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Improved Design Procedures for Ground Improvement using Pre- Fabricated Vertical Drains
Background/Objective: Ground improvement for soft saturated clay soil is often achieved by preloading combined with vertical drains. Use of vertical drains gives rise to smear zone and well resistance, which hinders consolidation. However, Indian code of practices doesn’t consider this aspect. Method: Computation of optimum spacing for vertical drains is iterative and tedious procedure. Therefore, an automate procedure using goal seek function of MS Excel is developed which gives optimum spacing instantly. Using developed spreadsheet, effect of smear zone has been studied by comparing field data to that obtained by using theoretical equations. Findings: Time estimates for target value of consolidation required in a project are better predicted by considering smear effects. Based on these findings it has been suggested to incorporate the effect of smear zone in Indian Codes for rational design of PVD. Application/Improvement: Using proposed modifications in Indian code of practices realistic estimate for desired consolidation can be found quickly.
Code of Practices, Optimum Design, PVDs, Radial Consolidation, Smear Zone.
- Eqyaabal MDZ, Ambica A. Construction of a road in the black cotton soil using fly ash. Indian Journal of Science and Technology. 2015 Nov; 8(32).
- Masoud M, Bonab MH, Davoudi M. Numerical estimation of the fundamental frequency of improved sites with stone columns. Indian Journal of Science and Technology. 2015 Aug; 8(19).
- Ravichandran PT, Prasad AS, Krishnan DK, Rajkumar PRK. Effect of addition of waste tyre crumb rubber on weak soil stabilization. Indian Journal of Science and Technology. 2016 Feb; 9(5).
- IS 15284 (Part 2): 2004 Design and construction for ground improvement- Guidelines. Part 2 Preconsolidation using vertical drains, Bureau of Indian Standard; 2004.
- Mandal JN, Kumar S, Fulzele R, Vaishampayan VV. Case studies on ground improvement using prefabricated vertical band drains. IGC; 2004. p. 453–6.
- Lakshmi R, Ambily AP, Gandhi SR. Design of vertical drains behind cargo berth at Kandla Port. Geopractice; 2005. p. 97–102.
- Mandal AK, Biswas P, Rao PJ. Design, construction and performance of high embankment on soft clay deposits. IGC 2009; Guntur. p. 798–802.
- Carrillo N. Simple two and three dimensional consolidation. Jnl Math and Phys. 1942; 21:1.
- Terzaghi K. Theoretical soil mechanics. New York: Wiley; 1943.
- Barron RA. Consolidation of fine grained soils by drain wells. Trans ASCE. 1948; 113:718–54.
- Leo C, Poulos S. On the effectiveness of sand drains. Canadian Geotechnical Journal. 1969; 6(3):287–326.
- Holtz RD, Holm BG. Excavation and sampling around some sand drains in Skå-Edeby, Sweden. Sartryckochpreliminararapporter. 1973; 51:79–85.
- Hansbo S. Consolidation of fine-grained soils by prefabricated drains. Proc., 10th Int Conf on Soil Mechanics and Foundations Engineering; Stockholm, Sweden; 1981; p. 677–82.
- Kjellman W. Record of the activities at the Swedish geotechnical insitute 1944-1948. Swedish Geotechnical Institute; Stockholm. 1949.
- Hansbo S. Consolidation of clay by band-shaped prefabricated drains. Ground Engineering. 1979:12(5):16–25.
- Indraratna B, Rujikiatkamjorn C, Sathananthan I. Radial consolidation of clay using compressibility indices and varying horizontal permeability. Canadian Geotechnical Journal. 2005; 42(5):1330–41.
- Walker R, Indraratna B. Vertical drain consolidation with parabolic distribution of permeability in smear zone. Journal of Geotechnical and Geoenvironmental Engineering. 2006; 132(2):937–41.
- Basu D, Basu P, Prezzi M. Analytical solutions for consolidation aided by vertical drains. Geomechanics and Geoengineering: An International Journal. 2006; 1(1):63–71.
- Lee NK, Chung SG. Reevaluation of the factors influencing the consolidation of ground by incorporating prefabricated vertical drains. KSCE Journal of Civil Engineering. 2010; 14(2):155–64.
- Onoue A, Ting N, Germaine JT, Whitman RV. Permeability of disturbed zone around vertical drains. ASCE Geotechnical Special Publication. 1991; 27:879–90.
- Hird CC, Moseley VJ. Model study of seepage in smear zones around vertical drains in layered soils. Géotechnique. 2000; 50(1):89–97.
- Müller R, Larsson S. Aspects on the modelling of smear zones around vertical drains. Proceedings of the 18th International Conference on Soils Mechanics and Geotechnical Engineering; 2013.
- Rixner JJ, Kraemer SR, Smith AD. Prefabricated vertical drains: Engineering guidelines. Federal Highway Administration; 1986.
- Canadian Foundation Engineering Manual. 4th ed. Canadian Geotechnical society; 2006
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