Numerical Simulation Analysis Of The Influence Of Excavation On The Displacement Of Adjacent Tunnel

Along with the country the city vigorously promote the edifice stacked layers,land resources have been difficult to meet the daily needs of people,underground shopping malls,underground parking lot,underground hotels,underground rail transportation and underground resources,enough to show the demand degree of people for underground resources.The foundation pit engineering is a kind of underground construction,infrastructure construction and underground excavation engineering construction,with the gradual increase of underground construction,excavation on adjacent tunnel,we must consider the tunnel and the surrounding buildings.In this paper,the tunnel deformation theory as a guide,combined with the actual engineering example of foundation pit excavation in Shenzhen Metro Line 2 by the modeling by FLAC3 D software,numerical simulation analysis for this situation leads to the change of displacement of adjacent tunnel excavation,the following specific ideas of this article:1,this paper introduces the present situation of the influence of excavation on the displacement of adjacent tunnel,summarizes the theory of tunnel deformation,the influence factors of deformation and the theoretical calculation method.In this paper,the structure model of the finite difference software FLAC3 D and the structural unit are also introduced.2,in the city of Shenzhen Metro Line 2 near the excavation based on the engineering background,considering the engineering geological conditions,engineering equipment parameters and engineering structure of physical size and other conditions,using finite difference software FLAC3 D for the engineering modeling,the project risk is the largest displacement of tunnel engineering to control below 1cm.The displacement of the tunnel level caused excavation and vertical displacement are simulated and analyzed,found that the change of displacement displacement monitoring in tunnel level is the largest displacement 1.03 mm,vertical displacement monitoring points in the tunnel is the largest of 8.18 mm were controlled within 1cm.Then through the concept of residual stress in the deformation theory of the tunnel,the final uplift of the foundation pit is calculated as 1.7577265 cm,and the results obtained by 2.13 cm are close to the results obtained by FLAC3 D.Finite difference method is used to calculate and analyze,the finite difference results are close to the analytical method,which shows that the analytical method and FLAC3 D numerical simulation results are reliable.3,the adjacent waters of the project should pay attention to the precipitation measures,the data excavation and tunnel based on,according to the relevant design specifications,develop Precipitation Scheme and corresponding measures,and drainage system settings.Based on the numerical simulation of dewatering engineering analysis can draw the conclusion: Considering precipitation under the premise of the excavation,the pit bottom uplift than without considering precipitation when bottom heave of foundation pit excavation.And if you consider the deformation degree of precipitation,tunnel is less than without considering the deformation degree of precipitation time.