Improving Expansive Shale Behaviour Using Soil Replacement and Rock Fill

Design and construction engineers in many parts of the world are very much concerned with the expansive soil behaviour when subjected to moisture increase. The geotechnical practice in the northern parts of Saudi Arabia considered partial replacement and rock fill as a tool to minimize damage and upheaval forces acting on light structures. This approach was approved by the municipal authorities and became a routine practice, although many failures were reported in projects considered soil replacement. This research study is aimed at investigating soil replacement and its role in minimizing uplift forces and volume change. The test results were discussed in view of the swelling behaviour of Tabuk's expansive shale material. The success or failure of this treatment depends on specific conditions. The paper discusses the influence of backfill type on the effectiveness of this method.