Studies on Seismic Design of Concrete Structures

首席研究员提出了混凝土结构抗震设计的概念，即混凝土结构不仅要在地震中安全，而且要在地震后能够使用。这一概念被日本土木工程师协会（JSCE）的混凝土标准规范所采用。本研究旨在确认概念的适当性，并发展设计方法。考虑到拟动力加载试验是研究钢筋混凝土柱非弹性性能的最有效工具，首次成功研制了一种个人计算机与执行器相结合的加载系统。利用该系统对钢筋混凝土柱试件和钢筋混凝土刚架试件进行了研究，获得了实际地震作用下的非弹性响应特性。并将计算结果与计算机程序计算的解析值进行了比较。两个值显示出令人满意的吻合。静态反向循环加载试验阐明了JSCE规范中规定的混凝土结构损伤等级分类的适当性。伪动力试验证实了每个损伤等级的设计值的适当性。对钢筋混凝土沉管隧道的抗震性能和设计进行了研究，发现隧道构件的柔性节点能够有效地抵抗地震运动。

The head investigator proposed a concept of seismic design of concrete structures in which concrete structures should be designed not only to be safe during earthquakes but also to fulfill serviceability after the earthquakes. This concept was adopted in the Standard Specification of Concrete of the Japan Society of Civil Engineers (JSCE). This study intends to confirm the appropriateness of the concept and to develop the design method.Since pseudo-dynamic loading test was the most useful tool to investigate inelastic behavior of reinforced concrete columns, a loading system using personal computer combined with actuator was developed successfully at first. By using this system, reinforced concrete column specimens and reinforced concrete rigid frame specimens were studied to obtain inelastic response characteristics under actual earthquake motions. The results were compared with the analytical values which were calculated by means of the originated computer program. Satisfactory coincidence was shown in both values.Static reversal cyclic loading tests clarified the appropriateness of the classification of the level of damage in concrete structures specified in the specification of JSCE. Pseudo-dynamic test confirmed the appropriateness of the design values specified for each damage level.Studies on seismic behavior and design of immersed reinforced concrete tunnels were carried out and flexible joints of tunnel elemants were found to be effective against earthquake motions.