EFFECT OF SPEED & WEIGHT TRAIN ON THE SURROUNDING VIBRATION TUNNEL ON THE GROUND SURFACE

Abstract

Development of technology has made it possible to excavate underground spaces in different geological conditions. With respect to the increase of usage and importance of tunnels in transportation systems in urban areas, it is necessary to investigate the response of dynamic loads due to train movements. To receive this purpose, one series of studies has been done on subway system in Tehran that named LINE4. Because these tunnels were excavated in soil, the model was considered as a continuum conditions, thus the commercial program FLAC3D is used.In this research, the effect of speed and weight train is studied on the surrounding vibration tunnel on the ground surface. To investigate the effect of train motions, speed and weight trains are assumed as the effective factors to calculate the vertical applied load transferred from wagons to the rails in terms of time in a longitudinal model. The analysis of train movements showed that particles velocity level in two directions (vertical and horizontal) increases with increase the train speed and weight. Also, the maximum velocity of particles is smaller than damage. Therefore, there is no concern about structure damages, but it can still cause people inconvenience. Also, effect of train weight in particles velocity level is more than of train speed.Andfinally,the result shows that, to reduce the vibration level, it is better to use light wagons in transportation systems..