分布式连接全装配RC楼盖建筑结构动力特性与地震响应分析

为研究采用分布式连接全装配RC楼盖(DCNPD)建筑结构的动力特性与地震响应规律,基于等效梁模型理论得到DCNPD的等效参数,进行了DCNPD结构在水平地震作用下的动力特性与地震响应分析。结果表明:DCNPD结构的周期大于现浇结构,高阶振型对结构的影响较大,需考虑更多的振型进行抗震分析;新型楼盖发生了明显的平面内变形,其变形在中部楼层表现较为明显;DCNPD结构水平剪力分配结果与规范采用的半刚性楼盖方法计算结果存在差异,采用规范半刚性楼盖取均值的方法将低估剪力墙分配的地震剪力;DCNPD结构楼层加速度相对于地面输入最大加速度得到不同程度的放大,与现浇结构存在较大的差异,表现为前者边榀抗侧力结构加速度小于后者,中榀抗侧力结构加速度大于后者。鉴于DCNPD结构动力特性与地震响应规律与现浇结构的显著差异,建议采用考虑楼盖实际刚度的串并联多质点系空间结构振动模型,进行结构的抗震分析与设计。

Analysis of dynamic characteristic and seismic response for discrete connected new-type precast RC diaphragm structure

For analyzing the dynamic characteristic and seismic response rule for discrete connected new-type precast RC floor diaphragm( DCNPD),the equivalent parameters of DCNPD structure are obtained based on the theory of equivalent beam model,the dynamic characteristic and seismic response analysis of DCNPD structure under horizontal seismic action are conducted. The results show that: the period of DCNPD structure is longer than the cast-in-place structure,and the influence of higher modes on the structure increases,so more vibration modes need to be considered for seismic analysis;an obvious in-plane deformation of the new floor occurres,and its deformation is most obvious in the middle floor;the results of the horizontal shear force distribution of the DCNPD structure are different from the results calculated by the semi-rigid floor method used by the specification,showing that the method of using the normative semi-rigid floor to take the mean value will underestimate the seismic shear force by the shear wall distributed,which has potential safety hazards;the acceleration of floor of the DCNPD structure is magnified to different degrees with respect to the ground input maximum acceleration,and there is a big difference with the cast-in-place structure,which shows that the acceleration of the side anti-lateral structure of the former is smaller than the latter,and the middle is greater than the latter. In view of the significant difference of dynamic characteristics,seismic response rules between cast-in-place structures and DCNPD structure,it is suggested to adopt the series-parallel multi-mass point space structure vibration model considering the actual stiffness of the floor for seismic analysis and design of the structure.