Research On Setting-out Technology Of New Control Network For Ballast General Speed Railway

In recent years,large track road maintenance machinery has been widely used in China,which has become the development trend of the operation and maintenance of general speed railway.Track maintenance and repair of large track road maintenance machinery requires to use the track survey data as a guide.Track control network is an important prerequisite for precision survey data.In China,there is generally a lack of a complete track control network for general-speed railway.Even if survey control networks of some general-speed railways have been constructed according to the code for engineering survey of high-speed railway,it is difficult to adapt to the needs of huge ballast general-speed railways in terms of survey cost and work efficiency.With the development of surveying and mapping technology,a new generation of track geometry state measurement trolley(track inspection trolley)integrating GNSS,INS,laser profiler and other technologies raises new demands of the track survey control system.Document No.4 of 2021,China State Railway Group Cooperation Limited has pointed out: to further promote the application of track precision measurement technology,it is necessary to standardize the construction of ballast general-speed railway track control network.Therefore,to study a set of new ballast general-speed railway control network,which can not only meet the development status of general-speed railway,but also conform the new generation of track geometry measurement trolleys,has become very necessary.The main work of this thesis is as follows:(1)According to the definition and maintenance rules of the ballast general-speed track straightness parameters,the measurement accuracy requirements are inverted.Combined with the nominal accuracy of the track inspection trolley,the accuracy of the observables of straightness parameters is estimated.The inversion measurement accuracy is compared with the accuracy estimated by the track inspection trolley.The results show that the track inspection trolley can satisfy the requirements of the maintenance rules for ballast general-speed railway.(2)The requirements for the control network of the rail inspection trolley are expounded,and the construction of a new GNSS reference control network is proposed.In the section with better GNSS signal.The measurement and data processing methods of the new control network are discussed,and the GNSS/INS combined model is introduced.Then the measured data of the Longhai railway was collected and analyzed.The results show that the accuracy indicators of the new GNSS reference control network can meet the accuracy requirement of generalspeed railway surveying.After the precise tamping of the track,the comprehensive improvement rate of the track orientation and unevenness indicators related to the accuracy of the new GNSS control network is 28.48%,and the TQI improvement rate is 30.1%,which shows that the application effect of the new GNSS control network is obvious.(3)Based on the requirement of the track control network for the ballast general-speed railway track measurement,a mileage offset control network is proposed in the section without GNSS signal.Using the Gauss-Legendre quadrature formula,the calculation model of the fixed pile coordinates of the mileage offset control network is deduced.The correctness of the model is verified by programming.The results show that the error of the fixed pile coordinate calculation model is less than 1mm.And the algorithm model does not involve the coordinate transformation of local coordinates and railway coordinates,there is no loss of accuracy.(4)The measurement and application process of the mileage offset control network are introduced.The error source of the control network observation is analyzed,and the modification model of the observation error is studied.The error sources of the measured data in the control network are analyzed,and the error correction model is deduced.Then the application effect of the control network is verified according to the measured data.The results show that with the constraint of the mileage offset control network,the inner coincidence accuracy in the horizontal and vertical directions can reach 2mm,and the outer coincidence accuracy is less 3mm in the horizontal direction and 4mm in the vertical direction.