Field of technology: Industrial Machinery and Processes
Patent granted on: Tue, 03 Feb 1998
A low friction slip-sleeve wrap for buried structures such as pipelines, pilings or the like. The pipe is coated in a polymer coating such as HDPE or FBE, then wrapped in a polymer mesh such as geonet or geogrid without any friction-increasing means such as friction coatings or fillings or bonding of layers. Finally, a layer of geotextile is wrapped over the polymer mesh layer. In addition to the reduction of friction and shear transfer from the ground to the pipe or foundation element, which acts to protect the structure from damage due to earthquakes or land slippage, the low friction slip-sleeve wrap of the invention has several other advantages. The porosity of the geotextile allows for cathodic protection. The geogrids, geonets, and geotextiles used in the wrap are relatively inexpensive and readily available. Moreover, the wrap can be applied in the field easily, with minimal time delay, and located as required along all or selected lengths of the pipeline or foundation element. Because the wrapping can be applied easily in sections, it also can be used on large conduits, including large diameter water pipelines (greater than 4 ft) and tunnels.