No. 12. Concrete Structures in Seismic Regions - 4th fib Symposium Proceedings - 6-8 May 2003 - Athens, Greece PDF format

As compared with rigid frames, the horizontal stiffness and lateral laad carryi ng capacity of R/C framed shear walls ( hereafter, referred to as "shear wall" ) are large. For this reason, the shear walls in R/C structures are important structural elements for the lateral laad such as earthquake laad. The shear behavior of R/C structural members generally has been estimated by the results of statie loading test at a comparatively slow speed. However, it is guessed that the shear behavior of R/C structural members estimated by the statie loading tests is different from that of high speed loading tests, because R/C structures are continuously subjected to reversed cyclic laad at various high speed during severe earth­quake and are deformed with high strain rate. Therefore, the effects of the loading rate on cracking pattern, failure mode, lateral load-displacement hysteresis response and lateral laad carrying capacity of shear walls have been investigated. Up to naw in Japan, a large member of the experimental studies have been conducted on materials such as concrete and reinforcement steel bars and on rad members such as beams and columns under high speed loading. However, the experimental data on plate mem­bers such as shear walls have been scarce. Only studies on the walls in reactor buildings and about 1/3 and 1/4 scale model shear walls carried out by authors have been reported. The object of this study is to make clear the effects of the loading rate on the cracking pattern, lateral load-displacement hysteresis response and lateral laad carrying capacity of the shear walls and to ascertain the conformity of the authors' strength reduction factor of the shear wall with an opening.