Study On Track Precise Inspection And Adjustment As Well As Its Reg- Ularity Optimization For High-speed Railways

In order to make the high speed, smooth and safety operation of the trains running on passenger-dedicated lines, design standards of high-speed railways pose higher requirements on track regularity. The chief means of effectively controlling the high track regularity is to inspect the track geometry state by precise track inspection technology and adjust the rail fastening system by precise adjustment of tracks. With the continuing development of ballastless tracks, the improving of operating speed and the increase of carrying capacity,some light, small and intelligent track-surveying trolleys equipped with multi-sensor have replaced traditional manual inspection methods and have become indispensable track static inspection tools for track construction and maintenance in high-speed railways. Especially,the track inspection technology and track-surveying trolleys for track geometric parameters,which use the static high-precision three-dimensional discrete measurement mode, are wide-ly used to inspect the track regularity state and adjust the track. However, whether the track-surveying trolley introduced from abroad or producted at home, the data processing methods and models in the trolley have not been fully publicized. In order to ensure the pre-cise inspection results of the track-surveying trolley, the trolley must be inspected in a spe-cial ballastless-track inspection field. For the purpose of ensuring the accuracy of inspection methods in the special inspection field, acquisition, processing and evaluation of track geo-metric data can be divided into three stages using a reference of track inspection technology of the stop-and-go mode in discrete measurement mode: the calculation and regularity for processing sectional measurement data, the computation of lateral and vertical deviations of-track points, and the inspection of middle and long wave irregularities. For the data pro-cessing method of track inspection points which only includes the survey station ad justment in the track-surveying mode which uses the measuring principle of polar coordinates method,a new adjustment method which is combining the known coordinates of survey stations with the measurement data of track gauge is proposed. Based on the shortcomings of existing methods for processing sectional measurement data and the characteristic that the interval between the adjacent survey stations of the total stations is between 50 and 70 m, this disser-tation proposes a novel method referred to as the regularity for processing sectional meas-urement data (RPSMD) method which takes measurement errors of overlapping and non-overlapping points into consideration. When the plane coordinates and elevations of track points have been computed and the sectional measurement data of survey stations have been processed, the external geometric parameters, which include lateral and vertical devia-tions and are key parameters of middle and long wave irregularities inspection and adjust-ment, will be calculated. Study on the deviation algorithms, which can be used in track in-spection and the track-surveying trolley, and of which computational efficiency and accuracy can meet the requirements of track construction, operation and maintenance. In view of the characteristics of the dense and massive track inspection points and high accuracy of re-quirement of high-speed railways, this dissertation proposes distance function model algo-rithm (DFA), vertical perpendicular to tangent model algorithm (NPTA) and longitudinal de-viation model algorithm with composite Simpson rule (LDACS) for calculating the mileage and lateral deviation of inspection points, and the equivalent calculations of DFA and NPTA in the curve are verified. The discussion about the accuracy and efficiency of those algo-rithms is given. To ensure safe running of a train and passenger comfort, the lateral and ver-tical profiles of 30 m and 300 m chords have been accepted as middle and long wave regu-larities in high-speed railways on the basis of the version of 10 m chord which is used in or-dinary-speed railways and can be inspected using the model of differential offset method.According to the measurement data, using the track adjustment scheme of the track-surveying trolley, the irregularity overrun rate after track adjustment is about 18.9 %.Therefore, this dissertation proposes a novel lateral and vertical profile irregularities of high density constraints of four point deviations model (HDFM) for improving accuracy of the model of differential offset method.Accurate and reliable track static inspection results are important basic for track precise adjustment. Precise adjustment of tracks can control the regularity of ballastless track of passenger-dedicated line, which is essential for ensuring the high track regularity. Using the three-dimensional coordinates measured by the track-surveying trolley, the analogue adjust-ment of fasteners can be achieved by a piece of special software. However, the major method used in the software for analogue adjustment is manual operation. In order to make the track regularity of the reference rail meet the requirements, low degree of automation of track an-alogue adjustment which is caused by manual operation results in repeated adjustment. Be-sides, using only gauge, change rate of gauge, cant and twist, lateral and vertical profiles of the non-reference rail cannot be as good as the profiles of the reference rail. Therefore, this dissertation proposes a novel adjustment algorithm called optimization algorithm of dou-ble-rails track fine adjustment (OADTFA), which is based on LI norm optimal principle. In OADTFA, the deviations of endpoints of reference chords participate in constraints of lateral and vertical profiles, which control not only irregularities of reference rail but also irregular-ities of non-reference rail. The strategy of choosing reference chord (e.g. 300 m) for section-al optimization adjustment is point by point. Finally, the optimally adjusted value of each fastener can be calculated by the simplex method. Because of inaccuracy remaining allowed adjustable values of track fasteners, the adjusted values of track fasteners may be beyond the allowed values, making difficult for precise adjustment of tracks. Therefore, this dissertation proposes a system of 'Fastener type—Adjusted values—Remaining allowed adjustable val-ues' (FAR), and adds a new constraint of remaining allowed adjustable values of track fas-teners and a new constraint of the differences in deviations of adjacent fasteners.According to the simulation and measurement data of high-speed railways, the experi-mental results show that:(1) Based on the track-surveying mode which uses the measuring principle of polar co-ordinates method, the accuracy of coordinates of track inspection points processed by a new adjustment method which is combining the known coordinates of survey stations with the measurement data of track gauge is obviously higher than that obtained only by the survey station adjustment.(2) The regularity for processing sectional measurement data (RPSMD) method which takes measurement errors of overlapping and non-overlapping points into consideration can be more reasonable for adjusting non-overlapping inspection points than currently available methods and also improves the accuracy and regularity of non-overlapping and overlapping inspection points. The accuracy of non-overlapping inspection points processed by the RPSMD method can be 2.68 times higher than that processed in the track-surveying trolley.(3) The calculations of DFA, NPTA and LDACS (M?5) algorithms meet the accuracy of the precise track inspection of high-speed railways. With all the three algorithms showing considerable computation efficiency,the efficiency of DFA is basically the same with NPTA and slightly higher than LDACS. The longer the easement curve is, the lower the efficiency and accuracy of DFA and NPTA are. The bigger the radius is, the higher the accuracy of LDACS is.(4) The novel lateral and vertical profile irregularities of high density constraints of four point deviations model (HDFM) can control lateral and vertical profiles of middle and long waves of the track anywhere, and optimize adjustments of fasteners.(5) The optimization algorithm of double-rails track fine adjustment (OADTFA) can automatically complete analogue adjustment, ensure the high regularity of double rails any-where, and give the optimally adjusted values of double rails.(6) In the system of Fastener type—Adjusted values—Remaining allowed adjustable values' (FAR), the constraint of remaining allowed adjustable vallues participates in the con-trol of track regularity, which solves the problem that track adjustment scheme may not be used for track precise adjustment due to the limitation of allowed adjustable values of fas-teners. The constraint of differences in deviations of adjacent fasteners can effectively com-pensate the irregularity of short wavelength caused by the constraint of allowed adjustable values and can further improve the regularity of tracks.