Undrained Bearing Capacity Factor Nc for Ring Foundations in Cohesive Soil
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VIEW THE REPLYPublication: International Journal of Geomechanics
Volume 21, Issue 2
Abstract
A ring foundation is a cost-effective circular beam foundation that is used to support tall and heavy circular onshore industrial structures, such as chimneys, cooling towers, storage tanks, and silos as well as offshore structures, such as wind turbines, and annular platforms. Compared with circular footings, ring foundations are more suitable and economical because they use less construction material. This study focuses on obtaining an undrained capacity for a ring foundation. A parametric finite element (FE) analysis will be carried out for circular and ring footings to evaluate the bearing capacity factors (Nc), which could be used by practicing engineers when designing foundations for onshore and offshore circular structures in cohesive soil. Variations in the geometry of ring foundation such that the ratio of inner to outer radius (Ri/Ro) was 0.2, 0.4, 0.6, and 0.8, the footing side roughness factors (α) of 0.2, 0.5, and 1, the foundation embedment depths (D/B) of 0, 0.25, 0.5, and 1 and the linearly increasing soil heterogeneity (kB/Su) of 0, 2, 5, 10, and 30 will be considered in this study. The results show variations of Nc with the varying Ri/Ro, roughness coefficient, embedment depth, and increasing shear strength of the soil. Based on the results of the analyses, a simplified equation is proposed using dimensional analysis to evaluate the undrained bearing capacity of a ring foundation. From the sensitivity analysis, the undrained shear strength of the soil was the most significant parameter followed by footing side roughness factor and Ri/Ro ratio in the evaluation of undrained bearing capacity.
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References
Benmebarek, S., M. S. Remadna, N. Benmebarek, and L. Belounar. 2012. “Numerical evaluation of the bearing capacity factor Nγ of ring footings.” Comput. Geotech. 44: 132–138. https://doi.org/10.1016/j.compgeo.2012.04.004.
Benmebarek, S., I. Saifi, and N. Benmebarek. 2017. “Depth factors for undrained bearing capacity of circular footing by numerical approach.” J. Rock Mech. Geotech. Eng. 9 (4): 761–766. https://doi.org/10.1016/j.jrmge.2017.01.003.
Boushehrian, J. H., and N. Hataf. 2003. “Experimental and numerical investigation of the bearing capacity of model circular and ring footings on reinforced sand.” Geotext. Geomembr. 21 (4): 241–256. https://doi.org/10.1016/S0266-1144(03)00029-3.
Butterfield, R. 1999. “Dimensional analysis for geotechnical engineers.” Géotechnique 49 (3): 357–366. https://doi.org/10.1680/geot.1999.49.3.357.
Choudhury, D., and K. S. Subba Rao. 2005. “Seismic bearing capacity of shallow strip footings.” Geotech. Geol. Eng. 23 (4): 403–418. https://doi.org/10.1007/s10706-004-9519-9.
Choudhury, D., and K. S. Subba Rao. 2006. “Seismic bearing capacity of shallow strip footings embedded in slope.” Int. J. Geomech. 6 (3): 176–184. https://doi.org/10.1061/(ASCE)1532-3641(2006)6:3(176).
Cox, A. D., G. Eason, and H. G. Hopkins 1961. “Axially symmetric plastic deformation of soils.” Proc. R. Soc. London Ser. A. 254: 1–45.
Eason, G., and R. T. Shield. 1960. “The plastic indentation of a semi-infinite solid by a perfectly rough circular punch.” J. Appl. Math. Phys. 11: 33–43. https://doi.org/10.1007/BF01591800.
Edwards, D. H., L. Zdravkovic, and D. M. Potts. 2005. “Depth factors for undrained bearing capacity.” Géotechnique 55 (10): 755–758. https://doi.org/10.1680/geot.2005.55.10.755.
El Sawwaf, M., and A. Nazir. 2012. “Behavior of eccentrically loaded small-scale ring footings resting on reinforced layered soil.” J. Geotech. Geoenviron. Eng. 138 (3): 376–384. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000593.
Gholami, H., and E. S. Hosseininia. 2017. “Bearing capacity factors of ring footings by using the method of characteristics.” Geotech. Geol. Eng. 35 (5): 2137–2146. https://doi.org/10.1007/s10706-017-0233-9.
Ghosh, P., and D. Choudhury. 2011. “Seismic bearing capacity factors for shallow strip footings by pseudo-dynamic approach.” Disaster Adv. 4 (3): 34–42.
Gourvenec, S. 2008. “Effect of embedment on the undrained capacity of shallow foundations under general loading.” Géotechnique 58 (3): 177–185. https://doi.org/10.1680/geot.2008.58.3.177.
Gourvenec, S. M., and D. S. K. Mana. 2011. “Undrained vertical bearing capacity factors for shallow foundations.” Géotech. Lett. 1 (4): 101–108. https://doi.org/10.1680/geolett.11.00026.
Hansen, J. B. 1970. A revised and extended formula for bearing capacity. Bulletin No. 28. Lyngby, Denmark: Danish Geotechnical Institute.
Hataf, N., and M. R. Razavi. 2003. “Behavior of ring footing on sand.” Iran. J. Sci. Technol. Trans., B 27: 47–56.
Hosseininia, E. S. 2016. “Bearing capacity factors of ring footings.” Iran. J. Sci. Technol., Trans. Civ. Eng. 40 (2): 121–132. https://doi.org/10.1007/s40996-016-0003-6.
Houlsby, G. T., and C. M. Martin. 2003. “Undrained bearing capacity factors for conical footings on clay.” Géotechnique 53 (5): 513–520. https://doi.org/10.1680/geot.2003.53.5.513.
Hu, Y., M. F. Randolph, and P. G. Watson. 1999. “Bearing response of skirted foundation on nonhomogeneous soil.” J. Geotech. Geoenviron. Eng. 125 (11): 924–935. https://doi.org/10.1061/(ASCE)1090-0241(1999)125:11(924).
Keshavarz, A., and J. Kumar. 2017. “Bearing capacity computation for a ring foundation using the stress characteristics method.” Comput. Geotech. 89: 33–42. https://doi.org/10.1016/j.compgeo.2017.04.006.
Kumar, J., and M. Chakraborty. 2015. “Bearing capacity factors for ring foundations.” J. Geotech. Geoenviron. Eng. 141 (10): 06015007. https://doi.org/10.1061/(ASCE)GT.1943-5606.0001345.
Kumar, J., and P. Ghosh. 2005. “Bearing capacity factor Nγ for ring footings using the method of characteristics.” Can. Geotech. J. 42 (5): 1474–1484. https://doi.org/10.1139/t05-051.
Laman, M., and A. Yildiz. 2007. “Numerical studies of ring foundations on geogrid reinforced sand.” Geosynth. Int. 14 (2): 52–64. https://doi.org/10.1680/gein.2007.14.2.52.
Lee, J. K., S. Jeong, and S. Lee. 2016a. “Undrained bearing capacity factors for ring footings in heterogeneous soil.” Comput. Geotech. 75: 103–111. https://doi.org/10.1016/j.compgeo.2016.01.021.
Lee, J. K., S. Jeong, and J. Q. Shang. 2016b. “Undrained bearing capacity of ring foundations on two-layered clays.” Ocean Eng. 119: 47–57. https://doi.org/10.1016/j.oceaneng.2016.04.019.
Martin, C. M. 2001. “Vertical bearing capacity of skirted circular foundations on Tresca soil.” In Int. Conf. Soils Mechanics and Geotechnical Engineering Part 1, 743–746. Rotterdam, Netherlands: Balkema.
Meyerhof, G. G. 1951. “The ultimate bearing capacity of foundations.” Géotechnique 2 (4): 301–332. https://doi.org/10.1680/geot.1951.2.4.301.
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.
Nadgouda, K., and D. Choudhury. 2019. “Seismic bearing capacity factor Nγe for shallow strip footing using modified pseudo-dynamic method.” In Geo-Congress 2019: Earthquake Engineering and Soil Dynamics, Geotechnical Special Publication 308, edited by C. L. Meehan, S. Kumar, M. A. Pando, and J. T. Coe, 12–21. Reston, VA: ASCE.
Nadgouda, K., and D. Choudhury. 2020. “Seismic bearing capacity factor Nγe for dry sand beneath strip footing using modified pseudo-dynamic method with composite failure surface.” Int. J. Geotech. Eng. in press. https://doi.org/10.1080/19386362.2019.1707994.
Naseri, M., and E. S. Hosseininia. 2015. “Elastic settlement of ring foundations.” Soils Found. 55 (2): 284–295. https://doi.org/10.1016/j.sandf.2015.02.005.
Nayyeri, S., M. Hajali, and C. A. Shdid. 2016. “Ring foundation on elastic subgrade: An analytical solution for computer modelling using the Lagrangian multiplier method.” Int. J. Numer. Anal. Methods Geomech. 40 (14): 2017–2030. https://doi.org/10.1002/nag.2521.
Nguyen, V. Q., and R. S. Merifield. 2012. “Two- and three-dimensional undrained bearing capacity of embedded footings.” Aust. Geomech. J. 47 (2): 25–40.
Pain, A., D. Choudhury, and S. K. Bhattacharyya. 2016. “The seismic bearing capacity factor for surface strip footings.” In Geo-Chicago 2016: Sustainability and Resiliency in Geotechnical Engineering, Geotechnical Special Publication 269, edited by D. Zekkos, A. Farid, A. De, K. R. Reddy, and N. Yesiller, 197–206. Reston, VA: ASCE.
Randolph, M., and S. Gourvenec. 2011. Offshore geotechnical engineering. New York: Taylor and Francis Spon Press.
Salgado, R., A. V. Lyamin, S. W. Sloan, and H. S. Yu. 2004. “Two-and three-dimensional bearing capacity of foundations in clay.” Géotechnique 54 (5): 297–306. https://doi.org/10.1680/geot.2004.54.5.297.
Sargazi, O., and E. S. Hosseininia. 2017. “Bearing capacity of ring footings on cohesionless soil under eccentric load.” Comput. Geotech. 92: 169–178. https://doi.org/10.1016/j.compgeo.2017.08.003.
Sharma, V., and A. Kumar. 2017a. “Influence of relative density of soil on performance of fiber-reinforced soil foundations.” Geotext. Geomembr. 45 (5): 499–507. https://doi.org/10.1016/j.geotexmem.2017.06.004.
Sharma, V., and A. Kumar. 2017b. “Strength and bearing capacity of ring footings resting on fiber-reinforced sand.” Int. J. Geosynth. Ground Eng. 3: 9. https://doi.org/10.1007/s40891-017-0086-6.
Sharma, V., and A. Kumar. 2018. “Behavior of ring footing resting on reinforced sand subjected to eccentric-inclined loading.” J. Rock Mech. Geotech. Eng. 10 (2): 347–357. https://doi.org/10.1016/j.jrmge.2017.11.005.
Skempton, A. W. 1951. “The bearing capacity of clays.” In Building Research Congress, 180–189. https://doi.org/10.1002/j.1477-8696.1951.tb01280.x.
Taiebat, H. A., and J. P. Carter. 2010. “A failure surface for circular footings on cohesive soils.” Géotechnique 60 (4): 265–273. https://doi.org/10.1680/geot.7.00062.
Tang, C., and K. Phoon. 2018. “Prediction of bearing capacity of ring foundation on dense sand with regard to stress level effect.” Int. J. Geomech. 18 (11): 04018154. https://doi.org/10.1061/(ASCE)GM.1943-5622.0001312.
Tani, K., and W. H. Craig. 1995. “Bearing capacity of circular foundations on soft clay of strength increasing with depth.” Soils Found. 35 (4): 21–35. https://doi.org/10.3208/sandf.35.4_21.
Terzaghi, K. 1943. Theoretical soil mechanics. New York: Wiley.
Vesic, A. S. 1973. “Analysis of ultimate loads of shallow foundations.” J. Soil Mech. Found. Div. 99 (1): 45–73.
Zhao, L., and J. H. Wang. 2008. “Vertical bearing capacity for ring footings.” Comput. Geotech. 35 (2): 292–304. https://doi.org/10.1016/j.compgeo.2007.05.005.
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Received: Nov 15, 2019
Accepted: Sep 2, 2020
Published online: Nov 23, 2020
Published in print: Feb 1, 2021
Discussion open until: Apr 23, 2021
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