Laboratory and numerical based analysis of floating sand columns in clayey soil

• Published in: International Journal of Geo-Engineering Vol. 10; no. 1; pp. 1 - 16
• Main Authors: Naseer, S., Sarfraz Faiz, M., Iqbal, S., Jamil, S. M.
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 18.10.2019; Springer; Springer Nature B.V; SpringerOpen
• Subjects: Analysis; Bearing capacity; Bearing strength; Civil Engineering; Clay soils; Columns (structural); Earth and Environmental Science; Earth Sciences; Finite element method; Floating columns; Foundations; Geoengineering; Geotechnical Engineering & Applied Earth Sciences; Hydraulics; Laboratories; Liquefaction; Mesh generation; Numerical analysis; Original Research; Sand; Sand columns; Sandy soils; Shear strength; Soft soils; Soil analysis; Soil bearing capacity; Soil investigations; Soil strength; Soil structure; Two dimensional analysis; Shear strength; Sand columns; Bearing capacity; Floating columns
• ISSN: 2092-9196; 2198-2783
• DOI: 10.1186/s40703-019-0106-6

The inclusion of sand columns results in enhancing the bearing capacity of clayey soil, increase the rate of consolidation, presentation of liquefaction in loose sandy soils and provide lateral resistance against the horizontal movement. This research aims at investigating the effects of floating columns in clayey soil with silty deposits by developing small scale laboratory models. The effects of sand columns on soils of different shear strengths, slenderness ratio (L/D) of columns were investigated. Group effect was also investigated by varying spacing between the columns. Experimental results were compared with the numerical analysis results. A 15-noded triangular mesh was generated using a finite element tool PLAXIS 2D. Finite element analysis was performed using Mohr’s Coulomb’s criterion considering undrained analysis for soft clayey soil and drained analysis for sand columns. It was concluded that the sand columns can significantly increase the ultimate loading capacity of soft soils. Results show that critical length for floating column ranges from 4 to 5.5 times the diameter of the column, beyond which bulging occurs and loading capacity decreased. The effect of group was also investigated and observed that with high spacing between the sand columns, the group efficiency decreased. The axial capacity of sand columns decreases while increasing spacing between the columns.