高层钢筋混凝土核心筒的抗震性能试验研究

Experimental study on seismic behavior of high-rise reinforced concrete core tube

共设计了5组钢筋混凝土核心筒试件,研究了相同轴压比、低周反复加载作用下配筋率、高宽比和加载角度等因素对钢筋混凝土核心筒抗震性能的影响。结果表明,5组钢筋混凝土核心筒试件的裂缝都呈竖向弯曲状、萌生于腹板墙体中部的连梁角落处,滞回曲线和层间位移滞回曲线都呈现出捏拢特征;HXT-1、HXT-2、HXT-3和HXT-5试件呈现出弯曲破坏形态,而HXT-4试件主要以剪切破坏为主。5组钢筋混凝土核心筒试件的侧移曲线形状相似,楼层侧移随着楼层高度增加而逐渐增大,都呈现“弯剪型”变形特征,其中,HXT-5试件的整体侧移相较其它试件更大,这主要与试件的剪切变形较为充分有关。增大配筋率或减小连梁跨高比会一定程度提高极限承载力,但是延性会相对降低;增大高宽比会降低极限承载力,而延性相对更好;加载方向从0°转变为45°时,试件的极限承载力增大,且极限承载力对应的位移明显增加。跨高比对钢筋混凝土核心筒的影响最大,其次为连梁配筋率,而高宽比和加载角度对强度衰减影响较小,HXT-4试件的强度衰减最为显著。

Five groups of reinforced concrete core tube specimens are designed,and the effects of reinforcement ratio,height width ratio and loading angle on the seismic performance of reinforced concrete core tube under the same axial compression ratio and low cyclic loading are studied.The results show that,the cracks of five groups of reinforced concrete core tube specimens are vertical bending and sprout at the corner of the coupling beam in the middle of the web wall,and the hysteretic curve and interlayer displacement hysteretic curve show pinch characteristics;HXT-1,HXT-2,HXT-3 and HXT-5 specimens show bending failure,while HXT-4 specimen is mainly shear failure.The lateral displacement curves of five groups of reinforced concrete core tube specimens are similar,and the floor lateral displacement gradually increases with the increase of floor height,showing the deformation characteristics of"bending shear type".Among them,the overall lateral displacement of HXT-5 specimen is larger than that of other specimens,which is mainly related to the sufficient shear deformation of the specimen.Increasing the reinforcement ratio or decreasing the span height ratio of coupling beam will improve the ultimate bearing capacity to a certain extent,but the ductility will be relatively reduced;Increasing the aspect ratio will reduce the ultimate bearing capacity,and the ductility is relatively better;when the loading direction changes from 0°to 45°,the ultimate bearing capacity of the specimen increases,and the displacement corresponding to the ultimate bearing capacity increases significantly.The span height ratio has the greatest influence on the reinforced concrete core tube,followed by the reinforcement ratio of coupling beam,while the height width ratio and loading angle have little influence on the strength attenuation,and the strength attenuation of HXT-4 specimen is the most significant.