Studies on various structural system design options for twisted tall buildings and their performances

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.     

A simplified model for analysis of high‐rise buildings equipped with hysteresis damped outriggers

A simplified model is developed to estimate the seismic response of high‐rise buildings equipped with hysteresis damped outriggers. In the simplified model, the core tube is considered as a cantilever beam, and the effects of outriggers on the core tube are considered as concentrated moments. Modal decomposition method is adopted to obtain the seismic response of the simplified model. To investigate the accuracy and effectiveness of the simplified model, a high‐rise building with a height of 160 m was adopted as the example structure, and its response subjected to a ground motion was analyzed using the simplified model. A corresponding finite element model was built and analyzed by a finite element program called SAP2000 (Computers and Structures, Inc. Berkeley, California, United States). The analysis results obtained from the two models were compared. To consider the randomness of the ground motion, comparisons between the two models were further conducted using another 22 ground motions. It is found that the analysis results obtained from the simplified model agree well with those obtained from the finite element model, and the computation time used for the simplified model is almost negligible compared to that used for the finite element model. Such observations demonstrate that the simplified model is accurate and effective. Copyright © 2013 John Wiley & Sons, Ltd.     

超高层建筑伸臂桁架“延迟连接”技术在沈阳恒隆广场主塔楼施工中的应用

在水平荷载起控制作用的超高层建筑中,设置伸臂桁架可以提高结构的整体工作性能,从而提高结构的抗侧刚度,控制结构的顶部位移,降低核心筒所承担的倾覆力矩。但是,伸臂桁架在施工阶段,由于内外筒施工不同步,结构布置不对等原因,会导致施工过程中内、外筒的变形存在一定差异,如果盲目施工,将会造成在伸臂桁架内部过早产生较大应力,导致结构成形后整体受力状况与原结构设计模型不符。通过研究,提出一种超高层伸臂桁架"延迟连接"的施工技术。该方法在沈阳恒隆广场主塔楼施工应用的情况表明,可有效解决外框与芯筒不均衡变形导致的伸臂桁架应力过大的问题,确保了伸臂桁架施工和使用阶段的结构性能。     

三体船耐波性的模型试验研究

通过三体船模型的耐波性试验,包括横摇试验、规则波中的迎浪试验,研究了三体船的耐波性能以及侧体纵向位置对三体船耐波性的影响。试验结果表明,航速对三体船耐波性能的影响与对单体船的影响类似,而侧体纵向位置对于三体船耐波性能的影响是比较大的。     

水平加强层在超高层钢结构中的应用研究

结合实际工程，深入地研究了设置水平加强层后超高层钢结构的地地震响应；通过对几种不同方案的比较，进一步研究了加强层的数量、抗弯刚度以及周边环带等对结构抗震性能的影响；最后本文提出了一种水平加强层刚度的选择方法，供工程应用参考。     

高层建筑结构腰架最佳位置研究

根据一种新的更接近实际情况的计算模型，即考虑梁柱节点为刚性节点，采用广义连续化方法，探讨各种结构参数对腰架最优位置的影响，以及顶部侧移减小和基底弯矩减小的腰架最优位置和数量。     

南京德基广场二期塔楼整体模型振动台试验研究

南京德基广场二期塔楼是一幢平面及立面均不规则的复杂超高层结构,结构采用了带加强层的框架-核心筒抗侧力体系。进行了1∶23缩尺比例的整体模型振动台试验,分析了试验中的现象、结构的动力特性、加速度反应、位移反应、关键部位的动应变反应,研究了结构的破坏机理和破坏模式,指出了结构的薄弱部位,评价了该结构体系的整体抗震性能。对结构的设计提出了薄弱层及其相邻层侧向刚度适当调整、下部楼层楼板开洞附近梁式楼板加强等方面建议。试验结果表明,虽然加强层会引起结构局部刚度、承载力突变,结构受力复杂化,并易形成薄弱部位,但总体上加强层的设置可使周边框架柱有效地发挥作用,增强了整个结构的抗侧力刚度。通过合理分析和设计,可使加强层的不利影响降低到较小的程度。     

地震作用下环带对带伸臂的框-筒结构力学性能的影响

对一60层的框架核心简结构通过改变水平伸臂、环带构件的设置情况而形成不同的结构方案,采用三维有限元分析软件ETABS进行地震作用下的动力分析,探讨地震作用下水平伸臂以及不同刚度环带对结构顶点侧移、核心筒剪力、外框柱轴力的影响。分析表明：环带的设置、环带本身的刚度对地震作用下高层框架一核心筒结构的顶点侧移影响不大;但环带能有效调整外框柱的轴力分布,更好的发挥外框柱的整体作用;环带的设置会加大水平加强层的剪力突变这一现象。     

水平加强层对筒中筒结构空间受力性能的影响

设置水平加强层可以降低由裙梁柔性导致的框筒剪力滞后效应,增强结构空间受力性能,提高结构抗侧刚度。通过对若干算例进行空间有限元分析,讨论了加强层的刚度、布置状况等对外框筒剪力滞后效应、结构抗侧刚度等的影响,并提出了加强层设置的建议。     

某水利枢纽施工塔机支腿破坏的仿真计算及断裂力学分析

对某水利枢纽施工塔机支腿拉板的受力进行了三维弹塑性仿真计算,并将计算结果与拉板断裂面的形态加以比较,依据断裂力学基础理论对支腿拉板的强度进行了定性与定量分析.由于存在应力集中现象,拉板在交变应力作用下逐步形成疲劳断面,从机理上论证了塔机倒塌事故发生的原因.分析结果有助于防止类似事故的发生以及对支腿拉板的重新设计改造.