A Atudy of Mutual Reactions among the Super-structure and Sub-structure of the Steel Bridge and Its Foundation

桥梁的活动靴和伸缩缝对桥梁的造价、抗震性能和行车舒适性产生了不利影响。这个项目的主题是表明这些部分可以从钢桥上拆除。为了证明这一点，分析了完整的模型，其中不仅包括上层和下层，而且包括其基础。将桩身和地基表面辐射的波分解为若干因素，建立了各因素的等效模型，并对桩身和地基表面辐射的波进行了等效处理，得到了桩身和地基表面辐射波的等效模型。它们被适当地组合起来，以表达构成桥梁系统的各部分之间的相互作用。这些模型用弹簧、质量和阻尼器来表示，使系统的非线性现象得以分析。作为计算和实验的结果，能够显示以下项目。1.基础的基础可以等效为叉形模型。弹簧常数与基础的曲率长度成正比，阻尼器的衰减常数与基础的底面面积成正比.桩基础可替换为2或3个系列分叉模型，因为波的圆柱形扩散非常好。至于活动鞋，在严重地震时受伤的可靠性非常高。从结构中移除可移动或铰链鞋和伸缩缝，在某些情况下不是那么昂贵并且相当经济。这种类型的伤害的可靠性比其他类型的伤害低。

The movable shoes and expansion joints of the bridge give negative effects to its fabrication cost, earthquake resistance and comfortable driving. The main theme of this project is to show that these parts can be removed from the steel bridge. In order of prove this, analysis of the complete model which involves not only super and substructure but also its foundations. Modeling of the stiffeness of the foundation which is most difficult, was able to be exhibited in this project.The waves which are radiated from the pile and the surface of the foundation, were divided into several factors and the equivalent model to each factor was built. They were conbined suitably to express the mutual reactions among the portions constructing the bridge system. These models, expressing with the spring, mass and the dash-pot, enable the non-linear phnomena of the to be anlysed. As the result of calculations and experiments, the following items were able to be shown.1. The foundation of the footing can be replaced to the equivalent forked model. The spring constant is proportional to the cicruit length of the footing and the attenuation constant of the dash-pot is proprtional to the bottom area of the footing.2. The pile foundation can be replaced to 2 or 3 series forked models because the wave diffusing cylindrically, exells.3. As to the movable shoes, reliablity of injury is very high on occasion of a severe earthquake.4. The structure from which movable or hinge shoes and expansion joints are removed, is not so expensive and rather economical on some conditions. The reliablity of injury of this type is less than otherwise.