A combination strategy of hollow-closed-wall in-filled trench and elastic bearing for reducing environmental vibration induced by high-speed train

Abstract With the rapid development of high-speed railway (HSR) in China, the problem of environmental vibration induced by HSR train has attracted critical concern. In this paper, a combination vibration reduction (CVR) strategy of hollow-closed-wall in-filled trench (HIT) and elastic bearing (EB) is proposed to decrease environmental vibration induced by HSR train, in which the depth of HIT could be well controlled to benefit the practical construction and economic cost. Based on the multi-body dynamics and finite element theory, HSR environmental vibration system is established and then divided into two sub-models including the ‘train-track-bridge’ vibration source sub-model and the ‘pile-soil’ vibration propagation sub-model. The two sub-models are connected via the force balance condition of the pier bottom. The verification of numerical models is conducted by comparing with the empirical formula and the ground data in the references. Then the attenuation law of environmental vibration is analyzed, and the vertical component is shown to be dominant in the HSR environmental vibration. On this basis, numerical simulations are performed to analyze the environmental vibration reduction under three strategies, namely the HIT, EB, and CVR. The results show that the HIT presents a distinct vibration reduction effect in the frequency range above 4 Hz and the vibration reduction becomes more obvious as the HIT's depth increases. However, the depth should be larger than 8 m to satisfy the code requirement; the EB presents an obvious reduction in the frequency range above 8 Hz; the CVR strategy not only further decrease the environmental vibration, but also effectively reduce the HIT's depth. By numerical analysis, the combination strategy of 6 m deep HIT and 2200 kN/mm vertical stiffness EB is recommended in the HSR environmental vibration reduction, which could also satisfy the limit of Chinese railway code.