某岩溶隧道涌水预报技术探索

Exploration on the Technology of Water Inflow Prediction for Karst Tunnel

研究目的:提高隧道涌水预报的可靠性和预报工作效率,减少盲目性,为现场施工地质超前预报寻找一种较为适宜的地质调查与分析的方法。研究方法:在勘察设计资料基础上,通过对隧道穿越区域地面及洞内工程地质及水文地质的实地调查,对岩溶发育的规律及隧道涌水进行相关性研究。研究结果:通过研究,得知深大断裂对深部岩溶洞穴与暗河发育具有控制作用,划分出了隧道穿越区内重点涌水区段;对重点涌水区段,选择与探测目的相适应的中短距离电法物探手段进行详细探测,并预测涌水规模;运用洞内地质编录信息对预报方案及相关技术参数进行修正,实现了预报体系的逐渐优化。研究结论:深大断裂对岩溶的发育控制作用显著,大型充水溶洞的总体发育方向与断裂走向相同;中短距离的高精度电法物探手段对水的敏感性强于弹性波法物探手段,适宜进行重点涌水区段的详细探测;岩溶区隧道涌水预报工作宜采用多手段协同预报的方法,以提高预报的可靠性及工作效率;预报的过程是一个不断优化的过程。

Research purposes： To improve the reliability and efficiency of water inflow prediction and to provide a suitable geology survey and analysis method for the geology prediction works during tunnel construction. Research methods： On the basis of survey and design data, studies are made on the karst development regularity and on the relations between the water inflow and the karst development by investigations on the engineering geology and hydrogeology of ground surface along the tunnel alignment and inside the tunnel. Research results： By means of studying on the development states and distribution regularity of the karsts in the prediction region, it is concluded that huge and deep fractures control the development of the deep karst caves and underground rivers and the critical water inflow sections within the tunneling region are determined; Small - medium distance electrical prediction methods compatible with the prediction aims are selected for the detailed prediction and determination of the water inflow scales in the critical water inflow sections. The geological data recorded inside the tunnel are used to modify the prediction programme and the relevant technical parameters so as to gradually optimize the prediction system. Research conclusions：Huge and deep factures control the development of the karsts and the general development orientations of the large - scale water - filling karst caves are the same as the orientations of the fractures ; the highly - accurate electrical prediction methods for small - medium distances, which are more sensitive to water than elastic - wave prediction method, is suitable for the detailed predictions in critical water inflow sections. A combination of different prediction methods should be adopted for the prediction of the water inflow in karst regions so as to improve the prediction reliability and the working efficiency; the prediction process is a gradually -optimized process.