Seismic Analysis Of The Asymmetric High-Rise Building

With the development of national economy, more and more asymmetric high-rise buildings are built. Because of their complex structure, much stress is laid on their seismic design and analysis. China is an earthquake active country, so the deep study of earthquake resistant behavior of asymmetric structure is of great significance. Incorporating with the model static and dynamic Finite-Element seismic analysis of a asymmetric structure in plan and elevation, the paper gives the earthquake resistant of such structure, and also establishes a foundation for further research and provides a reasonable design guidelines.It is necessary to decide the reasonable mode number when we analyze earthquake action in construction design. There are some advice and computation methods on reasonable mode number in some internal and external books, but these methods have no sufficiency testimonies, so it's important that how to decide the reasonable mode number in more rational method. The paper computes the required modes and analyzes their torsion effects on system.SAP2000, a FEA software, is used to conduct the finite element analysis of the structure, including static analysis, response spectrum analysis and time history analysis. The earthquake reaction of the structure was studied. By summarizing of the results, the data of internal force and deformation was got exactly. Because of the asymmetry of structure in plan and elevation, the paper computes the structure's reaction under seismic action by hypothesis of elastic floor and compares the results with that of rigid floor hypothesis.Finally, as compared the translation-torsion coupling seismic response of asymmetric high-rise building subjected to bi-directional with unidirectional earthquake motions, the results illustrate that the aseismic capacity of structure in the case of bi-directional earthquake is worse, which accords with the conclusion that Code for seismic design of building emphasizes. That is the torsion effect under bi-directional earthquake action on the structure with remarkably uneven and asymmetric distribution of mass and stiffness should be considered.