桁架式拱桥钢管拱肋混凝土灌注施工受力分析

摘要

Mechanical characteristics of ribs in truss type concrete-filled-steel-tube (CFST) arch bridges are analyzed during concrete pouring in tubes and stiffer plates. Simplified calculation method and spatial finite element method are both applied to analyze stress distribution in ribs during the process of concrete pouring, and precision of simplified method is evaluated on the basis of results comparison. Results show that the requirements of structural stress are well met during the process of concrete pouring in tubes, while both lateral central positions of stiffcr plates and interfaces between tubes and stiffer plates always exist high level structural stress during the process of concrete pouring in stiffer plates. Some section steels are suggested to strengthen stiffer plates in ribs. The calculation results indicate that simplified calculation methods proposed in this paper have a high precision for determination of pumping pressures during concrete pouring construction.%对钢管混凝土桁架式拱桥中钢管及缀板腔内混凝土灌注时拱肋的受力特性进行了分析.分别采用了平面简化计算方法及空间有限元法对拱肋混凝土灌注过程中的应力进行研究,并在对比两种方法计算结果的基础上对简化方法的精度进行了评价.研究表明:在钢管内混凝土灌注时一般可满足受力要求；而在缀板腔内混凝土灌注过程中,钢管与缀板交界处以及缀板横向中心位置始终存在较大的应力,建议对缀板腔进行型钢加劲.同时,本文提出的简化计算方法具有较高的精度,可用于指导此类桥梁拱肋混凝土灌注时泵送压力允许范围的确定.