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91.
Performance based design becomes an effective method for estimating seismic demands of buildings. In asymmetric plan tall building the effects of higher modes and torsion are crucial. The consecutive modal pushover (CMP) procedure is one of the procedures that consider these effects. Also in previous studies the influence of soil-structure interaction (SSI) in pushover analysis is ignored. In this paper the CMP procedure is modified for one-way asymmetric plan mid and high-rise buildings considering SSI. The extended CMP (ECMP) procedure is proposed in order to overcome some limitations of the CMP procedure. In this regard, 10, 15 and 20 story buildings with asymmetric plan are studied considering SSI assuming three different soil conditions. Using nonlinear response history analysis under a set of bidirectional ground motion; the exact responses of these buildings are calculated. Then the ECMP procedure is evaluated by comparing the results of this procedure with nonlinear time history results as an exact solution as well as the modal pushover analysis procedure and FEMA 356 load patterns. The results demonstrate the accuracy of the ECMP procedure. 相似文献
92.
The dynamic identification of a historical masonry palace located in Benevento (Italy) has been carried out. The case study is representative of many buildings located in historic Italian centres. Since the building has been instrumented by the Department of Civil Protection with a permanent dynamic monitoring system, some of the recorded data, acquired in various operating conditions have been analysed with basic instruments of the Operational Modal Analysis in order to identify the main eingenfrequencies and vibration modes of the structure. The experimental results have been compared to the numerical outcomes provided by a detailed three-dimensional Finite Element (FE) model of the building where Soil–Structure Interaction (SSI) has been taken into account. The comparison of experimental vs. numerical frequencies and vibration modes of the palace evidenced the role exerted by the subsoil on the dynamic response of the building. 相似文献
93.
Development of a hybrid simulation controller for full‐scale experimental investigation of seismic retrofits for soft‐story woodframe buildings 下载免费PDF全文
Xiaoyun Shao Weichiang Pang Chelsea Griffith Ershad Ziaei John van de Lindt 《地震工程与结构动力学》2016,45(8):1233-1249
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. 相似文献
94.
Discussion of ‘Modelling viscous damping in nonlinear response history analysis of buildings for earthquake excitation’ by Anil K. Chopra and Frank McKenna 下载免费PDF全文
John F. Hall 《地震工程与结构动力学》2016,45(13):2229-2233
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. 相似文献
95.
Damage response of multistorey r/c buildings with different structural systems subjected to seismic motion of arbitrary orientation 下载免费PDF全文
In the present study the combined influence of seismic orientation and a number of parameters characterizing the structural system of Reinforced Concrete (R/C) buildings on the level of expected damages are examined. For the purposes of the above investigation eight medium‐rise buildings are designed on the basis of the current seismic codes. The structural characteristics examined are the ratio of the base shear received by the structural walls, the ratio of horizontal stiffness in two orthogonal directions and the structural eccentricity. Then, the buildings are analyzed by nonlinear time response analysis using 100 bidirectional earthquake ground motions. The two horizontal accelerograms of each ground motion are applied along horizontal orthogonal axes, forming 72 different angles with the structural axes. The structural damage is expressed in terms of the Park and Ang damage index. The results of the analyses revealed that the damage level of the buildings is strongly affected by the incident angle of the ground motion. The extent at which the orientation of the seismic records influences the damage response depends on the structural system and the distance of the record to the fault rupture. As a consequence, the common practice of applying the earthquake records along the structural axes can lead to significant underestimation of structural damage. Also, it was shown that the structural eccentricity can significantly differentiate the seismic damage level, as well as the impact of the earthquake orientation on the structural damage. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
96.
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。 相似文献
97.
98.
海南农村民居以砌体结构为主,具有门窗开口大、层高较高和整体性强等特点.为了研究分析这类民居的抗震性能与抗震对策,在收集大量当地农村民居样本的基础上,综合出典型结构模型,并对该典型模型及基于该模型的隔震模型和加强结构模型分别进行了模拟地震振动台试验.试验结果表明:隔震技术能明显降低结构地震反应,在高烈度地区应适当推广和运用.原结构模型基本满足7.5度设防标准.在8度大震作用下,结构遭遇严重破坏但未倒塌,说明其具有一定的抗倒塌能力.结构加固后,整体抗震性能得到了加强.结合试验结果,给出了相应对策与建议. 相似文献
99.
Modified consecutive modal pushover procedure for seismic investigation of one-way asymmetric-plan tall buildings 总被引:1,自引:1,他引:0
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. 相似文献
100.