縮小６層RC造耐震壁付きフレーム建物試験体の振動台実験における崩壊挙動: RC造建物の崩壊余裕度定量化のための研究開発: Research and development for quantification of collapse margin of RC buildings

1. IntroductionThis paper describes shaking table tests of an RC building. The shaking table tests were conducted in E-Defense, through a special project to quantify collapse margin of buildings that are commonly seen in urban areas in Japan.2. Outline of the Shaking TestThe test specimen was a 30% scale model of a 6-story RC building designed according to the current Building Standard Law in Japan. The test specimen consisted of two moment-resisting frames in the longitudinal direction, and four frames with multi-story shear walls in the transverse direction. The two interior frames had shear walls and the others had nonstructural walls with openings from the second to the sixth stories.3. Outline of the Test ResultsAt the shakings in the tests, shear failure of walls at the first and second stories occurred, flexural hinges were formed at both top and bottom of the columns at the first story, and the building specimen collapsed finally with collision between balconies of its third and fourth stories and steel frame for safety.4. Details of the Test Results and Collapse ProcessRigid floor assumption didn't seem to be satisfied because shear deformation angle of slab between X1 and X2 frames became larger after the maximum shear capacity observed as shown in Figure 11.5. Relation of Input Wave and CollapseAfter the maximum response shear capacity, by the same input motion, the response of the second input increased than that of the first input as shown in Figure 13. It was indicated that, the response by the same earthquake at least twice should be considered to evaluate collapse margin.6. ConclusionShaking table tests of 30% scale 6 story RC building were conducted. The findings of this study are as follows:1) 1st and 2nd story walls were failed in shear manner, especially shear sliding failure was dominant. And load carrying capacities of 1st and 2nd story seemed to be observed during the tests.2) In the columns at 1st story, top and bottom hinges were formed, and these columns kept their capacities to carry vertical load through the tests, because of their high ductility. Though flexural failure at the member end of 2nd floor girder occurred with buckling of main bars, shear failure didn't occur.3) X2 frame, which consisted of continuous walls from 2nd to 6th stories with 2 columns at 1st story, had lower stiffness at the 1st story. The shear deformation angle of slab between X1 and X2 frame increased after the maximum response, case #3-5. It was indica