在富水粉砂地层中盾构到达段施工技术

通过苏州轨道交通1号线土建I-TS-05标塔园路站～滨河路站区间隧道盾构施工,介绍在苏州富水粉砂地层中盾构综合施工技术。施工中,克服了富水砂层下盾构到达加固区水平长度不足的困难,使用了在加固区外再施工一圈止水帷幕桩的地基加固技术,该技术可以使三轴加固土体与止水帷幕桩组合形成一个范围更大的端头地基加固区域,并在盾构到达段掘进中合理使用管片壁后二次注浆和聚氨酯,成功地阻断微承压水在盾构到达时涌出的路径,从而解决了富水砂层下盾构到达施工的涌水、涌砂问题。通过使用,该技术保证了2台盾构安全成功接收,在富水粉砂地层具有适用性广、安全可控等优点。

Construction Technology in Shield-approaching Area in Water-rich Silt Strata

Shield construction is adopted for the tunnel of civil construction contract I-TS-05 of suzhou rail transit line 1 between tower park road station and riverfront road station.This paper introduces the comprehensive construction technology in the water-rich silt stratum in Suzhou to overcome the problem that the shield can＇t sufficiently reach the reinforced area under water-rich silt by constructing a lap of water-stopping curtain pile outside the reinforced area to strengthen the foundation.The technology allows tri-axially reinforced soil and water-stopping curtain pile combined to form a broader reinforced area at the end of the foundation,and adopts rational use of secondary grouting and polyurethane lining in the region of shield tunneling,successfully blocking the emission path of the micro-pressure water as the shield approaches so as to solve the problem of water and silt gushing as the shield reaches the watery silt area.Through the use of the technology,the two tunneling shields are safely and successfully received.This technology has the advantages of wide applicability as well as good safety and controllability in water-rich silt strata.