Comparing Advanced Constitutive Models in Stability Analysis of Slopes on Liquefiable Layers under Seismic Loading Conditions

Document Type : Research

Authors

1 Assistant Professor, Dept. of Civil Engineering, Faculty of Engineering, Arak University, Arak, Iran.

2 Msc Student in Geotechnical Engineering, Dept. of Civil Engineering, Faculty of Engineering, Arak University, Arak, Iran.

Abstract

One of the most challenging issues in the field of geotechnical engineering is liquefaction that causes great damage to the earth slopes during earthquakes. Since seismic analysis and modeling of liquefaction phenomenon in loose saturated sandy soils requires the use of advanced constitutive models, two different approaches are used for analyzing the response of slopes on liquefiable layers, including (1) UBCSAND (UBC) and (2) Mohr Coulomb (MC) and Finn constitutive models. In the current paper, to assess the liquefaction potential, firstly a comparison will be done among different constitutive models, then seismic stability analysis of slopes on liquefiable layers are studied by finite difference method using FLAC2D. The results of dynamic analysis indicated that, estimated seismic displacements using advanced constitutive models are more accurate than the ones using common models. Subsequently, the effects of different parameters such as the thickness of liquefiable layer and the frequency content have been investigated. Finally, the relationship among mentioned parameters and horizontal displacement of the slopes is investigated using the MC, Finn and UBC constitutive models. It should be mentioned that, the reduction in frequency and increase in the thickness of liquefiable layer have an increasing effect on the horizontal displacement of slopes.

Keywords


1. Itasca., (2008). "Fast Lagrangian Analysis of Continua", Itasca Consulting Group, Inc, Ver 6.0.
2. Beaty M. H. and Byrne P. M., (2010). "UBCSAND constitutive model Version 904aR", Document report: UBCSAND Constitutive Model on Itasca UDM.
3. Mikola R. G. and Sitar N., (2011). "UBCHYST- A Total Stress Hysteretic Model", Jacobs Associates, Engineering Consultants.
4. Beaty M. H. and Perlea V. G., ( 2011). "Several Observations on Advanced Analyses with Liquefiable Materials", 31th Annual USSD Conference, U. S. Society on Dams, San Diego, California.
5. Seid-Karbasi M. and Atukorala U., (2011). "Deformation of a Zoned Rockfill Dam from a Liquefiable thin Foundation Layer Subjected to Earthquake Shaking" 31th Annual USSD Conference, U. S. Society on Dams, San diego, California.
6. Khalid M. S., (2013) "Dynamic Analysis of an Upstream Tailings Dam", Msc Civil Engineering with Specialization in Mining and Geotechnical Engineering, Lulea University of Technology, Sweden
7. Montgomery J., (2010). "Two Constitutive Models for Simulation of Liquefaction in Sandy Soils", ECI 284 Term Project..
8. Martin. G. R., Seed, H.B., Finn, W.D.L., (1975). "Fundamentals of Liquefaction Under Cyclic Loading", Journal of the Geotechnical Engineering Division, 101(5), pp. 423-438.
9. Byrne, P., (1991). "A cyclic shear-volume coupling and pore-pressure model for sand". In Proc.: Second International Conference on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics, Paper No. 1.24, 47-55.
10. Chatterjee K. and Choudhury D., (2012)."Seismic stability analyses of soil slopes using analytical and numerical approaches", Department of Earthquake Engineering Building, Indian Society of Earthquake Technology.
11. Dashti .Sh., D. Bray, J., (2013). "Numerical Simulation of Building Response on Liquefiable Sand", Journal of the Geotechnical and Geo-environmental Engineering, 139, pp. 1235-1249. [DOI:10.1061/(ASCE)GT.1943-5606.0000853]
12. Lysmer J. & Kuhlemeyer R.L., (1969). "Finite dynamic model for infinite media", Journal of the Engineering Mechanics Division, ASCE, 95(4), pp. 859-877.
13. Beaty M. H., (2011). "Summary of UBCSAND Constitutive Model", Beaty Engineering LLC, Beaverton, USA.
14. Finn, W. D. L., Lee, K. W., Martin, G. R., (1977). "An Effective Stress Model for Liquefaction", Journal of the Geotechnical Engineering Division, ASCE, 103(6), pp. 517-533.