Structure control techniques have been used to control vibrations in civil structures from natural and other types of hazards for many years. However, it is difficult to achieve effective reduction in the dynamic responses of the structures under seismic excitation for the reason that earthquake generates huge kinetic energy in short time interval, unless adopting very large conventional vibration reduction devices to absorb so much energy. A kind of mass damper, the accelerated oscillator damper is proposed in this article to improve the performance of vibration absorbers. The kinetic energy of the secondary mass is proportional to the square of its velocity, and speed of the secondary mass can be amplified through the transmission of the accelerated oscillator damper system, so that according to the principle of energy conservation, the more kinetic energy the secondary mass gets from the whole system, the more kinetic energy the building will lose. The proposed accelerated oscillator damper system is superior to the tuned mass damper system for short input durations and the maximum seismic response. Moreover, the investigation also shows that the transmission ratio plays a more significant role for vibration absorption than the mass ratio.

The nearly finished Xinghai Bay Bridge at the southern seaside of Dalian in China is a long-span, double-deck, cross-sea suspension bridge. This bridge is the largest span highway double-deck suspension bridge with anchorage at sea in China. In view of the particular problems posed by the surrounding conditions, functional requirements, and aesthetic considerations, this project required a special structural design and innovations in construction technology. These innovations—including the steel truss design and erection process, the main cable-anchoring strategy, and the anchorage foundation design and construction techniques—are detailed in this paper.

Vibration control has emerged as a significant concern in civil engineering, aiming to minimize the displacement and stress exerted on structures during seismic events. The accelerated oscillator damper (AOD), which is a damping device that depends on acceleration, has been demonstrated to be highly effective. However, in the case of traditional bridges, it is difficult to accurately place the secondary mass, spring, and damping components at the piers. Additionally, it has been found that as a general single-degree-of-freedom (SDOF) damping device, a significant limitation of the AOD system is its insufficient damping effect in the near-resonance region. This study presents a strengthened AOD with a liner spring (SAOD-LS), in which the secondary spring and damper are linked to the primary structure rather than being attached to the piers. This design not only provides enough space for the secondary system but also has a higher amplification factor of secondary spring and damping components compared with the original layout. In addition, we suggest a nonlinear spring device (NSD) that includes connecting rods and inclined linear springs arranged in a diamond configuration. This innovative design is intended to introduce nonlinear stiffness characteristics into the equivalent stiffness, thereby improving the device’s performance and providing effective anti-resonance features in the near-resonance region. We have confirmed the motion equations for the SAOD-LS and used finite element (FE) analysis to validate the formulation of the equivalent external force and deformation of the NSD. We have thoroughly investigated both the SAOD-LS and the strengthened AOD equipped with NSD as the secondary spring (SAOD-NSD) for their potential implementation in a bridge project. These damping systems demonstrate exceptional performance and robustness, making them highly suitable for enhancing structural resistance to seismic activity.