过海隧道在我国发展迅速,拟建的琼州海峡通道、渤海海峡通道等跨海通道将面临超长距离、超高水压隧道掘进安全等技术难题的重大突破。根据目前的研究和实践,盾构隧道掘进水压在0. 8 MPa 左右,一次掘进距离在8 km 以内。为解决高水压条件下过海盾构隧道安全掘进和运营期间安全服役的难题,以琼州海峡中线盾构隧道(水压1. 2 MPa、掘进长度12 km)为工程背景,采用工程类比、施工阶段关键技术分析的方法,对高水压长距离过海盾构隧道关键技术可行性进行分析,提出盾构主动换刀+被动饱和潜水带压换刀+非常状态冻结加固脱困的综合换刀技术以及可更换密封综合技术,可保障盾构超长距离掘进; 提出超高水压盾构复合式管片衬砌和内外结合的多道防水结构,可保障超高水压条件下盾构管片结构的安全服役。

The sea-crossing tunnels are developing rapidly in China. The proposed Qiongzhou Strait Passage and Bohai Strait Passage will face technical difficulties such as ultra-long distance and ultra-high water pressure tunneling. In the current research and practice, the water pressure of shield tunneling is about 0. 8 MPa, and the distance of one tunneling is within 8 km. Based on the engineering background of the Qiongzhou Strait Middle Line Shield Tunnel (water pressure of 1. 2 MPa, tunneling length of 12 km), the engineering analogy and construction key technologies are used to analyze the feasibility of high-pressure long-distance shield tunneling technology to solve the problem of safe tunneling and safe service during the operation of the shield tunnel under high water pressure. The following technologies, i. e. shield active tool change, passive saturation diving belt pressure tool change, integrated tool change technology for freezing and strengthening in extraordinary state and the comprehensive technology of replaceable seal,are put forward, which can guarantee the shield tunneling for long distance. Meanwhile, an ultra-high water pressure shield composite segment lining and a combination of internal and external waterproof structures are proposed to ensure the safe operation of the shield segment structure under ultra-high water pressure.