| 摘要 |
The invention relates to a trackbed liner which has a particular utility in a railway trackbed, as well as in other trackbeds such as tram trackbeds. In one embodiment, a trackbed liner (24) is disclosed which comprises: an upper support layer (26); a lower support layer (28); and at least one filtration layer (30) of a material having a plurality of pores and which is normally impermeable to liquid water, the filtration layer located between the upper and lower support layers. In use and under the load of a vehicle (34) acting on the trackbed (12), the filtration layer permits passage of liquid water upwardly therethrough but restricts the passage of solids materials, so as to restrict pumping erosion of material (22) located beneath the liner. Also disclosed is a method of renovating a trackbed comprising ballast contaminated with clay particles, the method involving the utilisation of the trackbed liner. The method comprises the steps of: removing contaminated ballast (120); following removal of contaminated ballast, laying the trackbed liner (24); and locating fresh ballast on an upper surface of the liner to provide a renovated trackbed. A method of manufacturing the trackbed liner and a method of displacing water from a trackbed utilising the trackbed liner are also disclosed. |
