Numerical investigation of seismic behavior in segmental assembled continuous beam bridges under near-fault ground motions.

Abstract

A comparative numerical investigation is carried out to assess the seismic performance of cast-in-place and segmental assembled piers in a continuous beam bridge subjected to near-fault ground motions. A comparative numerical study on the seismic behavior of continuous beam bridges with cast-in-place piers versus segmental assembled piers under near-fault ground motions is presented. A full-scale finite-element model of a six-span continuous bridge is developed using ABAQUS. Within this model, the seismic performance of two pier construction schemes-integral cast-in-place and precast segmental assembly-are investigated and compared. The pseudo-static method (Pushover method) is employed to investigate the seismic performance of various pier segmental assembly configurations, ultimately identifying the optimal configuration of segmental assembled piers that balances energy dissipation and self-resetting capacity. Considering pile-soil interaction and viscoelastic artificial boundary effects, nonlinear dynamic time history analysis is conducted on a bridge model with the optimal segmental assembled pier form. A comparative analysis was conducted on the relative displacement between the pier and beam, as well as the overall damage progression of continuous girder bridges with cast-in-place and segmental assembled piers, subjected to pulse-type and non-pulse-type seismic excitations. This study reveals the damage patterns of bridge structures under near-fault pulse seismic effects. It captures the dynamic response patterns and key failure locations of bridges under pulse effects, providing support for seismic design of near-fault bridges. Conclusions are drawn and can be applied in the actual seismic design and analysis of segmental assembled continuous beam bridges under near-fault ground motions.