Performance of Field and Numerical Back-Analysis of Floating Stone Columns in Soft Clay Considering the Influence of Dilatancy

Abstract

Ground improvement via stone column has gained popularity around the globe 4 as an effective ground improvement technique to improve the load bearing capacity of soft 5 soils. End-bearing stone columns are commonly used but occasionally floating stone columns 6 are adopted as it has been proven to achieve the necessary load carry capacity and serviceability 7 requirements. However, stone column parameters are often estimated without much basis for 8 simulation and design purpose due to lack of practical research and real-life case studies in this 9 area. Hence, in order to develop fundamental understanding on the load-settlement responses 10 of the floating stone columns in soft clays, detailed back-analysis was performed in this paper. 11Throughout the back-analysis, all the numerical models were validated by comparing the 12 analysis results with the field measurements. This study highlights (i) the existence of some 13 critical interpreted parameters, namely soil cohesion, c', friction angle, ' and dilation angle, 14 ' as well as (ii) soil-structure interaction mechanism that influences the load-settlement 15 responses of the floating stone columns. The successful characterization of the stone column 16 materials and the modeling technique of stone columns in finite element analyses have shown 17 great potential in assessing the real-life performance of floating stone columns in soft clays. 18

Soft Soil and Related Geotechnical Engineering Practice

“…Cyclic behavior of clay with ground composed of overconsolidated soil at the top is investigated by using data from three centrifuge tests under traffic loading in the paper by Qian et al (2018a). Ong et al (2018) used a numerical back-analysis procedure to understand the load-deformation behavior of floating stone columns in soft clay by comparing numerical predictions with field measurements. A finite-element analysis for bearing capacity of partially embedded pipeline in clay subjected to vertical and horizontal loading considering the effect of tensile capacity between the pile and soil is presented by Zhou et al (2018).…”

Model Test on Mechanical and Deformation Property of a Geomembrane Surface Barrier for a High Rockfill Dam

“…Due to the limitation of the test conditions, the real water seepage pressure was not simulated. In a real situation, seepage pressure and the phreatic surface will develop in the granular transition layer and dam body if the protective layer cracks [35]. That may cause the larger flexural deformation of the cushion and lead to further tension failure of the geomembrane.…”

Effects of Principal Stress Rotation on the Fluid-Induced Soil Response in a Porous Seabed

“…In the present model, the calculated time it takes for the residual pore pressure to reach its peak is 1100 µs, which is less than that predicted by Sassa and Sekiguchi [35] (1200 µs). This is because Sassa and Sekiguchi [35] did not consider the effect of out-of-plane stress, which is important for determining the plastic flow direction [57][58][59].…”