傍山浅埋长距离引水隧道成洞条件分析

Shallowly Buried Tunnel Conditions In Long Distance Water Diversion Project

“引汉济渭”二期工程承担着渭河两岸21个县市的输配水任务,对于实现引汉济渭工程总体效益至关重要。“引汉济渭”二期南干线引水骨干线路工程黄池沟至西安子午水厂段,引水隧洞长68.93 km,主要穿越秦岭北麓中低山。通过勘查发现影响引水隧道成洞的主要工程地质条件为秦岭北缘断裂带发育,隧洞分布较多的Ⅴ类及Ⅳ类洞室围岩。并且引水隧洞与断裂相遇地段易发生集中突水问题,预测涌水量达1260.6m3/d^18166.5m3/d。为确保“引汉济渭”二期工程引水隧洞工程的质量,需采取必要措施,使引水隧洞傍山浅埋地质条件基本实现隧洞成洞要求。

The second phase of the Hanjiang-to-Weihe River diversion project will provide water supply for 21 important counties and cities on both sides of the Weihe River.It is very important to realize the overall benefit of the project.Huangchigou to Xi’an Ziwu Waterworks section is the diversion backbone of the south line.The length of the diversion tunnel is 68.93 km,which mainly passes through the middle and low mountains in the northern foot of Qinling Mountains.By means of exploration and test,it is found that the main engineering geological problem affecting the tunnel formation is the development of the northern edge fault zone of Qinling Mountains.And the tunnel surrounding rock of full-length distribution of the tunnel is classⅤand classⅣwhich is broken and with poor self-stability.The concentrated water inrush can happen easily in the section where the diversion tunnel meets the fault and the predicted water inflow is 1260.6 m3/d^18166.5 m3/d.In order to ensure the quality of the diversion tunnel project and achieve the expected benefit,it is necessary to take measures to make the geological conditions basically realize the requirement of the diversion tunnel construction.