沪蓉高速公路乌池坝隧道区岩溶发育特征及其涌水分析

Analysis to gushing in Wuchiba tunnel and features of karstification

乌池坝隧道区有6种岩溶地貌类型,涉及2个岩溶水系统(3条地下河)。其中白岩坝地下河发育受碳酸盐岩层组类型控制,管道结构单一,具有侧向补给、纵向排泄的水文地质特征;龙潭和毛田地下河发育受构造控制,具有多分支、多级排泄的特征。本文将乌池坝隧道分成3部分5个岩溶区段,评价了各区段岩溶发育对隧道涌水的影响,认为从ZK 256+300至ZK 257+000段,岩溶涌水可能性极大。采用大气降水入渗系数法和地下水疏干法,对各岩溶区段隧道涌水进行计算预测,其中ZK 256+300至ZK 257+500段涌水量达31.3×104m3/d。

There are six types of karst physiognomy in Wuchiba and two karst water systems （with three underground rivers） relate to the tunnel. The Baiyanba subterranean stream is controlled by the types of carbonate rocks with simple conduit structure and featured hydrogeologically by being of lateral recharge and longitudinal discharge. The Longtang and Maotian subterranean streams are controlled by geologic structure and featured with multilevel conduit branch and discharge way. The Wuchiba highway tunnel is divided into three parts and five sections of karst zone by the author. Method of infiltration coefficient of precipitation, modulus method of groundwater runoff and analogy method of hydrogeology are adopted to calculate and forecast the rate of gushing water in each subsection. Then, the influence of karstification features in each subsection on gushing water is analyzed and concludes that the maximum rate of the tunnel attains to 31.3× 10^4m^3/d between ZK256＋300 to ZK257＋000 section.