Study on Reinforced Concrete Members with Damage Mitigation System

本课题通过对梁柱进行结构试验，研制出除梁柱结合面出现裂缝外，能减轻地震破坏的铰链隔震钢筋混凝土结构，并具有较高的吸能能力。为获得目标结果，在梁端铰区对纵梁钢筋进行不粘结，在不粘结区布置附加的抗弯钢筋，形成抗弯应力和纯应力的抵抗机制。2005财政年度进行了以钢筋布置和混凝土强度为参数的结构试验。结果表明，所开发的结构达到了目标性能。在此过程中，通过对试验结果的调查，考察了其基本结构特性，并提出了普通钢筋混凝土结构难以解决的梁端开口的加固方法。在2006财年进行验证性试验，获得了剪力的设计适用范围、主筋的非粘结区长度、开口的位置和开口之间的距离，这些都是完成该结构方法设计指南所需要的。为此，研究了具有本研究目标抗震能力的梁的结构方法和恢复力特性的性能评价方法。在此基础上，本课题完成了钢筋混凝土铰隔震梁减损体系的设计指南，包括适用范围、配筋细节和性能评价方法。

In this research project, the structural experiments of beams were conducted in order to develop the Hinge Isolated Reinforced Concrete Structures which can mitigate the seismic damage except for cracks on the boundary surface between beam and columns, and realize the higher energy absorption capacity. To obtain the targeted results, the longitudinal beam reinforcement in the hinge area at beam ends was un-bonded, and the additional flexural reinforcement which formed resistant mechanism against flexural and sheer stress was arranged in un-bonded area.In fiscal 2005, the structural experiments which set a bar arrangement and concrete strength as parameters were conducted. As a result, it was confirmed that the developed structure achieved the targeted performance. In the process, the fundamental structural characteristics were examined through the investigation of test results, and the strengthening method of the openings at beam ends was also developed, which is difficult for ordinary reinforced concrete structures.In fiscal 2006, confirmatory experiments were conducted in order to obtain the design scope of application of shear stress, the length of un-bonded area of main bars, the position of openings and the distance between openings, which were needed for the completion of the design guideline of this structural method. As a result, the structural method of beams with the targeted seismic capacity of this research and the performance evaluation method for restoring force characteristics were examined.Baced on the above results, the research project accomplished the design guideline for the Hinge Isolated Reinforced Concrete Beams with damage mitigation system, which consisted of the scope of application, bar arrangement details and performance evaluation method.