EFFECT OF LOADING RATE ON RESTORING FORCE CHARACTERISTIC OF RC PORTAL FRAME ANDFRAMED SHEAR WALL.

（负责人：小野先生，Esaki先生）根据实验结果得出以下结论。(1)不开孔和开孔剪力墙在高速荷载作用下的侧向承载能力大于低速荷载作用下的侧向承载能力。其增加系数与实测应变率计算的增加系数吻合较好。2)单调侧移荷载作用下无开口和有开口剪力墙的侧移承载力大于反向循环侧移荷载作用下的剪力墙。(3)开孔剪力墙在慢速率反循环荷载作用下的弯剪破坏和弯剪破坏串联转变为剪切破坏。4)将未开孔的剪力墙的弯剪破坏改为弯剪破坏模式。(负责人：A。通过1/3比例尺试件的横向荷载和正弦循环型倾覆力矩的几种幅值和频率组合试验，得到了RC门式刚架的恢复力特性。并利用建立的恢复力特性理想化模型，对7层单层试验型钢筋混凝土建筑的地震反应进行了数值计算，以反映试验结果的特殊性。计算结果表明，当建筑结构的刚度和强度随倾覆弯矩量的较大变化而波动时，将导致最大倾覆弯矩响应值减小。反之，波动会使层间位移的最大响应值增大。

(The person in charge : M. Ono, F. Esaki)The following conclusions reached at results of the experiments.1)The lateral load carrying capacity of shear walls without opening and with an opening subjected to the load at the high rate was lager than that at the slow rate. Its increased factor agreed well with the increased factor calculated by the observed strain rate. 2)The lateral load carrying capacity of shear walls without opening and with an opening subjected to monotonic lateral load was larger than that subjected to the reversed cyclic lateral load.3)The shear walls with an opening of the flexural failure and flexural-shear failure made series subjected to the reversed cyclic load at slow rate are changed to the shear failure made.4)The shear walls without opening of the flexural-shear failure made series are changed to the flexural failure mode.(The person of charge :A. Hiramatu)Restoring force characteristics of RC portal frames were obtained by the experimental tests on the specimens of 1/3 scale under both lateral loading and overturning moments of sinusoidal cyclic type having the several combinations of amplitudes and frequencies. And also earthquake responses of 7-story one bay pilot type RC buildings were calculated numerically using the idealized model of restoring force characteristics that had been constituted to represent peculiarity obseved on the experimental test results.The results from these calculaions indicate that the fluctuation of stiffness and strength of the building structures in response to a wide variation of the amount of overturning moment would cause the maximum response values of overturning moment to decrease. On the contrary, the fluctuation would cause the maximum response values of stoy drift to increase.