含楼梯框架结构的抗震性能以及楼梯降撑效果分析

发布时间：2018-06-26 01:02

本文选题：地震作用 + 框架结构　；参考：《南昌航空大学》2017年硕士论文

【摘要】：框架结构是多层钢筋混凝土建筑中应用非常广泛的一种结构形式,在这种结构中,楼梯和主体结构往往是通过整浇方式连接在一起的,两者之间形成了较强的约束作用。在地震作用下,具有可观刚度的梯板会随框架一起发生较大变形,导致楼梯和框架的相互作用很大,不仅使得楼梯容易发生破坏,而且对框架结构本身的抗震能力也产生了一定程度的削弱作用。通过对汶川地震灾后现场的调查和分析发现,框架结构中的楼梯破坏最为严重,并且楼梯也往往先于框架发生破坏。减弱楼梯和框架的约束效果可以减小地震中楼梯和框架的相互作用,基于这种想法,我们可以对楼梯进行降撑设计来降低这种相互作用对楼梯以及框架抗震能力的不利影响。本文用SAP2000建立10个6层的钢筋混凝土框架结构模型,它们分别是:1个纯框架结构(不含楼梯)的CKJ模型,1个含有板式楼梯的框架结构模型(即未进行降撑设计的模型B),8个含有降撑楼梯的框架结构模型。主要研究内容如下:(1)用SAP2000建立各模型,然后进行模态分析计算各模型的自振振型和周期,通过分析各模型的自振周期了解不同类型楼梯对框架结构的刚度贡献。(2)分别对各模型进行多遇地震下的反应谱分析和线性时程分析,验算了结构弹性层间位移角,并且对层间剪力、楼梯间处框架柱内力和框架梁内力、梯板的内力和消能减震支座的附加阻尼比进行了计算分析。(3)分别对各模型进行罕遇地震下的非线性时程分析,计算各模型层间位移角、层间位移、顶点位移、滑动支座的水平弹塑性变形以及消能减震支座的耗能,并且绘制出消能减震支座的滞回曲线。(4)对各模型分别进行Pushover分析,从而计算各模型的能力曲线和性能点,通过观察各模型构件的塑性铰发展情况分析各模型构件的屈服顺序,从而对各模型在小震、中震、大震性能点处结构和构件的状态进行评估。通过将9个含楼梯的框架结构模型与模型CKJ进行对比分析,可以了解这9种楼梯对框架结构的抗震性能影响程度;根据8个含有降撑楼梯的模型与模型B对比分析结果,可以评估出这8种降撑楼梯的降撑效果。因此,本文的研究能够为设计者对楼梯进行降撑设计提供参考,从而实现改善框架结构抗震性能的目的,具有良好的工程实际意义。
[Abstract]:The frame structure is a kind of structure form which is widely used in multi-story reinforced concrete building. In this kind of structure, the staircase and the main structure are often connected together by the way of integral pouring. Under the earthquake, the ladder plate with considerable stiffness will deform with the frame, which leads to the great interaction between the staircase and the frame, which not only makes the staircase vulnerable to destruction. Moreover, the aseismic capacity of the frame structure is weakened to a certain extent. Through the investigation and analysis on the scene after Wenchuan earthquake, it is found that the staircase damage is the most serious in the frame structure, and the staircase is often destroyed before the frame. Reducing the constraint effect of staircase and frame can reduce the interaction between staircase and frame in earthquake. Based on this idea, we can design stair to reduce the adverse effect of this interaction on the seismic capacity of staircase and frame. In this paper, 10 six story reinforced concrete frame structure models are established with SAP2000. They are: 1 CKJ model of pure frame structure (without stairs), 1 frame structure model with plate staircase (that is, model B), 8 frame structure models with falling stair. The main research contents are as follows: (1) each model is established with SAP2000, and then modal analysis is carried out to calculate the natural vibration mode and period of each model. By analyzing the natural vibration period of each model, the stiffness contribution of different staircases to the frame structure is understood. (2) the response spectrum analysis and linear time history analysis of each model are carried out respectively, and the displacement angle between the elastic layers of the structure is checked and calculated. The interstory shear force, the internal force of the frame column and the internal force of the frame beam at the staircase, the internal force of the ladder plate and the additional damping ratio of the energy dissipation support are calculated and analyzed. (3) the nonlinear time history analysis of each model under rare earthquake is carried out. The interstory displacement angle, interstory displacement, vertex displacement, horizontal elastic-plastic deformation of sliding support and energy dissipation of energy dissipation support are calculated, and the hysteretic curve of energy dissipation support is drawn. (4) pushover analysis is carried out for each model. The capacity curves and performance points of each model are calculated, and the yield order of each model member is analyzed by observing the development of plastic hinge of each model member. The state of structures and members at seismic performance points is evaluated. Through comparative analysis of 9 frame structure models with staircase and CKJ model, we can understand the influence of these 9 kinds of staircases on the seismic performance of frame structures, and according to the comparative analysis results of 8 models and model B with down-braced staircases, We can evaluate the effect of these eight kinds of stair. Therefore, the research in this paper can provide a reference for designers to design stair strut, and achieve the purpose of improving the seismic performance of frame structure, which has good engineering practical significance.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU352.11

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