A practical design method for reinforced concrete structures with viscous dampers

As a result of the 2008 Wenchuan Earthquake, the Chinese government issued a modified seismic code with increased protection categories and seismic intensities. According to the new code, a lot of school and industrial buildings need to be seismically retrofitted to satisfy the new seismic requirements. Compared to the retrofitting technology of seismic isolation, the installation of viscous dampers to those existing buildings is more realistic because of easy construction. However, the design of viscous dampers, which provides a high level of damping in a structure, is a relatively new application in China for a well-established and proven technology in other seismically active regions in the world. Only general information on the usage of viscous damper is given in Chinese code, which would potentially confuse engineers and researchers. Thus, the intent of this paper is to propose a practical design method for reinforced concrete (RC) structures with viscous dampers. The proposed design process is divided into two stages. In the preliminary stage, the quantity, mechanical parameters and configurations of the viscous dampers are determined. In the next stage, the reduction of deformations, additional damping ratio, and connection of the dampers to the structure are examined. An example is also given to demonstrate the application of the proposed method to retrofit a RC frame structure by viscous dampers. It is concluded that the proposed design method satisfies the urgent requirement of design and pushes the further development of research on viscous dampers.

► Adding viscous dampers is an effective way to retrofit buildings after earthquakes.
► A two-stage practical design method for RC structures with viscous dampers is proposed.
► First, quantity, mechanical parameters and configurations of dampers are determined.
► Second, structural deformations, damping ratio, and connection of dampers are examined.
► An example is given to demonstrate the application of the method.