Piece Structural System Dynamic Analysis Of Vertical Seismic Action

The high-rise building with connective structures includes twin towers or multi-towers connected by a joining (or connective corridor) to a definite height. Under the earthquake, towers which vibrate severally in the case of no connective structures will be an interaction because of the connection. Their responses are more complex than that of a single tower or twin towers without the connective structure, and vibration coupling and torsion increasing will occur. According to "Technical specification for concrete structures of tall building" (JGJ3-2003), the connective structure belongs to complex structures of tall building. Some more detailed analyses have been done for these structures in literature [1]-[9].In recent decades, vertical seismic action has become a more and more important subject to engineers. The earthquake macro-phenomena have demonstrated that the influence of the vertical seismic motion is obvious in high intensity area. Especially that the large-span connective structures become more sensitive to the vertical libration because of the large span. And the libration of the joining will lead to the destroy of the connecter and partial destroy of main body structures. According to "Design criterion of architectural aseismatic" (GB50011-2001), the long-cantalever and the others large-span structures should be calculated the influence of the vertical seismic action in 8 degrees and 9 degrees area. Therefore, the dynamic response analysis of this kind of structures is become very important for us. For that, the main dynamic analysis has been done to the large-span connective frame structures in vertical seismic action in this paper.In this paper the main research work includes followings:(1)The member model is carried out to describe the system of connective structures, and then it is discretized to form the model of serier-parallel-connection system with considering three degrees of freedom. In this paper the way of static condensation is used to eliminate the other displacement couplinged with the vertical displacement and get the characteristic matrix equation of the vertical libration.(2) ANSYS software in finite element method is used for the mode analysis of the single and whole structures .(3) Some problems are studied, such as the stiffness changes and the location changes of the connection, the connecting configuration between the connectionand towers and connected twin-tower structures with an enlarged base. Time-history analysis is carried out for symmetrical connective structures in finite element method to get correlative conclusion.