Influence Of Ground Surface Settlement And Adjacent Piles Induced By Tunnel Excavation.

With the development of city civilization in our country, tunnel construction has become an effective method to deal with the problem including the traffic jam, limited ground resource, environmental pollution and so on. Thus , the research on the ground surface settlement and terrain remove have attracted the engineering circle's attention.Besides, ground surface settlement induced by tunnel construction and post-construction is the main reason which cause kinds of buildings damaged in appearance and fu nctions. Futhermore, it brought great economic losses every year. Generally speaking, how to control ground surface settlement is mostly considered when designing tunnel, neglecting surrounding buildings. A numerical simulation on tunnel excavation has been did by using computer software on Flac3D and measured ground surface settlement in local at the same time. Based on these, the research that effect of ground surface subsidence induced by tunnel excavation on adjacent bridge piles is done. A comparative analysis of different factors which create surface subsidence is made.In order to research surface settlement induced by the tunnel construction and the effect of tunnel construction on piles ,many correlative data have been collected and) numerical simulation and calculation focusing on the problem are done either. From the result of calculation, the paper got some regularities and it will provide some academic directions for constructing pile foundation of buildings around the tunnel. Combining the scenario of tunnel construction excavation, the essentiality of all factors which influence the ground surface subsidence was discussed.By using of actual observation records and calculation results by Flac3D got some regularities such as diversity of transverse and longitudinal direction during tunnel excavation and variable regularity of stress field and displacement field from stratum , some conclusions can be got as follows:1. During the tunnel excavation, variant subsidence and average subsidence are increasing, but they tend to be stable value at last. 2. Comparison between actual observation record and calculation result by Flac 3D shows that the software can provide high reliability, it can simulate the variety of stress field and displacement field induced by tunnel excavation..3. The influence of tunnel excavation on soil around itself is stronger than the ground surface subsidence.4. Cmparitive analysis of ground surface points whether have second-string piles or not shows that the points which do not own second-string piles have deep subsidence. Especially the effect of the part near the tunnel's beginning and ending on the ground surface settlement is outstanding.