明挖隧道对下伏管线安全性影响及保护措施研究

Study on the Influence of Open-cut Tunnel on the Safety of the Underlying Pipeline and Protective Measures

地铁明挖隧道的施工及运营对临近地下管线存在显著影响,文章以地铁明挖隧道近接地下管线为工程背景,构建三维数值分析模型,采用数值模拟的手段完成了明挖隧道施作对既有地下给水管和污水管的安全性影响分析,并就相应的保护措施的效果展开研究。结果表明:两根管线的最大主拉、压应力及最大沉降均发生在管线与明挖隧道相交处,其受影响的范围大约在30m左右;未施作保护措施条件下,两根管线的最大主拉应力均超过许用应力,极易发生拉破坏;对管线提出施加保护结构、砂卵石换填和施作保护结构并进行砂卵石换填三种保护措施,三种措施下两根管线的最大累计沉降均小于规范控制要求,施加防护结构并换填和仅砂卵石换填条件下,两根管线的最大主拉应力均小于许用应力,防护效果较理想。相关研究结果可为类似工程的设计与施工提供技术支持。

The construction and operation of the subway open cut tunnel have a significant impact on the adjacent underground pipeline. Taking the subway open cut tunnel close to the underground pipeline as the engineering background, this paper constructs a three-dimensional numerical analysis model, uses the numerical simulation method to complete the analysis of the impact of the construction of the open cut tunnel on the safety of the existing underground water supply pipe and sewage pipe, and studies the effect of the corresponding protective measures. The results show that the maximum principal tensile stress, compressive stress and maximum settlement of the two pipelines occur at the intersection of the pipeline and the open cut tunnel, and the affected range is about 30m.Without protective measures, the maximum principal tensile stress of the two pipelines exceeds the allowable stress, which is easy to cause tensile damage. Three protective measures are proposed for the pipeline: applying protective structure, replacing sand and gravel, and applying protective structure and replacing sand and gravel. Under the three measures, the maximum cumulative settlement of the two pipelines is less than the control requirements of the specification. Under the conditions of applying protective structure and replacing sand and gravel only, the maximum principal tensile stress of the two pipelines is less than the allowable stress, and the protective effect is ideal.The relevant research results can provide technical support for the design and construction of similar projects.