The Prediction Of Surface Deformation Caused By The Excavation Of The Precipitation Tunnel Down Through Grouting Section Of The Gold Shop Of Mao Long

The method of prediction and analysis for surface deformation induced by cavern excavation is various.First,based on the monitoring data of surface deformation,peck fitting is used to determine the surface deformation trend caused by cavern excavation.Due to the complexity of the grouting soil and the variability of the existing environment,the prediction of the surface deformation caused by the tunnel excavation under the grouting condition can be calculated by numerical simulation.The most effective simulation calculation of the surface deformation and stress state after the excavation of the cavern can be used to provide effective deformation precondition for the construction of the unbroken section caverns.This paper based on the Beijing subway line 8 down through the Gold shop of Mao Long grouting period of cavern excavation numerical simulation,the ground deformation data of the excavated part of the guide tunnel is used as the inversion basis,and the excavation prediction is treated.The deformation trend and stress distribution characteristics of the ground surface after excavation are analyzed.The main work of this paper is as follows:（1）Characteristics of surface deformation induced by cavern excavation under grouting condition.The actual monitoring data based on Beijing metro line 8 between Wang Fujing north station and Wang Fujing station has is fitting inversion software is used to calculate silty clay in Beijing under the geological conditions of a specific,Peck formula caused by excavation in the settling tank width parameter K,settling tank i and inflection point distance and the change rule of maximum subsidence value S_max scope;By calculating,the peck correction formula for each of holes in the grouting section is obtained and analysis of the trend of surface deformation.（2）Determination of grouting and solid mechanical parameters.Soil samples were collected at the site,and laboratory experiments were carried out.The length of the grouting section was 50m,and two sampling experiments were conducted for the result of C、φ、μ、Es.According to the field test and relevant specifications,the range of the parameters of the inversion is determined.Through orthogonal test,a set of mechanical parameters of grouting soil which is closest to the test index is determined,and the best physical and mechanical parameters are applied to two grouting circles.Through numerical calculation,the subsidence values of the numerical results are verified with the measured subsidence values of the three measured sections.It provides reliable mechanical parameters for predicting the numerical calculation of excavation of unexcavated section.（3）The prediction of surface deformation caused by the excavation of the excavation section.When the results are basically consistent,the right guide tunnel is excavated and the same process is carried forward.The surface deformation trend of the two sides of the guide tunnel and the distribution of the soil stratum stress distribution are predicted and analyzed in the same process.