Current Science

Open Access Open Access  Restricted Access Subscription Access

Study of a Surface Raft Foundation in Dry Cohesionless Soil Subjected to Dynamic Loading


Affiliations
1 Bhabha Atomic Research Centre, Mumbai 480 005, India
2 Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721 302, India
 

In this study, behaviour of a raft foundation in dry cohesionless soil when subjected to dynamic loadings is presented. The numerical model is validated by model tests on shaking table and numerically by a plane strain finite difference program, FLAC 2D. In both shaking table tests and numerical analyses, the raft located in dry Kasai River sand in Kharagpur has been subjected to 10 cycles of equivalent sinusoidal loadings with an amplitude of 0.2412 g at a frequency of 2 Hz, which represents an irregular time history of the Loma Prieta Earthquake (1989). The results of the above study in terms of response time histories, bending moment and lateral displacement of the raft have been validated with numerical simulations, and the results are in reasonable agreement with the corresponding experimental findings. A methodology to study the behaviour of a raft foundation subjected to harmonic excitations has been proposed in terms of vertical deformations of the raft foundation in dry sand for a given value of dynamic (or degraded) factor of safety.

Keywords

Dry Soil, Dynamic Loading, Numerical Analysis, Raft Foundation, Shaking Table Test.
User
Notifications
Font Size

  • Richart, F. E., Foundation vibrations. Trans: ASCE, 1962, 127(1), 863–898.

  • Kishida, H., Damage to reinforced concrete buildings on Nigata city with special reference to foundation engineering. Soils Found., 1966, 6(1), 71–88.

  • Seed, H. B. and Idriss, I. M., Analysis of soil liquefaction: Niigata earthquake. J. Soil Mech. Found. Div. ASCE, 1967, 93(3), 83–108.

  • Richart, F. E. and Whitman, R. V., Design procedures for dynamically loaded foundations. J. Soil Mech. Found. Div. ASCE, 1967, 93(SM6), 168–193.

  • Richart, F. E. and Whitman, R. V., Comparison of footing vibrations with theory. J. SMFD, Proc. ASCE, 1967, 93(SM6), 143– 167.

  • Richards, R., Elms, D. G. and Budhu, M., Seismic bearing capacity and settlements of foundations. J. Geotech. Eng., 1993, 119, 662–674.

  • Yoshimi, Y. and Tokimatsu, K., Settlement of buildings on saturated sand during earthquakes. Soils Found., 1977, 17(1), 23–38.

  • Dobry, R and Gazettas, G., Dynamic response of arbitrarily shaped foundations. J. Geotech. Eng. Div. ASCE, 1986, 112(2), 109–125.

  • Dobry, R., Gazettas, G. and Stokoe, K. H., Dynamic response of arbitrarily shaped foundations: experimental verification. J. Geotech. Eng. Div. ASCE, 1986, 112(2), 126–154.

  • Gazettas, G. and Stokoe, K. H., Free vibrations of embedded foundations: theory versus experiment. J. Geotech. Eng. Div. ASCE, 1991, 117(9), 1382–1401.

  • Puri, V. K. and Das, B. M., Dynamic response of block foundation. In Third International Conference on Case Histories in Geotechnical Engineering, 1993.

  • Ragheb, A. M., Numerical analysis of seismically induced deformations in saturated granular soil strata. Ph D thesis, Department of Civil Engineering, Rensselaer Polytechnic Institute, NY, 1994.

  • Paolucci, R., Simplified evaluation of earthquake-induced permanent displacements of shallow foundations. J. Earthq. Eng., 1997, 1(3), 563–579.

  • Gajan, S. and Kutter, B. L., Contact interface model for shallow foundations subjected to combined cyclic loading. J. Geotech. Geo-Environ. Eng., 2009, 135(3), 407–419.

  • Omer, C., Nonlinear analysis of thin rectangular plates on Winkler–Pasternak elastic foundations by DSC–HDQ methods. Appl. Math. Modell., 2006, 31, 606–624.

  • Ribeiro, D. B. and Paiva, J. B., An alternative BE–FE formulation for a raft resting on a finite soil layer. Eng. Anal. Boundary Elem., 2015, 50, 352–359.

  • Mandal, J. J. and Roychoudhury, S., Response of rectangular raft foundations under transient loading. The 12th International Conference of International Association for Computer Methods and Advances in Geomechanics (IACMAG), Goa, 2008.

  • Wang, C. M., Chow, Y. K. and How, Y. C., Analysis of rectangular thick rafts on an elastic half-space. Comp. Geotech., 2000, 28, 161–184.

  • Stokoe, K. H., Kacar, O. and Van Pelt, J., Predicting settlements of shallow footings on granular soil using nonlinear dynamic soil properties. In Proceedings of 18th International Conference on Soil Mechanics and Geotechnical Engineering, Paris, 2012, pp.3467–3470.

  • Asgari, A., Golshani, A. and Bagheri, M., Numerical evaluation of seismic response of shallow foundation on loose silt and silty sand. J. Earth System Sci., 2014 123(2), 365–379.

  • Itasca, User’s Guide for FLAC Version 5.0, Itasca India Consulting, Nagpur, 2005.

  • Bhattacharya, S., Lombardi, D., Dihoru, L., Dietz, M., Crewe, A. J. and Taylor, C. A., Model container design for soil–structure interaction studies. Role of Seismic Testing Facilities in Performance Based Earthquake Engineering, Springer Series, 2011, vol. 22, pp. 135–158.

  • Lombardi, D. and Bhattacharya, S., Shaking table tests on rigid soil container with absorbing boundaries. Lisbon, 2012, 15WCEE.

  • Banerjee, R., Konai, S., Sengupta, A. and Deb, K., Shake table tests and numerical modeling of Kasai River Sand. Geotech. Geol. Eng., 2017, 35(4), 1327–1340.

  • Giri, D. and Sengupta, A., Dynamic behaviour of small-scale model of nailed steep slopes. Geomech. Geoeng.: Int. J., 2010, 5(2), 99–108.

  • Bandyopadhyay, S., Sengupta, A. and Reddy, G. R., Performance of sand and shredded rubber tire mixture as a natural base isolator for earthquake protection. Earthq. Eng. Eng. Vib., 2015, 14(4), 683–693.

  • Dash, S. R., Lateral pile–soil interaction in liquefiable soils. Ph D thesis, University of Oxford, UK, 2010.

  • Ha, I. S., Olson, S. M., Seo, M. W. and Kim, M. M., Evaluation of reliquefaction resistance using shaking table tests. Soil Dyn. Earthq. Eng., 2011, 31(4), 682–691.

  • Ramu, M., Prabhu, R. V. and Thyla, P. R., Development of structural similitude and scaling laws for elastic models. KSCE J. Civil Eng., 2011, 17(1), 139–144.

  • Iai, S., Similitude for shaking table tests on soil–structure–fluid model in 1 g gravitational field. Soils Found., 1989, 29(1), 105–118.

  • Wood, D. M., Geotechnical Modeling, Version 2.2, 2004.

  • BIS, IS 2720 methods of test for soils, part 13 – direct shear test. Bureau of Indian Standards, New Delhi, 1986.

  • Seed, H. B. and Idriss, I. M., Soil moduli and damping factors for dynamic response analyses. College of Engineering, University of California, Berkeley, USA, 1970.

  • Kawaguchi, T. and Tanaka, H., Formulation of Gmax from reconstituted clayey soil: its application to measured Gmax in the field. Soils Found., 2006, 48, 821–831.

  • Murthy, V. N. S., Soil Mechanics and Foundation Engineering, CBS Publishers & Distributors, New Delhi, 2009.

  • Elgamal, A., Yang, Z., Adalier, K. and Sharp, M. K., Effect of rigid container size on dynamic earth dam response in centrifuge experiments. Proceedings 16th ASCE Engineering Mechanics Conference, University of Washington, Seattle, WA, USA, 2003.

  • Dasgupta, S., Narula, P. L., Acharyya, S. K. and Banerjee, J., Seismotectonic Atlas of India and its Environs, Geological Society of India, Kolkata, 2000.

  • BIS, IS 1893 Indian standard criteria for earthquake resistant design of structures, part 1 – general provisions and buildings. Fifth revision. Bureau of Indian Standard, New Delhi, 2002.

  • Seed, H. B., Idriss, I. M., Makdisi, F. and Banerjee, N., Representation of irregular stress time histories by equivalent uniform stress series in liquefaction analysis. EERC-75-29, University of California, Berkeley, USA, 1975.

  • Chopra, A. K., Dynamics of Structures, Theory and Applications to Earthquake Engineering, Prentice Hall, 2015, 3rd edn.

  • Chi-Chin, T., Wei-Chun, L. and Jiunn-Shyang, C., Identification of dynamic soil properties through shaking table tests on a large saturated sand specimen in a laminar shear box. Soil Dyn. Earthq. Eng., 2016, 83, 59–68.

  • Kuhlemeyer, R. L. and Lysmer, J., Finite element method accuracy for wave propagation problems. J. Soil Mech. Found., Div. ASCE, 1973.

  • Lysmer, J. and Kuhlemeyer, R. L., Finite dynamic model for infinite media. J. Eng. Mech., 1969, 95(EM4), 859–877.

  • Vaid, Y. P. and Saitharan, S., The strength and dilatancy of sand. Can. Geotech. J., 1992, 29(3), 522–526.

  • Griffiths, S. C., Cox, B. R. and Rathje, E. M., Challenges associated with site response analyses for soft soils subjected to highintensity input ground motions. Soil Dyn. Earthq. Eng., 2016, 85, 1–10.

  • Chattaraj, R. and Sengupta, A., Liquefaction potential and strain dependent dynamic properties of Kasai River sand. Soil Dyn. Earthq. Eng., 2016, 90, 467–475.

  • Menq, F. Y., Dynamic properties of sandy and gravelly soils. Ph D dissertation, University of Texas, Austin, USA, 2003.

  • Hutabarat, D., Evaluation of one-dimensional seismic site response analyses at small to large strain level. Thesis (Master's), University of Washington, USA, 2016.

  • Groholski, D. R., Hashash, Y. M. A., Kim, B., Musgrove, M., Harmon, J. and Stewart, J. P., Simplified model for small-strain nonlinearity and strength in 1D seismic site response analysis. J. Geotech. Geoenviron. Eng., 2016, 142(9), 1–14.

  • Choudhury, S. S., Deb, K. and Sengupta, A., Behavior of underground strutted retaining structure under seismic condition. Earthq. Struct., 2015, 8(5), 1147–1170.

  • Karamitros, D. K., Bouckovalas, G. D. and Chaloulos, Y. K., Seismic settlements of shallow foundations on liquefiable soil with a clay crust. Soil Dyn. Earth. Eng., 2013, 46, 64–76.

  • Kramer, S. L., Geotechnical Earthquake Engineering, Prentice hall, 1996.

  • Richards, R., Elms, D. G. and Budhu, M., Seismic bearing capacity and settlements of foundations. J. Geotech. Eng., 1993, 119, 662–674.

  • Yang, J., Li, J. B. and Lin, G., A simple approach to integration of acceleration data for dynamic soil–structure interaction analysis. Soil Dyn. Earthq. Eng., 2006, 26, 725–734.

  • BIS, IS 456 plain and reinforced concrete code of practice. Fourth revision. Bureau of Indian Standard, New Delhi, 2000.

  • Terzaghi, K., Theoretical Soil Mechanics, John Wiley, New York USA, 1943.


Abstract Views: 280

PDF Views: 82




  • Study of a Surface Raft Foundation in Dry Cohesionless Soil Subjected to Dynamic Loading

Abstract Views: 280  |  PDF Views: 82

Authors

Raj Banerjee
Bhabha Atomic Research Centre, Mumbai 480 005, India
Aniruddha Sengupta
Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721 302, India
G. R. Reddy
Bhabha Atomic Research Centre, Mumbai 480 005, India

Abstract


In this study, behaviour of a raft foundation in dry cohesionless soil when subjected to dynamic loadings is presented. The numerical model is validated by model tests on shaking table and numerically by a plane strain finite difference program, FLAC 2D. In both shaking table tests and numerical analyses, the raft located in dry Kasai River sand in Kharagpur has been subjected to 10 cycles of equivalent sinusoidal loadings with an amplitude of 0.2412 g at a frequency of 2 Hz, which represents an irregular time history of the Loma Prieta Earthquake (1989). The results of the above study in terms of response time histories, bending moment and lateral displacement of the raft have been validated with numerical simulations, and the results are in reasonable agreement with the corresponding experimental findings. A methodology to study the behaviour of a raft foundation subjected to harmonic excitations has been proposed in terms of vertical deformations of the raft foundation in dry sand for a given value of dynamic (or degraded) factor of safety.

Keywords


Dry Soil, Dynamic Loading, Numerical Analysis, Raft Foundation, Shaking Table Test.

References





DOI: https://doi.org/10.18520/cs%2Fv117%2Fi11%2F1800-1812