Structural Analysis And Design Of Oriental Times Plaza In Xiamen

Multi-towers structure with transfer story, which is liable to satisfy the architectural function that small space should lay at the top of the building while big space on the bottom, have been applied widely, but methods and experiences about structural design of such complex tall building are absent at present and the relative regulations in the code are not definite and not liable to operate. In this paper, taking the structural design of complex tall building-Oriental Times Plaza in Xiamen as an example, the dynamic characteristics and analysis method as well as the seismic concept design of complex tall buildings are investigated, then, the rules, problems and corresponding solutions worth to pay attention to are summarized.Corresponding to the characteristics of Oriental Times Plaza in Xiamen which contains transfer story and three towers conjoined together, based on the systematic analysis of the design methods, research productions and practical applications of complex tall building especially with muti-tower and transfer story, the structure are analyzed using two current programs and the results from two program are compared, meanwhile, the constructional enforcement measures and main solutions of some key problems are proposed according to the dynamic response features of the structure. The main analysis conclusions which can directly apply in the design and be consulted by other projects are as following:(1) Earthquake action effects increase so seriously as to generate weak story, because of the change of mass and rigidity near the transfer story in structures with large base, multi towers and transfer story. The ratio of story shear rigidity as well as the equivalent lateral rigidity ratio of story above the transfer story to the story under the transfer story should be designed properly to avoid the transfer story becoming weak story, thus the shear walls and the columns in the large base will not yield before the elements above the transfer story;(2) The translation-torsion coupled effects and the vibration in the plane should be considered in analysis of structure with large base and muti-towers. Generally, the analysis model of structure should not be simplified into structure with only one tower unless the rigidity of large base are more than the one of the tower and it is necessary to make the elastic-plastic time history analysis;(3) It is necessary to make supplementary time history analysis of tall building with muti-towers when the layout of the structure is asymmetry. The number of modes should beselected according to the participant coefficient of mode when calculating the internal force by the response spectrum method;(4) The roof plate of large base which connect the towers together should be thick enough but not exceeding the proper scope that the towers and the large base can vibrate together,(5) In structures with large base and muti-towers, with increasing of the capacity of the large base, the inter-story shear force will increase while the inter-story displacement will decrease as to fulfill the ductility request to avoid the large base becoming weak story, but meanwhile, the upper story will turn into weak story, thus the coefficient r s should be within 2.0~3.0.