Physical and Numerical Modeling of Stone Column Behavior in Loose Sand

Stone column technique has been successfully applied for the foundation improvement. A rigid box with dimensions of 1.5 × 1.5 × 1.2 m equipped with a jacking-pump system was used to loading the stone column reinforced bed. Laboratory tests are carried out on stone columns with 6.3 cm diameter and different patterns surrounded by loose sand. The parameters varied in this experimental and numerical investigation are length, diameter and number of stone columns. The number of stone columns in these tests are 4, 5 and 9 and lengths of stone columns are 30, 40 and 50. A 40 × 40 × 2 cm steel plate is used as the model foundation. In these tests, the variation of bearing capacity ratio (BCR) and settlement reduction factor (SRF) are reported for different length and number of stone columns. The results show that by increasing the number and length of stone columns, BCR value will increase and SRF value will decrease. Finite-element analyses have also been performed using the ABAQUS software. The numerical results from the FEM were first validated with the experimental results and then some parametric analyses were conducted to investigate the effect of stone column diameter.