Full-scale experimental study on the single and group of soil-cement columns under vertical load applying for buildings

Abstract

This article presents the results of in-situ research on the soil-cement (SC) column as the foundation of buildings. A physical model was constructed consisting of two single SC columns, one group of three SC columns (G1), and another group of five SC columns (G2) with a diameter of 0.6 m and a length of 7.5 m. Among ten experimental columns, four SC columns were instrumented by strain gages to determine the load transfer and analysis of the skin and toe resistance distributions along the depth of the SC columns. These columns were constructed by the wet mixing method according to Japanese technology with two static blades to increase the quality of the mixture. The bearing capacity of the single SC column was measured as 1,180 kN, and the top and toe displacements were measured to be approximately 36.6 mm and 27.7 mm, respectively. For the group of SC columns, the skin resistance of the center and outer columns decreased by 4.17 % and 16.16 %, respectively, in comparison to the single column. The toe resistance of the SC column in the groups was significantly lower than that of the single column, from 45.10 % for the group G1, and up to 60.78 % for the group G2. The effect of the group of SC columns was also determined from the experiment with the group coefficients around 0.664 for group G1 and 0.554 for group G2. The research results from the full-scale model are essential in evaluating the group effects of the SC columns, especially in applications for the foundation of buildings.