TERRAM Railways
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Geosynthetics in railways and related applications A geosynthetic provides one or more of four functions when used in track-bed construction: Separation to maintain the integrity of adjacent soil types i.e. prevent intermixing TERRAM products, manufacturing and laboratory capability. Filtration to prevent leaching of soil particles TERRAM brand products are manufactured by PGI, the world’s top producer of nonwovens and the UK’s largest manufacturer of geotextiles. The TERRAM geotextiles, geocells and geocomposites along with other related materials such as geonets, pavers and grass...

Extending track-bed life using geosynthetics Sub-grade erosion pumping over a clay or silty subgrade. With ballast placed directly over a clay or silty subgrade there is the possibility of a slurry being formed at the ballast/subgrade interface; particularly if there are depressions or pockets at formation level. Regular traffic causes the ballast to oscillate at the interface which disturbs the clay/silt, and the presence of water in the pockets causes the particles to form a slurry. As the ballast dilates, the slurry moves into the void. The slurry is pumped upwards as the ballast...

Preventing Clay Pumping Placement of a sand blanket is time consuming and time is of the essence when working against the possessions’ clock. Replacing a sand blanket entirely PGI have continued to develop and evaluate likely candidates for a sand-blanket replacement knowing that the ideal product would have to be: TERRAM Hydrotex 7 Filter/protector Fine filter • Quicker to install • Lower in (installed) cost • More readily available • More environmentally friendly PGI recognised that its own development needed to be focused on the filter function as TERRAM PW1 alone is not capable of...

Preventing sub-grade erosion Preventing sub-grade erosion with fine soils, coarse soils and granular soils i.e. sand and gravel. Preventing sub-grade erosion with fine soils Fine soils are mixed soils, containing possibly all the grading sizes including clay silt, sand and gravel. The clay and silt fractions dominate its engineering properties/behaviour. Sub-grade erosion over fine soils can be prevented by the inclusion of a Hydrotex geocomposite at the ballast/subgrade interface. Preventing sub-grade erosion with coarse soils Ballast TERRAM Hydrotex Fine soil subgrade One of the most...

Ballast overweak sub-grade It’s accepted that a geogrid stiffens the ballast by providing reinforcement at its base, and that this is highly desirable when track is being constructed over a soft subgrade. Ballast over weak subgrades TERRAM PW4-LA is a composite of TERRAM PW1 and a geogrid which speeds up the installation time when both reinforcement and a filter/separator are both required. An extensive, full-scale, independent research programme was carried out by British Rail and this clearly showed that the use of a geogrid beneath ballast over a soft sub-grade: Low load-bearing capacity...

Controlling erosion on railway slopes Product pages TERRAM Geocells are three-dimensional blankets of interconnected cells which are placed on slopes, secured in position using pins, and filled with friable topsoil. Controlling erosion on railway slopes Once installed, a TERRAM Geocell provides immediate stability by confining the fill and greatly improves resistance to wind and run-off. With a topsoil fill, the stability is further enhanced as vegetation becomes established and a geocell can be used to establish vegetation on slopes where establishing cover would otherwise have been a...

TERRAM PW1 trackbed separator is designed to maintain separation between the adjacent sand/ballast layers within the trackbed construction, preventing the upward movement of fine sub-grade particles. TERRAM PW2 is a robust trackbed separator designed where the sub-grade soils are good but contain angular stone. This angular stone could damage a standard geotextile, so a robust geotextile that protects the separation geotextile is essential. TERRAM PW1 is suitable for where sub-grade soils are good, have sufficient strength and the particles are of even size. TERRAM Geosynthetics provide...

TERRAM PW9 is a Robust Separator for trackbed, designed where the sub-grade soils are good but contain angular stone. This angular stone could damage a standard geotextile, so a robust geotextile that protects the separation function of the geotextile is essential. TERRAM PW4-LA is a reinforced trackbed separator designed where the sub-grade is weak, ie. soft and boggy conditions. TERRAM PW9 is a mechanically entangled robust separator/filter that provides protection from angular stone damage. TERRAM Geosynthetics provide solutions for permanent way applications where loss of rail track...

TERRAM Hydrotex provides a permanent way solution for trackbed stability where clay pumping can cause loss of trackbed stability. TERRAM Hydrotex not only acts as a filter/separator for fine soils, but also removes the requirement for a sand blanket, preventing the upward movement of fine clay particles. TERRAM Hydrotex nonwoven composite consists of a central filter media, thermally bonded to two opposing mechanically entangled nonwoven robust filters, to create a geocomposite with sufficient strength and protection to be durable to the abrasion and point The traditional use of a sand...

Further market specific literature available: Road and Highways Ground Reinforcement Solutions • Pipelines / Utilities • Forestry & Landscaping Fruit & Viticulture www.tubex.com Application specific literature, product data sheets, case studies and installation guides are available on request or can be freely downloaded from www.terram.com Information contained herein is, to the best of our knowledge, accurate in all material respects. However, since the circumstances and conditions in which such information and the products mentioned herein can be used may vary and are beyond our control,...