AREMA Annual Conference & Exposition October 5-8, 2003 Chicago, Illinois

Transcription

1 AREMA Annual Conference & Exposition October 5-8, 2003 Chicago, Illinois Laboratory Test Results and Field Test Status Of Heavy Axle Loads On Concrete Slab Track Designed for Shared High-Speed Passenger and Freight Rail Corridors July 15, 2003 By W. P. Kucera D. N. Bilow C. G. Ball D. Li

2 Laboratory Test Results and Field Test Status of Heavy Axle Loads On Concrete Slab Track Designed for Shared High-Speed Passenger and Freight Rail Corridors William P. Kucera, P.E. Program Manager, Transit & Rail Systems Portland Cement Association 5420 Old Orchard Road Skokie, IL Phone: Fax: David N. Bilow, P.E., S.E. Director, Engineered Structures Portland Cement Association 5420 Old Orchard Road Skokie, IL Phone: Fax: Claire G. Ball Principal Engineer and Project Manager Construction Technology Laboratories, Inc Old Orchard Road Skokie, IL Phone: Fax: Dingqing Li, Ph.D., P.E. Senior Engineer Transportation Technology Center, Inc DOT Road P.O. Box Pueblo, CO Phone: Fax:

3 ABSTRACT Slab track for shared high-speed rail (HSR) and freight rail corridors is rapidly becoming both a practical and viable alternative to traditional track systems. Slab track makes track safer and meets the needs of shared high-speed rail and freight rail corridors by maintaining strict tolerances required by HSR and reliably supporting the increasingly heavy loads of freight without the excessive maintenance of ballasted track. Presented are the laboratory test results of an independent dual block track (IDBT), a 26-ft long reinforced cast-in-place concrete slab track system subjected to static and repeated loads from hydraulic actuators to simulate vertical and lateral wheel loads of 315,000-lb freight cars. The IDBT system supports the rail with separate concrete blocks, each resting in a rubber boot, which then are in turn supported on a concrete slab. The data is compared with the results of earlier testing on a direct fixation slab track. Results prove that slab track can accommodate the heavy axle freight rail loads while maintaining the required vertical and horizontal geometry. Presented also is the status of the construction and field testing of two slab track sections on the High Tonnage Loop at Transportation Technology Center in Pueblo, Colorado. The field test sections include a 250-foot length of IDBT discussed above, another 250-foot length of direct fixation slab track (DFST) that supports the rail with fasteners anchored directly into the slab, and 25-foot transition zones between the slab track and ballasted track at each end. Key Words: slab track, high-speed rail, shared corridor, heavy axle, concrete

4 INTRODUCTION Slab track is a railroad track support system that uses a reinforced concrete slab pavement for support of railway track. Slab track is typically supported on a subbase over a prepared subgrade. The track rails are supported by rail fasteners that are anchored to the slab (or intermediate concrete blocks) or are embedded directly into a trough cast with the slab. Slab track can be pre-cast, cast-in-place or slip-formed. While slab track for high-speed rail (HSR) has been used for decades in Europe and Japan, its use in North America has been limited. Now, as alternative modes of public transportation become necessary and as federal funds for these projects become available, the need for a safe, reliable, durable, and economical track support system that can endure the heavy axle loads imparted by freight traffic while maintaining the stringent tolerances required for high-speed rail is essential. Presented in this paper are the following; Detailed description of the design and laboratory tests on one continuously reinforced castin-place concrete slab track section; the individual dual block track. A paper presented at the AREMA 2002 Annual Conference discusses laboratory tests on the direct fixation slab track previously performed. Laboratory test results of two continuously reinforced cast-in-place concrete slab track sections; the direct fixation slab track and the individual dual block track. Description of slab track construction at field test site (each type of slab track). Discussion of slab track instrumentation and field tests (each type of slab track).

5 SLAB TRACK LABORATORY TESTS This section of the paper will focus on laboratory tests of the Individual Dual Block Track (IDBT), referred to as Low Vibration Track (LVT) by its supplier, The Permanent Way Corporation. A discussion of the direct fixation slab track (DFST) was presented in a previous research paper published by AREMA. The IDBT slab track was first constructed and tested in the structural laboratory of Construction Technology Laboratories, Inc. (CTL) using top-down construction methods to accurately position the individual dual block ties in the concrete slab. Although other methods are employed in the construction of slab track, the top-down method was chosen because of its inherent low cost and ease of attaining the strict tolerances required for high speed rail track systems. The system was constructed in accordance with Amtrak Standard MW 100 for Class 9 Track for a maximum speed of 200 mph. The slab track test section, shown in Figure 1, consists of a full-scale reinforced concrete slab measuring 15 thick, 10-6 wide, and 26-0 long, and bearing on an elastomeric pad which in turn bears directly upon the laboratory floor. The blocks, spaced at 2-0, support RE136 rail laid at a standard gage of 4-8 ½ with a gage tolerance of +1/16 and 3/32. The rail is held to the blocks by fastener clips. The laboratory specimen simulates an installation on mainline track. The total thickness of the concrete slab was determined by development of a two-phase concrete slab system; phase 1 consists of a 7-3/4 thick structural slab with two mats of reinforcement, and phase 2 consists of an unreinforced self-compacting concrete (SCC) to support the individual dual blocks. The slab width was chosen in part to correspond to the recommendations of AREMA, Chapter 8, Part 27 and to keep the subgrade pressures at values less than 20 psi,

6 assuring exceptional performance even in areas with poor soil. The 10-6 width also precludes the development of punch-out failures which are due to high edge loading and non-channelized vehicular loadings in road pavements. While railroad applications keep train loads channelized, a narrower slab width could lead to an edge loading condition with high concrete stresses and excessive slab deflections. The 26-foot slab length was determined by car geometry considerations to support the spacing of four freight car axles consisting of two end trucks with axle spacings of 6-0 and a spacing of 7-0 between axles across the coupler between cars. The slab extends approximately 3-0 at each end to run out the strains induced into the slab during testing. Two trucks were decided upon so that one is situated with the axle-loads directly over the fasteners to give maximum slab stresses while the other places the axles between fasteners to give maximum rail bending stresses. Fasteners were placed on 2-foot centers to correspond with spacing typically used in similar ballasted track applications in the US. The concrete used in construction of the IDBT structural slab (phase 1) was chosen for its simple mix design, availability, and ease of replication in all regions of the country. The concrete was a standard Illinois Department of Transportation mix, #D104 which is a 6-bag mix consisting of 560 lbs. of Portland cement, 150 lbs. of flyash, 964 lbs. of fine aggregate (FA-1), 1,987 lbs. of coarse aggregate (CA-11), 32 gallons of water, and water-reducing and air-entraining admixtures in each cubic yard of concrete. Also specified was a water to cement (w/c) ratio of 0.38, a slump of 3-inches +/- 1 inch, air content between 4 and 7%, a maximum aggregate size of 1-inch, and an unconfined compressive strength of 5,000 psi at 28 days. The steel reinforcement was specified to be uncoated and have a yield stress of 60,000 psi.

7 The SCC concrete used for phase 2 construction of the IDBT was used because of the tight clearances between the phase 1 slab and the tie blocks and the extreme flowability characteristics inherent in the SCC mix. Axim Concrete Technologies, Inc. provided the materials and mix design during construction of the IDBT. The IDBT fasteners, supplied by The Permanent Way Corporation were chosen because previous heavy load tests were successful and because of the historical success of the track system in many installations around the world. Of particular merit is the recent milestone, where the IDBT system has exceeded 10-million cycles of train loading in the Eurotunnel. The STL rail fastenings tested on the IDBT were developed by Sonneville International Corporation and are tensioned by a shoulder and locker combination instead of the inserts and bolts used in the Eurotunnel. RE 136 rail has been the standard for heavy haul freight lines and was therefore specified for use in the slab track test specimen. The elastomeric pad supporting the concrete slab was selected to simulate the soil conditions at TTCI. Laboratory Tests The test protocol identified five main tests to be performed: Tests to determine the spring constants of the IDBT system for verification of k-values used in slab track design and other tests typically performed on fastener systems to confirm their structural integrity.

8 Static load slab track tests to determine the response of the slab track system for comparison to structural analysis. Repeated load slab track tests to determine the behavior of the system under heavy repeated loads A drop-hammer test to ascertain the response of the system to impact loads. Modal analysis test to determine the dynamic behavior of the slab track system. Laboratory Test Set-Up All elements of the slab track system were constructed beneath a steel loading frame in the CTL laboratory. Eight vertical actuators consisting of two hydraulic rams each were connected to a central hydraulic oil pumping system and were supported by the steel frame directly above the slab track specimen. The actuators were used to apply the simulated vertical wheel loads to the top of each rail. Two horizontal hydraulic ram actuators were connected between the two rails to apply lateral loads to the rails. See Figure 2 for locations of the applied loads. The system simulated forces produced by the TTCI test train with 315,000 pound freight cars. The slab track was instrumented to monitor the following parameters during the tests. Rail deflection at and between fasteners Slab deflection Slab strain Rail strain Subgrade pressure Fastener displacement

9 Deflection of the slab track is significant in that the slab track must satisfy the allowable deflection specified in the Amtrak high speed rail operational criterion. The locations of instrumentation for slab and rail deflections were positioned to obtain the maximum expected values. Rail and fastener movements are measured relative to the top surface of the laboratory floor. Instrumentation for concrete strain gages, rail strain gages, and subgrade pressure cells were also positioned to obtain the maximum expected values. Slab strains were monitored with embedment strain gages cast inside the slab near the bottom surface and external strain gages bonded to the top of the slab. Rail bending strains were monitored with strain gages attached to the rail at the fasteners and midway between the fasteners. Figure 3 shows the IDBT slab track test set-up. Laboratory Test Loads The vertical and horizontal loads applied during the test were developed from a distribution of measured wheel set load data provided by TTCI for 39-ton axle freight cars operated on the High-Tonnage Loop (HTL) at the Transportation Technology Center, Inc. (TTCI). The information from TTCI included data measured at the leading and trailing axles on both sides of the train. The highest, and thus most conservative, values were used for development of the test load spectrum. The data indicated that a vertical wheel load of 68 kips would encompass all dynamic and static wheel loads at the TTCI HTL test track 99.99% of the time. A goal of 3-million cycles was chosen for the repeated load test to meet industry standard goals for similar track components. The vertical load spectrum is shown in Table 1 and the lateral load spectrum is shown in Table 2.

10 LABORATORY TEST RESULTS Static Load Tests Static load testing of the slab track was performed prior to the repeated load test using a vertical load up to 68 kips at each wheel location and a lateral load up to kips at each horizontal actuator location. Table 3 summarizes the maximum measured deflections, stresses, and strains during the static load test and compares the measured values to the calculated values at the same location on the slab track. The values are calculated using finite element analyses to model the rail, fasteners, concrete slab, and subgrade. Repeated Load Test Results The repeated load test was completed in March A thorough visual examination of the slab track, rail and fasteners, performed after completion of the test revealed that the slab track components remained intact and structurally sound during the 3 million repeated load cycles. CONSTRUCTION AND TESTING OF DFST AND IDBT SLAB TRACK SECTIONS Success of the laboratory tests prompted continuation of the slab track program with construction and subsequent testing of two slab track test sections at the Transportation Technology Center s (TTC) Facility for Accelerated Service Testing (FAST). These milestones would not have been possible without funding granted by the Federal Railroad Administration (FRA). Their interest has enabled the program to continue towards success with the appropriation of just under $1,000,000 for construction and field testing of the slab track test sections.

11 The designated test location is on Section 38 of the High Tonnage Loop (HTL) at TTC. Section 38 is on a bypass track section with a curve of 5 and a superelevation of 4 inches. The velocity and axle loading of the train has been previously described in the laboratory test section of this paper. The reader is reminded that the loads used in the laboratory tests were modeled after heavy axle load data originally obtained on Section 38. Preparation of the Subgrade and Subbase In preparation for slab track construction, the existing trackwork and ballast were first removed. The subgrade was then graded to the proper line and elevation, and compacted for placement of the soil-cement subbase. Soil-cement was chosen for the subbase material because of its excellent strength and durability characteristics and due to its successful placement in many projects across the country. Design of the soil-cement was performed by Construction Technology Laboratories and called for an optimum moisture content of 12.5% and a cement content of 5.5% based on soil weight. Compaction was specified to be 98% of the maximum, Modified Proctor, with the maximum being 118 pcf. The target compressive design strength was 700 psi. The contractor was able to achieve the design parameters and successfully placed the soil-cement subbase in April Subsequent cores resulted in 28-day compressive strengths between 780 and 840 psi. Direct Fixation Slab Track The direct fixation slab track (DFST), a steel reinforced rectangular concrete slab section with a depth of 1-0 and a width of 10-6 was built to the identical details as the section used in the laboratory except that the section was constructed in a curve and the length was increased to 250

12 feet. This length was regarded as sufficient to ensure that the instrumentation, located near the midpoint along the length, would not be impacted by the effects of the adjacent transition zone, ballasted track, or IDBT track sections. The construction method was specified as top-down construction, as was used in the laboratory, to ensure that the exacting tolerances of Class 9 track could be realized. The top-down method called for Iron Horse rail alignment fixtures to support and maintain the rails and fasteners at the proper elevation, gage, and cant as the concrete was placed beneath the DF fasteners. Amtrak supplied the rail alignment fixtures for this project. Slobber plates, attached beneath the direct fixation fastener during the concrete pour, were temporarily incorporated into the fastener system to ensure the concrete being placed beneath did not work up into the elastomeric configurations on the bottom of the fastener. The slobber plates also had the effect of providing for extended smooth and flat surfaces around the fasteners in the event that fastener placement had to be adjusted laterally or longitudinally to maintain alignment. Temperature variations at TTCI were of extreme concern; ambient temperature swings of 30 are common, while rail temperature ranges of 70 in 24 hours are typical. The strict tolerances dictated by Class 9 leave minimal room for human error and natural forces. To control the effect that temperature would have on construction operations, a number of measures were taken to ensure that the Class 9 track tolerances would be met including the following: Painting the rail white would help to mitigate the rail temperature swings, reducing the range between 10 and 15 F. Quick release clips would temporarily replace the e-clips during construction. These clips would be released after initial set of the concrete and thus allow the rail to expand and

13 contract as needed without dragging the fastener and inserts along with it before the concrete attained sufficient strength. Wire braces were installed every 10-feet to hold the rail in proper position and prevent the jig from racking and the rail from walking towards the inside of the curve. Placement of concrete within a pour window enabled the contractor the maximum amount of time to place concrete with minimal rail temperature differentials. Ambient and rail temperature data collected by TTCI in previous years gave a predictable window of opportunity when the range of temperatures would be within 15 F, and thereby have minimal impact on rail expansion/contraction during concrete placement. The data suggested that if concrete placement was initiated during the beginning of the peak rail temperature, the contractor would have a 7 to 8 hour window during which placement of concrete would coincide with a maximum rail temperature variation of 15 F. Placement of the concrete used the above methods with success. As concreting progressed, the surveying team checked elevation and alignment to ensure that the track would meet the specified tolerances. Curing consisted of the application of a curing compound supplemented by placement of plastic coated insulative blankets that further reduced moisture loss and helped to maintain constant temperatures. Subsequent inspection of the surfaces below the direct fixation fasteners showed the expected trapped bubbles, which were filled with a non-shrink grout. The slobber plates and the quick release fasteners were removed and e-clips were reinstalled. Track surveys confirmed that the track was constructed to the specified tolerances. Construction of the DFST is shown in Figure 4.

14 Individual Dual Block Track The individual dual block track (IDBT) was also built to the identical details as the section used in the laboratory except that the section was constructed in a curve and the length was increased to 250 feet as described in the preceding DFST section. The construction method was specified as top-down construction, as was used in the laboratory, to ensure that the exacting tolerances of Class 9 track could be realized. The method also used Iron Horse rail alignment fixtures as described in the previous section. Temperature variations discussed earlier were still of extreme concern in the IDBT section. The supplier of the block ties suggested that a different approach be taken to control the temperature effects. The following measures were taken: Steel braces were designed, manufactured, and installed every 10-feet to hold the rail in proper position. The brace was fitted with a structural angle at each end, one to bear on the toe of the rail, and the other to bear against the top inside corner of the concrete curb poured in Phase 1. The middle of the brace had a turnbuckle that enabled the track to be laterally adjusted for proper alignment. The system provided the necessary lateral resistance to maintain rail alignment during concrete placement and curing. Note that the braces were needed for Phase 2 concrete placement only. Placement of concrete in a pour window previously discussed in detail. Placement of Phase 1 concrete was completed in May 2003 using a standard Colorado Department of Transportation concrete mix. The top surface of the curb was trowel finished while the surface of the slab that later would support the Phase 2 concrete was raked to ensure

15 the rough finish required by PWC. Note that the Phase 1 concrete employed typical formed castin-place concrete methods as top-down procedures were required only for Phase 2 operations. See Figure 5 for a photograph of IDBT Phase 1 construction. In order to ensure that the small clearance between the top of the Phase 1 slab and the bottom of the boot block was properly filled with Phase 2 concrete, an SCC mix developed by Axim Concrete Technologies was used as discussed previously in the laboratory test section. Axim provided the mix design, materials, and field support during Phase 2 concrete placement and also was instrumental in preliminary field tests. As concreting progressed, the surveying team checked elevation and alignment to ensure that the track would meet the specified tolerances. Curing consisted of the application of a curing compound supplemented by placement of plastic coated insulative blankets that further reduced moisture loss and helped to maintain constant temperatures. Survey confirmed that the track was constructed to the specified tolerances. See Figure 6 for IDBT Phase 2 construction. Transition Zones The interface between the DFST and IDBT slabs was detailed to provide continuous steel reinforcement. The differential slab depths and elevations were addressed by tapering the appropriate slab dimensions so that a smooth transition and a gradually changing track modulus would result. At the end of each slab track section, a 25-foot transition zone was constructed. Figure 7 shows a photograph of the transition zone construction. A state-of-the-art design was developed that incorporated the following components:

16 Reinforced concrete sub-slab to support ballast above. Reinforced concrete sidewalls to retain ballast in the transition section. 12 ballast to support concrete ties. Prestressed concrete ties specifically spaced to match adjacent track moduli. Engineered tie pad with a specified resiliency. Construction operations were completed in July. Installation of instrumentation then proceeded with preliminary tests scheduled for the beginning of August.

17 INSTRUMENTATION FOR FIELD TESTS Extensive measurements have been designed for the slab track installed at FAST to achieve the following objectives: Quantify slab track performance Quantify the actual load environment and the corresponding vibration behavior of the slab track Quantify stress and deformation behaviors of the individual slab track and subgrade components, and Quantify slab track and transition stiffness characteristics Track Performance Monitoring The performance of the slab track and transitions under train operations will be quantified by the following measurements: Track geometry change Vehicle response and performance Rail wear and corrugation Inspections and maintenance records Track Geometry Change - Two methods will be employed to monitor geometry conditions of the test section (slab track and transitions) as a function of tonnage. One method is to survey elevation changes of the top of the two rails (TOR) using optical survey equipment. For the duration of the test, the changes of TOR elevations along and across the test track will indicate average track settlement and roughness development. A track geometry car will be used to

18 inspect the test section on a regular basis. The recorded geometry results will be compared with the AMTRAK Class 9 Standards. The results will be used to decide whether any geometry maintenance is needed for the slab track and transitions. In addition, the analysis of geometry recordings at various levels of the planned 100 MGT will indicate how the track geometry condition may degrade. Vehicle Response and Performance - During the two-year test period, vehicle performance tests will be conducted to quantify vehicle response to the slab track conditions. The vehicle response measurements will be dynamic wheel/rail forces (vertical and lateral) via instrumented wheel sets. These measurements will be conducted at speed up to 45 mph. The vehicle response measurements for the slab track will be compared to those for the ballasted tracks with similar curvature and superelevation on the HTL. Rail Wear and Corrugation - Rail profile and corrugation measurements will be performed for the test section to monitor if there is any significant wear and corrugation development. Inspections and Maintenance Records - Regular inspections will be conducted over the slab track. Any maintenance activities will also be recorded. Track Stiffness Measurements Tests will be conducted to characterize the stiffness of the slab track, transitions and 50 ft into the ballasted track sections. Two test methods will be used for this purpose. First is a stationary test method. Via this method, vertical track deflections of the rails will be measured under

19 incremental vertical wheel loading and unloading. Track modulus can be calculated from these test results. The second method is to use the Track Loading Vehicle (TLV) to measure deflection profiles along the test zone under a constant vertical wheel load (30-40 kips) while the TLV moves at 10 mph. This test will give a continuous stiffness profile of the slab track and transitions. Track Component Measurements Individual track and subgrade components will be instrumented to measure stress and deformation response under train operations. The results of these measurements will be used to determine how each component will perform, and how the axle loads will be transmitted from the wheel/rail interface to the subgrade. Rail - Strain gauges will be used on the rails to measure bending stresses under wheel loads and to measure vertical and lateral wheel/rail forces. Fastening - The fastening systems for the two types of slab track will be instrumented to measure vertical and lateral deformations (rails relative to the slabs) under static and dynamic wheel loads. Concrete Slab - Two types of transducers will be used for the concrete slab. One utilizes a strain gauge technique for measuring stresses of the slab and reinforcement bars. The other is a multi-

20 depth deflectometer for measuring slab deformation. Strain gages will be installed on the reinforcement bars and on the slab surface. Subgrade and Sub-Base - Pressure cells will be used to measure subgrade stresses. The multidepth deflectometers will also be used to measure deformations of the sub-base and the subgrade. Vibration Measurements In addition to the transducers described above (strain gauges, pressure cells, multi-depth deflectometers) that will be used to measure dynamic response of the slab track components, acceleration measurements will be used to characterize the vibration behavior of the slab track. Accelerometers will be installed on the rails and on the slab surface, at the slab track section and at the transitions. Measurement Schedule Table 4 summarizes all the tests and the measurement cycles for the field tests. The type of the measurement, whether dynamic under train operation, or static without train operation, is also specified. FIELD TESTS Base-line measurements of the completed slab track test sections will be taken by the FAST Geometry Car and are expected to be completed in August, In addition, initial passes of

21 the heavy axle loads train will cross the sections and the resulting data will be collected and studied. Preliminary results will be presented at the AREMA Annual Conference in October. CONCLUSION The concrete slab track has met all predicted expectations and has performed well during laboratory testing. The fairly good agreement between the measured behavior and the calculated behavior of the slab track demonstrates the validity of the method of analysis used during the design of the track. Construction of the test sections at TTCI has proven that slab track can be constructed to Class 9 standards. Reasonable expectations of actual installations in a mainline track system would be that slab track has the strength to effectively support heavy axle loads of freight trains and the durability to maintain strict tolerances required by high speed rail operations. Slab track would therefore increase safety and keep required maintenance at a minimum.

22 ACKNOWLEDGEMENTS Federal Railroad Administration The authors would like to acknowledge the Federal Railroad Administration for their interest in slab track and for significant funding under the BAA-2001 Program. Their help has enabled two slab track test sections to be constructed at TTCI in Pueblo, Colorado and has helped to ensure the success of the PCA Slab Track Research and Demonstration Program. PCA Expert Panel The authors would also like to acknowledge the present and former members of the Slab Track Expert Panel for their work in the development of the Concrete Slab Track Research and Demonstration Program. Panel members and their respective affiliations follow; Claire Ball Construction Technology Laboratories, Inc. David Bilow Portland Cement Association Steven Chrismer LTK Engineering, Ltd. Nathan Higgins Hatch Mott and MacDonald William Kucera Portland Cement Association Kenneth Laine Transportation Technology Center, Inc. Richard Lanyi* Canadian National Railway Dingqing Li Transportation Technology Center, Inc. Mohammad Longi Longi Engineering Hamid Lotfi Construction Technology Laboratories, Inc. Gene Randich Consultant Nicholas Skoutelas Amtrak Bernard Sonneville The Permanent Way Corporation Ted Sussmann U.S. Department of Transportation/RSPA/Volpe Center Shiraz Tayabji * Construction Technology Laboratories, Inc. Jan Zicha Consultant *Former panel member

23 Other Individuals and Organizations In addition, the authors would also like to acknowledge the contributions and hard work of particular individuals and organizations involved with the continued success of the slab track program, namely; Bill Moorhead Trammco, LLC William Osler Advanced Track Products, Inc. Bernard Sonneville The Permanent Way Corporation Anderson Bray The Permanent Way Corporation Bill Horr The Permanent Way Corporation Jim Wamelink Axim Concrete Technologies, Inc. John Zuspan Marta Track Constructors, Inc. Allan Zarembski ZETA-TECH Associates, Inc. Amtrak Iron Horse Engineering

24 TABLES AND FIGURES Table 1 Table 2 Table 3 Table 4 Vertical Load Spectrum for Repeated Load Tests Lateral Load Spectrum for Repeated Load Tests Summary of Static Test Observations Field Test Measurement Schedule Figure 1 Figure 2 Figure 3 Figure 4 Section through IDBT Slab Track Laboratory Test Load Locations IDBT Laboratory Test Set-up Construction of DFST Figure 5 Construction of IDBT Phase 1 Figure 6 Construction of IDBT Phase 2 Figure 7 Construction of Transition Zone

25 Table 1 - Vertical Load Spectrum for Repeated Load Test Vertical Wheel Loads from TTCI Section 38 Number of Cycles for the Slab Track Test for the Trailing Axle at 40 MPH Wheel Percent of Time Probability of Number of Number of Cycles Test Number MGT Vertical Load Occurrence Exceedance Cycles Exceeding the of Cycles for Cycles in kips Average Vertical Load Selected Selected % % 327 3,000, % 99.99% 6,550 2,999, % 99.77% 18,994 2,993, % 99.14% 46,501 2,974, % 97.59% 79,249 2,927, % 94.95% 180,111 2,848, % 88.94% 213,554 2,668, % 81.82% 199,557 2,454, % 75.17% 195,483 2,255, % 68.66% 177,235 2,059, % 62.75% 163,720 1,882, % 57.29% 164,975 1,718,719 1,446, % 51.79% 166,231 1,553, % 46.25% 173,768 1,387, % 40.46% 158,104 1,213, % 35.19% 151,709 1,055, % 30.13% 180, , % 24.12% 191, ,647 1,021, % 17.75% 197, , % 11.17% 150, , , % 6.16% 99, , % 2.85% 51,529 85, , % 1.13% 23,271 33, % 0.35% 6,981 10,638 30, % 0.12% 3,324 3, % 0.011% % 0.011% , Total % 3,000,000 3,000,

26 Table 2 - Lateral Load Spectrum for Repeated Load Test Lateral Wheel Loads from TTCI Section 38 Number of Cycles for the Slab Track Test for the Leading Axle at 40 MPH Percent of Time Probability of Number of Number of Cycles Test Number Wheel Lateral Load Occurrence Exceedance Cycles Exceeding the of Cycles in kips Average Lateral Load Selected % % 30,000 3,000, % 99.00% 210,000 2,970, % 92.00% 300,000 2,760, % 82.00% 390,000 2,460, % 69.00% 555,000 2,070, % 50.50% 630,000 1,515, % 29.50% 375, , % 17.00% 225, ,000 1,446, % 9.50% 150, , % 4.50% 60, ,000 1,021, % 2.50% 45,000 75, , % 1.00% 15,000 30,000 30, % 0.50% 15,000 15,000 3,657 Total % 3,000,000 3,000,001

27 Table 3 - Summary of Static Test Observations Parameter DFST Calculated (FEM Analyses) Measured (Laboratory Tests) IDBT DFST IDBT Rail Deflection (at fastener) inch * inch inch Rail Stress (vertical load only) 14,800 psi * 12,100 psi 10,100 psi Slab Deflection (under rails) Maximum Transverse Strain in the Slab inch * inch inch 70 microstrain * 83 microstrain 37 microstrain Maximum Longitudinal Strain in the Slab 40 microstrain * 43 microstrain 14 microstrain * Values pending final analysis.

28 Table 4 Field Test Measurement Schedule Measurement MGT Dynamic Static TOR elevation 0, 0.5, 1, 2, 5, 10, 20, 50, 100 X Geometry car By FAST schedule X Vehicle performance 0, 50, 100 X Rail wear and corrugation 0, 10, 20, 30, 40, 50, 75, 100 X Visual inspection and mapping Weekly X Track modulus and stiffness 0, 10, 50, 75, 100 X X Rail stresses/wheel loads 0, 25, 50, 100 X X Fastening deformation 0, 25, 50, 100 X X Slab (re-bar) stresses & deformation (multi-depth deflectometer) 0, 25, 50, 100 X X Slab movement survey 0, 25, 50, 100 X Subgrade stress & deformation (multi-depth deflectometer) 0, 25, 50, 100 X X Acceleration (vibration) 0, 25, 50, 100 X Others As necessary

29 Fig. 1 - Section Through IDBT Slab Track Phase 1 concrete (reinforced) and phase 2 concrete (dashed unreinforced)

30 Fig. 2 - Laboratory Test Load Locations

31 Full size concrete slab track section, L=lateral load, V=vertical load Fig. 3 - IDBT Laboratory Test Set-up

32 Slab track under construction beneath loading frame Fig. 4 - Construction of DFST

33 Top-down construction of slab in FAST Section 38 Fig. 5 - Construction of IDBT Phase 1

34 Construction of slab in FAST Section 38

35 Fig. 6 - Construction of IDBT Phase 2 Top-down construction of slab using SCC, reinforcement at ends only

36 Fig. 7 - Construction of Transition Zone 25-foot transitions at each slab track interface with ballasted track