Presto Geosystems  

Appleton,  WI 
United States
https://www.prestogeo.com/applications/railroad/

• Booth: 1813

Solving track & slope stabilization issues with 3D GEOWEB®.

Reinforce track and overcome stability and drainage challenges in soft soil environments and in heavy, repeated loading areas with the industry’s ‘go to’ solution—Presto Geosystems’ GEOWEB® 3D system. The 3D system is a versatile solution for ballast reinforcement, yard stabilization and erosion protection of embankments and stormwater channels. Reduce settlement, ballast abrasion, movement and rotation for extended ballast life. Reduce cross section thickness by as much as 50% for material savings.  The fast to deploy and install system minimizes down time for emergency repairs. Accredited research results at AAR-TTCI, University of Kansas and Oregon State University validate the system’s performance subjected to heavy repeated loads.  Complimentary project evaluation service. 

Brands: GEOWEB Track Ballast Reinforcement, GEOWEB Embankment Stabilization, GEOWEB Right-of-Way Stabilization, GEOTERRA Site Access Mats

 Videos

 Press Releases

• Railroad Ballast Performance Improvement Using GEOWEB 3D Geocells (Sep 06, 2019)

  Railroad ballast performance improvement using Geoweb® 3D Geocells

  by Bill Handlos, PE

  Keywords: Railroad, Geocell, Ballast

  Every year, railroads dedicate a great deal of capital and maintenance expense towards the creation and upkeep of high quality ballast layers. Enduring well-designed ballast is quite literally the foundation on which a successful rail line operates. With ballooning rail traffic carrying heavier loads than ever, GEOWEB cellular confinement (Geocell) effectively takes the pressure off critical ballast systems.

  Oregon State University (OSU) recently performed state-of-the-art, three-dimensional dynamic Finite Element modeling to analyze the reinforcing benefit of GEOWEB geocells in railway applications. This study was completed in cooperation with the University of Kansas (KU) who simultaneously performed a testing program of Geocell reinforced ballast placed over weak subgrade material using HDPE GEOWEB material.

  The digital modeling results were reinforced by the laboratory tests and showed a significant decrease in settlement of the railway ballast when GEOWEB confinement was used. The use of GEOWEB technology not only decreased settlement, but reduced pressure on point-to-point aggregate load transfer contact which in turn resulted in less damage to ballast aggregate particles leading to less progressive deformation and longer maintenance frequencies of the entire ballast embankment. In short, more cycles means less track down-time for maintenance.

  The research results were clear.  The benefits of applying GEOWEB Geocell confinement for reinforcement of real ballast over weak subgrades includes:

  ·         Significant decrease in ballast settlement. The confinement influence reduced settlement equivalent to more than 8 inches (20 cm) of ballast.

  ·         Decrease in subgrade interface pressure by nearly 50% for weak subgrades. The decreased pressure in subgrade results in lower subgrade settlements.

  ·         Increase in ballast resiliency after many cycles--resulting in decreased rate of cyclic settlement.

  ·         Decrease in lateral heave and movement of the ballast material.

  ·         Redistribution of vertical stresses on the subgrade--resulting in higher shear strength and reduction in plastic deformation.

  ·         For the largest loading conditions used in the analysis, the strains in the GEOWEB geocell were low (less than 1%) and within the elastic range for typical geosynthetic materials. The maximum tensile strains were localized at the bottom corners of the Geoweb cells, illustrating the importance of adequately durable seams.

  ·         Strains in the Geoweb ballast layer were low (less than 1%) even under heavy, freight loadings over very soft sub grades. Stress concentrations were found at the seams, highlighting the importance of Geoweb seam strength during loading condition.

     

  A Better Built Ballast

  The benefits of GEOWEB confined ballast are substantiated through rigorous testing. Conventional ballast reinforcing materials (eg geogrids, Hot Mix Asphalt (HMA)) do not have the strengthening attributes that GEOWEB geocells can provide, especially in soft subgrades.  Building a more stable ballast layer with less settlement, higher shear strength, and less maintenance requirements is possible when built with GEOWEB geocells.

  For more information, see https://www.prestogeo.com/applications/railroad/ .

• Queensland Rail Utilizes GEOWEB 3D Ballast Reinforcement in Soft Soil Area (Sep 06, 2019)

  BALLAST REINFORCEMENT IN HIGH STRESS AREAS

  Frequent track maintenance issues for the Queensland Rail were reduced using a variety of innovative geosynthetic  products including the GEOWEB® Soil Stabilization System.

  THE PROBLEM

  Queensland Rail (QR) manages a very large network of mainline track across Queensland including the Suburban lines in and around the Ipswich region. QR needs to maintain problematic sites across their network. In order to carry out this work, QR is required to shut down parts of their rail network for up to 48 hours. While this work is typically scheduled for weekends, each track closure can be very costly and disruptive to service.

  Booval Railway Station, located in Ipswich, is a large city immediately west of Brisbane with a very high water table and soft saturated subgrade that supports the track. In mid-January, QR carried out maintenance at Booval Station. The first part was the uptrack approach to the Railway Station (approx. 330 ft long). The second part was the transition zones on each side of the concrete bridge overpass (approx. 165 ft long).

  RAIL STATION LOAD SUPPORT SOLUTION

  The existing platform approach had a very high water table and saturated subgrade. Approximately 330 ft of existing track, sleepers and ballast material were removed from the uptrack approach. Because of the extremely soft subgrade conditions, a 3-inch ballast layer was placed and compacted as a ‘flood mat’. A layer of non-woven geotextile was installed over the ballast as a separation layer—the GEOWEB® 3D system was placed over the geotextile and filled with gravel. An additional 4 inch layer of gravel was placed and compacted over the GEOWEB® sections. A layer of Tracktex™ geocomposite was installed over the gravel.

  SOIL REINFORCEMENT OF BRIDGE ABUTMENTS

  Adjacent to the railway platform is a short concrete bridge that passes over Bergin Street. The same cross-section for the platform approach was adopted, but the GEOWEB® system acted as a transition zone from natural ground to the concrete bridge abutment. The GEOWEB® system plays a critical role in controlling differential settlement and distributing stress in the bridge approach area.  Approximately 165 ft of existing track, sleepers and ballast material were removed from the bridge abutments and replaced with the GEOWEB system.

  The GEOWEB® system stabilizes the track support material by preventing lateral movement of the infill and plays a vital role in decreasing maintenance and service interruptions.

  The GEOWEB® 3D soil confinement system is effective in reducing maintenance in high impact areas. By stiffening the ballast layer, movement and deflection is limited and maintenance in these critical transition zones is significantly reduced

• AAR/TTCI Research Proves GEOWEB 3D System Superior Geosynthetic for Track Stabilization (Sep 06, 2019)

  GEOWEB® System Delivers 14 Times Reinforcement Benefit of Other Geosynthetics for Track Subballast Support

  TEST FACILITY & SCOPE:

  The Association of American Railroads’ (AAR) research facility near Pueblo, CO, the Transportation Technology Center (TTCI), contains the Facility for Accelerated Service Testing (FAST) track where years of extreme stress conditions can be applied in a few months. 

  On FAST’s High Tonnage Loop, a 2.7 mile ‘loop track’ dedicated to High Axle Loads (called HALs, denoting 39-tons or more), some remarkable testing has been performed on the GEOWEB System.

  TESTING CRITERIA:

  The goal of the testing at AAR/TTCI’s FAST (Facility for Accelerated Service Testing) track was to evaluate the effects of repeated heavy loads on the GEOWEB System installed over a soft subgrade.

  The soft subgrade was constructed from highly expansive Vicksburg Buckshot Clay, an ASTM “Reference Soil” imported from Mississippi for this purpose. The clay was placed at 30% moisture content in a five foot deep, 700 foot long trench along a section of the High Tonnage Loop, known as the Low Track Modulus (LTM) test zone. The test train operations are designed to accumulate approximately 1 million gross tons (MGT) per day, running on a continuous basis at no more than 40 mph speed.

  Numerous geosynthetic materials had previously been tested under the track in the LTM zone, but ballast tamping was still required on an average every 15 MGT of loading.

  For the test, the GEOWEB System was placed in the sub-ballast layer in readiness for the repeated application of 39 ton axle loads. To ensure that the testing would capture the ‘worst case’ condition for clay subgrades, fire hoses were used to simulate two 500 year rainfall events, saturating the highly expansive clay subgrade during a dry mid-winter period between snow storms and snow melt conditions. Researchers found that the ballast support offered by the GEOWEB System was not affected by the added water.

  The GEOWEB System prior to this testing had provided excellent load support across soft subgrade conditions for heavy load applications including track subballast , ports and intermodal/bulk handling yards with daily truck traffic and parking, as well as for heavy load and soft subgrade problems for highway and transportation structures.

  Prior to installation of the GEOWEB System, the unreinforced track over this section of highly expansive clay had required ballast tamping every one million gross tons (MGT) of loading under 315,000-pound car operation. 

  An early testing report of the GEOWEB installation prepared by Steve Chrismer at TTCI in Railway Age (9/97) noted that the track geometry error was still well within acceptable limits after (at that time) 64 MGT operation without ballast tamping (already more than 4 times the average reinforcement benefit provided by other geosynthetic products such as geogrids and geotextiles).

   Crismer commented that the testing and track geometry measurements would continue, at least until the track required surfacing so that the actual improvement in tamping cycle can be determined.  However, two years later, Steve’s successor Joe Lopresti indicated that, after almost 180 MGT, still with only minimal loss of track geometry, TTCI had decided to 

  stop waiting for the track to require resurfacing. They discontinued the testing and eventually removed the GEOWEB installation in order to free up this section of soft deformable clay subgrade for other planned projects.

  After more than two years torture testing with a total load of 206.6 million gross tons (including the incidental train traffic involved in maintaining the less successful sections) the GEOWEB section continued to perform flawlessly. At the end of TTCI’s monitoring, the GEOWEB installation had provided almost 14 times the average reinforcement benefit of other geosynthetic products tested with no indication of reduced system effectiveness or need for ballast tamping. 

  Also, the permanent track deformation after 180 MGT accumulated load was less than 30% of the allowable deformation margins permitted by the FRA.

  GEOWEB® SYSTEM PERFORMANCE RESULTS

  The outstanding performance of the GEOWEB Cellular Confinement System in this ‘worst case’ field testing program conducted by TTCI correlates well with field installations and research programs conducted with the GEOWEB Cellular Confinement System for highway and rail applications.

  The research at TTCI supports the evidence that the GEOWEB cellular confinement technology offers far greater performance benefits for ballast support applications than geogrids and geotextiles, and it offers a solution for situations where other geosynthetic products fail to deliver long term stabilization.

• CSX Rail Laydown Yard Reinforced with GEOWEB 3D Soil Confinement System (Sep 06, 2019)

  GEOWEB 3D CONFINEMENT SYSTEM REINFORCES ACTIVE HEAVY LOAD AREAS AT CSX RAIL LAYDOWN YARD

  PROJECT OVERVIEW:

  The CSX Charleston, SC Intermodal terminal aggregate surface lot required base reinforcement due to poor subgrade conditions.  The two areas included one area to support 120,000 pound reach stackers lifting and moving 10,000 pound containers and an existing grass area to support empty chassis parking.

  GEOWEB® LOAD SUPPORT SOLUTION

  CSX Project Engineer Wendi Leanhardt contacted Staci Smith, PE, Regional Engineer for ACF Environmental for assistance and solutions to stabilize a soft sub base for the container yard facilities.  Wendi, Staci and Bryan Wedin, P.E., Chief Design Engineer for Presto Geosystems, worked together to develop a solution.  CSX obtained geotechnical information on the site’s soils to 1) determine if it could be used for the GEOWEB infill and 2) assess the current base stability of each site. 

  DESIGN SOLUTIONS

  Presto Geosystems provided separate design recommendations for the reach stacker and chassis parking areas utilizing the on-site material which eliminated the need to haul in select fill.  Each design was calculated factoring in the sub base type/strength, loading weight, and frequency of traffic.

  ECONOMICAL AND EFFICIENT SOLUTION SHORTENS DOWNTIME, REDUCES MAINTENANCE

  Eliminating the need to import costly fill, the downtime of the yard was significantly reduced which was especially important due to the high volume of tractor trailers the facility handles on a daily basis. 

  The reach stacker area used a high strength woven geotextile, three inches of aggregate base, GEOWEB GW30V6 (mid-size cell, 6 inch deep) sections and two-inch wearing surface.  The chassis parking area utilized a high strength woven geotextile and GEOWEB GW30V6 sections with a two inch wearing surface.  Both areas will have minimal maintenance to maintain the surface.

  In both locations, the GEOWEB sections were anchored with ten, 18-inch long No. 4 rebar capped with Presto’s patented ATRA® Stake Clips.

  TOTAL GEOWEB-REINFORCED PROJECT:

  A total of 1.75 acres of laydown yard was stabilized with the GEOWEB Cellular Confinement System in May of 2015.  As of December 2015, the areas were functioning according the requirements set by CSX.

• GEOWEB 3D System Stabilizes FEC Intermodal Container Transfer Facility (Sep 06, 2019)

  PROJECT SUMMARY

  The GEOWEB® system, consisting of a 6-inch deep mid-size cell over a high strength woven geotextile, was installed on each side of the 4 roller compacted concrete (RCC) gantry crane ways at the Port of Everglades, FL intermodal container facility.  The GEOWEB system is used to control differential settlement on the areas adjacent to the crane ways.  The crane ways consist of 18 inches of RCC installed on sheet piles 7 ft. on center.  The infill specified for the GEOWEB system was ¾ inch limerock with limited fines to allow drainage.  With the unique benefits of GEOWEB confinement, the contractor was allowed to substitute a lesser quality, on-site fill material which  resulted in  of coarse, screened sand.

  Maintenance Reduction in High Impact Zones

  The FEC was one of the first port facilities in Southeast Florida to use roller-compacted concrete (RCC)

  PROVEN SOLUTION

  The GEOWEB system is a thirty year proven solution for heavy load applications over soft subgrades in the rail/intermodal industries. The 3D confinement system solves soft soil challenges for roadways, intermodal/port yard surfaces, bridge abutments and high-stiffness trackbed foundations.

  PAVEMENT PERFORMANCE

  The GEOWEB solution behaves like a semi-rigid slab which improves load distribution and reduces vertical stresses reaching the sub grade.  The end result will be a more durable sub grade that increases pavement life by preventing long term settlement and consolidation.

  Presto Geosystems’ GEOWEB® system offered a solution for stabilizing sand infill and preventing long-term differential settlement in the gantry crane ways located under the Roller Compacted Concrete (RCC).

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