Research purposes:Based on the shield engineering of some interval tunnel in Beijing subway line eight,it used FLAC simulation to predict the deformation laws of surface and its nearby building caused by shield construction, the goal is to offer a technological support for the determination of reasonable construction parameters and the establishment of the on-site monitoring project when safety through surface buildings in shield tunnel construction.
Research conclusions:(1)Numerical simulation was adopted to investigate the laws of surface deformation caused by the tunnel shield construction of Beijing subway,the lateral ground settlement curve is basically symmetrical in horizontal direction,and buildings have greater influence on surface deformation on the surrounding area compared with its region. The maximum differential settlement is 8. 09mm.(2)According to the prediction results of numerical simulation,the Bi-directional tunnel excavation affected range of surface is 36m that mainly in tunnel center. The excavation face affected area is 24m in the frontage and 20 m in the rear, so it should be mainly monitored during construction.(3)The practice shows that the measured curves are identical with the simulation curves. The numerical simulation is effective means for predicting the laws of surface and adjacent building deformation caused by shield construction.(4)The research results can be used to make adjacent building deformation control scheme caused by shield construction.