A Numerical and Experimental Investigation of a Special Type of Floating-Slab Tracks

Abstract

This thesis presents a research study on the dynamic behavior of a special type of FST used in recently built subway system in Doha, Qatar. The special FST has a continuous concrete slab with periodic grooves for which the track can be modeled as periodic structure with a slab unit having two elements with different cross sections. Extensive numerical and experimental investigations were conducted on a multi-unit full-scale mockup track. The numerical investigations were carried out using both a fast running model based on the Dynamic Stiffness Method and a detailed Finite Element model. In the experimental campaign, experimental vibration test was performed to identify the actual vibration response of the mockup track. Results from the experimental investigations were then used for verifying the numerical models and carrying out a model updating exercise for the fast running model. The model updating process was carried out according to an automated hybrid optimization approach. Finally, the updated model was extended to an infinite model and used in a parametric study to investigate the influence of varying groove’s thickness on the dynamic behavior of the special track with infinite length for both bending and torsion scenarios. The parametric study suggested that reducing the thickness below 50% of the full thickness of the slab significantly affects the dynamic behavior of the special FST.