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

桥梁的活动鞋和伸缩缝对桥梁的造价、抗震性和行驶舒适性产生不利影响。这个项目的主题是表明这些部件可以从钢桥上移除。为了证明这一点，对整个模型进行了分析，该模型不仅包括上部结构和下部结构，还包括其基础。在这个项目中，最困难的基础刚度建模得以展示。将桩基和地基表面的辐射波划分为若干因子，并建立了各因子的等效模型。将它们适当地组合在一起，以表示构成桥梁体系的各部分之间的相互作用。这些模型分别用弹簧、质量和仪表盘来表示，使分析系统的非线性现象成为可能。作为计算和实验的结果，可以显示如下项目：基础的基础可以替换为等效的分叉模型。弹簧常数与基础的回路长度成正比，减震罐的衰减常数与基础的底部面积成正比。2、由于波浪的圆柱扩散，可将桩基础替换为2系或3系叉型桩基。至于活动鞋，在严重地震的情况下，损伤的可靠性非常高。在某些情况下，从可移动或铰链鞋和伸缩关节中移除的结构并不那么昂贵，而且相当经济。这种伤害的可靠性比其他伤害要低。

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.