Tunnelling in complex geological strata is a challenging task that can affect the performance of shield machines and result in unexpected hazards. Therefore, extensive knowledge of unfavourable environments and shield operational parameters is essential for ensuring successful and safe tunnelling. This study aims to analyse the geological and hydrological conditions of the Chunfeng Tunnel and present the key construction technologies of a large slurry shield machine when crossing complex strata. To this end, attempts were made to (i) discuss the geological and environmental challenges encountered during the tunnelling process and present some early interpretations based on the database information, (ii) analyse the factors affecting tunnel performance and simulate the ground surface settlement along the tunnel alignment and (iii) discuss the countermeasures under adverse ground conditions and propose future directions. The results revealed that tunnelling in fault zones with soft upper and hard lower strata led to severe wear of disc cutters and controlling the tunnelling parameters could provide a suitable method for adjusting the construction process. This study leveraged extensive experience gained during tunnelling using a large slurry shield machine, with special emphasis on mixed ground strata, by providing valuable insights and suggested responses for effective tunnelling strategies.

中文翻译：

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在密集城市中心使用大型泥浆盾构机掘进的地质挑战

在复杂地质地层中开挖隧道是一项具有挑战性的任务，可能会影响盾构机的性能并导致意想不到的危险。因此，对不利环境和盾构操作参数的广泛了解对于确保成功和安全的隧道掘进至关重要。本研究旨在分析春风隧道地质水文条件，提出大型泥浆盾构机穿越复杂地层的关键施工技术。为此，我们尝试（i）讨论隧道开挖过程中遇到的地质和环境挑战，并根据数据库信息提出一些早期解释，（ii）分析影响隧道性能的因素并模拟沿隧道的地表沉降。 (iii) 讨论不利地面条件下的对策并提出未来方向。研究结果表明，在上松下硬的断裂带中开挖，圆盘滚刀磨损严重，控制开挖参数可以为调整施工工艺提供合适的方法。这项研究利用了使用大型泥水盾构机进行隧道掘进期间获得的丰富经验，特别强调混合地层，为有效的隧道掘进策略提供了宝贵的见解和建议的应对措施。