关键词: 单护盾TBM, 刀盘, 盾体, 优化改造, 软岩地层

Abstract: In the first stage construction of Taohe River Water Diversion Project in Gansu Province, the surrounding rock of No.7 tunnel mainly consists of Ⅴ class soft ~very soft rock of tertiary system, and the first single shield TBM in China was used to excavate the tunnel. According to the surrounding rock characteristics, equipment operation condition and function defects, the shield cutter head as well as the shield body were comprehensively optimized. Moreover, 3D finite element method was used to analyze the mechanical characteristics of the shield structure. The construction practice indicated that optimal reformation improved the construction efficiency and security. After optimization, the average excavation progress reached 1094.0m per month, creating a new record of the excavation by single shield TBM in water-contained loose fine sandy layer and the extremely soft rock layer.

Key words: single shield TBM, cutter head, shield body, optimization modification, soft rock layer