Neoloy Geocells shown to be the best solution for rail track stabilization, improving track quality and reducing maintenanceRead more
The Challenge – Reducing Railway Maintenance
The 457-mile mainline Northeast Corridor, from Washington DC to Boston is one of the highest volume rail corridors in the world, carrying 2,200 commuter and freight trains daily. A problematic section of track in the state of Maryland passes through soft clay subgrade with poor drainage that fouls the ballast. High speed railways are very sensitive for track geometry degradation. This necessitates frequent, expensive tamping every 3-4 months and results in speed limitations and a degradation of service.
Innovative Technology for High Speed Railways
As part of Federal Railway Administration (FRA) program to promote innovative technologies that will advance high speed railways, Amtrak (US National Railroad Corporation), Harsco Rail Consulting Group and Columbia University – have evaluated several geosynthetics solutions. Click Here to read Prof. Alan Zarembski testimonial.
Neoloy Geocells provide the best performance for Railway Track Reinforcement
After evaluating several soil stabilization solutions, including moisture barriers, geogrids and HDPE geocells – Neoloy Geocells showed the best results for track reinforcement:
Neoloy Geocells – the Best Solution for Railway Track Reinforcement
Neoloy Geocells are made of a unique Novel Polymeric Alloy (NPA) providing the following properties:
These properties provide the best performance for railway track reinforcement – track geometry is preserved for long-term, at the lower costs.
The Neoloy Geocell system is based on a hybrid structure of geocell on geogrid working platform. Neoloy Geocells Category D (Heavy Duty) were installed at the ballast/sub-ballast interface. The geogrid was installed on the subgrade layer as a working platform.
Fast Implementation, Quick Investment Return
Knowledge transfer for the Amtrak installation team went smoothly. The entire operation took place during a long weekend when the track was removed from service. Standard Amtrak quality ballast and sub-ballast were used. The impact of Neoloy was noticeable immediately – the trucks hauling infill caused severe rutting to the wet mud subgrade as they approached the installation area, but easily traversed the areas in which Neoloy Geocells were already installed with no rutting whatsoever.
In the permafrost bogs of Russia, Neoloy® Geocells provide track reinforcement, increasing bearing capacity, speed and loads.Read more
Russian Railways (RZhD) is the government-owned railway company of Russia, and is one of the largest in the world, in terms of employees (1.2 million), traffic, rolling stock and length of the track.
In the Arkhangelsk Province of the RZD (Russian Railways) the rail embankment and structural support layers, traversing through permafrost bogs, are subject to steady deformation. Neoloy Geocells were deployed to strengthen the track formation layers in “ailing” sections by forming a semi-rigid beam that provides uniform rigid support of the upper structural layers and reduces settlement and accumulated degradation caused by the weak subgrade.
Neoloy Geocell Solution – Increases Speeds & Loads
After removing the old track and ballast, 15 cm of Neoloy was installed in the sub-ballast layer. Infill consisted of a sand-gravel mixture, with 6-10 cm compacted overfill. The infill was dropped from a rail chute at a height of several meters without damage to the stiff cell walls. A new layer of 60 cm ballast, along with new sleepers and rails were laid down on the top layers.
The Head Supervisor of the Geotechnical Evaluation Center of RZD, Vitaly Leonyuk, stated that: “the Neoloy reinforcement subbase layer prevents deformation in the embankment and structural layers as a result of the dynamic loading” and “it enables trains to pass over these problematic sections at higher speeds and at heavier axle loads.” RZD plans to install 68 thousand square meters of Neoloy Geocells in the rehabilitation of 13.6 km of problematic track in this Northern region.
Rail Track Rehabilitation Over Problematic Subgrade, despite weak subgrade, rail track rehabilitation with Neoloy®Geocells improved durability, sustaining track geometryRead more
As part of its program to upgrade and rehabilitate track and construct new lines, Israel Railways adopted the Neoloy Geocell technology as its preferred method for track rehabilitation over problematic subgrade. This includes improving load support over soft sandy soils and restraining volumetric change in fat clay soils.
A new 16 km Southern rail line from Tel Aviv passes through a number of suburbs, originally built over sand dunes. Whereas, the route passes through weak subgrade, the rail authority and geotechnical consultants decided to utilize Neoloy Geocells to reinforce the substructure along the entire line. In addition to improving the load bearing capacity, Neoloy was selected for its overall performance, durability and long-term cost savings in track operations and maintenance.
Conventional subgrade improvement methods include thick layers of expensive ballast and subballast and/or the use of geogrids for reinforcement. However geogrids require high quality subballast aggregate, while their zone of confinement is limited. Reduction of the subballast layer is minimal, and these solutions require frequent maintenance.
Neoloy Geocell Solution
The Tel-Aviv to Ashdod rail line utilized Neoloy Geocells of 20 cm wall height for subgrade reinforcement of the subballast layer. A total of 200,000 m2 is being installed in 12m wide sections along the 16 km rail route. Medium grade, fine granular infill material was sufficient for the heavy load support needed for the railway substructures. Whereas, the Neoloy vertical zone of influence provides 30-50% more confinement and reinforcement than other solutions, attrition of the aggregate and ballast infill is reduced significantly. The result is that track geometry is sustained for longer periods of time thereby reducing the number of expensive maintenance cycles.