Seismic retrofit of an existing single-plane steel cable-stayed bridge was performed against large-scale (Level 2) site-specific ground motions. Three-dimensional non-linear dynamic response analyses were carried out considering irregularly-shaped subsurface layers. The application and effectiveness of seismic response control design using hysteretic shear panel dampers with low yield strength steel is discussed by comparing seismic response reductions of shear panel dampers with those of displacement limiting devices.