| High-rise frame structure of reinforced concrete is the main structure form of office,residential, shopping malls and other buildings in China’s earthquake region, so its seismic performance received much attention of researchers and engineers.Seismicdesign based on performance is an advanced theory in the current world, the design of structural engineering based on performance objectives, the structure and component’s ability to fight earthquake is predictable. The method is convenient for engineers to improve design until it satisfies the requirements of building codes or the owner. The performance-based design has great difference from the concept of traditional seismic design,it is widely used in the current super high-rise structure.In the seismic design of buildings, the control of the lateral stiffness of reinforced concrete structures is a major contradiction. The measures are taken to improve the grade of concrete, increase the amount of reinforcement and the section size of components to meet the requirements of building codes for the lateral stiffness of structure. But these measures will increase the cost of the project, affect the use of the building function, and make the economy rationality of the structure is poor. Therefore, this paper takes a four story RC frame structure in the 0.3g area of Haikou as an example, it study and discuss the reasonable limit value of the displacement of the RC frames in the high seismic intensity area by comparing the conventional design and the performance design.The main content of this paper is as follows.1. Briefly describes the development process of seismic theory of building structures and the requirements of the world’s norms on the displacement angle between the layers.2. The nonlinear analysis software Perform-3d and the choice of the structural component model are introduced in detail. In this paper, the frame column is used as the object of analysis. The fiber model is more detailedand can better show the deformation of column members,but the calculation is large. In the paper,the beam element is not the focus of the study and more. Therefore the plastic hinge model is used for the frame beam.The plastic hinge model has many advantages, such as fast calculation speed, high efficiency,clear concept and so on.3. Comparative analysis of two frame structure models 1- model with conventional method - small earthquake elastic design, drift angle as the frame structure of 1/551;2-model using aseismatic performance design, elastic layer displacement angle for the frame structure of 1/502. The YJK software was used to make the small elastic design of the model, and the Perform-3D software was used to analyze the elastic-plastic behavior of the model.4. The elastic-plastic calculation results of the two models show that At the earthquake fortification, most of the column members of the model 1 have yield, and all column members of model 2 haven’t yield ,except for second story column. At the rare earthquake,two models have not collapsed.5. In the Chinese code for seismic design of buildings, the limit value of elastic Inter-storyDisplacement Angle is 1/550. Butthe limit value is not a necessary condition for seismic design of structures in the high intensity region. In this paper,the performance of the frame column of model 2 is designed,its seismic performance is better than model 1. As a result, the limitation of the elastic Inter-storyDisplacement Angle of the frame structure is too strict. In this paper, it is suggested that the elastic Inter-storyDisplacement Angle is used as an auxiliary index to consider the relaxation of the standard limit, or directly on the structure in seismic design calculation. |
PDF Full Text Request