上忙碑隧道岩溶涌突水风险研究

Study on the Risk of Karst Water inrush in Shangmangbei Tunnel

永德(链子桥)至耿马(勐简)高速公路内的上忙碑隧道位于我国云南省,该隧道所处区域地质环境条件复杂。隧道洞身穿过岩溶地区,溶蚀管道与宽大裂隙发育,进而产生较大的溶蚀通道以及相互连通的暗河系统,易产生涌水突泥的风险。通过实地调查、钻探及物探等基本手段查明了隧址区环境地质条件,在此基础上对岩溶发育特征、地下水补径排特征及其垂向分布特征展开分析研究,采用径流模数法和降水入渗法对隧道涌水量进行了定量计算和定性分析,给出了涌突水危险性分段评价。研究表明,隧道施工中遇地下管道系统或地下暗河,可能发生较大规模涌突水现象,可溶岩段内岩溶涌突水危险性评价总体为一般-较高危险。

Shangmangbei Tunnel of the expressway from Yongde(Chain Bridge)-Gengma(Mengjian)is located in Yunnan Province of China with complicated geological environment.The tunnel body passes through the karst area with corrosion channel and wide fissures further developing into a large corrosion channel and interconnected underground river systems,which is prone to the risk of water inrush and mud inrush.Therefore,environmental geological conditions of the tunnel site have been identified through investigation,drilling,geophysical exploration and other basic means.On this basis,the karst development,the relationship between groundwater recharge and drainage,and the vertical distribution characteristics are analyzed to carry out quantitative calculation and qualitative analysis for tunnel water inflow through runoff modulus method and rainstorm infiltration method,thereby evaluating the water inflow risk section by section.The study shows that large-scale water inrush may occur in case of any underground channel system or underground river encountered in tunnel construction.Therefore,there is general or severe risk of karst water inrush in the soluble rock section.