超大跨公路隧道机械化施工不等厚初支方案研究  

Research on preliminary bracing scheme of different thickness for mechanized construction of super span highway tunnel

作　　者：祝鑫 Zhu Xin(Guangdong Communication Planning&Design Institute Group Co.,Ltd.,Guangzhou Guangdong 510507,China)

机构地区：[1]广东省交通规划设计研究院集团股份有限公司,广东广州510507

出　　处：《山西建筑》2024年第24期149-155,共7页Shanxi Architecture

基　　金：广东省省级科技计划项目(编号:2021B1111610002)。

摘　　要：隧道内采用机械化钻爆施工时易出现超挖现象,文章分析了三臂凿岩台车因自身结构尺寸以及作业空间影响,从几何角度得出,凿岩台车周边眼外插角由凿岩机半径、钻杆机长度、掌子面预留空间长度、初支厚度以及一次爆破进尺多个参数确定,并根据掌子面预留空间与钻杆外露长度的关系,推导出了外插角计算公式。然后以深汕西城仔山超大跨公路隧道机械化施工作为依托,选取Ⅳ级围岩作为试验对象,通过对衬砌初支喷混参数的优化,并结合现场进尺和掌子面预留空间,提出了不等厚初支单元方案,采用数值模拟分析了不等厚初支单元结构的受力体系,现场监测数据表明该支护体系满足当前围岩级别承载需求,从源头上降低了三臂凿岩台车超挖工程量,为后续公路隧道机械化施工超挖控制提供参考。When mechanical drilling and blasting is used for tunnel construction,this paper analyzes the three-armed tunnel boring machine due to its own structural dimensions and working space limitations,from a geometric perspective,and concludes that the outward angle of the surrounding holes of the boring machines is determined by the radius of the drilling machine,the length of the drilling rod,the length of the pre-reserved space in the working face,the thickness of the initial support,and the length of the first blasting advance.Based on the relationship between the pre-reserved space and the length of the exposed drilling rod,the paper derives an equation for calculating the outward angle.Then,relying on the mechanized construction of the super-span highway Chengzaishan tunnel in the project of Shenshanxi,theⅣ-class surrounding rock is selected as the test object.Through the optimization of the spray mixing parameters of the lining primary support and the distance from the site footing and the footing surface to the primary support end,the unequal thickness primary support unit scheme is proposed.The numerical simulation is used to analyze the stress system of the unequal thickness primary support unit structure.

关 键 词：不等厚初支 外插角 凿岩台车 超挖 钻爆作业 隧道机械化 

分 类 号：TU997[建筑科学—市政工程] U455[建筑科学—桥梁与隧道工程]