Study On The Effect Of Land Subsidence On Subway Tunnel Structure

Xi’an is located in the northwest where water resource shortages.nonuniform settlement in Xi’anregion is very serious which is caused by excessive exploitation of ground water in the last few decades.Inrecent years,although the pumping of groundwater has been limited,There is a certain degree of ground subsidence.At present Xi’an subway is in a rapid constructionperiod,Subway lines may pass through the nonuniform settlement area,which may lead to the deformationof the subway tunnel and affect the normal operation.That is the reason that raise the ground subsidence bypumping water on the effect of subway tunnel deformation.The main research work and conclusion asfollows:To analyze the characteristics of the ground subsidence in Xi’an and predict its tendency.In the lastfew decades,there are three kinds of ground subsidence curve,including regular and irregular funnelshape.Solve the minimum radius of settlement curve, the relation between the total settlement errands andthe minimum radius of settlement curve are processed with Origin in radius200meters of funnelcenter.The bigger the total settlement errands are,the smaller the minimum radius of settlement curve willbe.There are integrated tunnel and constructed tunnel，the main deformation of subway tunnel are thetransverse deformation and the longitudinal deformation.To analyze the subway tunnel deformation theoryand made theoretic calculations.The longitudinal deformation of the constructed tunnel is in the elastic limitcorrupt state,the limit of minimum radius of segments longitudinal deformation is2034m.Integrated tunnelis in the elastic limit corrupt state，and the limit of minimum radius of segments longitudinal deformation is4063m.The transverse deformation of entiretied and constructed tunnel are both in the elastic limit corruptstate,the solution of the maximum and minimum of the segments’cross-section radius.Using finite differential code FLAC3Dto imitate the pumping water on the effect of subway tunneldeformation.And to analyze the minimum radius of the circular tunnel’s longitudinal deformation and thetransverse section deformation of the transverse deformation on the condition of with and without groundfissure.There are difference between the analytic solutions and numerical solutions,but it shows that theground subsidence by pumping water has significant effect on the subway tunnel deformation.The result of this paper enrich the theory of the ground subsidence by pumping water on the effect ofsubway tunnel deformation.It has provided references to reduce pumping water and control the subwaytunnel deformation for the future.