实测高层建筑抗震分析中填充墙刚度的影响

对高层建筑结构进行抗震分析时,结构设计软件PKPM通常以周期折减系数来考虑填充墙对结构刚度的影响.以来宾市高层实测项目中8栋高层为研究对象,对其进行随机振动测试并在有限元软件Sap2000中建模,利用实测数据对有限元分析模型进行校验并比较校验前后的抗震分析结果.在Sap2000中建立高层建筑模型并采用与PKPM软件相同的方式考虑填充墙的影响,计算结果表明2种模型具有可比性.利用壳体模型和斜撑模型分别在Sap2000软件中对填充墙进行模拟,并利用现场实测数据对模型进行校验.用Sap2000模型代替PKPM模型进行小震作用下线弹性阶段的地震反应分析,与PKPM软件的计算结果对比后发现相较于修正后的Sap2000模型计算值,PKPM模型计算的未经折减的层间剪力是Sap2000模型的1/2左右,而水平位移和层间位移角却是Sap2000模型的3~4倍.根据JGJ 3-2010《高层建筑混凝土结构技术规程》建议的周期折减系数为0.7~1.0,设计取值更为保守.

Influence of Infill Wall Stiffness on Seismic Analysis of High-rise Building

When structural seismic analysis is conducted on high-rise buildings, the impact of the infill wall stiffness on the structure response is usually considered by the fundamental period reduction factor in the PKRM software. In this paper, eight high-rise buildings in the Laibin High-Rise Testing Project were examined. These buildings were tested for ambient vibration and seismic analysis, which were also modeled and calibrated by the Finite Element (FE) Sap2000 software. First, eight FE models for the eight buildings were built in Sap2000. The same modeling for infilled wall using PKPM was also calculated, and the comparison of these two calculation results demonstrates the comparability of these two models. Next, shell model and diagonal strut model were adopted in the modeling of infill wall, and the models were calibrated by using the data from test. Thereafter, Sap2000 model was used for seismic response analysis instead of PKPM model. Finally, the seismic response spectrum analysis in linear elastic status was conducted under small earthquake. The comparison of the calculation results from PKPM software shows that, compared with the calculated value of calibrated model, the unreduced floor shear force calculated by PKPM is half of that by Sap2000, and the inter story displacement and inter story drift calculated by PKPM is three to four times of that by Sap2000. Moreover, the value of fundamental period reduction factor suggested by Technical Specification for Concrete Structures of Tall Building (JGJ3-2010) is 0.7~1.0, which is more conservative to the results obtained from the analysis.