Study On The Disturbance Effects Of Shield Tunnel Passing Through Existing Pipeline Vertically

The impact of shield tunnel on the surrounding environment has become an important research topic,in which the impact of shield on the surrounding pipeline is particularly prominent.At present,there are still some weaknesses in the study of the influence of shield tunnel on the surrounding pipeline.Most studies only considered the influence of single factor on pipeline deformation.In this paper,the sensitivity analysis of the main factors influencing the pipeline displacement is provided,which can provide reference for the design and construction of the actual project.Based on the theory of elastic foundation beam,the mechanism of formation and pipeline deformation caused by tunnel construction is discussed.The mechanical effects of rigid pipeline and flexible pipeline by tunneling are analyzed,and the prediction method of pipeline deformation and force is put forward.Based on the FLAC3 D finite difference numerical simulation and the measured results,the paper analyzes the rule of the construction of the double line tunnel on the pipeline and the ground surface settlement.After the construction of the left line tunnel,the lateral sedimentation and pipeline displacement curves are in Gaussian distribution,and the maximum settlement of the pipeline and the surface are in the center of the left-hand tunnel center.After the excavation of the right line tunnel is completed,the main settlement range of the surface and pipeline becomes larger.The surface settlement is larger than that of the left-channel tunnel,and the sedimentation curve of the two tunnels is gentle.The maximum settlement becomes between the two tunnels.The pipeline settlement is "one peak and two valley".The maximum settlement value of the pipeline near to the left line tunnel.The influence of six main factors on pipeline settlement is studied numerically.The vertical displacement and maximum settlement of the pipeline are increases gradually with the increase of pipeline depth,tunneling excavation rate and tunnel diameter.The vertical displacement and maximum settlement of the pipeline decrease gradually with the increase of the pipeline diameter,the excavation pressure ratio and the pipe-tunnel spacing.With the increase of the tunneling excavation rate and the tunnel diameter,the main settlement range of the pipeline is increased.Pipeline depth,excavation surface support pressure ratio,tunnel diameter and pipeline maximum settlement is basically linear relationship.Gray correlation analysis method was used to analyze the influence of each factor on the maximum settlement of pipeline.The influence of the degree of sensitivity on the settlement of pipeline is from the order of Tunnel diameter,pipe-tunnel spacing,pipeline diameter,pipeline depth,the excavation pressure ratio,tunneling excavation rate.