Abstract:

As an innovative presupporting method in tunnel construction, FreezeSealing Pipe Roof (FSPR) is applied to Gongbei Tunnel of Hong KongZhuhaiMacau Bridge. An effective freeze control system, which contains master freezing tubes, enhancing freezing tubes and limiting tubes, is established for building up the frozen curtain, maintaining its stability during excavation and controlling the volume of frozen soil to limit frost heave dynamically. Field test is carried out to confirm the real freezing effect. The results of test indicate that the FreezeSealing Pipe Roof can achieve good waterproof curtain in the actual tunnel construction condition. The mode of “hot control” can inhibit the growth of frozen soil wall around limiting tubes, while the “cold control” has influence on the whole frozen wall.

Key words: freezesealing pipe roof, field test, Hong KongZhuhaiMacau Bridge, freezing mode, controled freezing