Effectiveness of Mono Sand Piles in Soft Cohesive Ground

Abstract

Soft cohesive formations are extensively distributed across the earth’s land mass. They mainly comprise medium to high plastic clays deposited by thousands of years of geological activity. In Pakistan, the upper and lower plains of the Indus Valley have several square kilometers of cohesive ground. The cohesive soils are vulnerable to moisture variations and lack friction. Hence, they are not considered an ideal ground for foundation support. The raft foundation and traditional reinforced concrete piles are effective solutions, but are uneconomical. Sand piles can replace these expansive foundations for moderately loaded structures; however, their effectiveness is required to be supported by field and research investigations. This study presents FEM-based numerical investigations on the performance of a single sand pile on soft cohesive ground. The pile is loaded with the 100 kPa pressure, representing a moderately loaded structure. The stress–strain behaviors and overall pile settlement results are graphically presented. The sand pile, the stiffer material, could hold most of the stresses while maintaining volumetric strains up to 10%, thus allowing better load transfer to the naturally soft ground.

Keywords

• cohesive soil
• foundation settlement
• numerical modeling
• sand pile
• stress distribution