Experimental Study on Effect of Varying L/D Ratios of Steel Slag Columns on Bearing Capacity of Soft ClayAuthor : K. Vaitheswari and S. Sathyapriya
Volume 7 No.1 Special Issue:April 2018 pp 41-44
Rapid urbanisation and growth of infrastructure in the present days resulted in dramatic increase in demand for land space. Presence of soft clay deposits in construction sites poses major problems to the structure resting on it during or after construction. A different approach for stabilization has been obtained by incorporation of steel slag columns, which is a by-product of steel manufacturing industry. Straight shafted granulated steel slag column group was adopted for which the ultimate load carrying capacity was derived from the lateral resistance offered by the surrounding soil. Floating type steel slag columns resting on soft clay layer was arranged in equilateral triangular pattern. This pattern of arrangement was preferred as it was known to provide a more uniform consolidation between columns as per IS 15284 (part 1).Well graded granulated steel slag of size range 2mm-10mm with specific gravity 3.57 and moisture content 2.76% was used. It also had an abrasion value, impact value and crushing strength of 5.47%, 27.75 % and 39.38% respectively. A comparison was made between unreinforced and reinforced soil and variations in bearing capacity and settlement was determined for different L/D ratios. L/D ratios of 3, 5, 6, 8, 10 for steel slag columns has been adopted .Settlement reduction factors for reinforced clay bed was found to be 1.75, 1.85, 2.53, 4.1, 6.1 times of unreinforced clay soil for the L/D ratios of 3, 5, 6, 8, 10 respectively. The bearing capacity factor Nc was obtained as 5.51, 9.09, 12.670, 15.71, 20.26, 24.83 for different L/D ratios of 3, 5, 6, 8, 10.
Stone columns, Granulated steel slag, Triangular pattern, Settlement reduction factor
 A.P. Ambily and S.R. Gandhi, “Experimental and Theoretical Evaluation of Stone Column in Soft Clay”, Journal of Geotechnical and Geoenvironmental Engineering, April 2007.
 R.D. Barksdaleand, R.C. Bachus, “Design and Construction of Stone Columns”, FHWA report no. rd. 83/026, Vol. 1, Federal Highway Administration, Washington D.C., 1983.
 K.S. Beena, “Ground Improvement Using Stone Column”, Int. Conf. on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics, 2010.
 BIS: 15284 (Part 1): 2003, “Design and Construction for Ground Improvement – Guidelines”.
 K.R. Datye and S.S. Nagaraju, “Installation and Testing of Rammed
Stone Columns”, J. Geotech Div.,ASCE, Vol. 17, 1977.
 Hussein H. Karim, Mohammad M. MahmoodandRaida G. Renka, “Soft Clay Soil Improvement Using Stone Columns and Dynamic Compaction Techniques”, J. Geotech Div., ASCE.
 ImanHosseinpour, Mario Riccio and Marcio S.S. Almeida, ”Numerical Evaluation of a Granualar Column Reinforced by Geosynthetics using Encasement and Laminated Disks” Journal of Geotextiles and Geomembranes, pp. 1-11, 2014.
 Karun Mani and K. Nigee, “A Study on Ground Improvement Technique using Stone Column”, J. Geotech Div., ASCE, 2014.
 Kausar Ali, “Effect of Encasement Length on Geosynthetic Reinforced Stone Columns”, International Journal of Research in Engineering and Technology, Vol. 3, 2014.
 S.Murugan and K. Rajagopal, “Studies on the Behaviour of Single and Group of Geosynthetic Encased Stone Columns”, J.Geotech.Geoenviron.Eng., Vol. 136, No.1, pp. 129-139, 2010.
 J. Pivarc, “Stone Columns – Determination of the Soil Improvement Factor”, Slovak Journal of Civil Engineering, Vol. XIX, No.3, pp. 17-21, 2011.
 Pradip Das,“A Study of the BehaviorOf Stone Column in Local Soft and Loose Layered Soil”,Electronic Journal of Geotechnical Engineering, Vol.18, 2013.
 G.M. Smitha and C.S. Vishwanath, “Strengthening of Expansive Soil to Reduce Settlement”, International Journal of Research in Engineering and Technology, Vol.4,2014.
 Y.K. Tandel, C.H. Solanki and A.K. Desai “Reinforced Granular Column for Deepsoil Stabilization: A Review”, International Journal of Civil and Structural Engineering,Vol.2, No.3, 2017.