盾构始发端头垂直冷冻加固施工技术

Construction Technology of Vertical Freezing Reinforcement of Shield Launching End Wall

盾构始发与接收是盾构隧道施工的关键,为了保证盾构机进洞与始发施工安全,需要对盾构始发端头的土体加固。以苏通GIL综合管廊工程实例,研究了盾构始发施工垂直冷冻加固的冻结方案设计与施工技术要点,并探讨了施工应注意的事项。实测结果得到冻结壁交圈时间为22d,达到设计厚度时间为35d,冻结壁平均温度在-15℃以下,验证了冷冻加固法在盾构始发工程上的可行性。

Shield launching and receiving are the key points in process of shield tunnel construction.In order to ensure the shield launches safely,the soil around the tunnel shield-launching end must he reinforced.This paper took Sutong GIL comprehensive pipe corridor project as an example,studied the design of freezing plan and key technologies of shield launching construction,and the points for attention in construction were put forward.Test results show that the closure time of freezing wall is 22 days,reaching the designed thickness in the 35 days,and the average temperature of freezing curtain is below-15℃.The actual engineering practices prove the feasibility of freezing reinforcement method in the construction of shield launching.