Author : Al-Waily, Mohammed
journal of kerbala university,
2012, Volume 8, Issue 2, Pages 268-279
The efficiency of a group (Eg) of stone or lime columns is defined as the ratio between the capacity of each stone or lime column in the groupto the capacity ofsingle stone (lime) column. In this study, the group efficiency of 16 model stone and lime columns installed in soft clay arecalculated. These groups consist of 2, 3 and 4 columns. The tests were conducted on stone and lime columns with length to diameter ratio (L/D) of 9.A special compression machine was manufactured for carrying up these tests. The foundation steel plate have 120 mm diameter and 5 mm thickness. The spacing between all columns equals twice the stone or lime column diameter (D), center to center.
The stone (lime) column capacity is taken as the load corresponding to a settlement equals to 50% of the diameter of stone (lime) column. The results illustrated that the group efficiency decreases with increasing the number of stone columns, also the stone columns provided higher efficiency than lime columns in the soil of shear strength (cu= 8 kpa), but the lime columns provided higher efficiency than stone columns in soil of cu= 14 kPa.