Shaking table testing and numerical modeling of continuous welded ballast track on bridges under longitudinal seismic loading

Abstract

In order to confirm the validity of the ideal elasto-plastic resistance model applied to the ballast track under seismic loading, this paper studies the seismic response of continuous welded ballast track on bridges through the shaking table test and presents a process of updating the model based on the test results. The results indicate that the track constraint can improve the low order natural frequency of bridges significantly, and reduce the displacement response of the bridge. When ballast beds are effectively in a dynamic reciprocating state while under seismic loading, a structural change between the granules will occur, wherein some will flow and redistribute. The dynamic hysteretic change of the ballast longitudinal resistance is complex and quite different from that of the ideal elasto-plastic hysteretic route, and the ballast longitudinal resistance performance degenerates. If ballast longitudinal resistance is assumed to be ideal elastic-plastic resistance, the actual beam displacement response will be underestimated and the calculated rail seismic force will be greater than the test result. Moreover, the equivalent stiffness coefficient and damping coefficient of the ballast dynamic resistance characteristics could be obtained by model updating, and the simulation results coincide well with the test results.

Evaluating the Performance and Stability of the Highway Subgrades in Seismic Events, a Case Study of the Changning Earthquake, Sichuan

“…Refs. [ 11 , 12 , 13 ] simulated the seismic dynamic response and damage process of fill subgrades through large shaking table model tests. As for the numerical method, Morteza and Hamidreza [ 14 ] performed a 3D finite-element simulation for railway subgrades.…”

Longitudinal Seismic Response of Continuously Welded Track on Railway Arch Bridges

“…2018, 8, x FOR PEER REVIEW 5 of Selection of Seismic WavesThe calculations presented here require seismic waves as input, in order to explore the seismic response characteristics of continuously welded ballasted track on arch bridges. From among the existing recorded seismic waves, the El-Centro seismic wave (USA, 1940, NS), San Fernando (1971) seismic wave and James RD (1979) seismic wave were selected as inputs for ground motions in the model[10] (as shown inFigure 4), with characteristic periods of 0.66 s, 0.28 s, and 0.46 s, respectively. When discussing the dynamic response of continuously welded ballasted track on arch bridges under seismic loading, the acceleration peak values were set to 0.4 g.…”