Construction of road foundations on soft ground using lightweight tyre bales

Road construction over soft ground presents technical challenges. When traffic flows and the consequent need to construct and maintain the roads within limited budgets are factored in such challenges can be substantial. There are two broad approaches to such construction: above ground, or floating, construction and below ground construction. Above ground construction has often employed bundles of twigs, called fascines, to provide a degree of resistance to differential settlement. This approach generally works best where a relatively stiff material, such as fibrous peat, overlies a less competent material, such as amorphous peat. Below ground construction is generally preferable in less incompetent materials, or in poor materials of shallower depth such that removal is a viable option. The use of modern geotextile materials in combination with lightweight tyre bales allows both construction and service loads to be effectively spread as described in this paper. (A)