Study On The Strengthened Story Of High-rise Buildings With Frame-core Tubes

Over the recent decade, the strengthened stories in the high-rise buildings with frame-core tube structures are widely applied in practical engineering. When the overall lateral stiffness of the structure cannot meet the design requirements, larger stiffness of the horizontal outriggers or rigid rings can be placed in the available space of the refuge stories and the facility stories to form strengthened stories of the frame-core tube high-rise buildings. When subject to wind action, use of the strengthened story in the structure is more preferable; however, it shows a certain amount of limitation under earthquake action. Therefore, it is of critical importance to investigate the mechanical and damage characteristics of this type of structural system. This paper examines the setting issues of the strengthened stories of high-rise buildings with frame-core tubes based on an engineering example of the project proposal of the Changsha Poly International Plaza.In order to have a more clear understanding on the influence of the strengthened stories on the structure, the following researches are carried out, as shown below:1. The research on the engineering project design has done. By using SATWE software to simulate the proposed scheme of Changsha Poly International Plaza, the model of structural static calculation is explored, wind and earthquakes actions used in the calculation are interpreted, and the period, displacement, internal forces of structure are analyzed. In addition, the time history analysis of the elastic dynamic is carried out to compare with the time history analysis of the static effect, regarding to the final results and the force curves.2. The research of the strengthened stories effect on the elastic properties of high-rise buildings with frame-core tubes has done. On the basis of previous modeling, different solutions of strengthened stories (different quantities of strengthened stories and component forms) are analyzed computationally. Thus, the effects of those solutions on the period, lateral displacement and stress performance of structures are obtained. 3. The research of static pushover analysis of frame-core tube high-rise buildings with different settings of strengthened stories has completed. Using finite element software PUSH to perform the static pushover analysis of structure, the reaction performance of such structures under the relatively high magnitude of earthquakes is investigated in details. With regard to the modeling on four different settings of strengthened stories, it is able to analyze the sequence and position of the hinge, and compare their structural capacity curves, which reflects the weakness area between the strengthened story and its adjacent story. In addition, by using the method of dichotomous classification, an optimized design has been made by increasing the amount of horizontal outriggers and using "limited stiffness" of rigid rings.From the research above, the conclusions are worthwhile to be referred by the in-depth design of strengthen stories in the high-rise buildings with frame core tubes.