Dynamic Response of Foundation Reinforcement to Underpass System Under Train Load

Abstract:

Field tests and numerical simulation were carried out to study the dynamic response of the underpass system of tunneling beneath the railway embankment under the train load. A finite element model has been established to study the effect of the elastic modulus of the reinforced soil and reinforcement depth on the vibration acceleration of ground surface and additional stress of tunnel crown. The results show that the main vibration frequencies of ground surface are caused by the periodic distribution of train wheels, sleeper spacing and specific driving speeds. The amplification of ground surface vibration and the reduction of the attenuation rate of high frequency vibration appear by the reinforced foundation. The vibration acceleration of the ground surface increases with the increase of elastic modulus of the reinforced soil. The reinforcement depth of the foundation exceed to tunnel buried depth, which can effectively reduce the additional dynamic stress of the tunnel.

Key words:railway embankment;vibration response;numerical simulation;crossing project;foundation reinforcement