Bridge Design
The Tamsui-Tamsui Bridge is a new landmark in northern Taiwan, situated on a vital transportation route. In addition to its basic transportation functions, it also bears the heavy responsibility of maintaining a lifeline in the event of major disasters. Therefore, this project was designed and inspected to the highest standards suitable for the environmental conditions of the bridge site, in terms of seismic and wind resistance design, hydrological and hydrological analysis, and corrosion resistance and durability, all in accordance with the standards of large bridges around the world.
-Shock-resistant design-
Located at the junction of the Eurasian Plate and the Philippine Sea Plate, Taiwan experiences frequent earthquakes and is one of the world's six strongest earthquake zones. The seismic design of the Tamsui-Jiangmen Bridge, in addition to conducting seismic response spectrum and seismic duration analysis based on the "Seismic Design Code for Highway Bridges" issued by the Ministry of Transportation in June 2009, also incorporates fault source parameters and actual recorded seismic data within a 50km radius of the construction site for "Site Seismic Hazard Analysis," using the maximum seismic scenario as the target for the bridge's seismic design. By adjusting the structural load distribution and installing various vibration isolation and reduction devices such as HFR, FVD dampers and friction pendulum bearings at appropriate locations, bridge structural system engineers can effectively control the bridge vibration frequency, resist severe earthquakes of magnitude 7 or above, ensure structural safety, and safeguard the lifeline function after an earthquake.
Distribution of fault focal points near Tamkang Bridge
Tamkang Bridge Support System and Stress Description
When an earthquake strikes, the forces acting on a bridge can be divided into two types: horizontal forces and vertical forces. The horizontal forces can be further divided into two types: those in the direction of vehicle traffic and those perpendicular to the direction of vehicle traffic (i.e., the longitudinal and transverse directions of the bridge), for a total of three directions of force.
Vertical seismic force
The stress is directly transmitted to the foundation by the supports installed on the top of all the piers; the cable stays on the bridge deck transmit the stress to the main bridge towers in the form of tension, and then to the foundation in the form of vertical pressure.
Horizontal seismic force
Longitudinal: It mainly consists of 7 HFR dampers installed on the main bridge tower and 4 FVD dampers installed at both ends of the bridge, which reduce the force and transmit it to the foundation through hydraulic means.
Laterally: The FPB steel supports installed on the top of all inner piers and the synthetic rubber pads arranged laterally on the bala side of the bridge tower work together to reduce the force and transfer it to the foundation through frictional collision energy dissipation.