钢筋混凝土框架结构插入钢结构楼层后的抗震性能研究

发布时间：2018-03-08 03:24

本文选题：钢结构增层　切入点：模态分析　出处：《长安大学》2017年硕士论文　论文类型：学位论文

【摘要】：钢结构增层是近年来运用较为广泛的一种房屋增层形式,它与混凝土结构相比,有良好的技术性、安全性和经济性,且具备质量轻、抗震性能好、施工快等优点。然而,到目前为止,我国还没有颁布针对钢结构增层建筑的设计以及施工规范。钢结构增层之后的混合结构还存在以下问题:钢结构增层后的混合结构竖直方向上的刚度和质量分布不均匀,原混凝土结构和钢结构阻尼比不同,且两者之间连接困难等等,都对混合结构的整体抗震性能造成影响。为深入研究钢结构增层后混合结构的抗震性能,本文主要工作如下:首先,结合西安市区某钢结构增层改造项目,采用结构设计软件PKPM分别对原钢筋混凝土框架结构和插入钢结构楼层后的混合结构进行建模。对两种结构的整体模型进行了模态分析、振型分解反应谱分析以及多遇地震下的动力时程分析。然后采用有限元分析软件ETABS同时建立了原结构和混合结构的三维有限元模型,进行了两种结构罕遇地震下的动力弹塑性时程分析。模态分析结果表明:原混凝土框架结构在插入钢结构楼层后,因刚度增大而周期减小。弹性分析结果表明:楼层最大水平位移整体减小,钢结构楼层处减小最多,约34%,层间位移和层间位移角变化规律相似,即整体减小,钢结构楼层处减小约17.4%,钢结构楼层及其下相邻楼层层间剪力增大约9%。弹塑性分析结果表明:在罕遇地震作用下,混合结构楼层最大水平位移整体上减小,在兰州人工波下减小的最多,约为33.41%,层间位移和层间位移角的变化规律相似,相比于原结构也都有所减小,兰州人工波罕遇地震作用下,在钢结构楼层处,层间位移和层间位移角减小值最多,约31.1%,楼层剪力在插入钢结构楼层后整体增大,在兰州人工波作用下增大最多约44.85%,同时塑性铰先出现在梁端,后出现在柱端,其发展符合强柱弱梁的设计准则。弹性及弹塑性分析都表明,插入钢结构楼层后由于部分柱高减小,且构件增多,致使结构整体刚度增大,层间剪力增加。在进行类似改造设计时要注意这种趋势造成上部结构构件内力的增大及基础内力的增大,由此可能对结构需要进行必要的加固补强;同时由于钢结构楼层主梁与原柱半层处相连,要注重此处节点设计及施工,以满足强柱弱梁的设计要求。
[Abstract]:Compared with concrete structure, steel structure is widely used in recent years. Compared with concrete structure, it has the advantages of good technology, safety and economy, light quality, good seismic performance, fast construction and so on. So far, China has not promulgated the design and construction code for the steel structure building. There are still the following problems in the mixed structure after the steel structure is raised: the stiffness and mass distribution in the vertical direction of the hybrid structure after the increase of the steel structure is not uniform. The damping ratio of the original concrete structure and the steel structure is different, and the connection between the two structures is difficult, which has an effect on the overall seismic performance of the hybrid structure. The main work of this paper is as follows: first, combined with a steel structure in Xi'an urban area, The structural design software PKPM is used to model the original reinforced concrete frame structure and the hybrid structure inserted into the steel structure floor respectively. The modal analysis of the whole model of the two structures is carried out. The mode decomposition response spectrum analysis and the dynamic time history analysis under frequent earthquakes are analyzed. Then the 3D finite element model of the original structure and mixed structure is established by using the finite element analysis software ETABS. The dynamic elastic-plastic time-history analysis of two kinds of structures under rare earthquake is carried out. The modal analysis results show that the original concrete frame structure is inserted into the steel structure floor. The elastic analysis results show that the maximum horizontal displacement of the floor decreases as a whole, and the steel structure floor decreases the most, about 34. The variation law of the interstory displacement and the interstory displacement angle is similar, that is, the overall decrease. The shear force between the steel floor and its adjacent floors increases by about 9. The elastic-plastic analysis results show that the maximum horizontal displacement of the mixed structure floor decreases as a whole under the action of rare earthquakes. Under the artificial wave of Lanzhou, the most decrease is about 33.41, the variation law of the interstory displacement and the interstory displacement angle is similar, compared with the original structure, it is also reduced. Under the earthquake action of Lanzhou artificial wave, under the action of the steel structure, at the floor of the steel structure, The interstory displacement and the interstory displacement angle decrease the most, about 31.1. after inserting into the steel structure floor, the floor shear force increases as a whole, and under the action of Lanzhou artificial wave, the maximum increase is about 44.85.The plastic hinge appears first at the beam end and then at the column end. Its development accords with the design criterion of strong column and weak beam. The elastic and elastoplastic analysis shows that the stiffness of the whole structure is increased due to the decrease of the column height and the increase of the members after the insertion of the steel structure floor. It is necessary to pay attention to the increase of the internal force of the superstructure member and the increase of the internal force of the foundation when carrying out the similar retrofit design, which may lead to the necessary reinforcement and reinforcement of the structure. At the same time, due to the connection between the main beam of the steel structure floor and the half story of the original column, the design and construction of the joint should be paid attention to in order to meet the design requirements of the strong column and the weak beam.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU352.11

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