基于内力突变的带加强层混合框—筒结构分析

发布时间：2019-02-13 04:15

【摘要】：近年来，全国各地涌现出了一大批可作为城市地标的超高层建筑，为了适应更高的建筑高度，传统的钢筋混凝土结构逐步被性能更加优良的型钢混凝土组合结构所取代。在框架-核心筒结构中设置水平伸臂加强层是控制结构侧移的一种常用手段，但同时会引起结构刚度、内力突变，对抗震不利。因此，重点考虑内力突变因素，对型钢混凝土组合框-筒结构的加强层设置进行优化具有重要的工程实际意义。本文以一栋36层、140.4m高的实际带加强层的型钢混凝土组合框-筒结构为原型，利用有限元软件ETABS建立了简化模型，通过对变量不同的十八组方案进行对比分析，研究了钢桁架伸臂加强层的位置、数量和刚度对型钢混凝土组合框-筒结构以下力学性能的影响：（1）结构自振特性；（2）水平荷载作用下位移；（3）7度多遇地震作用下内力等，并在此基础上结合工程实际对方案进行了优选，得出了以下主要结论。设置水平伸臂加强层在适当位置可以有效增加结构抗侧刚度，减小结构自振周期和水平侧移，加强层设置在中部时地震作用下内力突变最大；设置多道加强层位移效果更好，内力突变会减小，但核心筒剪力增大较多且不经济。随着加强层刚度的增加，在位移减小更多的同时内力突变更剧烈，设置两层高的加强层可以大幅减小结构的内力突变。对实例工程而言，一道加强层设置在0.8H处可取得较好的位移和内力突变效果，实际工程中得出了在满足结构总体抗侧刚度要求的同时应尽量使加强层刚度最小，，并可以考虑将加强层布置为两层楼高进一步减小结构在地震作用下的内力突变等相关结论。
[Abstract]:In recent years, a large number of super-tall buildings which can be used as urban landmarks have emerged all over the country. In order to adapt to the higher building height, the traditional reinforced concrete structure has been gradually replaced by the reinforced concrete composite structure with better performance. It is a common method to control the lateral displacement of frame-core tube structure by setting a horizontal cantilever strengthened layer, but at the same time, it will cause structural stiffness and internal force abrupt change, which is unfavorable to earthquake resistance. Therefore, considering the sudden change of internal force, it is of great practical significance to optimize the strengthening layer of steel reinforced concrete composite frame-tube structure. In this paper, a 36 story, 140.4 m high steel reinforced concrete composite frame-tube structure is used as the prototype, and the simplified model is established by using the finite element software ETABS, and the 18 groups of different variables are compared and analyzed. The influence of the position, quantity and stiffness of the steel truss extension arm strengthened layer on the mechanical properties of the steel reinforced concrete composite frame-tube structure under the following conditions is studied: (1) the natural vibration characteristics of the structure; (2) displacement under horizontal load, (3) internal force under frequent earthquake of 7 degrees, etc., and based on this, the scheme is selected in combination with engineering practice, and the following main conclusions are obtained. The lateral stiffness of the structure can be increased effectively and the natural vibration period and horizontal lateral displacement of the structure can be reduced by setting the horizontal extension arm strengthened layer in the proper position. The internal force mutation is the largest when the strengthening layer is set in the middle part of the earthquake. The displacement effect of multi-channel strengthened layer is better and the sudden change of internal force will decrease, but the shear force of core tube increases more and is not economical. With the increase of the stiffness of the strengthening layer, the internal force mutation is more severe while the displacement decreases more, and the internal force abrupt change can be greatly reduced by setting the two-story high strengthening layer. For the practical engineering, the displacement and internal force sudden change effect can be obtained by setting a strengthened layer at 0.8H. In the actual engineering, it is concluded that the stiffness of the strengthened story should be minimized while satisfying the overall lateral stiffness requirement of the structure. We can also consider the conclusion that the strengthening story should be arranged as two stories height to further reduce the sudden change of internal force of the structure under earthquake action and so on.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU973.14

【相似文献】