复合地层大口径顶管管道结构内力影响因素分析

Analysis of Influencing Factors of Internal Force of Large Diameter Pipe Jacking Structure in Composite Stratum

现有顶管管道结构的设计均采用平面应变模型,且假定管周为均质地基土,通过选取典型地质条件进行管道结构的内力计算和配筋,一旦工程设计所选择的岩土物理力学参数与实际出入较大,就可能带来工程质量问题。基于某复合地层中的大口径顶管工程,分别采用荷载结构法和地层结构法,分析管侧不同地质条件下的管节内力变化规律,结果显示:在竖向荷载一定时,管侧土的物理力学参数越好、地下水位越低,计算得到的管道内力越大;当管顶上覆回填土时,地层损失率越大,管道结构的内力就越大,施工时应严格控制地层损失率,以保障管道结构安全。

The design of pipeline structures with top pipes adopts a plane strain model and assumes that the pipe circumference is a homogeneous foundation soil.By selecting typical geological conditions for internal force calculation and reinforcement of the pipeline structure,once the physical and mechanical parameters of the rock and soil set in the engineering design do not match the actual situation,engineering quality problems can be caused.Based on a large-diameter pipe jacking project in a composite formation,the load structure method and the formation structure method were used to analyze the internal force variation of the pipe joint under different geological conditions on the pipe side wall.The results showed that when the vertical load was constant,the better the physical and mechanical parameters of the pipe side soil,and the lower the groundwater level,the greater the calculated internal force of the pipeline.When the top of the channel is covered with backfill soil,the greater the formation loss rate,the greater the inner strength of the pipeline structure.During construction,the formation loss rate should be strictly controlled to ensure the safety of the pipeline structure.