高黎贡山隧道1号竖井工作面预注浆循环段高分析与应用

Analysis and Application of Circulating Drilling Hole Depth of Working Face Pregrouting for Shaft No.1 of Gaoligongshan Tunnel

为解决深大铁路竖井建井工作面超前预注浆快速堵水施工问题,以大瑞铁路高黎贡山隧道1号竖井风化花岗岩地层采用工作面预注浆方式加固堵水为例,根据井检孔和开挖揭示的地质情况,针对性地制定“探注结合”的工作面预注浆方案。通过现场试验,总结分析深大竖井工作面预注浆设计、钻孔效率和各种注浆段高等对注浆效果和施工效率的影响,得出高黎贡山深大铁路1号竖井掘进中工作面预注浆加固堵水的合理循环段高为60 m。合理段高的设置使综合施工进度提高6.3%~15.8%,可保证工作面预注浆堵水效果,还可提高建井的综合施工效率、节约施工成本。

Pregrouting technology is often adopted to rapidly seal the water leakage of the working face of the deep and large vertical shaft constructions of a railway.In this paper,a case study is conducted on the shaft No.1’s water seal of the Gaoligongshan tunnel on Dali-Ruili railway in weathered granite formation using working face pregrouting.A targeted working face pregrouting scheme of exploration+grouting is determined according to the geological conditions revealed through inspection holes and excavation results.Based on field tests,the influences of the pregrouting scheme,drilling efficiency,and drilling hole depth on grouting effect and efficiency are analyzed;in conclusion,the optimal depth of the shaft No.1’s drilling hole of the Gaoligongshan tunnel is 60 m.A rational drill hole depth can help in improving comprehensive construction progress by 6.3%~15.8%,guarantee the water seal effect of working face pregrouting,improve comprehensive construction efficiency,and save construction cost.