Study On DOT Shield Tunnel Construction Disturbance And Its Impact On Surrounding Structures

With the development of urban construction, land resources are dwindling, and traffic congestion and other problems have become increasingly prominent. Shield tunneling plays an important role in the development of urban underground space. The effects of shield construction disturbances on surrounding environmental are an important topic of urban environmental geotechnics. Surrounding soil is inevitably disturbed during shield tunneling construction, and thus it endangers the neighboring building (structure) building, its foundation and adjacent underground pipelines and so on. For grouting effect, soil displacement and additional stress caused by the Double-O-Tube (DOT) shield tunnel method, is still a lack of sufficient knowledge, it is important to explore the law of soil disturbance and its impact on the surrounding structures caused by DOT shield tunneling. Not only has it production practice needs, but also has some theoretical research value. From the theoretical research needs, this dissertation focuses on the its unique construction technology of DOT shield tunnel to carry out a wide range of research. The main work and results are as follows:Based on the generalized Darcy and two types of fluid equations, synchronous grouting diffusion mechanism of DOT shield tunnel segment was analyzed. Newtonian fluid, non-Newtonian Bingham fluid segment slurry grouting diffusion radius formula were separately derived, which can calculate the synchronous grouting parameters and size of the slurry diffusion radius in segment shield tail void and the pressure distribution of segment ring at different time.Based on the random medium theory, the three-dimensional (3D) soil deformation calculation formula caused by soil loss is derived in Double-O-Tube (DOT) shield tunneling. Considering the friction between the cutter facade, side and soil, the soil3D soil displacement formulas were deduced by caused by using Mindlin solution. Combined with additional driving positive force, frictional resistance force, shield tail grouting force, the3D soil deformation formula of caused by DOT construction caused by three-dimensional soil displacement formula was deduced.Based on the source-sink method, the three-dimensional additional stress formula caused by DOT shield tunnel construction soil loss was derived. Combined with additional driving positive force, frictional resistance force, shield tail grouting force, the3D soil additional stress formula of caused by DOT construction caused by three-dimensional additional stress formula was deduced.Combined with additional driving positive force, frictional resistance force, shield tail grouting force, the effect of DOT shield tunnel construction on adjacent underground pipelines, buildings pile, parallel existing tunnel were separately analyzed.Considering the interaction of building-soil-tunnel, the grillage beams foundation frame building vertical crossed by DOT shield tunnel was simulated by3D MIDAS/GTS software, and the impact of construction on the building was analyzed.