WSS注浆技术在大连地铁区间隧道下穿凌水河施工中的应用

Application on WSS Grouting Technology While Tunnel Passing Through the Lingshui River of Dalian Subway

大连地铁1号线区间隧道学苑广场站—海事大学站下穿既有凌水河,穿越淤泥质粉质黏土层、富水卵石层,且拱顶存在直径1200mm的自来水管及500mm煤气管线,工程难度大,安全风险高。为顺利施工,釆取二重管无收缩WSS注浆工法加固下穿河道周围土体,从钻孔参数设计、工艺流程、工艺要求、浆液配置、施工要点等方面对加固过程进行了详细阐述。同时,从监控量测的角度给出了加固期间监测项目、监测频率及预警指标等监控量测措施和质量保证措施,提出了一套适用于试验室和现场注浆质量检测的工艺标准。结果显示,采用二重管洞内全(半)断面注浆,注浆范围沿隧道两侧外扩3m,隧道顶部外扩5m,梅花形布孔,布孔间距1.5m×1.5m,压力范围0.15-0.75MPa,保证了周围建筑、既有管线的安全,可为WSS工法在类似环境中地铁施工提供参考经验。

Considering the geological and construction difficulties, such as silty clay, water-rich pebble layer, as well as c1 200 mm water pipes and c500 mm gas tubes existed on the top of tunnel, the author presented the option of duplex pipe grouting to strengthen soil mass for the metro tunnel passing through the Lingshui River between the section of Xueyuan Square Station and Maritime University Station in Dalian Line 1. Technical aspects such as drilling parameter designing, technological process, engineering techniques, injected parameter and grouting construction points were specifically introduced that could ensure the safety of around buildings and existed pipes on the top of the tunnel. Meanwhile, the author focused on the monitoring measures such as monitoring items, frequencies and warning indicators, and a set of quality test standard applied for both experiment and construction site was introduced. Results indicated that the duplex pipe grouting technique was used on full ( half) section faces, and grouting range was 3 m outward along both sides of the tunnel, 5 m outward at the top of the tunnel with quincunx layout, 1.5 m×1.5 m hole spacing, and pressure range of 0. 15 ~0. 75 MPa was feasible. It ensured the safety of the surrounding buildings and existed tubes, and could provide reference for the application of WSS construction method in metro construction under similar environment.