某超高层巨型支撑框架—核心筒结构地震倒塌研究

发布时间：2018-03-26 14:51

本文选题：超高层结构　切入点：巨型构件　出处：《清华大学》2013年硕士论文

【摘要】：随着超高层建筑的迅猛发展，超高层结构已成为土木工程领域的研究热点。由于超高层结构体系复杂，体量庞大，与传统高层结构有较大不同，目前相应的设计方法和计算模型的研究都较为有限，尚不能适应工程应用的发展。本文以实际工程项目为背景，，对某超高层巨型支撑框架-核心筒结构（结构高度约550m）的两个主要初步设计方案--全支撑方案和半支撑方案开展了研究，主要内容包括：（1）对超高层结构中巨型构件的数值计算模型进行了文献调研和初步研究。建议对该超高层结构，采用分层壳模型模拟组合剪力墙，纤维模型模拟巨型支撑，基于有限元软件二次开发子程序的纤维模型模拟巨型柱。并对方钢管混凝土柱轴压承载能力的尺寸效应开展了研究，通过试验数据与计算结果的比较，发现现有的设计计算公式存在着不同程度的随着构件尺寸增大而计算值偏大的趋势，提出了考虑尺寸效应的承载力修正建议。（2）对该超高层巨型结构开展了抗震弹塑性分析、地震倒塌模拟和地震倒塌易损性分析。抗震弹塑性分析结果表明该超高层巨型结构设计较强，具有较高的抗震能力，在8度设计大震下仍基本保持弹性；地震倒塌易损性分析结果表明该超高层巨型结构具有较高的抗地震倒塌安全储备；而地震倒塌模拟的结果表明，在极端罕遇地震下，该超高层巨型结构的倒塌模式为竖向倒塌，而不是水平倾覆倒塌。全支撑结构模型的抗震能力与半支撑结构模型相当，而混凝土用量有明显降低。（3）建立了该超高层巨型结构的弯曲-剪切模型和杆系简化模型。弯曲-剪切模型由弯曲梁和剪切梁组成，可以考虑结构弯曲变形和剪切变形的组合。通过合适的参数取值，弯曲-剪切模型可以准确把握结构的基本动力特性并极大节省计算工作量。杆系简化模型将三维模型简化为二维模型，可以准确计算结构的基本动力特性并预测结构的非线性地震响应。简化模型可为结构方案初步设计和方案比选提供参考。（4）采用该超高层巨型结构的杆系简化模型进行了结构耗能计算。通过计算结构在不同地震动强度下的耗能，可以定量评价结构各类构件的耗能贡献，明确各类构件的耗能主次关系，同时可以明确结构的区域耗能分布情况，从而为结构的性能化设计提供参考和依据。
[Abstract]:With the rapid development of super-tall buildings, super-high-rise structures have become a research hotspot in the field of civil engineering. At present, the research of the corresponding design method and calculation model is very limited, so it can not adapt to the development of engineering application. This paper takes the actual engineering project as the background. In this paper, two primary design schemes of a super-tall mega braced frame-core tube structure (the height of structure is about 550 m)-full bracing scheme and half bracing scheme are studied. The main contents are as follows:. In this paper, the numerical calculation model of mega-members in super-tall structures is investigated and preliminarily studied. It is suggested that laminated shell model be used to simulate composite shear wall and fiber model be used to simulate giant braces. Based on the secondary development of the finite element software subroutine fiber model is developed to simulate giant columns. The size effect of axial compression capacity of concrete filled steel tubular columns (CFST) is studied. The experimental data are compared with the calculated results. It is found that the existing design calculation formulas tend to be larger with the increase of the member size to varying degrees, and some suggestions are put forward to amend the bearing capacity taking into account the size effect. The aseismic elastic-plastic analysis, earthquake collapse simulation and seismic collapse vulnerability analysis of the super-tall mega structure are carried out. The results of seismic elastic-plastic analysis show that the super-tall mega structure is of strong design and high seismic resistance. The results of seismic collapse vulnerability analysis show that the super-tall mega structure has a high safety reserve against earthquake collapse, and the results of earthquake collapse simulation show that under extremely rare earthquakes, the earthquake collapse simulation results show that, The collapse mode of the super-tall mega structure is vertical collapse rather than horizontal overturning collapse. The seismic capacity of the full-braced structure model is similar to that of the semi-braced structure model, but the concrete content is obviously reduced. The bending shear model and the simplified bar system model of the super tall mega structure are established. The bending shear model consists of a bending beam and a shear beam. The combination of bending and shear deformation of the structure can be considered. The bending shear model can accurately grasp the basic dynamic characteristics of the structure and greatly reduce the computational workload. It can accurately calculate the basic dynamic characteristics of the structure and predict the nonlinear seismic response of the structure, and the simplified model can provide a reference for the preliminary design of the structural scheme and the selection of the scheme. The energy dissipation of the structure is calculated by using the simplified model of the super tall mega structure. By calculating the energy dissipation of the structure under different ground motion intensity, the energy consumption contribution of various structural members can be quantitatively evaluated. The main and secondary relationships of energy consumption of various kinds of components can be defined, and the distribution of energy consumption in the region of structures can be determined, thus providing a reference and basis for the performance-based design of structures.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU973.17;TU973.31

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