Effects of concrete materials on the vibration of the adjacent tunnel and surroundings by DEM and experiment

Abstract

Concrete material can reduce the disturbance of train vibration to adjacent tunnels during the operation of near-distance twin tunnels. This paper adopts the discrete element method (DEM) and experimental model (scaled by 1:20) to study the influence of the train vibration at the speed of 120 km/h on the static and dynamic characteristics of the adjacent tunnel's liner and sleeper. The region between the twin tunnels was set as the concrete zone (CZ) to explore the effect of train vibration waves. The distance between twin tunnels is set to 0.25 D, where D (6.2 m) is the diameter of the tunnel. Foam brick (FB) is the similar materials of CZ in similar experiment. The DEM and similar experiments obtained similar results. The CZ (FB) can effectively block the propagation of the train vibration waves in T1, thus reducing the disturbance to the T2 liner and sleeper. Next, the CZ with four thicknesses and six heights are discussed with DEM, and it is found that thickness and height have a significant influence on the isolation effect of CZs, so the size should be selected according to actual engineering needs. This study provides a reference for studying the vibration reduction effect of CZs on adjacent tunnels during train operation.