粘滞阻尼器在连体高层结构中的抗风减振效果

主要研究设置粘滞阻尼器的连体高层结构风振响应及风动力荷载作用下粘滞阻尼器对结构内力、变形、加速度及能量耗散的控制效果。根据连体高层结构刚性模型的风洞试验，得到风压系数时程数据。通过编制基于风洞试验的风荷载时程处理程序WINDHIST V2.0，可将风洞试验数据进行处理并导入有限元程序进行风振时程分析。对连体高层结构进行多工况风振时程分析，结果显示：设置粘滞阻尼器能减小连体结构内力及变形，内力的控制效果优于变形的控制效果。连体结构顶部加速度是由脉动风的动力效应引起，粘滞阻尼器能有效地控制结构顶部楼层加速度。     

大底盘双塔连体带转换层复杂高层结构的抗震性能分析

大底盘多塔连体带转换层的复杂高层结构是一种新型结构形式。利用ETABS有限元分析软件建立了20种结构计算模型,采用振型分解反应谱法对大底盘双塔连体带转换层复杂高层结构进行地震反应分析:1)大底盘等高双塔连体带转换层复杂高层结构和大底盘等高双塔带转换层复杂高层结构(非连体)的地震反应分析;2)大底盘等高、不等高双塔连体结构带转换层的地震反应对比分析;3)裙房层数对大底盘等高双塔连体带转换层结构的抗震性能影响;4)转换层对大底盘等高双塔连体带转换层结构的抗震性能影响;5)连体(连体位置变化、连体层数变化)对大底盘等高双塔连体带转换层结构的抗震性能影响。     

厦门英蓝国际金融中心双塔高位连体结构分析

厦门英蓝国际金融中心T3塔楼为双塔高位连体结构,地上37层,结构高度166m,在30～37层设置7层连接体,连接体跨度约40m。对整体和分塔模型进行了地震动力响应特性分析,由于连接体与塔楼相互影响,双塔连体时结构的扭转效应增加显著,连接体上下层侧向刚度突变明显,连接体相关楼板应力较大。通过罕遇地震弹塑性时程分析,对结构的薄弱部位采取相应的抗震加强措施。与反应谱分析方法相比,采用弹性时程分析方法研究高位连体结构的竖向地震作用效应更安全可靠。通过风洞试验研究复杂风环境作用下的高层建筑受力特性。     

某超限高层建筑复杂连体结构设计北大核心

某连体建筑两侧塔楼体型差异较大,为超限高层复杂连体建筑,采用框架-剪力墙+连体桁架的结构体系。针对连体桁架结构选型进行优化分析,针对连体结构整体模型,进行小震弹性分析、中震性能化验算和大震动力弹塑性分析。随后对连体结构的关键问题进行了研究,包括关键构件和节点的设计、抗连续倒塌能力以及大震下结构的变形和损伤情况。分析结果表明,超限高层复杂连体结构的结构体系合理,具有较好的整体性,关键构件和节点的设计均能达到预设的性能目标,且连体结构具有较好的抗连续倒塌能力。     

空间屋盖连体结构设计方法的工程应用

近年来我国出现了许多复杂的连体结构,表现形式主要分为空间屋盖连体结构和水平连廊连体结构两种。某已建工程为由三个混凝土单体及上部空间桁架组成的屋盖连体结构,针对此类连体结构,采用多个软件进行了总装与拆分模型的模拟,考虑各部分的相互影响,进行包络设计;同时对关键构件进行抗震性能设计,使结构能够实现预定的性能目标。总结空间屋盖连体结构设计方法,可为类似的空间屋盖连体结构提供技术参考。     

泰禾长安中心连体塔楼结构设计与研究

泰禾长安中心连体塔楼为一地上21层、地下5层的斜交连体结构,结构高98.7m,埋深23.3m,顶部4层为25m跨连体,塔楼采用钢筋混凝土框架-核心筒结构,连体采用钢结构。八宝山断裂穿过场地,开展了地震安评确定地震作用,并对安评成果的应用进行了探讨。建筑形体复杂,通过风洞试验确定幕墙和结构风荷载,给出了风荷载确定方法。结构顶部有大跨连体和大悬挑,下部有多层裙房,采取合理措施控制了结构的不规则性,用性能化设计方法来保证抗震安全,重点比较了连体楼盖的剪力估算方法。基底为不均匀地基,综合安评、初勘及详勘成果,明确了基底土层特性,考虑荷载大小、差异沉降及经济性等因素确定了主楼和裙楼的地基基础方案,通过专项论证优化了抗浮设防水位,解决了裙房的整体抗浮问题。     

非对称连体双塔高层建筑的风荷载分布特征风洞试验研究

以某近距离非对称连体双塔高层建筑为研究对象,基于刚性模型表面测压风洞试验,得到两个单塔楼的平均风压系数分布,并计算得到双塔楼局部、整体体型系数和平均整体体型系数,以此为基础研究了双塔楼结构的风荷载分布及其相互之间的干扰效应。结果表明:由于相邻塔楼和连体结构的干扰,塔楼局部迎风面出现负压,背风面出现正压;干扰效应对X向风荷载影响更为明显,双塔楼平均整体体型系数未超出规范要求,按规范设计偏于安全;中间连体由于"狭缝效应"Y向体型系数比较大,应加强风荷载设计。     

当代MOMA工程高层多塔楼、高位悬挑及连体结构设计与施工关键技术研究

首次对多塔楼复杂连体的滑动连接进行了研究,应用了摩擦摆式防震支座,保证了连体和塔楼抗震安全;通过对高层复杂结构体系、高位大悬挑结构、大跨度复杂连体结构等进行综合性的研究,成功地解决了当代MOMA工程复杂结构的设计与施工技术难题;首次对整体建筑群风环境和行人舒适度进行研究,提供了风荷载合理取值,并对行人的舒适度问题提出了改进措施。     

双塔连体复杂体型高层结构抗震分析和设计

结合上海浦东新区某厂房工程实例,阐述了双塔连体复杂高层结构的体系选型、连体方式、超限判别及抗震加强措施等。通过反应谱法、弹性时程及静力弹塑性分析等方法,采用了多模型多程序对其进行详细的抗震性能评估。分析结果表明：合理的抗震体系和措施能确保连体复杂高层结构的抗震性能。     

连体跨度对对称双塔连体结构地震影响

高层建筑连体结构具有独特的外形,近年来在实际中的应用较为广泛。由于连体的存在,使得连体自身的受力和变形较复杂,连体对塔楼的影响也较大。从连体跨度的改变这一因素出发,通过对几个模型的比较分析,对对称双塔连体结构在水平地震作用下的动力响应进行了探讨,得到一些对工程设计有用的结论供参考。     

空冷支架结构管柱体型系数与群柱效应研究

空冷支架结构下部为大直径群柱,上部为钢桁架平台,结构抗风设计时许多参数还不清楚。为掌握该类结构风压分布规律,对1∶150的刚性模型,进行风洞试验研究。同时利用FLUENT6.1流体软件对结构管柱所处风场进行数值模拟,获取不同工况下管柱的整体体形系数。详细介绍风洞试验结果与管柱表面风压试验数据处理方法,将试验结果与数值模拟结果进行对比,验证了CFD数值模拟技术的可行性。     

Wind effects on the world’s longest spatial lattice structure: Loading characteristics and numerical prediction

The 486-m long roof structure of Shenzhen Citizens’ Centre is the world’s longest spatial lattice structure. This paper presents some selected results from a combined wind tunnel and numerical simulation study of wind effects on the extra-long-span roof structure. In this study, simultaneous pressure measurements on its entire roof are made in a boundary layer wind tunnel, and the measured wind pressures, such as mean, root-mean-square (rms) and peak pressure coefficient distributions on the roof are presented and discussed. Based on the measured data from a number of pressure taps, a numerical simulation approach using backpropagation neural networks (BPNN) is developed for the predictions of wind-induced pressure time series at other roof locations which are not covered in the wind tunnel measurements. The BPNN is trained with the pressure data time series measured from adjacent pressure taps. The good performance of the developed neural network is demonstrated by comparing the predictions with the model test results, illustrating that the BPNN approach can serve as an effective tool for the design and analysis of wind effects on large roof structures in conjunction with wind tunnel tests.     

空冷支架结构挡风墙风压分布试验研究

空冷凝汽器支架结构是一种新型的工业建筑,该类结构抗风设计时有许多参数不很清楚,而我国现行荷载规范给定的风参数不能直接采用。结合空冷支架结构的特点,制作了1∶150的刚性模型,进行了风洞试验研究。详细介绍了空冷支架结构上部挡风墙表面平均风压的风洞试验结果及风洞试验数据处理方法,探讨了挡风墙风压分布规律的几个重要影响因素,所得结论对该类结构抗风设计有重要的指导意义。     

常熟市展览中心风荷载试验研究

介绍了常熟市展览中心模型风洞试验概况和主要试验成果。在无周边建筑和有周边建筑的情况下,分别测得了不规则屋盖和围护结构的风洞模型试验数据,分析了各测点在各个风向角下对应的平均风压系数变化规律,对类似形状的屋盖结构具有参考意义。     

Wind effects on a long-span beam string roof structure: Wind tunnel test, field measurement and numerical analysis

The Guangzhou International Convention & Exhibition Center (GICEC) with roof dimensions of 210 m wide and 457 m long is the largest exhibition center in Asia and the 2nd largest of this kind in the world. This paper presents results from a combined study of wind tunnel test, full-scale measurement, and numerical analysis of wind effects on the long-span beam string roof structure. In the wind tunnel test, wind-induced pressures including mean and fluctuating components were measured from the roof of a 1:300 scale GICEC model under suburban boundary layer wind flow configuration. The Proper Orthogonal Decomposition (POD) method and the quasi-steady approach as well as probability analysis were adopted to estimate the characteristics of the fluctuating wind pressures on the roof. On the other hand, full-scale measurements of wind actions and wind-induced structural responses of the roof were conducted during the passage of Typhoon Nuri. The field data such as wind speed, wind direction, and acceleration responses, etc., were continuously and simultaneously monitored from a wind and structural response monitoring system installed on the roof structure during the typhoon. Detailed analysis of the field data was performed to investigate the characteristics of the typhoon-generated wind and the wind-induced vibration of the long-span roof structure under typhoon condition. The dynamic characteristics of the roof were determined from the field measurements and comparisons with those calculated from the finite element model (FEM) of the structure were made. The damping ratios of the roof structure were estimated by means of the random decrement method and the amplitude-dependent damping characteristics were presented and discussed. Finally, the full-scale measurements were compared with the model test results to examine the accuracy of the wind tunnel test results and to identify possible modelling errors in the numerical study. The results presented in this paper are expected to be of considerable interest and of use to researchers and professionals involved in designing long-span roof structures.     

Numerical modeling of the flow conditions in a closed-circuit low-speed wind tunnel

A methodology for numerically simulating the flow conditions in closed-circuit wind tunnels is developed as a contribution to the general philosophy of incorporating Computational Fluid Dynamics (CFD) in wind tunnel design and testing and to CFD validation studies. The methodology is applied to the full-scale Jules Verne climatic wind tunnel in which experimental data have been obtained. Due to the specific features of this closed-circuit wind tunnel, the conventional CFD modeling approach, in which only the flow in the wind tunnel test section is modeled, is inadequate. To obtain accurate results the entire wind tunnel has to be modeled. In the numerical closed-circuit wind tunnel, the conventional flow inlet and outlet are replaced by a single “fan boundary condition”. Special attention is given to the theoretical background and the practical implementation of this type of boundary condition in the CFD model. The numerical model is validated for the case of an empty wind tunnel and for the case in which a block-type building is placed in the test section. It will be shown that this methodology can generally reproduce the wind tunnel measurements of mean velocities with an error equal to or less than 10% despite the occurrence of multiple flow separations upstream of the test section. This provides perspectives for the future use of this methodology as a tool for wind tunnel design and testing and for CFD validation purposes.     

上海浦东国际机场(一期工程) 航站楼钢结构研究与设计

本文介绍了上海浦东国际机场第一期工程中的航站楼钢结构研究设计,包括其特点和分析,特别是抗震和抗风设计。文中并简要地阐述了其模型风洞试验的结果。     

大跨屋盖结构风洞试验模型的设计方法讨论

通过理论分析及风洞试验研究大跨屋盖结构风洞试验的模型设计问题。以气承刚度理论为主线阐述了内压传播方程及赫姆霍兹频率、四周封闭屋盖结构及墙面开孔屋盖结构的频移特性和气承刚度的相似性模拟准则,考虑了墙体柔度在理论分析中的关键作用。设计制作了大跨平屋盖刚性模型和气弹模型进行墙面开孔前后的风洞试验,试验结果与理论分析较为吻合。研究结果证明了气承刚度相似性模拟在大跨屋盖结构风洞试验中的基础性作用,并指出在模型设计中调整结构内部容积是模拟气承刚度最有效的措施,而保证刚度比的一致性则是试验成功的关键。     

椭球面屋盖与圆锥面玻璃幕墙的风压分布特征

结合杭州大剧院主体结构风压分布的风洞试验研究 ,详细介绍了风洞试验及数据处理方法 ,讨论了在不同风向角下椭球面屋盖和圆锥面玻璃幕墙的风压分布 ,并与荷载规范中类似结构的风压分布进行了比较。为了便于整体结构设计 ,根据结构的实际情况对椭球面和圆锥面进行分块并给出相应的分块风压数据 ,根据各风向角下的风压分布特征给出了整体结构抗风设计的最不利风向角。     

北京中关村软件广场“光盘”风洞试验研究

北京中关村软件园“光盘”结构造型独特,对风荷载比较敏感,规范没有给出其设计风荷载取值。采用刚性测压模型对单独的“光盘”体及“光盘”与周围建筑的组合体进行了风洞试验,考虑高度换算系数和体型系数,对“光盘”结构的风荷载特性进行了探讨,结果表明,在结构设计中应该充分考虑风荷载的实际分布,应对多种风向角对应的风荷载分别进行整体结构分析。