类矩形盾构法隧道施工关键技术探索

Key Techniques for the Quasi-Rectangular Shield Tunnelling

目前盾构法隧道均设计为圆形断面,但圆形盾构隧道存在断面空间利用率低的弱点。类矩形盾构法隧道在断面空间利用率上存在较大优势,同时在相同覆土情况下较圆形隧道更具有适用性。但类矩形盾构因其断面形状特殊,施工中可能面临诸如排土困难、开挖面失稳、轴线偏差、管片拼装困难等难题;另外,类矩形盾构施工环境保护也有相当的难度,由此衍生出了大量信息的使用和管理问题。本文通过分析类矩形盾构法隧道施工在推、拼、压以及环境影响和综合管控上的重难点,针对具体工程问题进行了研究和探索,论述了土体改良、轴线控制、同步注浆、管片拼装、综合管控和环境影响监测等相关技术方面的探索路径和初步成果,为进一步开展类矩形盾构法隧道的建设提供了更可靠的依据和建议。

Compared with the common shield tunnel which has a defect of low section availability due to its circular shape,the quasi-rectangular shield tunnel shows greater advantage on this aspect and is more suitable under the same overburden conditions.However,the special section shape also causes some problems during its construction,such as difficult soil extraction,unstable working face,axis deviation,difficulties in segment erection and environmental protection,as well as a large number of derivate problems on information utilization and management.In this paper,based on an analysis of the key and difficult points regarding the thrusting,erecting,grouting of the shield machine,environmental impact and comprehensive management and control,studies were carried out aiming at some specific projects,and some technical explorations and primary achievements concerning soil conditioning,axis control,synchronous grouting,segment erection,environment monitoring and comprehensive management and control were discussed emphatically as well.