龙厦铁路象山隧道岩溶区段施工技术研究

Research on Construction Technology in Karst Area of Xiangshan Tunnel of Longyan-Xiamen Railway

研究目的:龙厦铁路象山隧道DK 24+083～DK 24+232和YDK 24+098～YDK 24+304段为半封闭岩溶洼地,周边为花岗岩、砂岩全风化地层。溶洞、溶槽、管道相互连通,形成一个巨大的储水构造。隧道采取全断面帷幕注浆后,开挖时发生大规模突水突泥,造成淹井灾害,地表坍陷。通过地表施作洞内"透水不透泥"堵水塞,完成进口端反坡安全抽水。随后对岩溶区段采取信息化综合注浆技术,采取"两端夹击、泄水降压、注浆加固、管棚支护"完成溃口处理。研究结论:(1)通过地表深孔投料注浆,可以实现"透水不透泥"堵水塞结构的施作;(2)信息化综合注浆技术在满足质量的基础上,比全断面帷幕注浆施工速度提高1倍以上;(3)采取"两端夹击、泄水降压、注浆加固、管棚支护"的施工原则,成功地处理了突水突泥溃口。

Research purposes： The sections of DK 24 ＋ 083- DK 24 ＋ 232 and YDK 24 ＋ 098 - YDK 24 ＋ 304 of the Xiangshan Tunnel of the Longyan - Xiamen Railway are in the areas with the closed karst senke, granite and fully weathering sandstones. The karst cave, karst groove and pipelines are interconnected to form a huge water store structure. After conducting full face curtain grouting, the large - scale water and mud bursting occurred to flood the shaft and cause the ground collapse when excavation was done. The drainage was completed on the back slope of the entrance end by using the plugger that can be passed through by water but not by mud in the ground of the tunnel. Subsequently, the informalization comprehensive grouting technology was used for the karst section, and for reinforcing the breaking open, the drainage for reducing the pressure, the grouting for reinforcing and the pipe roof for supporting were conducted on both ends.Research conclusions： （ 1 ） The plugger that is passed through by water but not by mud can be used by grouting into the deep hole on the ground. （2） Based on meeting the quality reuirement, the construction speed can be doubled by using the informalization comprehensive grouting technology, compared with the full face curtain grouting technology. （3） the principle of drainage for reducing the pressure, the grouting for reinforcing and the pipe roof for supporting can be used for reinforcing the breaking open caused by water and mud bursting.