Application of dynamic vibration absorbers on a double-deck circular railway tunnel to minimize the radiated vibration energy flow induced by a moving load

Abstract

The aim of this study is to investigate the efficiency of Dynamic Vibration Absorbers (DVAs) as a vibration abatement solution for railway-induced vibrations in the framework of a double-deck circular railway tunnel infrastructure. Specifically, it is studied the efficiency of an optimized set of DVAs placed on the interior floor which has the objective of reducing the vibration energy flow radiated by the tunnel infrastructure when a moving harmonic point load is circulating along the track which is located at the upper floor of the double-deck tunnel. A previously developed analytical model of the superstructure-tunnel ground system is employed to calculate the energy flow due to a moving harmonic point load over the track. The model describes the dynamics of the interior floor using the thin plate theory and considers the Pipe-in-Pipe (PiP) model to describe the coupled tunnel-soil system. The track model consists of two Euler-Bernoulli beams, as a model of the rails, coupled with the interior floor with continuous springs, which model the sets of direct fastening systems. In the basis of this model, a Genetic Algorithm (GA) is used to obtain the optimal parameters of the DVAs set for the minimization of the vibration energy flow radiated by the tunnel. The parameters of the DVAs set to be optimized are the mass, stiffness, damping ratio and position of the DVAs. The results indicate that the DVAs would be and effective solution for the abatement of the vibration energy flow induced by this kind of infrastructure.