冻结法在江底取水隧道修复工程中的应用

Application of Ground Freezing Method to Repair Project of River Bottom Water Taking Tunnel

常熟发电厂江底盾构取水隧道施工中,发生突水涌砂事故后,采用填充冻结法来形成临时冻结封堵墙;然后排出隧道内积水,构筑永久封堵墙,为隧道工程下一步施工的安全、顺利进行提供了保障。实践表明,采用填充冻结法施工临时封堵墙,与隧道内灌注水下混凝土方法施工临时封堵墙相比,在复杂地质条件下,能有效防止突水涌砂事故发生,对隧道本体损伤较小,对相邻建筑物影响较小,且人员无需进入积水隧道内施工,可控性、安全性较高,具有推广应用价值。

During a construction of a river bottom shield water taking tunnel for Changshu Power Generation Plant, a backfill ground freezing method was applied to form a temporary freezing sealing wall after a water inrush and sand burst accident occurred. Then the standing water in the tunnel was drained and a permanent sealing wall was build to provide a protection to the following safety and successful construction of the tunnel project. The practices showed that in comparison with the application of a concrete pouring in water method in the tunnel to build a temporary sealing wall, under the complicated geological condition, the application of the backfill ground freezing method to build the temporary sealing wall could effectively prevent a water inrush and sand burst accident occurred, would have a less damage to the tunnel structure, a less influence to the neighboring buildings and would have no person required to work in the tunnel with standing water. Thus the backfill ground freezing method could have a high control and high safety with a promotion and application value.