盾构隧道刀具更换技术综述

盾构穿越复杂水文地质地层时，常因刀盘刀具过量磨损而导致盾构被迫停机，这已成为困扰盾构施工的重要难题之一，进行刀具更换是目前解决这一难题，恢复盾构掘进的主要方法。然而，工程界尚未形成系统的盾构换刀技术体系。针对这一问题，在对已有技术研究理解和总结的基础上，阐述了盾构刀具更换技术的内涵和主要分类，并结合典型盾构工程换刀作业实例和笔者所在课题组的研究成果，对加固地层-常压换刀、基于常压可更换刀盘设计的换刀、带压换刀等3种主要换刀技术的原理、技术流程、关键技术、适用范围和优缺点等进行系统的分析和总结。最后介绍了日本最新的刀具更换技术，并对中国盾构隧道刀具更换技术进行了展望。结果表明：地层加固-常压换刀技术和带压换刀技术都是在常规刀盘设计条件下形成的，其关键都是保障开挖面地层的稳定性；差别在于，前者是使加固开挖面地层达到自稳后，在常压条件下实施的，而后者则是通过泥浆渗透成膜等辅助工艺提高开挖面地层的闭气性后，在气压支护条件下实施的；对于基于常压可更换刀盘设计的换刀技术来说，开挖面地层的稳定性不需要重点考虑，盾构机特殊的中空刀盘辐臂和常压可更换刀具设计才是该技术的关键。

Technical Review of Cutter Replacement in Shield Tunneling

Shield tunneling machines are often used in complex hydrogeological environments and have to be frequently shut down owing to excessive wear of the cutters. This has become one of the important problems affecting construction during tunneling operations. Cutter replacement is the primary method of solving this problem and restoring tunnel shields. However, a scientific system of cutter replacement has not yet been formulated for the engineering field. On the basis of understanding and summarizing existing research, a technique and classification of shield cutter replacement were expounded. Three main techniques of cutter replacement, namely exchanging cutters under normal pressure after formation reinforcement, exchanging cutters based on the design of permanent pressure replaceable cutter, and exchanging cutters under pressure, were utilized frequently in construction sites. The principles, processes, key technologies, applications, advantages, and disadvantages were analyzed and summarized based on typical cutter replacement operations and research results of the project. Moreover, the latest cutter replacement techniques used in Japan were introduced, and the cutting tool replacements for shield tunneling in China were evaluated. The results show that, the cutter replacement techniques under normal pressure after formation reinforcement and under pressure were formulated for conventional cutterhead design, and the key requirements were to ensure the stability of the excavation face. The differences between these were that, the former was performed under normal pressure after stabilizing the excavation face to achieve self-stability, whereas the latter was conducted under the condition of air pressure support using the auxiliary technology of slurry infiltration and filter cake formation to improve the air-tightness of the excavation face. The stability of the excavation face was not considered for the cutter replacement owing to the design of the permanent pressure replaceable cutterhead. The significance of this technique is the special design of the hollow cutter arm and the permanent pressure replaceable cutter for the shield machine.