A Practical Approach For Computing Soil Bearing Capacity Under Shallow Foundations Using Vibro-Replacement Method

This paper presents a practical approach for designing, erecting, and testing stone columns using the vibro-replacement method to improve soil bearing capacity under shallow foundations (isolated and raft foundations) for any typical building under small or medium loading conditions. Usually, the vibroreplacement method is used in soils with cohesive layers of mixed deposits, loose sand, or both. Vibroreplacement methods create reinforced, compacted columns in poor soils, which provide reinforcement for soft cohesive soils to improve bearing capacity and reduce settlement. Vibro technologies provide quick and costeffective solutions for areas of weak and unconsolidated soils. Usually, a geotechnical consultant suggests alternative methods for improving the engineering characteristics of subsoil at a selected site by several methods such as piles, complete replacement using backfill, and improving the subsoil using the vibroreplacement method (stone columns), the method considered in this study. A backfill size of aggregate material from limestone quarries ranging from 2.50 mm to 10 mm is recommended for stone columns. A 300 mm-thick layer of well-compacted fill material is suggested as a sandwich between the bottom of the foundation and the stone columns as a practical procedure after completion of soil improvement and removal of mud to provide uniformity of foundation loading on the soil.