敞开式TBM在软弱围岩中掘进反力保障措施

Safeguard Measures of Boring Force of Open-type TBM in Weak Surrounding Rock

敞开式TBM掘进时推力和扭矩均通过撑紧洞壁的撑靴抵消,在软弱围岩条件下,经常会出现撑靴打滑、无法撑紧洞壁等现象,不能为TBM掘进提供可靠的反力,严重影响TBM掘进效率及成洞质量。结合工程实践,系统研究敞开式TBM在软弱围岩地质条件下掘进反力保障技术,确保撑靴撑紧洞壁时具有合理的接地比压,开发了局部沙袋填充、整体沙袋支垫、枕木支垫、喷射混凝土回填、现浇混凝土回填、注浆加固等措施,具有良好的应用效果。

When the open-type TBM is boring, the thrust and torque will be counteracted by the grippers which hold tight the wall. Frequently, the grippers are unable to hold tight the wall due to slipping, which can＇ t supply enough reaction force for TBM boring, it seriously affects the efficiency of TBM construction and the quality of tunnelling in weak surrounding rocks. Combined with the engineering practice, the paper systematically studied the boring force protection technology of open-type TBM in weak surrounding rocks, the ground pressure was ensured reasonably when the grippers were holding tight the wall. A series of technical measures were developed, such as local sandbags filling, overall sandbags supporting, sleepers supporting, backfilling of shotcrete and on-site concrete, and grouting reinforcement. The above measures have achieved good application results.