Saving Millions On Retaining Walls And Revetments For Depressed Motorways In Stiff Unsaturated Clay

In regions where the climate is semi-arid to arid and the watertable is low, clay above the watertable is unsaturated and stiff. Recent improvements in unsaturated soil theory allow the design shear strength of this clay to be estimated with sufficient confidence for engineering purposes. This shear strength is significantly greater than that formerly used in retaining wall and revetment design and allows the use of more light-weight retaining walls. Hence the wall uses significantly less steel and concrete. This leads to environmental benefits and considerable cost savings. This paper describes briefly how to design and build such walls.