对围岩的作用机理和隧道变形的影响。
但是,上述 构的稳定性,给隧道和高速公路的建设提出了严峻研究多侧重于分析围岩压力与单一岩层、围岩等级 的挑战[2...