Performance-Based Seismic Research On A Large Base Double-Tower Over-Limit High-Rise Structure In Tianshui

The double-tower structure with large chassis has novel architectural shape and diversified use functions.It can meet the use requirements of owners and reflect the design personality of designers.In recent years,it has been applied more and more in practical projects.However,due to its extremely complex force,the torsion effect of this kind of building structure under earthquake is larger,and its damage is more serious.Previous earthquake disasters have also shown that complex high-rise buildings are prone to damage or even collapse as a whole.Therefore,it is particularly important to study its seismic performance to ensure the safety of structures under different earthquake action.In this paper,an asymmetric two-tower over-limit high-rise structure with large chassis in Tianshui is selected as the research object,and its seismic performance is analyzed and studied.Under the action of frequent earthquakes,Midas/Gen and YJK-A software are used to analyze the whole structure and single tower structure of Tower A and B respectively by mode decomposition response spectrum method.Seven seismic waves are selected by YJK-A software and elastic time history supplementary analysis of the whole structure is carried out at the same time.Seven seismic waves are selected by YJK-EP software for dynamic elasticplastic analysis of the whole structure under rare earthquakes.The following conclusions were obtained:(1)Structural floors have uniform mass distribution,reasonable layout of anti-lateral force components,no significant torsion effect,no obvious weak layer,members are in an elastic state,and the maximum inter-story displacement angle is less than the limit requirements of frame-core tube structure and frame-shear wall structure in grade D performance objectives;(2)There is no damage hinge at the junction of the skirt floor and the main building,but there is tension and compression damage hinge at the side column of the floor and there is a sudden change in the stiffness of the floor.The structure of the floor should be strengthened in design;(3)Under seismic excitation,the elastic-plastic time history curve and the elastic time history curve are separated,and the amplitude and frequency are not synchronized,so the structural materials enter the plastic state under seismic excitation;(4)With the input of seismic wave,slight damage occurs on the wall limbs in the reinforced area.The damage of frame beams is obvious and large in number.The local damage of columns and walls is serious,and there is no overall damage.The main bearing walls did not suffer large area plastic damage,and the structure remained upright eventually.Under rare earthquakes,there would be no overall collapse of the structure;(5)The key components of the structure can achieve the seismic performance target of magnitude D or above,and the overall structure meets the design concept of "small earthquake is not bad,large earthquake is not collapsed".