浅埋暗挖法在大跨隧道中的应用探讨

On the Application of the Method of Undercutting with Shallow Overburden to Long-spanned Tunnels

针对北京地铁成府路车站工程地质和周边环境的实际情况,在原设计的基础上提出了设置大管棚、更改钢格栅施作方法以及采用二次衬砌施工支撑转换技术等相应的工程措施。监测结果显示:所采取的措施得当,有效地减小了隧道施工对地层的扰动,将地表沉降控制在规范规定的有效范围内。为软弱地层中采用浅埋暗挖法进行大跨度隧道施工提供了有益的借鉴。

With the specific geological conditions and surrounding environment of the Chengfulu Station of the Beijing Subway taken into consideration, suggested are a few corresponding engineering measures in the paper upon the basis of the original design, such as the provision of large-tube sheds and the change of the construction methods of the steel grids and the adoption of the support-changing techniques for the sec- ondary lining. The monitored results show that, with the technical measures adopted, the disturbed condi- tions of strata were effectively minimized and the surface subsidence values were found less than the per- missive values of the criterion specified in the specifications. The project may serve as a useful referrence for the construction of long-spanned tunnels to be built by the method of undercutting with shallow over- burden in the soft stratum.