ABSTRACT To enhance the structural robustness of bridges, a rocking arch‐shaped segmental pier with a double sliding system was previously proposed as a low‐cost solution to protect bridges in developing countries. The rocking behavior is triggered by halting the sliding motion, which increases the horizontal load‐bearing capacity and limits displacement, thereby preventing brittle failure under extreme seismic events. Although the feasibility was verified through cyclic loading tests under quasi‐static conditions, such testing is insufficient to represent dynamic response characteristics under seismic excitations. In this study, the dynamic behavior of a vault‐shaped pier system, derived from the rocking arch‐shaped pier concept and designed for damage‐avoidance under bidirectional seismic excitations, is investigated through shaking table tests. The results demonstrated that, even under strong dynamic excitation, the system adhered to the prescribed multi‐stage response sequence with remarkable dynamic stability. Negligible abrasion of the sliding system and no discernible damage were observed despite multiple input motions and repeated high‐velocity collisions. The proposed system exhibits consistent performance under rocking initiated in any direction, with the joints reliably opening to accommodate bidirectional motions. The four‐pier configuration exhibits larger acceleration responses under both unidirectional and bidirectional excitations, whereas the three‐pier configuration initiates rocking more readily under unidirectional excitation. Furthermore, pier systems with different mechanisms were investigated via finite element simulations. The numerical results revealed that the interactive coordination between sliding and rocking mechanisms effectively compensates for the limitations of each individual response mode, offering desirable damage‐avoidance performance even when subjected to extreme excitations.
Feng et al. (2026) studied this question.