Analysis Of Seismic Performance And Optimization Design Of An Vertical Irregular Exceed-code High-rise Frame-shear Wall Structure

With the speedy development of Chinese economy and the rapid progress of urbanization,the use of high-rise buildings with high space utilization has become more and more popular.Frame-shear wall structure,as a common structural system,is widely used in high-rise buildings for its advantages of dual lateral resistance,flexible use space and good economy.However,due to the different functions of the upper and lower structures,high-rise buildings often need to be equipped with a lower-level Equipment Sandwich Floor,which is called the "equipment mezzanine".The existence of mezzanine often easily causes the structure to be irregular in the vertical direction,which is mainly reflected in the changes in the lateral stiffness and shear capacity of the upper and lower floors,and the structure has weak and soft layers,which causes the structure to become an exceed-code high-rise building.In order to ensure the safety and reliability of the structure under the earthquake action,engineering designer need to take certain measures for the mezzanine,otherwise the engineering cost will increase greatly.Based on an example of a Frame-shear Wall Structure with a lower-level Equipment Sandwich Floor,this paper uses two different mechanical models modeling by YJK and ETABS software to analyze the forces and deformations under frequently occurred earthquakes,and discriminates structural irregularities.It was found that the existence of lower-level equipment mezzanine resulted in multiple irregularities in the structure.In order to address the mentioned problems,the author reviewed the related literature and combed the calculation concept of layer stiffness ratio,and determined the calculation method suitable for the selected engineering example in this paper.Various adjustment schemes based on two different concepts were proposed and related indicators were calculated.Their improvement effects were evaluated,and a scheme that could effectively improve the vertical irregularity of the structure under frequently occurred earthquakes was determined and its analysis of seismic performance under rare earthquake was added.Then,with the theory based on the three-dimensional solid degenerate virtual merging element,a finite element program was used,the three models were respectively subjected to elastic-plastic analysis under the action of two horizontal seismic forces,and Similarities and differences in seismic performance of the original scheme and the adjustment scheme were discussed in frequently occurred earthquakes and rare occurrences,and relevant conclusions are drawn.Then selecting some typical sections of the ground floor,the mechanics characteristic of the slab reinforcement was analyzed.The characteristics of the floor reinforcement in different parts of the slab are studied.At the same time,the space cooperation effect of the beam-slab-column wall is explored.Finally,a brief comparison of the economy between the original scheme and the adjustment scheme is made,which confirms the feasibility of the adjustment plan.Through the study of this subject,the measures of the common treatment of Equipment Sandwich Floor,the "combining layer" methods,have been studied and demonstrated in detail,providing guidance and reference suggestions for the design of similar projects.