水下超大直径盾构联络通道建设方案对比研究——以广州海珠湾隧道工程为例

Comparative Study on Construction Schemes for Connecting Channel of Underwater Super-Large Diameter Shield Tunnel:A Case Study on Haizhuwan Tunnel in Guangzhou,China

针对在越江海高水压水下超大直径盾构隧道联络通道施工过程中缺乏足够的工程技术标准和案例经验、设计与施工面临众多挑战问题,以广州海珠湾超大直径盾构隧道区间的6条联络通道工程为例,对工程地质补勘资料及现场施工情况进行分析,揭示原矿山法设计施工方案存在的不足,并基于此提出“矿山法结合地层冻结加固方案”和“机械顶管法施工方案”2种优化方案;随后在安全性、经济性、施工工期等方面对不同工法进行综合优选分析,同时引入碳排放指标进行绿色低碳评估。研究结果表明:1)机械顶管法在安全性和施工效率上优于其他方案,能够显著缩短施工周期;2)相比矿山法结合地层冻结加固方案,机械顶管法方案碳排放量减少了2 747.51 t CO_(2e)。

In the construction process of underwater and high water pressure large-diameter shield tunnel connecting channels,the design and construction face numerous challenges due to the lack of sufficient engineering technical standards and case experience.To address these issues,case study is conducted on six connecting channels of Haizhuwan large-diameter shield tunnel in Guangzhou,China,to explore a more applicable construction scheme.First,an in-depth analysis of the engineering geological supplementary investigation data and on-site construction conditions is conducted to reveal the deficiencies in the original mining method design and construction scheme.Then,two optimized schemes,mining method combined with ground freezing reinforcement scheme and mechanical pipe jacking construction scheme,are proposed.Thereafter,a comprehensive optimal selection analysis of different construction methods is performed in terms of safety, cost-effectiveness, and construction period, and carbon emission indicators are introduced for green and low-carbon assessment. The results show that the mechanical pipe jacking method is superior in safety and construction efficiency to other schemes, significantly shortening the construction period;and the carbon emissions are reduced by 2 747.51 tCO_(2e) compared to the mining method combined with ground freezing reinforcement scheme.