【作者】 杨超；

【导师】 欧进萍；

【作者基本信息】 大连理工大学 ， 防灾减灾工程及防护工程， 2011， 硕士

【摘要】 随着社会经济的发展和城市人口的增加,近些年,我国涌现出了一大批高层和超高层建筑。在发达国家,高层钢结构凭借其自重轻、强度高、变形能力强和施工周期短等优势已经得到了广泛应用。作为世界钢产量最多的国家,钢结构已经成为未来中国高层建筑的重要发展方向。抗侧刚度是高层钢结构设计过程中所考虑的重要因素,目前已有许多运用普通单层单跨支撑控制结构侧移的研究成果。对于带大型支撑的高层钢结构,虽然已有许多建成和在建的案例,但国内针对它的研究却相对较少。本文即研究带有此种支撑的高层钢结构的抗震性能。主要内容如下：(1)在相同的荷载和使用条件下,利用有限元软件SAP2000和Midas/GEN,设计用钢量基本相同的四种高层纯钢结构：框架结构、大型支撑—框架结构、巨型框架结构、巨型框架—支撑结构,进行模态和反应谱分析,比较带大型支撑钢结构和另外两种结构的弹性刚度和变形。(2)对上述四种结构进行Pushover分析,比较带大型支撑钢结构与另外两种结构在罕遇地震性能点处的地震反应、结构的失效模式和整体抗震性能。(3)以平面大型支撑—框架模型为例,改变大型支撑的截面和节点连接方式,通过模态分析、反应谱分析和静力非线性Pushover分析,比较大型支撑的截面和连接方式对结构的地震反应的影响。(4)以空间大型支撑—框架结构为例,改变大型支撑的布置方式,通过模态分析、反应谱分析和静力非线性Pushover分析,比较大型支撑的布置方式对结构的地震反应、失效模式和整体抗震能力的影响。(5)将大型钢支撑受压屈曲段用防屈曲支撑替换,比较替换后的结构与原结构的Pushover分析结果。本文分析结果表明：大型支撑—高层钢结构具有良好的抗侧能力,但是支撑屈曲引起的刚度退化也较严重；在一定范围内增大大型支撑截面,可以获得更高的承载力；支撑采用钢、铰接的不同方式与结构连接时,结构的弹性刚度几乎不变,弹塑性阶段承载力有所下降。以结构构件立体化和抗侧力体系最大化的方式布置大型支撑,可以获得更好的抗震性能；防屈曲支撑可以防止普通大型支撑受压屈曲引起的刚度和承载力骤降,限制其所在楼层的层间侧移,提高结构的地震承载力。更多还原

【Abstract】 As the development of social economy and the growth of city population, there are a large number of tall buildings built over the past few years. In developed countries, tall steel buildings are used widely because of the advantages such as light weight, hard stiffness, good deformation capacity, short construction period, and so on. As the steel annual output of China has been the top one in the world for years, steel buildings are considered to be the trend of development here.Lateral stiffness is is one of the most important factors considered during the design of tall steel buildings and there are a large number of researches on structures with traditional braces which are used to control the lateral displacement. However, for the super braced high steel buildings, the researches is still limited, despite the fact that there are a huge number of them being built or built already. In this paper, we will study the seismic performances of this kind of buildings and compare their performances with others. The main contents are as follows:(1) The design of four structures including a frame, a super braced frame, a mega frame and a mega braced frame under the same load and using conditions, with nearly the same steel consumption, the model and response spectrum analysis of these four structures, and the comparision of results.(2) The pushover analysis of the four structures designed and the comparision of results in rare earthquake, failure mode and the seismic capacities of the models.(3) Taking 2-D super braced frame as an example, discuss the seimic performances using model, response spectrum and pushover analysis when the cross section and joint connection of the super braces are changed.(4) Taking 3-D super braced frame as an example, discuss the seimic performances using model, response spectrum and pushover analysis when the disposal mode of super braces is changed.(5) Replace the buckling parts of super braces with buckling restrained braces, and compare the results of pushover analysis before and after the replacement.The results show:Super braced high steel buildings have a large lateral stiffness, but the buckling of super braces could induce a significant degradation of stiffness. Enlarging the cross section of super braces in certain range can improve the stiffness and load-bearing capacity of the models. The models with different joint connection systems have the same linear stiffness, but the models in which the super braces connect to the structures using hinge connections have a lower inlinear load-bearing capacity. The structures that designed follow the the three-dimensional principium and has a wider lateral force resistant system perform better in the pushover analysis. Buckling restrained braces can avoid the fast degradation of stiffness and load capacity that caused by the buckling of ordinary braces and improve the integral seismic capacity of super braced structures.更多还原