Modified consecutive modal pushover procedure for seismic investigation of one-way asymmetric-plan tall buildings

The effects of higher modes and torsion have a significant impact on the seismic responses of asymmetric-plan tall buildings.A consecutive modal pushover(CMP) procedure is one of the pushover methods that have been developed to consider these effects.The aim of this paper is to modify the(CMP) analysis procedure to estimate the seismic demands of one-way asymmetric-plan tall buildings with dual systems.An analysis of 10-,15-and 20-story asymmetric-plan buildings is carried out,and the results from the modified consecutive modal pushover(MCMP) procedure are compared with those obtained from the modal pushover analysis(MPA) procedure and the nonlinear time history analysis(NLTHA).The MCMP estimates of the seismic demands of one-way asymmetric-plan buildings demonstrate a reasonable accuracy,compared to the results obtained from the NLTHA.Furthermore,the accuracy of the MCMP procedure in the prediction of plastic hinge rotations is better than the MPA procedure.The new pushover procedure is also more accurate than the FEMA load distribution and the MPA procedure.     

上海市商务办公楼租金差异及其影响因素

上海房地产市场在国家房产新政下出现了较大的转折,商务办公楼市场升温。本文从总体上分析了上海部分区域商务办公楼的平均租金差异,并选择商务办公楼比较集中的南京路、延安路和淮海路三条线路作为典型调查区段,共采集24个样本区域、66幢甲级商务办公楼、492个具体样本资料,运用多元线性回归分析方法,揭示了上海市商务办公楼租金差异与地理区位、服务设施、交通条件、平均层数、平均停车位及绿化景观6个影响因子的相互作用关系。回归分析结果表明:服务设施和停车位是影响上海市商务办公楼租金差异的主要因子;其次为绿化景观、地理区位和交通条件;而平均层数的影响甚微。最后针对上海商务办公楼多中心化趋势,就有关问题进行了分析和讨论。     

福州江滨地区超高层建筑灌注桩成孔工艺分析

以福州江滨地区2个有代表性的超高层建筑桩基础工程实例为依据,通过无卡式冲击 正循环,旋挖 气举反循环,回转 泵吸反循环3种成孔工艺之间的比对,提出了在福州市江滨地区超大粒径厚层卵石与花岗岩地层灌注桩施工成孔工艺方面的一些见解,认为回转 泵吸反循环是较为可靠的工艺。     

Effect of depth of soil stratum on performance of buildings for site-specific earthquakes

Towards formulating guidelines for performance evaluation of buildings to site-specific earthquakes, studies are reported in literature on the effect of various critical parameters. No study is, however, reported on the effect of depth of soil stratum. In this paper, a methodology is proposed and applied for performance evaluation of buildings for site-specific earthquakes including depth of soil stratum as a parameter. The methodology integrates independent procedures meant for performance evaluation of buildings and site-specific seismic analysis. Application of the proposed methodology enables to determine performance point of a building in terms of inelastic displacement and base shear. Numerical application of the methodology is demonstrated using the particulars of Delhi region. Two typical RC buildings (B1 and B2) with significantly different inelastic behaviour, assumed to be located on soil depths ranging from 10 to 200 m are chosen for the application study. Capacity spectra of the buildings are generated from nonlinear static analysis. Studies indicate that for building B1, with elasto-plastic behaviour, the depth of soil stratum strongly influences demand on inelastic displacement compared to that on inelastic base shear. For building B2, with continuously varying inelastic behaviour, the depth of soil stratum is observed to have significant influence on both the inelastic base shear as well as inelastic displacement. Responses of the buildings are compared with that obtained based on design spectrum of Indian seismic code. For both the cases, inelastic displacements as well as inelastic base shears are underestimated by Indian seismic code for certain depths of soil stratum. Proposed methodology enables the calculation of realistic values of inelastic base shear and corresponding displacement of a building for site-specific earthquakes by considering the actual characteristics of soil stratum.     

高层钢结构地震失效模式控制的失效路径修正法

本文主要研究高层钢框架结构的地震失效模式及其控制方法。首先,给出了高层钢结构的地震失效模式的分析方法;其次,提出了根据结构的失效路径来加强构件对高层钢结构的地震失效模式进行控制的方法;然后,提出了结构整体抗震能力的分析方法以及分别相应于设计能力和屈服能力的能力储备分析方法;最后,通过对一座15层的钢框架结构进行典型地震动下的极限时程分析和极限pushover分析,得到高层钢框架结构的失效模式和整体抗震能力以及相应于最弱失效模式的能力储备,并验证了本文中地震失效模式控制方法的有效性。本文的研究表明,高层钢结构的地震失效模式控制可以采用结构失效路径修正(薄弱构件加强)来实现。     

超高层建筑设计地震动参数的研究

本文以沈阳市世纪华丰文化广场工程场地为例,在地震危险性分析的基础上,进行土层地震反应分析,对超高层建筑设计地震动参数的确定进行研究,为抗震设计提供可靠依据。     

Development of a hybrid simulation controller for full‐scale experimental investigation of seismic retrofits for soft‐story woodframe buildings

Hybrid simulations of a full‐scale soft‐story woodframe building specimen with various retrofits were carried out as part of the Network for Earthquake Engineering Simulation Research project – NEES‐Soft: seismic risk reduction for soft‐story woodframe buildings. The test structure in the hybrid simulation was a three‐story woodframe building that was divided into a numerical substructure of the first story with various retrofits and a full‐scale physical substructure of the upper two stories. Four long‐stroke actuators, two at the second floor and two at the roof diaphragm, were attached to the physical substructure to impose the simulated seismic responses including both translation and in‐plane rotation. Challenges associated with this first implementation of a full‐scale hybrid simulation on a woodframe building were identified. This paper presents the development and validation of a scalable and robust hybrid simulation controller for efficient test site deployment. The development consisted of three incremental validation phases ranging from small‐scale, mid‐scale, to full‐scale tests conducted at three laboratories. Experimental setup, procedure, and results of each phase of the controller development are discussed, demonstrating the effectiveness and efficiency of the incremental controller development approach for large‐scale hybrid simulation programs with complex test setup. Copyright © 2016 John Wiley & Sons, Ltd.     

Discussion of ‘Modelling viscous damping in nonlinear response history analysis of buildings for earthquake excitation’ by Anil K. Chopra and Frank McKenna

This discussion deals with recommendations in the paper on appropriate damping formulations for use in nonlinear response history analysis of buildings. Concern over potentially excessive damping forces and moments should extend beyond the damping moments produced by the stiffness proportional part of Rayleigh damping that corresponds to rotational springs used to explicitly model plastic hinges. The key to an appropriate damping formulation for nonlinear analysis is a realistic mechanism that allows all damping forces and moments to be meaningfully assessed. Then features can be added to keep these forces and moments within reasonable bounds. Copyright © 2016 John Wiley & Sons, Ltd.     

基础隔震结构健康监测系统的设计与实现(Ⅱ):系统实现

作为保障工程安全和研究结构灾变机理的重要手段,结构健康监测为研究基础隔震技术在实际工程应用中的问题提供了技术保证。基于"基础隔震结构健康监测系统的设计与实现(Ⅰ):系统设计"中的设计方法,研究某超长基础隔震结构健康监测系统的总体设计、传感器选型与测点布设、数据采集与传输方案及数据库结构设计,并对该系统已获取的监测数据进行初步分析。分析结果表明,该基础隔震结构健康监测系统协调运行状态良好,能实现其预期功能。基于性能状态评价指标对该结构状态进行评价,表明该基础隔震结构性能状态良好。     

基于自由振动响应的基础隔震建筑减震能力评估方法研究

目前国内外已修建完成了大量隔震建筑,但仅有少量经受了地震检验,绝大部分隔震结构减震能力能否达到设计目标尚存疑问.本文针对基础隔震建筑,提出了一种基于自由振动响应的减震能力评估方法.首先,对隔震建筑进行多级幅值初位移自由振动原位试验,获取结构的抗震能力曲线;其次,根据地震反应谱建立地震需求曲面,进而确定隔震结构性能点;最...