大跨径无缝准连续梁桥RPC钢管混凝土灌注桩参数优化分析

Optimization analysis of RPC steel concrete cast-in-place pile body parameters of large span seamless quasi-continuous beam bridge

为了解决无缝桥梁桩基存在易腐蚀、打桩难等问题,以某无缝准连续T梁大桥为研究背景,通过有限元分析建立了大桥整体模型以及二维弹簧框架简化模型,开展了桩基受力性能有限元分析.将各层地基土的水平抗力比例系数m值换算成一个等效的m值,针对桥台RPC混凝土(活性粉末混凝土)灌注桩桩身正截面受荷载作用效应的压应力、拉应力进行了对比分析.结果表明,m值、桩径对桥台RPC钢管混凝土灌注桩桩身正截面受力特性影响显著,桩身截面入土深度为2.4D~5.5D时产生的拉应力与压应力值最大.

In order to solve the problem of easy corrosion and difficult piling of the pile foundation of seamless beam bridge,taking a seamless quasi-continuous T-beam bridge as the research background,the overall model of the bridge and the simplified model of two-dimensional spring frame were established through finite element,and the finite element analysis of the mechanical performances of pile foundation was carried out.The horizontal resistance proportional coefficient m of each layer of foundation soil was converted into an equivalent m value,and the compressive stress and tensile stress of the normal section of the abutment RPC concrete(reactive powder concrete)cast-in-place piles under loading condition were compared and analyzed.The results show that m value and pile diameter have significant effects on the mechanical characteristics of the normal section of the abutment RPC concrete cast-in-place piles,and the tensile stress and compressive stress are the largest when the depth of pile section under the soil is 2.4 D to 5.5 D.