Seismic Performance Analysis Of The Double-tower-connected High-rise Steel Structure With Viscoelastic Dampers

The Double-tower-connected structure with enlarged base is a new topic to the high-rise building's structural design at present. According to the application and less research analysis in overall seismic performance of the double-tower-connected structure both at home and abroad, as well as smaller damping and capacity of energy dissipation and more sensitive to seismic etc. weaknesses the high-rise steel structure it has, the question that is improving the seismic performance of structure is raised in this article. In order to improve the seismic performance of structure, we can make use of structural vibration control, such as viscoelastic damper which is a passive control device. Viscoelastic dampers can dissipate seismic energy by increasing the structural damping, so as to achieve the goal of improving structural overall seismic performance.Finite element software MIDAS/GEN was used to establish structural three dimensional model which is based on a 25-storey double-tower-connected high-rise steel structure in this paper. According to characteristics of the structure, three different positions of layout program of viscoelastic dampers are taken in the paper, and then MIDAS/GEN was used to analyze structural vibration characteristics four kinds of programs and elastic time-history analysis under frequent earthquake action. At last, vibration characteristics and seismic effects of dampers'three different programs are compared, conclusions are following:(1) Natural vibration periods of three controlled structures are much smaller than that of non-controlled structure, but the change is very small, which shows that viscoelastic damper can enhance structural seismic capacity mainly by increasing structural damping.(2) Viscoelastic dampers which are laid on braces of connector location can reduce structure's torsion effect under high mode and increase horizontal movement.(3) Viscoelastic dampers can inhibit structure's seismic response significantly, and can reduce largest shear and displacement of non-controlled structure remarkably, as well as be able to make time-history curves of top floor's displacement, velocity and acceleration present reduced trend with the change of time which shows that viscoelastic dampers can improve seismic performance of structure largely, thus make the safety of structure has a reliable guarantee. (4) Both dampers laid in the internal tower and lay in braces of the enlarged base and connector can reduce the seismic response of X, Y directions at the same time; but dampers which are laid on braces of connector location only can control the seismic response of X direction.In general, for double-tower-connected steel structure of high-rise building, appropriate viscoelastic dampers lay in structure can improve the seismic performance significantly and ameliorate the habitability of the building, thus make the safety of structure has a reliable guarantee.