Study On Seismic Design Method Of Viscous Dampers Used In Rc Frame On The Slope

As one of the typical structure types, the characteristic of bottoms restricted unequally high lead to the congenital vertical irregularity of the structure on the slope. As some seismic damage investigations reflect, the first floor above the scarp is always the weak storey, of which the ground columns bearing heavy shear force are easily damaged. One of the problems which still puzzle many scholars and engineering designers is that how to improve the seismic performance of structures on the slope.This paper transforms the structure on the slope into the ordinary structure with bottoms restricted equally high according to the feature of bottoms restricted unequally high, and formulates the installation scheme of viscous dampers of structure on the slope by using the equal model’s structural parameters and the two distribution methods of damping constant, then use the dynamic time-history analysis method to study the seismic performance of structure with dampers, and search the seismic performance patterns of structure with different layer number of down-floors and layer cross out number after being installed dampers.The main conclusions achieved are as follows:① According to the equal rigidity theory, this paper puts forward the way of transforming the structure on the slope into the ordinary structure, then the dampers installation and seismic design method of structure on the slope can obey the design rules of generally regular frame structure. Then according to the performance targets, this paper searches for the application range of this equal method, and the results demonstrate that the effectiveness have business with the layer number of down-floors and layer cross out number.② The effectiveness of the method of storey damping constant proportion to the storey shear force is better than the average distribution method. Moreover this way can take account the different damper demand of different storeys. This paper gives the advice that we should choose the method of storey damping constant proportion to the storey shear force.③ The seismic reflection of floors below the scarp is less than the floors above the scarp. When the layer number of down-floors is less than 5, as the storey drift angle of floors below the scarp is much smaller than targets limited value, the practical engineering can ignore the installation of the floors below the scarp.④ The weak storey of structure on the slope is generally located at the first and the second floor above the scarp, with the layer number of down-floors and layer cross out number increasing, the beam end and the bottom of column of the part connected to the ground become easier damaged, while the down-floors get damaged lighter. Because of the energy dissipation of the viscous dampers, the whole degree of structure’s plasticity development is reduced. Because of the detrimental effect of the axial force, the damage degree of some components which are connected to the dampers is increased. Giving the advice that we should take account the the axial force detrimental effect on the connection nodes by the dampers.