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Mauricio Morales‐Beltran Gürsoy Turan Onur Dursun Rob Nijsse 《The Structural Design of Tall and Special Buildings》2019,28(1)
The use of a single set of outriggers equipped with oil viscous dampers increases the damping ratio of tall buildings in about 6–10%, depending on the loading conditions. However, could this ratio be further increased by the addition of another set of outriggers? Should this additional set include dampers too? To answer these questions, several double damped outrigger configurations for tall buildings are investigated and compared with an optimally designed single damped outrigger, located at elevation 0.7 of the total building's height (h). Using free vibration, double outrigger configurations increasing damping up to a ratio equal to the single‐based optimal are identified. Next, selected configurations are subjected to several levels of eight ground motions to compare their capability for avoiding damage under critical excitations. Last, a simplified economic analysis highlights the advantages of each optimal configuration in terms of cost savings. The results show that, within the boundaries of this study, combining a damped outrigger at 0.5h with a conventional outrigger at 0.7h is more effective in reducing hysteretic energy ratios and economically viable if compared with a single damped outrigger solution. Moreover, double damped outrigger configurations for tall buildings exhibit broader display of optimal combinations, which offer flexibility of design to the high‐rise architecture. 相似文献
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Damped outriggers for tall buildings draw increasingly attentions to engineers. With a shaking table test, two models of a high‐rise steel column‐tube structure are established, one with outriggers fixed to the core and hinged at the columns, whereas the other's cantilevering outriggers are connected to columns by viscous dampers. According to their dynamic properties, five earthquake waves are selected from the Ground Motion Database of Pacific Earthquake Engineering Research Center (PEER), and two artificial waves are generated by software SIMQKE_GR. Under various peak ground accelerations (PGAs), nonlinear time‐history analysis is applied to compare structural elastic seismic responses, including accelerations, inter‐story drifts, base shear force, damper's response and additional damping ratios. It is concluded that under minor earthquakes, accelerations, inter‐story drifts and base shear force of structure with damped outriggers are larger than or nearly equal to those of the one with fixed outriggers, and the viscous dampers hardly work. But as PGA increases, the contrary situation happens, and the effect of viscous dampers is enhanced as well. The additional damping ratio reaches around 4% under mega earthquakes. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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C. J. Fang P. Tan C. M. Chang F. L. Zhou 《The Structural Design of Tall and Special Buildings》2015,24(12):797-820
This paper presents a general solution for performance evaluation of a tall building with multiple damped and undamped outriggers. First, general rotational stiffness (GRS) is proposed to model an outrigger that consists of the stiffness of perimeter columns and an outrigger connection and the damping of dampers in an outrigger. By utilizing the dynamic stiffness method, the GRS can be represented by complex stiffness in an outrigger element. To analyze the dynamic characteristics of a tall building with multiple outriggers, a dynamic transcendental equation is obtained from the combination of the GRS and dynamic stiffness method. The structural responses can be calculated through the Fourier transform based on this equation. Moreover, the GRS can also be blended into a finite element (FE) model to generate an augmented state‐space equation for the analysis of the dynamic characteristics and structural responses. Applications to various outriggers are illustrated. In the numerical analysis, good agreements are found between the GRS and the FE that validates the proposed method, and the performances of various outrigger systems are evaluated parametrically. As the results of a tall building with multiple damped or undamped outriggers, the proposed method is capable of providing an optimally parametric design with respect to the position of outriggers, damping, and core‐to‐column and core‐to‐outrigger stiffness ratio. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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The damped outrigger system emerged as an improvement of the conventional outriggers with the aim to provide supplemental damping and to contribute to the vibration control in super tall buildings where this system is usually applied. In addition to viscous dampers (VDs), buckling‐restrained braces (BRBs) have also been employed as energy dissipating members in outriggers. Nevertheless, the combined use of outriggers with VDs and BRBs in the same structure has not yet been studied. Such combination can contribute to achieve an effective multiperformance design of super tall buildings. This paper presents a study whose main objective was to determine the optimal vertical combination of two types of energy dissipation outriggers to control the seismic responses of a 9‐zone super tall model structure. Outriggers with VDs (OVDs) and outriggers with BRBs (OBRBs) were placed at the different zones of the structure considering all the possible combinations and in configurations of up to four outriggers. The effects of these combinations on the seismic performance of the structure were studied through parametric analysis and optimization methods. This form of the outrigger system is defined in this paper as combined energy dissipation outrigger system. The results indicate that when two energy dissipation outriggers are used, the combination of OBRB plus OVD shows superior seismic performance compared with other double‐outrigger configurations. In addition, the results show that the locations of OVDs and OBRBs play an important role in the structure behavior; it was found that it is more beneficial to place OBRBs above OVDs. 相似文献
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Kyoung Sun Moon 《The Structural Design of Tall and Special Buildings》2014,23(5):319-333
Employing twisted forms for tall buildings is a recent architectural phenomenon. This paper studies various structural system design options for twisted tall buildings and their performances based on lateral stiffness. Twisted tall buildings of various heights and rates of twist are designed with different types of contemporary tall building structural systems, such as diagrids, braced tubes and outrigger systems. The heights of the studied buildings range from 60 to 100 stories, and the rates of twist range from 0° to 3° per floor. As the rate of twist increases, the lateral stiffness of the tower decreases. The stiffness reduction rate caused by twisting is very much dependent upon the structural systems employed for twisted tall buildings. While an emphasis is placed on the structural performance of twisted tall buildings, other aspects, such as architectural and constructional issues, are also discussed holistically. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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液体黏滞阻尼器在高层和超高层建筑中起到抗震和抗风的结构保护作用,已经在国内外得到广泛认可。近十年来,在国内应设计院委托,前后计算分析了近20个高层、超高层建筑工程,其中7座已经被业主和超限审查通过,4个工程已经完成,3座已在施工或正在准备施工,还有几座在和业主讨论中,还有一半以上的建筑因各种原因阻尼器不能被采用,但在阻尼器的设计计算过程中,发现有很多创新点或启发,希望和设计者分享。在超高层结构发展应用过程中,美国的阻尼器设备公司在阻尼器开发方面也有很多发展,均做一简单介绍,供讨论参考。 相似文献
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软钢阻尼器的优化配置方法探讨 总被引：2，自引：1，他引：1
从理论上探讨了软钢阻尼器发挥最佳减震效果时结构应具备的条件。首先基于等效粘滞阻尼比的定义,推导了软钢阻尼器结构等效粘滞阻尼比的表达式,据此,进一步确定了结构等效粘滞阻尼比取最大值时的阻尼装置受剪承载力分配率,将其定义为最优分配率,从而明确了使软钢阻尼器的耗能量达到最大时软钢阻尼器结构所应具备的条件。 相似文献
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南亚之门工程位于云南省昆明市,塔楼建筑高度366m,为我国目前8度地区拟建的超高建筑之一。采用巨型框架-混凝土核心筒结构体系,层23以下建筑平面呈正方形,层23以上削角,建筑平面呈逐渐缩小的八边形,并在建筑顶部形成与底部旋转45°的内接正方形平面。置于平面四角的巨柱在层23一分为二形成8根倾斜角柱,并在设备层设置环带桁架,与巨柱形成抗侧刚度较大的巨型框架,与核心筒一起承担地震作用。环带桁架与核心筒通过加强层的楼板协调变形,起到"虚拟伸臂"的作用。采用速度型粘滞阻尼器增加结构阻尼,以减小地震作用。 相似文献
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以某299.3m超高层框架-核心筒结构为研究对象,针对该工程的自身特点提出了设置屈曲约束支撑、肘节式和人字形连接黏滞阻尼器的3种耗能减震层控制方案。在8度小震作用下,对比分析了不同控制方案对耗能减震层内力突变的减震控制效果,同时对黏滞阻尼器采用肘节式和人字形两种连接方式的耗能率进行对比分析。结果表明,带肘节式连接减震方案能有效地降低耗能减震层位置处的内力突变,减震层位置剪力墙剪力突变幅值的最大降幅达46.2%,大大降低了加强层构件连接部位应力集中效应,验证了黏滞阻尼器采用肘节式连接比人字形连接具有更高的耗能效果,耗能率最大提高133.1%,证明了带肘节式连接耗能减震层对超高层结构抗震的有效性和可行性。 相似文献
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The Tall Building Initiative project of Pacific Earthquake Engineering Research Center has been expanded to investigate the seismic performance and possible retrofit of existing tall buildings. A candidate 35‐story steel building with representative details from the early 1970s was analyzed following several guidelines, which revealed a wide range of potential inadequacies. Thus, a two‐level retrofit approach was examined that focused on achieving the collapse prevention limit state under the major basic safety earthquake (BSE‐2E) hazard level prescribed by ASCE 41. This paper focused on a Level‐2 retrofit that used fluid viscous dampers to augment Level‐1 retrofits. For this approach, feasible damper locations and overall effective damping ratios were first evaluated through a series of preliminary studies, and then a two‐phase design method was used to refine the distribution and mechanical properties of the dampers. Thorough assessments of the refined design were carried out following several design guidelines, including ASCE 41, FEMA 351, and FEMA P‐58. The results indicated that the proposed retrofit method of using fluid viscous dampers could achieve the retrofit goal and provide a cost‐effective means of improving the structural behavior and reducing economic losses in a major seismic event. 相似文献
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随着高层以及超高层建筑结构不断向更高和更柔的方向发展,强风作用下这类建筑的传统设计方法有时已经无法完全满足结构的抗风设计要求。因此,提出了采用振动控制来抑制结构风致振动控制的新方法。论文首先概述了高层建筑中风振控制的方法及其国内外的研究现状,然后对其中的调谐质量阻尼器(TMD)、主动调谐质量阻尼器(ATMD),以及摩擦阻尼器这3种控制方法详加评述,最后进一步指出我国风振控制研究的发展方向。 相似文献
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A structure must meet many performance requirements to survive an earthquake. For a super high‐rise structure, the dominant control performance metric is stiffness when considering earthquake resistance because the lateral displacement of the structure often does not meet the requirements of the code even if the structure meets strength requirements. For moderate and major earthquakes, stiffness and strength play a leading role jointly. Viscous damper (VD) and buckling restraint brace (BRB) are damping devices that are commonly used in modern engineering. The efficiencies of these devices are different for different situations, and combining them can yield improved structural vibration mitigation. In this study, the performances of VD and BRB are summarized. A kind of virtual VD model with an additional damping ratio is proposed on the basis of which a VD priority placement analysis method is developed, and an optimal design is proposed. A detailed analysis of various stress states of a BRB is also performed, and a BRB arrangement method based on brace stress level analysis is proposed. The two kinds of vibration damping equipment are combined in the structure, and a practical design method for a hybrid vibration damping system is proposed. The accuracy of the proposed method is verified by considering a 10‐story plane frame. Finally, a hybrid vibration mitigation design for different objective damping ratios is performed for a super tall building project, and the design results are compared. The analysis results show that a VD can effectively increase structural damping and reduce the seismic response of the structure. A BRB is used to replace supports that experience high stress and reduce their section size, thereby reducing costs. Therefore, the proposed hybrid vibration damping structure is cost effective while providing good energy dissipation and is thus promising for engineering applications. 相似文献
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Mohammad Javad Goodarzi Majid Moradi Pedram Jalali Moein Abdolmohammadi Seyed Milad Hasheminejad 《The Structural Design of Tall and Special Buildings》2023,32(11-12):e2017
Fragility curves development in structures has always been a focus of research interest among structural and earthquake engineers for which the maximum story drift is usually considered as the engineering demand parameter (EDP) known as the conventional approach. This paper aims at calculating the fragility curves of a tall building with outrigger braced system by considering the plastic strain energy as the EDP and compare it with the conventional approach. In addition, the effect of optimizing the position of outriggers on the exceedance probability of the structure under near- and far-fault seismic loadings is investigated in this paper. Fragility curves of this structure in four performance levels including immediate occupancy (IO), life safety (LS), collapse prevention (CP), and instability is extracted based on the conventional method. The fragility curves for the aforementioned performance levels are also extracted based on the plastic strain energy and compared with the conventional approach. The results have demonstrated that optimizing the location of the bracing system would lower the exceedance probability of the structure. Moreover, the exceedance probability of the investigated building with outrigger braced system under far-fault records in various levels is more than that of near-fault records. It is also concluded that the conventional approach would lead to more conservative results compared with the energy approach. 相似文献
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Faisal Nissar Malik Chinmoy Kolay 《The Structural Design of Tall and Special Buildings》2023,32(7):e2003
Tall buildings suffer from low inherent damping and high flexibility. Therefore, a core-outrigger system is often used to stiffen such buildings. A modified form, known as the damped outrigger system, wherein vertically oriented dampers are installed between outriggers and perimeter columns, has been recently developed to supplement the damping. This paper studies the efficacy of a viscously damped outrigger system through dynamic analysis of a 60-story tall building subjected to nonconcurrent earthquake and wind excitations. Two ground motion sets (100 accelerograms) are used for the former and wind tunnel test data for the latter. Effects of three building parameters, namely, (i) the core-to-column stiffness ratio, (ii) the outrigger location, and (iii) the damper size, on the dynamic characteristics and seismic and wind responses are evaluated. Effects of damper nonlinearity on seismic and wind responses are also investigated considering energy-equivalent nonlinear viscous dampers. Finally, the optimum values of these parameters are determined. For example, the optimum outrigger location is found to be between to , where is the height of the building. The results also show that the damped outrigger system significantly outperforms the conventional one for seismic excitation, and it is very effective in reducing the wind-induced floor accelerations, provided the parameters are chosen appropriately. 相似文献
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地震作用下合肥电视塔粘滞流体阻尼器减震的优化参数分析 总被引：3，自引：1，他引：3
本文以合肥电视塔为工程背景,探讨了粘滞流体阻尼器对高耸电视塔在强震作用下地震响应的振动控制。分别进行了电视塔在EL-Centro波、Taft波和人工合成的合肥波作用下,线性粘滞流体阻尼器对合肥电视塔地震响应的控制分析,并对阻尼器的参数进行了优化设计。分析表明,采用最优参数的粘滞流体阻尼器可以明显减小电视塔的地震响应。 相似文献