铁路单线隧道钻爆扰动范围的研究

以禾洛山隧道为研究对象,针对施工难度最大的Ⅳ级围岩地段,在施工现场进行钻爆参数试验,得到合理的钻爆参数,隧道的超欠挖得到有效控制;然后在试验研究的基础上,采用三维有限差分软件FLAC3D,对上下台阶钻爆施工对松动圈的影响距离和围岩中产生的松动圈大小进行研究分析。研究结果表明,上台阶钻爆施工对松动圈的影响距离为6～8m,下台阶钻爆施工对松动圈的影响距离为8～10m;松动圈最终大小(厚度)为2.5m;上下台阶合理的间距为10m,这利于减小松动圈的大小和符合初期支护快速封闭的原则。利用研究结果指导钻爆参数和初期支护参数的选择,使隧道施工的质量、进度和安全性得到明显提高,对类似工程具有一定的指导意义。

STUDY ON RANGE OF BROKEN ROCK ZONE OF BLAST-CONSTRUCTING SINGLE LINE RAILWAY TUNNEL

The Ⅳ level rock of Heluoshan tunnel is the most difficult part of construction work,where some blasting tests were carried out in situ in order to gain the optimal blasting parameters and effectively control the back break of blasting rock.Based on the testing results using FLAC3D,a 3D finite difference software,a research was carried out in detail to analyze the distance of execution of blasting works on bench from top to bottom affecting the broken rock zone,and the range of the broken rock zone.The study indicated that the distance of execution of blasting works on top bench affecting the broken rock zone was 6～8m;the distance of execution of blasting works on bottom bench affecting the broken rock zone was 8～10m;the range of broken rock zone was 2.5m;The optimal distance between top bench and bottom bench was 10m,which could be good for decreasing the range of the broken rock zone,and accord with the principle of rapid closure of primary support.According to the study results,the blasting parameters and primary support parameters were chose which greatly improved the quality,progress and security of tunnel construction.Similar program could get some guiding help from this project.