The Performance-based Seismic Design And Analysis Of A Transfinite High-rise Structure With Oblique Lateral Force Components

With the acceleration of urbanization,the form of regular architecture has been unable to meet the requirements of modernization of urban construction.The super high-rise building with inclined columns and inclined walls has unique architectural facade effect,which is well received by architects both at home and abroad.Compared with the common structure,the mechanical characteristics and design of the italic structure are more complex.At present,the correlation studies about italic structure are very little and the code does not give the design method of this kind of building.In view of the above problems,this paper combines performance-based seismic design method,takes a transfinite high-rise project with oblique lateral force members in Qingdao as an engineering example,uses YJK and MIDAS two softwares to design and analyze the structure,puts forward the corresponding strengthening measures.Specific research work and conclusions are as follows.First of all,the over-limit of the structure is judged and the corresponding seismic performance targets are formulated.The structure that has torsional irregularity,floor discontinuity,multiple irregularities belongs to B-class height overrun structure.Secondly,the seismic design of the structure is carried out under small earthquake,In addition,it analyzes the elastic time of the structure as a supplementary check calculation,the analysis finds that the oblique columns can reduce the interlayer displacement Angle of the structure,Vertical braces can improve the lateral stiffness of the structure and reduce the top level displacement.The structure can meet the performance target of “the structure will not be damanged under small earquathe”.Thirdly,the middle seisms calculation and un-yield analysis of key components under major earthquake are conducted.The studies show that: the shear reinforcement of key components such as oblique column is normal and the shear capacity of the section under the large earthquake meets the requirements.The structure is able to meet the performance targets of elasticity under moderate earthquake,unyield under the major earthquake.In order to observe the whole process of component damage more clearly,the elastoplastic calculation is conducted,the results show that the interlayer displacement Angle of the structure is less than the norm limit and the structure meets the performance goal of “the structure will be stable under rare earthquake”,complies with the design requirements of “trong columns and weak beams”.And then,the influence of inclined column and inclined wall on structure are studied,the results of calculation show that the oblique column has a large influence on the shear force and bending moment of the normal straight column,and the influence is related to the distance from the oblique column,the further away from the oblique column,the smaller the influence is;The horizontal force component of the inclined column makes the floor beam connected with the inclined column bear the greater axial force.Besides,the inclined wall structure produces both vertical displacement and a certain amount of horizontal displacement under load;There is a large vertical displacement difference between two ends of horizontal beam plate connecting the straight wall and inclined wall,and the farther from the connecting part,the greater the displacement difference.Finally,according to analysis results,the corresponding strengthening measures and suggestions are put forward for similar engineering design reference.