典型不良地质条件下输水隧洞安全分析

Safety Analysis of Water Conveyance Tunnel under Typical Unfavorable Geological Conditions

以杭州市第二水源千岛湖配水工程输水隧洞为研究对象,采用数值模拟法,对含溶洞、软弱夹层不良地质条件下隧洞初衬时稳定性进行分析,以研究隧洞结构应力、应变分布特征及变化规律,及时发现隧洞穿越不良地质时可能发生的工程异常或隐患。结果表明,含溶洞工况下,隧洞拱腰和拱脚处的位移和应力均有较大幅度的增大;含软弱夹层工况降低了隧洞围岩的整体刚度,隧洞结构各部位的位移均略有增大。

Taking the water conveyance tunnel of Hangzhou Second Water Source Qiandao Lake Distribution Project as the research object,the numerical simulation method is used to analyze the initial lining stability of the tunnel under unfavorable geological conditions including karst caves and weak interlayers,in order to study the structure stress,strain distribution characteristics and change law of tunnel,and discover in time the engineering anomalies or hidden dangers that may occur when the tunnel passes through bad geology.The results show that the displacement and stress of the arch waist and arch foot of the tunnel increase greatly under the condition of karst cave,and the condition of soft intercalation reduces the stiffness of surrounding rock and the displacement of each part of tunnel structure increases slightly.