大跨径覆土波纹钢圆管涵稳定性分析

覆土波纹钢圆管涵随跨径增大,在施工过程中,波纹管涵环向受压的土-结相互作用还未形成,可能会出现失稳情况.依据某6m管涵实体工程建立了有限元模型,计算其施工过程中的变形规律,并与实测值对比,验证了有限元模型的正确性.对比分析了不同跨径管涵屈曲荷载,选择8m跨度的圆管涵,通过有限元模型分别模拟了基底和回填土层、管涵以上大型施工机械作用对结构屈曲荷载的影响.结果表明:在基底和回填土层填料、压实度不符合要求,以及填土高度小于最小覆土厚度的情况下,在管涵上方施工机械作用,都会使结构稳定性能大大降低.可通过增加横向、斜向拉筋和底部支撑等方式来增加结构稳定性,其中增加底部支撑的效果最为显著.

Stability analysis on long-span buried corrugated-steel-plate pipe culverts

With the span’s increase of corrugated-steel-plate pipe culvert,it may lose stability be-fore the soil-structure interaction forms during construction stage.According to the 6 m-span pipe culvert engineering,this paper establishes finite element (FE)models and calculates the de-formed regularities.The validity is verified by comparing finite element model (FEM)results and measured value.An 8m-span pipe culvert is chosen as the FEM after comparing different bulking loads with different culverts’spans.The influence to structure’s bulking load can be simulated under basement,backfilling layer and large machinery on the crown separately.Results show that the stability of the structure largely decreased under inconformable requirements such as base-ment and backfilling conditions.Neither does large machinery on the top of the culvert during construction,when backfilling height is less than the minimum thickness of backfill.Structure’s stability can be enhanced by adding transverse(or declining)tension bar or adding bottom sup-port.The effects on enhancing stability are most significant when adding bottom support.