Tunnels
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Tunnels |
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t1 t2 Tunnel drainage and Protection layer
Bored Tunnels The world's biggest tunnel projects are being executed in mountainous regions by means of Tunnel Boring Machines (TBM). Providing adequate drainage is an essential factor in making these tunnels a safe and extending their service life. With bored tunnels, especially with the New Austrian method, geosynthetic drainage and protection layers are a permanent feature. They are applied directly to the unfinished spray concrete coating of the rock face to drain off water and provide protection to the tunnel liners.
Colbond's years of experience with Enkamat and Enkadrain as drainage and protection layers in tunneling, and the specific experience in using polymer materials, resulted in the development of special product types and an official approval given in Switzerland for the NEAT (German “Neue Eisenbahn – Alpen – Transversale”) projects currently under construction in the Lötschberg base tunnel and Gotthard base tunnel
With cut and cover
tunnels, as with other structures, a long and safe service life is
a high priority and is influenced by the design of the drainage
system. The installation of geocomposites at tunnel projects is a
proven method to drain off water safely and protect the tunnel
sealing system.
Enkamat serving as an erosion control matting in landscape and hydraulic engineering. Enkadrain in all sorts of drainage applications in building construction and civil engineering, to transport water either vertically or horizontally. Enkamat is a three-dimensional open mat; Enkadrain is a composite consisting of an open matting drain body provided on one or both sides with a non-woven geotextile. Both Enkamat and Enkadrain are valuable materials for solving a large variety of protection problems in tunnel construction. Either type of matting can be installed as sheet or strip drainage. The choice of the material is determined by local conditions, tunnel construction techniques, and the volume of water to be handled. Other factors influencing the choice may include rock or soil movements, heat expansion, the need to relieve static loads, and the desire to absorb contact noise. The matting has been tested and approved by leading European Testing Institutes for use in civil engineering, tunnel construction and mining. Because of their composition geosynthetic non-wovens do not qualify as high-performance drainage materials. They are subject to clogging by silt particles contained in the water. AIso, nonwovens take roughly 10 times longer to handle a given volume of seepage than open mats of the same weight. Enkadrain and Enkamat are:
Enkamat is used in double shell rock tunnels - e.g. constructed in the New Austrian Tunnelling Technique - in which waterproof liners are part of the tunnel design. Enkamat serves as a protection and drainage layer. As a protection layer, it shields the liner from being punctured or torn. As a drainage layer, it handles excess water, diverting it to the drainage pipes. Fine particles, which might clog filters, pass unimpeded into the drainage pipes which can, if necessary be cleared by flushing.
Enkadrain is used in other rock tunnels, with special waterproofing zones or without, e.g. when the concrete itself is impervious. In cut-and-cover tunnels the use of Enkadrain with a filter layer on both sides can be very cost effective.
Enkadrain serves as a protection layer, filter and drainage layer. As a protection layer it absorbs potentially damaging forees, thereby preserving the integrity of the waterproofing. As a filter layer it retains smail soil particles and thus keeps the drain free from sediments. As a drainage layer it handles excess water and diverts it to the drainage pipes.
Installation of Enkamat and Enkadrain Enkamat and Enkadrain can easily be cut by means of scissors or a knife. The mats can be easily installed because they adapt to any form or contour, including sharp edges, angles and curves. Installation can also be undertaken in freezing conditions, at temperatures as law as -10°C (+ 14 F). Lining system in rock tunnels |
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t5 t6 For some references of geocomposites please click the link: REFERENCES |
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This general information in this website reflects our best knowledge at publication. The information may subject to change. We do not accept liability arising from the application of the information. Please do not hesitate to ask for more detailled information. |
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For more information : Phone : 90,216,3863274 Fax: 90,216.3586737 email: imtekltd@yahoo.com |
Enkadrain
ve Enkamat
One
product requirement in this particular application is that it must
be capable of following the irregularities of the tunnel walls.
Cut
and Cover Tunnels
