Abstract
A laboratory investigation is presented for undisturbed samples of a silty sand under saturated conditions. The soil was sampled from test pits south of Rüdlingen in North–East Switzerland, where a landslide triggering experiment was carried out on a steep forest slope. The aim of the work was to characterise the behaviour of the soil in triaxial tests, in the light of the possible failure mechanisms of the slope. Conventional drained and undrained triaxial tests were conducted to detect critical state conditions as well as peak shear strength as a function of confining pressure. Soil specimens were also exposed to stress paths simulating in situ water pressure increase to study the stress–strain response and to enhance the ability to predict failure conditions more accurately in the future. Possible unstable response along the stress paths analysed was investigated by means of second order work and strain acceleration. The results show that temporary unstable conditions may be encountered for this soil at stress ratios below ultimate failure and even below critical state line, depending on void ratio, drainage conditions and time dependent compressibility. A modified state parameter is explored as a potentially useful tool to discriminate conditions leading to eventual collapse.
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References
Fischer, C., López, J., Springman, S.M.: Remediation of an eroded steep slope in weathered sandstone after a major rainstorm. In: International Conference on Landslides, pp. 878–883. Hong Kong (2003)
Springman, S.M., Kienzler, P., Casini, F., Askarinejad, A.: Landslide triggering experiment in a steep forested slope in Switzerland. In: 17th International Conference on Soil Mechanics and Geotechnical Engineering, 5–9 Oct, Alexandria (2009)
Colombo, L.: Large shear box for analysing strength mobilisation in unsaturated conditions. Master Thesis, Politecnico di Milano (2009)
Vaughan P.R., Kwan C.W.: Weathering, structure and in situ stress residual soils. Géotechnique 34(1), 43–59 (1984)
Jommi, C.: Remarks on the constitutive modeling of unsaturated soils. Exp. Evid. And Theor. Approaches in Unsaturated Soils, Tarantino, Mancuso Eds., Balkema, Rotterdam, pp. 139–153 (2000)
Vaunat, J., Gens, A., Pontes Filho I.D.S.: Application of localization concepts to discontinuous water content patterns in unsaturated media. In: Proceedings of NUMOG VIII, vol. 1, pp. 179–184. Swets and Zeitlinger, Lisse (2002)
Buscarnera G., Nova R.: Modelling instabilities in triaxial testing on unsaturated soil specimens. Int. J. Numer. Anal. Meth. Geomech. (2009). doi:10.102/nag.832
Anderson S.A., Sitar N.: Analysis of rainfall-induced debris flows. J. Geotech. Eng. ASCE 121, 544–552 (1995)
Ng C.W.W., Fung W.T., Cheul C.Y., Zhang L.: Influence of stress ratio and stress path on behavior of loose decomposed granite. J. Geotech. Eng. ASCE 130(1), 36–44 (2004)
Anderson S.A., Riemer M.F.: Collapse of saturated soil due to reduction in confinement. J. Geotech. Eng. ASCE 121, 216–220 (1995)
Springman S.M., Jommi C., Teysseire P.: Instability on moraine slopes induced by loss suction: a case history. Géotechnique 53(1), 3–10 (2003)
Nova R.: The failure concept in soil mechanics revisited. In: Labuz, J.F., Drescher, A. (eds) Bifurcations and Instabilities of Geomechanics, pp. 3–16. Balkema, Lisse (2003)
Imposimato S., Nova R.: An investigation on existence and uniqueness of the incremental response of elastoplastic models for virgin sand. Mech. Cohes.-Frict. Mater. 3, 1–16 (1998)
Lancelot L., Shahrour I., Mahmoud A.M.: Instability and static liquefaction on proportional strain paths for sand at low stresses. J. Eng. Mech. ASCE 130(11), 1365–1372 (2004)
Wang G., Sassa K.: Factors affecting rainfall-induced landslides in laboratory flume tests. Géotechnique 51(7), 587–599 (2001)
Chu J., Leroueil S., Leong W.K.: Unstable behaviour of sand and its implication for slope instability. Can. Geotech. J. 40, 873–885 (2003)
Olivares L., Picarelli L.: Shallow landslides triggered by intense rainfalls on natural slopes covered by loose unsaturated pyroclastic soils. Géotechnique 53(2), 283–287 (2003)
Take W.A., Bolton M.D., Wong P.C.P., Yeung F.J.: Evaluation of landslide triggering mechanisms in model fill slopes. Landslides 1, 173–184 (2004)
Ng C.W.W., Springman S.M., Alonso E.E.: Monitoring the performance of unsaturated soil slopes. J. Geotech. Geoenviron. Eng. 6, 799–816 (2008)
Lade P.V.: Experimental observations of stability, instability and shear planes in granular materials. Ing. Arch. 59(2), 114–123 (1989)
Lade P.V., Pradel D.: Instabilty and plasti flow of soils. 1: Experimental observations. J. Eng. Mech. ASCE 116(1), 2532–2550 (1990)
Castro G., Poulos S.J.: Factors affecting liquefaction and cicling mobility. J. Geotech. Eng. ASCE 103(6), 501–516 (1977)
Vaid, Y.P., Chern, J.C.: Cyclic and monotonic undrained response of saturated sands. Adv. in the Art of Test. Soils Under Cycl. Cond., Am. Soc. of Civ. Eng. Convention, Detroit, pp. 120–1478 (1985)
Lade P.V., Nelson R.B., Ito Y.M.: Non-associated flow and stability for granular materials. J. Eng. Mech. ASCE 113(9), 1302–1318 (1987)
Lade P.V., Nelson R.B., Ito Y.M.: Instability of granular materials with non-assoiated flow. J. Eng. Mech. ASCE 114(2), 2173–2191 (1988)
Lade P.V., Bopp P.A., Peteres J.F.: Instability of dilating sand. Mech. Mater. 16, 249–264 (1993)
di Prisco C., Imposimato S.: Time dependent mechanical behaviour of loose sand. Mech. Cohes.-Frict. Mater. 17(1), 45–73 (1996)
di Prisco C., Imposimato S.: Experimental analysis and theoretical interpretation of triaxial load controlled loose sand collapses. Mech. Cohes.-Frict. Mater. 18(2), 93–120 (1997)
Lade P.V., Yamamuro J.A.: Effects of non-plastic fines on static liquefaction of sands. Can. Geotech. J. 34, 905–917 (1997)
Yamamuro J.A., Lade P.V.: Steady-state concepts and static liquefaction of silty sands. J. Geotech. Geoenviron. Eng. 9, 868–877 (1998)
Zlatovic S., Ishihara K.: Normalized behavior of very loose non-plastic soils: effects of fabric. Soils Found. 37(4), 47–56 (1997)
Chu J., Leong W.K.: Effect of fines instability behaviour of looose sand. Géotechnique 52(10), 751–755 (2002)
Wood F.M., Yamamuro J.A., Lade P.V.: Effect of depositional method on the undrained response of silty sand. Can. Geotech. J. 45, 1525–1537 (2008)
di Prisco C., Imposimato S., Vardoulakis I.: Mechanical modelling of drained creep triaxial tests on loose sands. Géotechnique 50(1), 73–82 (2000)
Lyapunov A.M.: Problème général de la stabilitè des mouvements. Annales de la Faculté de Sciences de Toulouse 9, 203–274 (1907)
Hill R.: A general theory of uniqueness and stability in elastoplastic solids. J. Mech. Phys. Solids 6, 236–249 (1958)
Vaid Y.P., Eliadorani A.: Instability and liquefaction of granular soils under undrained and partially drained states. Can. Geotech. J. 35, 1053–1062 (1998)
Nova R.: Controllability of the incremental response of soils specimens subjected to arbitrary loading programmes. J. Mech. Behav. Mater. 5(2), 193–201 (1994)
Darve F., Laouafa F.: Instabilties in granular materials and application to landslides. Mech. Cohes.-Frict. Mater. 5, 627–652 (2000)
Lignon S., Laouafa F., Punier F., Khoa H.D.V., Darve F.: Hydro-mechanical modelling of landslides with a material instability criterion. Géotechnique 59(6), 513–524 (2009)
Laouafa F., Darve F.: Modelling of slope failure by a material instability mechanism. Comput. Geotech. 29, 301–325 (2002)
Arenson, L.: Unstable alpine permafrost: a potentially important natural hazard. Ph.D dissertation, IGT_ETHZ, http://e-collection.ethbib.ethz.ch/show?type=diss&nr=14801, Zürich (2002)
Head K.H.: Manual of soil laboratory testing, 3: effective stress tests. Wiley, Chichester (1998)
Nocilla A., Coop M.R., Colleselli F.: The mechanics of an Italian silt: an example of ‘transitional’ behaviour. Géotechnique 56(4), 261–271 (2006)
Han C., Vardoulakis I.: Plane-strain compression experiments on water-saturated finr-grained sand. Géotechnique 41(1), 49–78 (1991)
Khoa H.D.V., Georgopulos I.O., Darve F., Laouafa F.: Diffuse failure in geomaterilas: experiments and modeling. Comput. Geotech. 33, 1–14 (2006)
Navarro V., Alonso E.E.: Secondary compression of clays as a local dehydration process. Géotechnique 51(10), 859–869 (2001)
Been K., Jefferies M.G.: A state parameter for sands. Géotechnique 35(2), 99–112 (1985)
Romero, E., Jommi, C.: An insight into the role of hydraulic history on the volume changes and anisotropic clavey soils. Water Resources Research, 44, (2008) doi:10.1029/2007WR006558
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Casini, F., Jommi, C. & Springman, S. A laboratory investigation on an undisturbed silty sand from a slope prone to landsliding. Granular Matter 12, 303–316 (2010). https://doi.org/10.1007/s10035-010-0182-y
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DOI: https://doi.org/10.1007/s10035-010-0182-y