Design And Analysis For Seismic Behavior Of Connected Twin-tower Structures With An Enlarged Base

The tall building with connective structures includes twin towers or multi-towers connected by a connective structure (or connective corridor) in a location along its height. Under the earthquake, towers which vibrate severally if there is no connective structures occur interacting because of the connection. Their responses are more complex than that of a single tower or twin towers without the connective structure. Vibration coupling and torsion increasing will occur. So the seismic behavior is not good as that of a single structure. According to "Technical specification for concrete structures of tall building" (JGJ3-2003), the connective structure belongs to complex structures of tall building. They should be designed as a strict seismic configuration.The connective structure coordinates the deformation between two towers. Under the earthquake, it is subjected for a force from the vertical loads, also tension, compression, bending and shearing from coordinating the deformation between two towers. Therefore it is important to analyze the seismic behavior of the connection in connected tower structures.In this paper the main research includes followings:1) Some problems are studied, such as the connecting configuration between the connection and towers, the stiffness changes and the location changes of the connection. Elastic response-spectrum analysis is carried out for unsymmetrical connective structures and symmetrical connective structures respectively by use of SATWE software in finite element method to get the earthquake responses of structures. It is concluded that the effect by the changes of supporting form, stiffness and location of the connection is not important. The connection between twin towers can enhance the whole stiffness and the natural periods decreases.2) To investigate the dynamic response, the response spectrum analysis and elastic time-history analysis are carried out for a practical structure. By EPDA software the elastic-plastic time-history analysis and static elastic-plastic analysis (Push-over) are completed to evaluate the structural seismic behavior.3) The weak areas are found and strengthening configuration for those areas ispresented. It makes a valuable reference for designers when designing this kind of structures.