Seismic Design Based On Performance Of A High-Rise Building And Analysis Of Strengthened Layer

With the development of modern science technology, high-rise buildings start to spring up in China. Building structures have become increasingly sophisticated in order to meet various needs, in which the choice of strengthened layer and seismic design of high-rise building have become the focus of the scholars from different countries.On the basis of summing up the seismic analysis method, a high-rise building beyond code limits with 164.0 meters height and 49 above-ground layers is analyzed in this paper. The structure applies the concrete frame-core tube system, in which there are two refuge layers on 16th and 32nd floor. In order to study the displacement and inner force response and optimize the structure, the main works are carried out as follows:1) Elastic analysis of the high-rise building under frequent earthquake and wind load is conducted by applying the finite element program Midas Building. The computation results include natural vibration periods, period ratio, story drift angle, shear, overturning bending moment, shear-weight ratio, lateral stiffness ratio, shear bearing capacity ratio of the structure, etc. According to the results, the indicators of the overall structure can meet the requirements of the specifications concerned.2) Dynamic elastic-plastic time history analysis of the high-rise building under rare earthquake is conducted by applying the finite element program. According to the calculations, the maximum of elastic-plastic story drift angle is 1/150 and no main lateral resisting components are severely damaged.3) Based on the former study, four finite element models with different number of strengthened layers are established to analyze the effects of lateral resisting optimization because the depth-width ratio of the core tube in Y direction is a little large. By comparison of the free vibration analysis of the 4 different models, it is found that strengthened layers can decrease the natural vibration period by increasing the integral stiffness of the structure and have a greater influence on low order vibration periods compared with high order periods.4) By comparison of static analysis under wind load, response spectrum analysis under frequent earthquake and dynamic elastic-plastic analysis under rare earthquake of the 4 different models, it is obviously found that strengthened layers can decrease the lateral displacements effectively. However, the strengthened layers can cause the sudden change of story drift angle and inner force of core tube and frame nearby. On the other hand, the plastic state proportion of the shear wall near strengthened layers can increase within the structure. Hence, the conclusions in this paper can provide a reference for the designation of similar kinds of projects.