Impact Analysis Of Grouting Correction Simulation On Shield Tunnel And Related Numerical Research

During the long-term operation of subway,shield tunnels often undergo uneven settlement because of the long-term traffic loads on shield tunnels,and uneven distribution of geological conditions.In addition,the construction adjacent to subways sometimes has adverse effects on subways.In order to ensure the long-term operation’s safety of the subway,grouting is often used to correct the deviation of the offset tunnel.In order to study the development law of tunnel deformation during grouting,numerical analysis and engineering application are combined for analysis.Firstly,by the analysis of the tunnel monitoring data during the injection process,the time-history analysis of the tunnel displacement and the deformation of the tunnel cross section is focused,and the deformation of the tunnel is studied in conjunction with the distribution of the disease.Secondly,a new fluid-solid coupling grouting simulation method is proposed.Simultaneously,the method is used to simulate the remedation project,which verifies the rationality of it.Finally,the method of combining the orthogonal test analysis with the parameter analysis is used to analyze the horizontal grouting and vertical grouting respectively.The main conclusions are as follows:(1)Many diseases such as water leakage,staggered platform and cracks have occurred in the tunnel,which will affect the effect of grouting rectification.The grouting process should be arranged reasonably.Different procedures will produce different rectification effects.The earlier the injection,the better the grouting effect.The farther the post injection area is from the former,the better the grouting effect.The vertical grouting pipes should be set symmetrically according to the current position of the tunnel section as far as possible.(2)In the numerical model,the grouting pressure set at the grouting point can correspond to the grouting pressure or the slurry flow in the actual project,which can help to study the dynamic grouting process of the slurry.and the simulation method can simulate infiltration grouting and compaction grouting.But it is not suitable for split grouting simulation.The change of soil strength after grouting should be considered in the numerical model.(3)For different purposes of grouting rectification,such as vertical displacement,horizontal displacement,vertical convergence and so on,the main influencing factors of grouting effect and their laws are not the same,which should be adjusted according to the actual purpose of remedation.Although the orthogonal test can analyze the primary and secondary influencing factors and greatly improve the test efficiency.the optimal value obtained may not be the overall optimal value,and improper parameter selection is not conducive to the reflection of the law.Because the number of tests is small,the result of a single test has a large impact on the reflection of the test law.In order to ensure the scientificity of the analysis results,the orthogonal test should be combined with the parameter analysis.