Analysis Of The Influence Of Shield Driving Parameters Of Changsha No.1 Metro Line On The Surface Subsidence

With the implementation of the strategy of urbanization and modernization in China,the underground space development has been rapid development,and the construction of urban subway network has become the mainstream of development of urban underground space.Along with the problem of large-scale subway construction,urban environmental geotechnical engineering,geological disasters will become increasingly prominent.Because of Changsha No.1 Metro Line Shield cross section of shops and partially surrounding the passage of time building construction,renovation and expansion is more,how to effectively control surface subsidence project became difficult.Based Changsha No.1 Metro Line North Star Delta Station-Kaifu Temple station shield tunnel engineering example,statistics earth pressure balance shield driving parameters of the interval in some segments,and preliminary analysis of the relationship between the parameters,further Discussion by numerical simulation of the impact of driving parameters on surface subsidence proposed construction corresponding control measures.The main research contents and results are as follows:(1)This paper introduces the main method of metro construction and the type of disaster accident caused by construction,and draws the statistical analysis of the accident: when the ground collapse and settlement of the subway construction accidents occurred more than 61%of the column,and 70% of the accidents are from tunnel construction;From the subway shield construction technology and key technology of relevant settlement caused by shield construction are summarized.(2)Statistics of the North Star Delta Station-Kaifu Temple Station actual shield tunneling parameters Right Line range segment,and to explore the relationship between the parameters,summarized the different strata more suitable tunneling parameters;combined with engineering geological map of a typical analysis longitudinal settlement settlement rules and laws of the transverse center axis of surface measuring points measuring points to determine the scope of the settlement in longitudinal surface cutter in front of about 10 m,about 25 m behind the shield tail.That this two stage through the shield and shield tail emerge to control the settlement of key stage,the two stages of sedimentation value and deposition rate are larger.(3)According to the project background instance,using the finite element software ANSYS shield construction process simulation,numerical simulation were compared with the results of the monitoring results,to verify the reliability of the model,and by adjusting thepartial tunneling parameters to simulate different conditions subsurface subsidence response,providing technical support for the subsequent construction improvements.(4)Targeted lists subway construction in common disasters and treatment measures,and proposed control measures ground displacement of concrete construction.Before and after the construction control effect,and found that the measure of the range of the surface subsidence value is small,the basic can be controlled within the 10 mm.