FLAC simulation on footbridge pile foundation across shield tunnel

Through establishing numerical analysis model,it analyzes and forecasts footbridge pile foundation ground surface settlement across shield tunnel between Xi'an subway No.1 line Beidajie station-Wulukou station.Calculation results show that the existence of pile foundation prevents the extension of subsider in width in some points.If the two lines are not excavated at the same time,it will leads to certain inclination of the footbridge.It suggests that preventive measures should be taken in construction.The maximum ground surface displacing value is-10 mm,which is in safe domain.Therefore,it is unnecessary to carry on grouting reinforcement for ground layer.