Deformation Mechanism Of High Speed Railway Subgrade Under The Action Of Horizontal Seismic

In order to fit the rapid economic development,the speed of the train has been improved, our country substaintially increases the speed of the train,reduces the running time, promotes the development of the economy by increasing the speed of existing lines,constructing passenger dedicated line and developing high speed railway.However, roadbed may appear in different degree of damage when the earthquake struck, as our country is a frequently earthquake-attacked nation. It is great significant to research on high-speed railway response laws under earthquakes because of the strict demand of the roadbed and track for high-speed railway.In the paper, three-dimensional model of high speed railway was established by using ANSYS finite element software. Seismic response calculation analysis was carried out on the high speed railway based on time history analysis method.The following conclusions are made by changing the height of roadbed, roadbed side slope and seismic intensity to analysis acceleration, stress and displacement law of roadbed:(1) Road base acceleration is greater than the ground acceleration, approximately reach the maximum in the subgrade surface.(2) Upper roadbed slope and road shoulder vulnerable to pull crack. The stress intensity of upper roadbed slope and road shoulder has a certain regular with roadbed slope height, slope and seismic intensity.(3) Deformation of the roadbed under earthquake: the foot of roadbed slope swell, roadbed slope bottom expanding and road base settlement. The above variable increased with the increasing of seismic intensity, roadbed height, roadbed slope.(4) Track structure may be friction and slip after seismic intensity reaching a certain value. Friction-sliding is widely influenced by seismic intensity and the Coefficient of friction between Concrete support layer and Concrete support layer.(5) The longitudinal stress of track structure is greater than the transverse stress under earthquake. With seismic intensity increased, track structure stress increased. With roadbed modulus of elasticity increased, track structure stress increased.