适用于城市高层建筑群的震害预测模型研究

A URBAN SEISMIC DAMAGE ANALYSIS MODEL FOR TALL BUILDING GROUPS

高层建筑是城市建筑的重要组成部分,现有建筑震害预测模型难以满足城市区域高层建筑群震害分析的要求。该文提出了一套非线性多自由度弯剪耦合模型(NMFS)以及其参数标定方法。该模型:1)能模拟高层建筑显著的弯剪耦合变形行为。与传统的剪切层模型对比,该模型能准确的模拟高层建筑的层间位移角包络,其结果与精细有限元模型的结果非常接近;2)具有非常高的计算效率。与精细有限元模型对比,该模型的计算加速比超过60000倍;3)参数标定简单。仅需要借助于少量的建筑属性信息(结构高度、建设年代、设计信息和结构类型)就能生成整个模型的弹塑性参数;4)能输出各层时程响应以及层间位移角情况,使未来基于工程需求参数(EDP)的区域高层建筑经济损失预测成为了可能。论文针对一栋典型高层结构详细展示了模型的建立与标定流程,并对标定参数的准确性进行了校验。最后对北京CBD地区高层建筑群进行了震害模拟,验证了该方法在城市区域中应用的可行性。该文的成果期望为未来区域高层建筑的地震损失预测提供参考。

Tall buildings are very important parts of urban building groups and current building computational models are not able to meet the requirements of urban seismic analysis for tall buildings. In this work, a nonlinear multiple degree-of-freedom（MDOF） flexural-shear（NMFS） model and its corresponding parameter determination method are proposed. The model has the following advantages： 1） Appropriate consideration of nonlinear flexural-shear deformation mode of tall buildings. Compared with traditional nonlinear MDOF shear（NMS） model, the accuracy is significantly improved and the response result agrees well with the refined finite element（FE） model; 2） High computational performance, which is more than 60000 times faster than the refined FE model; 3） Very convenient parameter determination. The nonlinear parameters of the model can be determined using limited building data（i.e., structural height, year of construction, site condition and structural type） of each building; 4） The ability to output time-history responses and inter-story drifts, which may facilitate the future engineering demand parameter（EDP） based loss estimation for tall building in urban area. In this study, a representative tall building is selected to demonstrate the modelling and parameter determination processes of the proposed NMFS model. Verifications are made by comparing with the refined FE model. Finally the method is used to perform the urban seismic analysis for the Central Business District（CBD） of Beijing, which proves the applicability of the method for tall buildings in urban area. Outcomes of this work are expected to provide a useful reference for future works on urban seismic loss estimation of tall buildings.