杭州市第二水源千岛湖配水工程施工期观测分析

Safety Monitoring Analysis of the Water Distribution Project of Qiandao Lake,the Second Water Source of Hangzhou City

通过杭州市千岛湖配水工程的洞脸边坡、隧洞围岩变形、支护结构应力应变、围岩松动圈等原型监测,评价洞脸边坡及围岩稳定性、支护安全性;通过安全监测管理云平台,发现隧洞开挖穿越不良地质等岩层时可能发生工程的异常现象或隐患,精准发布围岩变形、钢拱架应变、边坡失稳等26次超限报警,采取加固措施后围岩及支护结构趋于稳定。岩溶区围岩完整性检测隧洞长11.04 km,查明测线范围内存在的岩溶发育情况及岩石裂隙发育情况,围岩松动圈监测推断各孔的围岩松动圈位置。监测成果为工程排险争取时间,为初期支护、二衬支护及加固方案设计等提供关键依据,确保工程施工安全和经济性。

Through prototype monitoring of face slope,tunnel surrounding rock deformation,support structure stress and strain,loose circle of surrounding rock of the water distribution project of Qiandao Lake,the stability of slope and surrounding rock and the safety of support were evaluated.Using safety monitoring management cloud platform,it was found that the abnormal phenomenon or hidden trouble may occur when the tunnel is excavated through the unfavorable geological rock stratum;and twenty-six over-limit alarms,such as surrounding rock deformation,steel arch strain and slope instability,were accurately issued.The surrounding rock and supporting structure tended to be stable after taking reinforcement measures.Surrounding rock integrity of 11.04 km tunnel in karst area was detected by ground penetrating radar,to find out the karst development and rock fracture development within the survey line.The location of the surrounding rock loose zone of each hole was deduced by using ultrasonic detection method.Monitoring results save time for project risk elimination and provide the key basis for the design of primary support,secondary lining support and reinforcement scheme to ensure the safety and economy of construction.