Seismic Design for Bridges with Short Piers in High Earthquake Intensity Zones

Abstract

Aimed at short bridge piers that are vulnerable to brittle shear failure in high earthquake intensity zones, seismic design countermeasures for bridges with short piers were put forward in combination with the Guidelines for Seismic Design of Highway Bridges (JTG/T B02-01-2008). Based on a designed simple two-span pre-stressed concrete T-beam bridge located in a high earthquake intensity zone, specific schemes and suggestions, including seismic isolation technology, multi-column pier design, composite short column (Fiber Reinforced Plastic (FRP) or steel tube), or high-strength transverse reinforcement, were proposed, respectively. By using the numerical analysis model for seismic isolation and the multi-column pier design scheme established by the special finite element software MIDAS, the maximum longitudinal and lateral loads of bridge piers and the pile foundations of different designs under E2 earthquake excitation were compared. It is found that the seismic demand of short piers and foundations for bridges could be decreased significantly by using a seismic isolation design or a multi-column pier design suitable for seismic design of bridges with short piers in high earthquake intensity zones, and the mechanical behavior of short piers and foundations under strong earthquake could be improved. The proposed design schemes could be selected by designers in the seismic concept design stage to improve the seismic performance of bridges with short piers.