Interference Effect of Closely Spaced Footings Resting on Granular Fill over Soft Clay
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Volume 19, Issue 1
Abstract
In the present paper, the interference effects on bearing capacity and settlement behavior of two closely spaced identical footings resting on the surface of granular fill (sand layer) of limited thickness underlain by soft clay have been studied by laboratory model tests. Three pairs of model footings with different shapes are used to study the effect of the aspect ratio of footing on footing interference. The width (B) and length (L) of the footings are selected in such a way that the aspect ratio or L:B ratio of the footings is varied as 1.0 (square), 1.5 (rectangular), and 2.0 (rectangular). Results show that the maximum interference factor for closely spaced footings on a single-layer sand bed is 40% higher in magnitude compared with the sand-clay layered soil bed or homogeneous clay bed. Furthermore, the interference factors increase with the increase in the L:B ratio of the footings. The optimum spacing ratio is independent of the L:B ratio of the footings, and it is 1.5 times the width of the footings. Based on the load-spread mechanism and the deformation of sand-clay interface, an analytical solution has been proposed to determine the bearing capacity of two closely spaced rectangular footings.
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References
Abu-Farsakh, M., Q. Chen, and R. Sharma. 2013. “An experimental evaluation of the behavior of footings on geosynthetic-reinforced sand.” Soils Found. 53 (2): 335–348. https://doi.org/10.1016/j.sandf.2013.01.001.
ASTM. 2016a. Standard test methods for maximum index density and unit weight of soils using a vibratory table. D4253-16. West Conshohocken, PA: ASTM.
ASTM. 2016b. Standard test methods for minimum index density and unit weight of soils and calculation of relative density. D4254-16. West Conshohocken, PA: ASTM.
Consoli, N., F. Rosa, and A. Fonini. 2009. “Plate load tests on cemented soil layers overlaying weaker soil.” J. Geotech. Geoenviron. Eng. 135 (12): 1846–1856. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000158.
Das, B. M., and S. Larbi-Cherif. 1983. “Bearing capacity of two closely-spaced shallow foundations on Sand.” Soils Found. 23 (1): 1–7. https://doi.org/10.3208/sandf1972.23.1.
Das, B. M., V. K. Puri, and B. K. Neo. 1993. “Interference effects between two surface footings on layered soil.” Transp. Res. Rec. 1406: 34–40.
Dash, S. K., and M. C. Bora. 2013. “Influence of geosynthetic encasement on the performance of stone columns floating in soft clay.” Can. Geotech. J. 50 (7): 754–765. https://doi.org/10.1139/cgj-2012-0437.
Deb, K., N. K. Samadhiya, and J. B. Namdeo. 2011. “Laboratory model studies on unreinforced and geogrid-reinforced sand bed over stone column-improved soft clay.” Geotext. Geomembr. 29 (2): 190–196. https://doi.org/10.1016/j.geotexmem.2010.06.004.
Demir, A., M. Laman, A. Yildiz, and M. Ornek. 2013. “Large scale field tests on geogrid reinforced granular fill underlain by clay soil.” Geotext. Geomembr. 38 (Jun): 1–15. https://doi.org/10.1016/j.geotexmem.2012.05.007.
Demir, A., A. Yildiz, M. Laman, and M. Ornek. 2014. “Experimental and numerical analyses of circular footing on geogrid-reinforced granular fill underlain by soft clay.” Acta Geotech. 9 (4): 711–723. https://doi.org/10.1007/s11440-013-0207-x.
Ghazavi, M., and A. A. Lavasan. 2008. “Interference effect of shallow foundations constructed on sand reinforced with geosynthetics.” Geotext. Geomembr. 26 (5): 404–415. https://doi.org/10.1016/j.geotexmem.2008.02.003.
Ghosh, P., P. K. Basudhar, V. Srinivasan, and K. Kunal. 2015. “Experimental studies on interference of two angular footings resting on surface of two-layer cohesionless soil deposit.” Int. J. Geotech. Eng. 9 (4): 422–433. https://doi.org/10.1179/1939787914Y.0000000080.
Ghosh, P., and S. R. Kumar. 2011. “Interference effect of two nearby strip surface footings on cohesionless layered soil.” Int. J. Geotech. Eng. 5 (1): 87–94. https://doi.org/10.3328/IJGE.2011.05.01.87-94.
Giroud, J. P., and L. Noiray. 1981. “Geotextile-reinforced unpaved road design.” J. Geotech. Eng. Div. 107 (9): 1233–1254.
Gourvenec, S., and K. Jensen. 2009. “Effect of embedment and spacing of cojoined skirted foundation systems on undrained limit states under general loading.” Int. J. Geomech. 9 (6): 267–279. https://doi.org/10.1061/(ASCE)1532-3641(2009)9:6(267).
Griffiths, D., G. Fenton, and N. Manoharan. 2006. “Undrained bearing capacity of two strip footings on spatially random soil.” Int. J. Geomech. 6 (6): 421–427. https://doi.org/10.1061/(ASCE)1532-3641(2006)6:6(421).
Hanna, A. M., and G. G. Meyerhof. 1980. “Design charts for ultimate bearing capacity of foundations on sand overlying soft clay.” Can. Geotech. J. 17 (2): 300–303. https://doi.org/10.1139/t80-030.
Hazell, E. 2004. “Interaction of closely spaced strip footings.” Fourth year project report. Oxford, UK: Dept. of Engineering, Univ. of Oxford.
Hegde, A. M., and T. G. Sitharam. 2015. “Three-dimensional numerical analysis of geocell-reinforced soft clay beds by considering the actual geometry of geocell pockets.” Can. Geotech. J. 52 (9): 1396–1407. https://doi.org/10.1139/cgj-2014-0387.
Huang, C., and F. Menq. 1997. “Deep-footing and wide-slab effects in reinforced sandy ground.” J. Geotech. Geoenviron. Eng. 123 (1): 30–36. https://doi.org/10.1061/(ASCE)1090-0241(1997)123:1(30).
Ilamparuthi, K., and K. Muthukrishnaiah. 1999. “Anchors in sand beds: Delineation of rupture surface.” Ocean. Eng. 26 (12): 1249–1273. https://doi.org/10.1016/S0029-8018(98)00034-1.
Islam, M. A., and C. T. Gnanendran. 2012. “Behaviour of two closely spaced strip footings placed on stiff clay.” In Proc., 11th Australia-New Zealand Conf. on Geomechanics, 1275–1280. Melbourne, Australia: Piling Contractors.
Islam, M. A., and C. T. Gnanendran. 2013. “Behaviour of two closely spaced strip footings placed on a stiff clay bed under cyclic loading.” Geotech. Test. J. 36 (2): 1–6. https://doi.org/10.1520/GTJ20120126.
Kenny, M. J., and K. Z. Andrawes. 1997. “The bearing capacity of footings on a sand layer overlying soft clay.” Géotechnique 47 (2): 339–345. https://doi.org/10.1680/geot.1997.47.2.339.
Khing, K. H., B. M. Das, V. K. Puri, S. C. Yen, and E. E. Cook. 1994. “Foundation on strong sand underlain by weak clay with geogrid at the interface.” Geotext. Geomembr. 13 (3): 199–206. https://doi.org/10.1016/0266-1144(94)90035-3.
Kumar, A., and S. Saran. 2003. “Closely spaced footings on geogrid reinforced sand.” J. Geotech. Geoenviron. Eng. 129 (7): 660–664. https://doi.org/10.1061/(ASCE)1090-0241(2003)129:7(660).
Kumar, J., and M. Bhoi. 2009. “Interference of two closely spaced strip footings on sand using model tests.” J. Geotech. Geoenviron. Eng. 135 (4): 595–604. https://doi.org/10.1061/(ASCE)1090-0241(2009)135:4(595).
Kumar, J., and P. Ghosh. 2007a. “Ultimate bearing capacity of two interfering rough strip footings.” Int. J. Geomech. 7 (1): 53–62. https://doi.org/10.1061/(ASCE)1532-3641(2007)7:1(53).
Kumar, J., and P. Ghosh. 2007b. “Upper bound limit analysis for finding interference effect of two nearby strip footings on sand.” Geotech. Geol. Eng. 25 (5): 499–507. https://doi.org/10.1007/s10706-007-9124-9.
Laman, M., and A. Yildiz. 2003. “Model studies of ring foundations on geogrid-reinforced sand.” Geosynth. Int. 10 (5): 142–152. https://doi.org/10.1680/gein.2003.10.5.142.
Lavasan, A. A., and M. Ghazavi. 2012. “Behavior of closely spaced square and circular footings on reinforced sand.” Soils Found. 52 (1): 160–167. https://doi.org/10.1016/j.sandf.2012.01.006.
Lee, K. M., V. R. Manjunath, and D. M. Dewaikar. 1999. “Numerical and model studies of strip footing supported by a reinforced granular fill–soft soil system.” Can. Geotech. J. 36 (5): 793–806. https://doi.org/10.1139/t99-053.
Love, J. P., H. J. Burd, G. W. E. Milligan, and G. T. Houlsby. 1987. “Analytical and model studies of reinforcement of a layer of granular fill on a soft clay subgrade.” Can. Geotech. J. 24 (4): 611–622. https://doi.org/10.1139/t87-075.
Mabrouki, A., D. Benmeddour, R. Frank, and M. Mellas. 2010. “Numerical study of the bearing capacity for two interfering strip footings on sands.” Comput. Geotech. 37 (4): 431–439. https://doi.org/10.1016/j.compgeo.2009.12.007.
Mandel, J. 1965. “Plastic interference of continuous footings.” In Vol. 2 of Proc., 6th Int. Conf. on Soil Mechanics and Foundation Engineering, 127–131. Montreal: University of Toronto Press.
Meyerhof, G. G. 1951. “Ultimate bearing capacity of foundations.” Géotechnique 2 (4): 301–332. https://doi.org/10.1680/geot.1951.2.4.301.
Meyerhof, G. G. 1963. “Some recent research on the bearing capacity of foundations.” Can. Geotech. J. 1 (1): 16–26. https://doi.org/10.1139/t63-003.
Naderi, E., and N. Hataf. 2014. “Model testing and numerical investigation of interference effect of closely spaced ring and circular footings on reinforced sand.” Geotext. Geomembr. 42 (3): 191–200. https://doi.org/10.1016/j.geotexmem.2013.12.010.
Noorzad, R., and E. Manavirad. 2014. “Bearing capacity of two close strip footings on soft clay reinforced with geotextile.” Arabian J. Geosci. 7 (2): 623–639. https://doi.org/10.1007/s12517-012-0771-7.
Okamura, M., J. Takemura, and T. Kimura. 1998. “Bearing capacity predictions of sand overlying clay based on limit equilibrium methods.” Soils Found. 38 (1): 181–194. https://doi.org/10.3208/sandf.38.181.
Omar, M. T., B. M. Das, S. C. Yen, V. K. Puri, and E. E. Cook. 1993. “Ultimate bearing capacity of rectangular foundations geogrid-reinforced sand.” Geotech. Test. J. 16 (2): 246–252. https://doi.org/10.1520/GTJ10041J.
Palmeira, E. M., and M. G. Cunha. 1993. “A study of the mechanics of unpaved roads with reference to the effects of surface maintenance.” Geotext. Geomembr. 12 (2): 109–131. https://doi.org/10.1016/0266-1144(93)90002-6.
Patra, C. R., B. M. Das, and C. Atalar. 2005. “Bearing capacity of embedded strip foundation on geogrid-reinforced sand.” Geotext. Geomembr. 23 (5): 454–462. https://doi.org/10.1016/j.geotexmem.2005.02.001.
Saha Roy, S., and K. Deb. 2017a. “Bearing capacity of rectangular footings on multilayer geosynthetic-reinforced granular fill over soft soil.” Int. J. Geomech. 17 (9): 04017069. https://doi.org/10.1061/(ASCE)GM.1943-5622.0000959.
Saha Roy, S., and K. Deb. 2017b. “Effects of aspect ratio of footings on bearing capacity for geogrid-reinforced sand over soft soil.” Geosynth. Int. 24 (4): 362–382. https://doi.org/10.1680/jgein.17.00008.
Saran, S., and V. C. Agarwal. 1974. “Interference of surface footings on sand.” Indian Geotech. J. 4 (2): 129–139.
Sharma, R., Q. Chen, M. A. Farsakh, and S. Yoon. 2009. “Analytical modeling of geogrid reinforced soil foundation.” Geotext. Geomembr. 27 (1): 63–72. https://doi.org/10.1016/j.geotexmem.2008.07.002.
Shin, E. C., and B. M. Das. 2000. “Experimental study of bearing capacity of a strip foundation on geogrid-reinforced sand.” Geosynth. Int. 7 (1): 59–71. https://doi.org/10.1680/gein.7.0166.
Skempton, A. W. 1951. “The bearing capacity of clays.” In Vol. 1 of Proc., Building Research Congress, 180–189. Ottawa: National Research Council of Canada.
Srinivasan, V., and P. Ghosh. 2013. “Experimental investigation on interaction problem of two nearby circular footings on layered cohesionless soil.” Geomech. Geoeng. 8 (2): 97–106. https://doi.org/10.1080/17486025.2012.695401.
Stuart, J. G. 1962. “Interference between foundations, with special reference to surface footings in sand.” Géotechnique 12 (1): 15–22. https://doi.org/10.1680/geot.1962.12.1.15.
Swain, A., and P. Ghosh. 2016. “Experimental study on dynamic interference effect of two closely spaced machine foundations.” Can. Geotech. J. 53 (2): 196–209. https://doi.org/10.1139/cgj-2014-0462.
Terzaghi, K. 1943. Theoretical soil mechanics. New York: John Wiley & Sons.
Vesic, A. 1973. “Analysis of ultimate loads of shallow foundations.” J. Soil Mech. Found. Div. 99 (1): 45–73.
West, J. M., and J. G. Stuart. 1965. “Oblique loading resulting from interference between surface footings on sand.” In Vol. 2 of Proc., 6th Int. Conf. on Soil Mechanics and Foundation Engineering, 214–217. Montreal: University of Toronto Press.
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International Journal of Geomechanics
Volume 19 • Issue 1 • January 2019
Copyright
© 2018 American Society of Civil Engineers.
History
Received: Aug 10, 2017
Accepted: Jun 25, 2018
Published online: Oct 17, 2018
Published in print: Jan 1, 2019
Discussion open until: Mar 17, 2019
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