小半径曲线地铁隧道盾构施工技术

Shield Boring Technology for Metro Tunnels on Curves with Small Radius

针对上海市轨道交通9号线一期工程R413东西出入线的小半径盾构隧道施工的综合难题,采用数值模拟分析、文献调研等方法,对盾构机选择、管片选择、管片壁后注浆加固、临时纵向加强肋、加强螺栓复紧、盾构推进轴线预偏、盾构测量与姿态控制、盾构施工参数选择、土体损失及二次注浆、盾构纠偏量及盾尾与管片间的间隙控制等问题进行研究,并提出详细的施工和设计措施;进而对盾构进入缓和曲线后,盾构卡壳、盾尾管片外弧面碎裂、盾尾衬砌管片角部碎裂等施工难题给出解决措施,保障了小半径盾构隧道施工的顺利进行,对今后类似工程施工有一定的借鉴作用。

On basis of the problems met in shield boring of the small-radius curve section of the first stage R413 project on line 9 of Shanghai Metro, the author mainly studies on shield machine and segment selection, backfilling grouting behind the segments, temporary longitudinal strengthening rib, segment bolt re-tightening, offsetting of shield boring axis in advance, measurement and attitude control of shield machine, shield boring parameter selection, ground loss and secondary grouting, boring direction correcting, control of the gap between the segment and tail skin, by means of numerical simulation and literature research. Furthermore, the author provides some detailed measures on construction and design. The author also provides solutions for such problems as blocking of shield machine, break of extrados of segments under tail skin and edge breaking of segments under tail skin occurring after the shield machine reaches the transition curve. These measures ensure the successful and safe construction of small-radius shield-bored tunnel. This paper can provide references for similar projects in the future.