硬岩地层大直径泥水盾构隧道管片上浮偏移控制技术

Segments Floating and Offset Control Technology for Large-Diameter Slurry Shield Tunnels in Hard Rock Strata

针对大直径泥水盾构在硬岩地层掘进中管片易上浮和偏移(曲线段)的问题,结合前人研究成果,对地下水量、同步注浆填充效果及管片位移变化趋势等进行了分析,认为引起管片上浮偏移的主要原因是泥浆后窜稀释同步注浆浆液,使管片处于“游离”浮动状态,在曲线段盾构调向过程中产生的侧向力会使管片左右偏移。研究制定了向盾壳外注入止水材料封堵建筑空隙的措施,通过对比盾尾油脂、克泥效浆液、快凝泥浆(盾壳泥)注入试验,以及对掘进过程中同步注浆压力的持续监控、管片开孔检查注浆质量、持续测量管片姿态变化,验证了该措施控制管片上浮偏移的有效性,且注盾壳泥更加经济、可靠。

In view of the problem that large diameter slurry shield tunneling is easy to float and offset segments(curved section)in hard rock strata,the article makes a study on the groundwater volume,synchronous grouting filling effect,and the change trend of segment displacement based on the analysis of previous research results,and concludes that the main reason for the segment floating and offset is that the slurry flows backward to dilute synchronous grouting slurry,so that the segment is in a“free”floating state,the lateral force generated during the direction adjustment of curved segment shield will make the segment offset from left to right.The measures of injecting water stop materials outside the shield shell to seal the building gap have been researched and developed.By comparing the injection tests of shield tail grease,mud control slurry and quick setting mud(shield shell mud),as well as the continuous monitoring of synchronous grouting pressure during the excavation process,the opening of segments to check the grouting quality,and the continuous measurement of segment attitude changes,the effectiveness of this measure to control the segment floating and offset has been verified,and the shield shell mud injection is more economical and reliable.