ASSESSMENT OF TRACK QUALITY IN TRIAL TEST SECTIONS BY SPOT AND CONTINUOUS METHOD ASSESSMENT OF TRACK QUALITY IN TRIAL TEST SECTIONS BY SPOT AND CONTINUOUS METHOD

. The quality of track alignment and track geometry is an essential precondition of safe and economical operation of railway track. The paper provides an analysis of diagnostics of relative track geometry parameters and evaluation of measurement deviations carried out by the spot and continuous method in sections of the ballasted track, transition areas and sections with the slab track structure.


Introduction
The ballasted track has been proven for many decades. From the structural point of view, the ballasted track is referred to as a railway track whose track skeleton is stored in railway ballast. In the case of high line tonnage and axle load and increasing track speeds, it appears that such a structure has its operational and economical limits [1]. The ballasted track is characterized by "floating" placement of track skeleton which causes the growth of dynamic forces during each passage of a train. This can be and usually is the cause of gradual degradation of the track geometry. The need of elimination of irregularities in the track geometry forces the operator to regularly remove the diagnosed track deficiencies by time-consuming and costly maintenance works. This phenomenon grows with increasing track speed and thus increases the maintenance costs and the share of track possessions. In this way the attractiveness of the track for passengers can be reduced. It is sufficient, however, to only replace the weakest structural element of the ballasted track -the track ballast by another more suitable structural element which shows no plastic behavior. The term slab track, as defined in [2], refers to such a structure of railway superstructure in which a spread function of railway ballast is replaced by reinforced materials, and which is placed on a concrete or asphalt substructure (slab). The slab track structure consists of (top-down): • track superstructure -rails and fastenings of the rails to the rail support, -rail support (sleepers, single supporting points, prefabricated or monolithic slab), -concrete foundation layer (CFL) or asphalt foundation layer (AFL), -hydraulically bonded foundation layer (HBL); • track substructure (if the slab track construction is built on earthworks) -frost protective layer (FPL), -subsoil layers (consolidated or improved material of earthworks), -consolidated soil or bedrock.

Experimental section parameters
The experimental sections are situated on the modernized double-track railway line Nove Mesto nad Vahom -Puchov and are located in the areas of the portals of the tunnel Turecky vrch. The track speed in both tracks is 160 km.h -1 , which ranks the railway line to the category of velocity range No. 4 (RP4). The superstructure of each section is constructed as a construction with ballast bed and the slab track RHEDA 2000 ® (in tunnel, on bridges and on earthwork). The construction of the superstructure in transition areas is constructed as improved ballast placed in the concrete trough.
The monitoring of the track geometry aims to determine the condition of the parts of the track structure and the entire track. This kind of monitoring is one of the basic diagnostic activities by which also the traffic and climatic load and the effects of maintenance on track skeleton are monitored. The

Assessment of results of track alignment design and track geometry diagnostics
The assessment of results of the track alignment design and track geometry is carried out according to the valid technical standards and regulations [5]. The diagnostics of structure layout and track geometry of the track section:

Diagnostic methods and equipment
The diagnostics of the track alignment design and track geometry by the spot method is realized by gauge-checkers ROBEL ( Fig. 1) and GEISMAR. The spot method is used to control deviations of gauge ΔRK (mm) and cant PK (mm) and monitoring is performed at each fastening point of the rail support [4].
For the sake of comprehensive diagnostics, each section No.  The comprehensive diagnostics of the track alignment design and track geometry by continuous method is carried out by continuously measuring trolley KRAB TM -Light (Fig. 2). The measurement is referred to as continuous, but in fact, the data is recorded with the measuring step of 250 mm [5] and [6]: • gauge deviation RK (after calculating the change of gauge ZR is also recorded), • alignment of right rail SR (after calculating the alignment of left rail SL is also recorded), • rail top level of right rail stVR (after calculating the rail top level of left rail VL is also recorded), The results of measurement before putting sections into operation (MSO) obtained by the spot method have been compared to operational measurements (PO1, PO2, PO3 and PO4) and the differences are shown in Table 2 -measurement of gauge deviations ΔRK and Table 3 -measurement of cant deviations PK [8] and [4].
The The measured parameters were evaluated according to the limit input deviations for acceptance of works with the use of new material (MSO) and according to the operational deviations and limit operational deviations (PO1, PO2, PO3 and PO4) in Table  1 [7].
The deviations of the relative geometric parameters of the track for RP4 [5]  Differences of measurement of PK -operational measurement (PO1, PO2, PO3, PO4) and measurement before putting sections into operation (MSO) Table 3 Track / section

PO1-MSO PO2-MSO
where b and m are numerical constants determined on the basis of the SDV statistics of relevant parameter and speed zone.
Considering the Railways of the Slovak Republic, the results of the quality section evaluation of the track according to quality marks are indicative and additional and are not binding for the evaluation of RK state. The measures which are set for individual intervals of quality marks are recommendatory according to Table 4.
improvement of the quality of all sections after their maintenance [9] and [10].
The continuous method used for overall superevaluation of the test sections (so called "section evaluation") is, in accordance with [2], given by the quality number of the section evaluated (QN), and the quality mark (QM) of SR parameters (SL), RK, PK and VR (VL). The The scale of quality marks (QM) according to quality section evaluation [6] Table 4 Interval of quality marks Verbal assessment of the section according to the quality mark Color of the quality mark in printed output 0 < QM ≤ 2 the state of track geometry is satisfactory in the section evaluated no color marking 2 < QM ≤ 3 it is recommended to design the repair of track geometry in the section evaluated into the maintenance work plan green color 3 < QM < 4 it is recommended to perform the repair of the track geometry in the section evaluated before the nearest inspection violet color 4 ≤ QM ≤ 6 it is recommended to perform immediate measures in the section evaluated to ensure the safety of operation red color sections shows direct connection. The section with the lowest quality shown by evaluation by both methods is the section No. 1 in the area of the southern portal. The output of diagnostics is a set of information about the railway track quality. By using it, it is possible to predict further progress of the structure and then plan maintenance interventions.
The essential preconditions for the competitiveness of rail transport are sustainability and reliability of railway line operation. Only the development of various diagnostic methods and assessment of track alignment and track geometry can ensure the quality of the track geometry parameters, reduce maintenance costs, extend the service life of the structure and increase the competitiveness and attractiveness of railway lines in long-term perspective.

Acknowledgement
The paper contains partial results of the grant VEGA 1/0597/14"Analysis of methods used to measure the unconventional railway track construction from the point of view of accuracy and reliability".
The development of the track alignment design and track geometry of monitored sections is shown in Tables 5 -8.
The evaluation of deviations of the track alignment design and track geometry in velocity zone RP 4 according to [7 and 6] is calculated separately for sections with the ballasted track (BT), for transition areas (TA) and sections with the slab track structure (ST).
From the overview of the track section quality it is clear that local errors noticed before putting sections into operation were eliminated by maintenance interventions carried out after input measurements. The section with the lowest quality shown by evaluation is the section of track No. 1 in the area of the southern portal, where occurence of local errors is the highest. This section also is of the lowest quality mark and number of quality. There is expected improvement of the track section quality after maintenance interventions.

Conclusions
The comparison of the results of diagnostics obtained by spot method and also by continuous method in the experimental