The Research On The Mechanical Characteristics Of Two-tower Connecting Structures Subjected To Seismic Action

The twin-tower connected structures which widely developed in recent years are a new structure system. It is composed of two towers and an overhead body joining the two towers together. Many scholars in home and abroad have done a lot of experimental and theory researches on the structures, but most of them used the discrete method, and they did little study on the connecting body and the joint. Studies on structural properties, static behaviors and dynamic characteristics, seismic and wind-induced responses of the Double-Tower-Connected Structures are given systematically in this paper, which gives help to a deeper understanding of the basic conception for the Double-Tower-Connected Structures. Based on the existing research findings, semi-rigid connections to analyze the system and the static & dynamic characteristic of the connecting body are presented in this paper .Firstly, the computation model for analyzing the twin-tower connected structural which are commonly used in projects were generalized, and the structures properties under loads and its applicable conditions of each form were analyzed. Secondly, piecewise continuous series-parallel connection model is taken as the computational modal for the enlarged-base-multi-tower-connected structures.Comparing with the single tower structures, the twin-tower connected structures are a system comprising with multiple components, and it's so important to grasp the interaction mechanism among the components. Comparing with the Double-Tower- Connected Structures without connections, the connections are the keys to interco- -nnect the components and emphasis is put on the analysis of the connections in this paper. Effects of many factors, such as symmetry of two towers, connections stiffness and location etc., on the static and dynamic behaviors, seismic and wind-induced responses of the Double-Tower-Connected Structures are investigated in detail.Both modes of the symmetry twin-tower connected structures when the connecting body lacated in different locations and the asymmetry twin-tower connected structures, and the response of the connecting body on which vertical earthquake acts were analyzed by using the response spectrum method. The twist and coupled modes of the asymmetry twin-tower connected structures were more complicated than the symmetry ones. The taller position of the connecting body, and the more asymmetry of the two towers, the greater response of the connecting body on the vertical earthquake.For the beam-to-column joint between the towers and the connections, people always treat as fully rigid or pinned ones to simplify the calculation of the steel frames in traditional designs. In fact, most of beam-to-column connections will be either pinned or fully rigid ones. They belong to semi-rigid ones. Extensive studies show that the behaviors of semi-rigid connections would make great effects on the behaviors of steel frames, such as the internal forces, the horizontal deflection, the ultimate load-bearing capacity and the daynamic behaviors, which could not be neglected to design the steel frames. According to the mechanics performance of semi-rigid connections, the elastic stiffness matrix and geometrical stiffness matrix of this kind of structures are generalized by revising its rotation-displacement equations.