Seismic Response Analysis Of A Large Chassis With A Large Base Of Twin Towers

Big chassis towers connected structure is a high-rise building structure form, it is formed by podium chassis and connecting body is set in a high position to connect relatively independent towers together. Such architectural appearance is novel and unique,and space can be used effectively, at the same time, it can also satisfy the using multifunction demand of the project owner. Therefore, this kind of structure has gradually become the popular choice of high-rise buildings. Such structures are large in vertical, the stiffness of the upper structure reduces seriously, the roof of the podium is a weak positions, at the same time, each tower will interact when the structure under seismic action due to the existence of the connecting body, making the structure suffer strong couple effect. This article is on the basis of the information about the big chassis twin towers conjoined structure at home and abroad, combined with practical engineering,thorough research is carried on the dynamic characteristics of large chassis twin towers conjoined structure under frequent earthquakes to provide the basis for the application of this kind of structure in the future, and to provide reference for further research. This paper mainly includes the following four aspects:(1) PMSAP software is used to establish single and twin towers finite element models, and three twin towers models with connect bodies respectively arranged on the up, middle and the bottom of the structure.(2) PMSAP software is used to analyze the dynamic characteristics of each model,research shows that the dynamic characteristics and seismic response of the double tower,twin towers and the twin towers conjoined structure are different obviously, connecting body also has significant impact on the dynamic characteristics and seismic response of the twin towers conjoined structure. The earthquake response of the single tower and the twin towers is very normal, twin towers conjoined structure torsion effect enhanced obviously. The higher the connecting body position is, the stronger the connection effect between the two towers is, and at the same time as the additional quality of conjoined itself, the maximum floor displacement and the maximum interlayer displacement angle will become greater. Connecting body lays on a low position, the two towers connected effect is not obvious, seismic responses of the twin towers conjoined structure is closer to the twin towers.(3) PMSAP software is used for the internal force analysis of the components of each connection object itself and the conjoined structure. The structural vibration mode and the internal force changes of connecting body and connectors are analyzed considering the vertical seismic action.(4) The elastic time history analysis under frequent earthquakes is carried out on the twin towers conjoined structure, then compare the result of the analysis with the result of mode decomposition response spectrum method.