Technology Research On Undergoing Existing Building By Shallow Tunneling Method

In dense urban construction of shallow tunnel, the situations of undergoing through buildings are so common. Tunnel excavation process will inevitably disturb the surrounding formation, resulting in generating additional internal forces and deformation to the undergoing buildings. Under the existing building through the construction process, the deformation features are: bending deformation, settlement, horizontal deformation, tilt deformation, in which the building is more harmful to tilt, bend and stretch horizontally, the actual process often complex deformation characteristics appear. thus affecting normal use and safety of existing buildings. In order to ensure a safe and orderly construction of shallow tunnel, meanwhile do not affect the safe use of existing buildings, the need to study the impact of shallow tunnel construction undergoing existing buildings is urgent.In this paper, we choose Xi’an Metro Line 4 Hansen Village ~ Tonghua door tunnel beneath the Golden Flower Hotel as background, to study the tunnel through Midas / gts numerical simulation and the use of surface-site monitoring data. Expand research work and results are as follows:(1) Step method was used, leaving the core of the simulation analysis and comparison of indigenous and full-face method, draw up and down stairs is more suitable to stay Core Soil excavation engineering practice; Moreover, bolt by choosing three different parameters, different open dig footage and different reinforcement measures, and several numerical simulation analysis and comparison of the displacement field, the Xi’an Metro Shallow Tunneling Method construction design can be made.(2) The data(≤15mm) is obtained after the monitoring from the project site, which meet regulatory requirements. To ensure the normal engineering construction, does not affect the safe use of existing buildings. We analyzed by comparing simulation results with field monitoring data, results measured displacement values vault, vault settlement and horizontal convergence value hance level convergence value and numerical simulation are close error of <5%, to verify the numerical simulation of the actual project has a very important role in guiding.(3) Describes four schemes to protect the existing buildings when the undergoing method was taken. Combined with the actual results grouting concrete reinforcement method is more suitable for the protection of the building. In the end, a more suitable design to protect existing building will be on progress.