岩溶深长隧道水文地质调查分析与涌水量预测方法研究

Study on Hydrogeological Survey and Analysis and Water Inflow Prediction Method of Karst Deep and Long Tunnels

本文综合分析某段岩溶隧道水文地质情况,预测评估隧道涌突水量,有效遏制地质灾害,只有保证隧道安全施工,才能实现岩溶深长隧道的成功通行。研究结果表明:某隧道是比较典型的一种强岩溶隧道。隧道底层属于上白垩系罗镜滩组地表岩溶与石灰质砾岩发育,隧道内分布很多漏斗、洼地以及地下洞,大气降水通过漏斗与落水洞直接渗透至地下;分析岩溶水位、地质构造以及水系统发现,该隧道已经具备岩溶涌水条件,且隧道位于季节变动带和饱水带,所以隧道施工揭露溶洞概率相对较大,尤其是雨水较大时,很容易引发突泥或突水等地质灾害,隧道涌水存在突发性强、压力高以及水量大等特性,很容易引发重大事故;对比实际和预测的突水量、突水时间,预测的涌水量基本符合实际涌水量,说明预测的涌水量具有合理性。

This paper comprehensively analyzes the hydrogeological conditions of a karst tunnel,predicts and evaluates the water inrush of the tunnel,and effectively curbs geological disasters.Only by ensuring the safe construction of the tunnel,can the successful passage of the karst deep and long tunnel be realized.The results show that a tunnel is a typical strong karst tunnel.The bottom layer of the tunnel belongs to the karst and calcareous conglomerate developed on the surface of the Luojingtan Formation of the Upper Cretaceous System.There are many funnels,depressions and underground caves distributed in the tunnel.Atmospheric precipitation directly seeps into the ground through the funnels and sinkholes.Through analysis of karst water level,geological structure and water system,it is found that the tunnel already has karst water gushing conditions,and the tunnel is located in the seasonal variation zone and water-saturated zone,so the probability of exposing karst caves during tunnel construction is relatively large,especially when the rainfall is large,it is easy to cause geological disasters such as mud or water gushing,and the tunnel water gushing has characteristics such as strong suddenness,high pressure and large water volume,which is easy to cause major accidents.Compared with the actual and predicted water inrush and water inrush time,the predicted water inflow basically conforms to the actual water inflow,which shows that the predicted water inflow is reasonable.