Seismic Control of Cable-stayed Bridge Using Negative Stiffness Device and Fluid Viscous Damper under Near-field Ground Motions

ABSTRACT

Under near-field ground motions, fluid viscous dampers (FVDs) are effective in controlling deck longitudinal displacement but lead to the increase of bending moment and shear force at tower base. Negative stiffness (NS) devices are introduced in combination of FVDs for the bridge. The NS devices lengthen the fundamental vibration period of the bridge to reduce the spectrum acceleration whereas FVDs introduce extra damping to the bridge system to reduce the deck displacement. After implementing NS devices, designers have more options of designing FVDs for seismic control of the cable-stayed bridges while maintaining the design requirements under near-field seismic excitations.

KEYWORDS:

• Cable-stayed bridge
• seismic control
• fluid viscous damper
• negative stiffness device
• shear force