刚性梁柔性拱组合桥型在山区高速公路设计中的应用

山区桥梁常常需要较大跨径的连续刚构桥来跨越山谷深沟,虽然中国最大跨径已达301 m,但运营后暴露的问题不少,由于各种原因主跨跨中产生了不同程度的下挠以及腹板裂缝,给桥梁的运营安全及国家的财产带来了很大影响和损失。近几十年来国外发展的刚性梁柔性拱组合桥型,其独特的结构形式对克服主跨下挠变形有显著的预防作用,笔者以贵州省赤水至望谟高速公路仁怀至赤水段桐梓河特大桥为例,对刚性梁柔性拱组合桥型的应用进行介绍。

多种桥型组合在新324国道提升改造工程中的应用

结合新324国道提升改造工程实例,介绍了复杂地形及场地受限情况下多种桥型组合设置的工程经验。在项目前期通过因地制宜地选择桥梁结构形式,达到了优化设计方案、降低工程造价、减小施工难度、缩短工期、提高结构安全系数的目的,对同类型桥梁建设具备重要的参考价值。

大跨径斜拉拱桥结构受力的敏感性分析

斜拉拱桥充分发挥了斜拉桥与拱桥的优点，造型新颖美观，别具一格，影响结构受力因素较多。通过对湘潭市湘江四大桥主桥（120＋400＋120）m斜拉钢管混凝土飞燕式拱桥进行结构受力的敏感性分析，提出了大跨径斜拉拱组合桥结构受力敏感性分析思路与方法，以供同类桥型设计参考。

Optimizing selection of bridge raft based on fuzzy matter-element model and combination weighting

It＇ s a necessary selection to support the maneuver across Yangtze River by floating bridge constructed by portable steel bridge and civilian ships. It is a comprehensive index for the scheme of bridge raft, containing a variety of technical factors and uncertainties. The optimization is the selection in the constructing time, quantity of equipments and man power. Based on the calculation result of bridge rafts, an evaluating system is established, consisting of index of spacing between interior bays, raft length, truss numbers, operation difficulty and maximal bending stress. A fuzzy matter element model of optimizing selection of bridge rafts was built up by combining quantitative analysis with qualitative analysis. The method of combination weighting was used to calculate the value of weights index to reduce the subjective randomness. The sequence of schemes and the optimization resuh were gained finally based on euclid approach degree. The application result shows that it is simple and practical.