Settlement Evaluation of Soft Soil Improved by Floating Soil Cement Column

Abstract

This study focuses on the settlement of soft soil improved by floating soil cement columns in a small-scale physical test. The effect of area improvement ratio (ap) and column height (Hc) on the improved ground under design load (Wd) were investigated via small-scale physical modeling tests. The area improvement ratios of 21.7, 32.5, and 43.4% and column heights of 50 and 100 mm were examined. The models were instrumented to measure displacements and soil pressures. Two loading scenarios were applied on treated and untreated soils. The first series was conducted under strain controlled mode to identify the failure mechanism. The second series was conducted under design load to evaluate the stress distribution, settlement, and failure pattern. The settlements also were measured using particle image velocimetry (PIV) technique. The PIV showed that the final settlement of the improved ground decreases as the area improvement ratio (ap) increases and the column height (Hc) increases. For controlling the distribution of stresses, an intermediate range of area improvement ratio is recommended. In addition, this study proved that the PIV technique is an effective optical method to simulate ground deformations at the lowest strain without performing a full-scale test.