Fluid damper (FD), also named as hydraulic damper, uses the cylinder type structure filled with silicon oil. It produces the damping by using the viscosity property of the fluid during the movement. For the cable-stayed bridge of and the suspension bridge, the main beam will produce a large displacement under the action of the vehicle’s braking force and the traveling vehicle load, which will produce a large longitudinal bending moment at the bottom of the bridge tower. However, the fluid damper can effectively inhibit the response to ensure the normal application and safety of the bridge. The fluid damper is generally installed between the beam and the abutment. In ordinary circumstances (for example, the displacement of the bridge due to heat expansion and cold contraction), the damper does not work; If a large displacement of the bridge is caused by a large braking force, a wind force or a seismic force, the fluid damper will work to dissipate the input energy for protection of the bridge structure.
Guiping Yujiang Double-track Super Major Bridge of Nanning – Guangzhou Railway, Tianxingzhou Bridge, Lanzhou North Loop Line, Nanxi Yangtz River Bridge
This bridge was located at the branching river of Tianxingzhou at 9.5 miles down the Wuhan Yangtze River Second Bridge, with 4657m long in total. The Nancha main bridge is three-plane cable-stayed bridge with double tower of 98+196+504+196+98m, the upper is highway, the lower is railway; The Beihan main bridge is pre-stressed concrete continuous bridge, highway & railway are side by side, and the highway is up the river, while the railway is down the river. We designed FD 2000kn/±350mm because of the complicated situation of Tianxingzhou Bridge which is used for highway and railway in both, so that it can avoid the influence of earthquake and train braking force. One side of the damper is connected with lower boom of the steel beam, and the other side is connected with the beam of the main tower.
Nanguang Railway is the key line for connecting Guangxi, Yunnan and South China. It is the most convenient railway from Guangxi to Zhujiang Delta Area; it is also a new fast passageway for Yunnan and west area of Guizhou to arrive in Zhujiang Delta Area. Its main line is bi-line type and the line space is 4.6m. Yujiang River Dual-line Bridge at Guiping Line lies on the river from Yujiang Guigang to Guiping with 3909.7 long. The main bridge is twin-tower steel truss cable-stayed (36+96+228+96+36)m. Fluid damper uses the viscous property of fluid to generate damping when running. The damping effect is very obvious, which can be used repeatedly and it is one of the efficient ways to control bridge structure vibration.