Analysis On The Deformation Of The Upper Arch Of A Section Of Subgrade In The Second Double Track Of Lanxin And Study On The Treatment Measures

Taking the cause analysis,data observation and treatment measures of the upper arch deformation of the second double track subgrade in Lanxin as an example,this paper comprehensively introduces the topography,meteorological features,geology and hydrology of the upper arch deformation section of the second double track subgrade in Lanxin,and focuses on the distribution and engineering treatment measures of wind sand and wind erosion,loess,swelling rock,soft soil and soft soil,saline soil.The problems of track speed limit,bridge and culvert defects caused by subgrade camber deformation of the second double track in Lanxin are listed,and the importance of this study is clarified.Through the research and analysis of the causes of the deformation of the upper arch of the second double track subgrade in Lanxin,this paper puts forward the control measures and suggestions in three aspects: the degree of compaction of the fill,the control of the fill and the influence of the water.Through the analysis of the fill’s degree of compaction,the main factors of the compaction are obtained.Through the analysis of the improper control of the fill,the main factors of the control of the fill are obtained.Through the analysis of the influence of the water,the source and the outlet of the water in the subgrade are obtained Causes of impact.It provides the technical basis for the deformation treatment of the upper arch of the subgrade.In particular,the paper focuses on the analysis of the problems caused by the action of subgrade soil,filler and water.By consulting the files and analyzing the design and construction technology before and after the problems occurred,it is believed that the chemical reaction between the acid and alkali in water and the concrete filler of the ballast bed may cause the camber of the ballast bed.This paper introduces the dynamic and static monitoring scheme adopted in the deformation detection of the upper arch of the second double track subgrade in Lanxin,and discusses the methods,principles and basis of the electronic level elevation monitoring,Amberg trolley track monitoring and other monitoring means.This paper analyzes in detail the three schemes of electronic level elevation monitoring,Amberg trolley track monitoring and settlement displacement meter layered monitoring,and compares the feasibility,scope of application,advantages and disadvantages of the three observation methods,so as to provide the basis for the implementation of deformation observation.In this paper,combined with the topography and equipment status of the deformation section of the second double track subgrade in Lanxin,the observation results of the above deformation monitoring scheme are described in detail,and the results are verified and compared.Through the use of electronic level elevation,Amberg trolley track and deformation displacement meter layered static monitoring method,the monitoring andanalysis scheme is comprehensively applied to the change of subgrade upper arch before and after k2532 of the second double line in Lanxin.Through the monitoring and analysis of the location,magnitude and depth of deformation of subgrade upper arch,the "expansion and deformation rate is fast from November to December 2017,and then Relatively stable,after March 2018,it fell back,but it did not reach the initial value;therefore,the above three schemes are feasible,and they confirm each other,all of them can monitor the subgrade settlement law ",which provides a sufficient basis for the subgrade camber deformation treatment.In this paper,it is discussed that the deformation of the upper arch of the subgrade should first be well intercepted and drained.Through the engineering measures such as drainage ditch and intercepting ditch,the water sources that may be poured into the subgrade should be intercepted and dredged,so as to reduce the reaction between acid-base particles and sulfide in cement caused by precipitation,form new expansion materials,and reduce the main source of the deformation of the upper arch of the subgrade.Secondly,we should do a good job in the treatment of the deformation of the upper arch of the subgrade,the main methods are cutting and thinning the supporting layer,digging the soil and forced landing,and digging the foundation bed and falling the road.This paper discusses the main basis for setting up interception and drainage measures.This paper discusses in detail the construction standards,control measures and technological process of the interception and drainage measures,including the replacement of improved soil outside the subgrade toe,subgrade drainage ditch,interception wall,interception ditch and drying pond,so as to achieve the purpose of strengthening the interception and drainage measures.In order to rectify the plane and elevation changes of the line design caused by the deformation of the upper arch of the subgrade,through practice on the site,for the places where the amount of the upper arch of the subgrade is not large,the method of digging out soil and forced landing is adopted to drill holes in the filling part of the subgrade,and the method of rolling and pressing by the train to make the track bed fall down is adopted;for the places where the amount of the upper arch of the subgrade is less than 14 cm,the method of cutting and thinning the supporting layer is adopted to cut the road bed mechanically After adjusting the height and direction of the bed slab,the reinforcement and grouting repair technology for cutting the supporting layer shall be improved;for the places with arch less than 30 cm above the subgrade,the hidden excavation method shall be adopted to excavate the surface layer of the subgrade bed below the supporting layer manually,and the grouting repair technology shall be improved after adjusting the height and direction of the bed slab.In this paper,the cutting and thinning process of the deformation supporting layer of the subgrade upper arch is discussed in detail,and the amount of the upper arch of the track is confirmed through the Resurvey of the track elevation and the on-site recheck;the lateral displacement of the track is limited by the setting of the limiting pier,and the form,reinforcement,layout requirements and action modes of the limiting pier are described in detail;the cutting and removal method of the supporting layer is discussed through the horizontal drilling,cutting and removal of the supporting layer;through the Through the vertical support and lateral limit,the temporary fixing measures of ballastless track bed after the cutting of the supporting layer are discussed,and the arch elevation of the track is restored through the fall of the track structure.At the same time,the paper discusses the technology and steps of the method of forced landing of the deformed clay on the upper arch of the subgrade and the method of undercutting the subgrade bed,and analyzes the advantages and disadvantages of the three methods of construction and treatment and their applicable scope.Based on the analysis of monitoring data in the later stage of subgrade camber deformation construction,the conclusion that the trend of subgrade camber is basically stable is obtained,which has a strong reference value and guiding significance for the deformation monitoring and construction treatment of high-speed railway camber.