Transverse Seismic Response of a High-Pier, Long-Span Stiff-Skeleton Arch Bridge Equipped with Transverse Steel Dampers

This study numerically examines the transverse seismic response of a high-pier, long-span stiff-skeleton arch bridge equipped with transverse steel dampers (TSDs). A three-dimensional SAP2000 model represents the primary bridge members predominantly with elastic beam elements. Nonlinear behavior is concentrated in the spherical steel damping bearings (SSDBs), gap links, and idealized TSD links. A sequential staged discrete screening evaluates TSD yield strength, initial gap, and post-yield stiffness ratio using displacement, elastic force-demand, and hysteretic-response indices. Fifteen recorded motions are then used to examine response trends across pulse-period groups. Nine pulse-like records are also decomposed to compare the original motions with their residual components. Within the predefined candidates, 3000 kN, 150 mm, and 15% provide the selected balance among the adopted response indices. This combination is conditional on the candidate set, stage order, bridge model, and input motions, and is not a global multi-parameter optimum. An additional 15-record check of the 13 unique parameter configurations found that no candidate minimized representative bearing, pier, and arch responses simultaneously. This supports interpreting the retained values as a conditional compromise. Exploratory record-level tests identify false-discovery-rate-controlled group differences for pier-top displacement, arch-rib displacement, and arch-rib bending moment; most force-demand indices do not show resolved group differences in this small set. In the nine paired original–residual comparisons, median peak-response reductions range from 16.8% for pier-base shear to 76.9% for arch-rib bending moment, although the pier-base shear change is not statistically resolved. These findings provide comparative numerical demand trends for the investigated bridge. They do not constitute member-capacity verification, physical-device validation, or a general seismic-safety assessment.