隧洞开挖单循环进尺对超挖量的影响研究  

Study on Influence of Each Advance on the Quantity of Over-excavation in Tunnel Construction

作　　者：杨玉银[1] 李俊峰[1] 杨仕杰 郝利军[1] 白军平 YANG Yuyin;LI Junfeng;YANG Shijie;HAO Lijun;BAI Junping(Sinohydro Bureau 5 Co., LTD, Chengdu, Sichuan, 610066)

机构地区：[1]中国水利水电第五工程局有限公司,四川成都610066

出　　处：《四川水力发电》2021年第2期79-82,共4页Sichuan Hydropower

摘　　要：针对隧洞开挖施工中普遍认为的单循环进尺越大、超挖量越大的问题,对应于隧洞左侧墙、右侧墙、顶拱提出了单循环进尺与孔底径向超挖的计算模型与计算公式,并根据所提出的计算模型与公式对单循环进尺2 m、2.5 m、3 m、3.5 m、4 m进行了验算和实践检验,验算结果及实际钻孔爆破结果表明:单循环进尺的大小对径向超挖有影响,但其影响程度很小,不足以影响单循环进尺的选择,比如单循环进尺2.5 m与3.5 m相比,其孔底径向超挖最大相差0.74 cm,理论平均径向超挖最大相差0.37 cm。It is commonly believed that the longer each advance,the more over-excavation happens during tunnel excavation.This paper sets up a calculation model and formula between radial over-excavation at the bottom of the blasting hole and each advance on left wall,right wall and arch of the tunnel.According to the calculation model and formula,over-excavation under advances of 2 m,2.5 m,3 m,3.5 m and 4m are calculated and tested in practice.Both the calculation and the actual drilling and blasting results indicate that the length of each advance has an effect on radial over-excavation,but in small quantity,which cannot influence the choice of each single advance.Taking 2.5m advance and 3.5 m advance for example,the maximum difference of radial over-excavation at the bottom of the blasting hole is 0.74 cm,and the maximum difference of theoretical average radial over-excavation is 0.37 cm.

关 键 词：隧洞开挖 单循环进尺 超挖量 影响 研究 

分 类 号：TV7[水利工程—水利水电工程] TV52