60F. SCHLOSSER· L. DORMIEUXnics and Foundations Division, ASCE, vol. XCII,nO SM 1.SEED H.B., MARTIN G.R. (1966), The Seismic Coefficientin Earth Dam Design, Journal of the Soil Mechanicsand Foundations Division, ASCE, vol. XCII,nO SM3.SEED H.B., CHAN C.K. (1966), Clay Strength UnderEarthquake Loading Conditions, Journal of the SoilMechanics and Foundations Division, ASCE,vol. XCII, nO SM2.SEED H.B., LEE K.L., IDRISS LM. (1969), Ana/ysisof the Sheffield Dam Failure, Journal of the SoilMechanics and Foundations Division, ASCE,vol. XCV, nO SM6.SEED H.B., WHITMAN R.V. (1970), Design of EarthRetaining Structures for Dynamics Loads, LateralStresses in the Ground and Earth Retaining Structures,ASCE.SEED H.B., IDRISS LM., LEE K.L. (1975), DynamicAnalysis of the Slide in the Lower San Fernando DamDuring the Earthquake of February 9, 1971, Journal ofthe Geotechnical Engineering Division, ASCE, vol. CI,nO GT9.SEED H.B. (1979a), Considerations in theEarthquake-Resistant Design of Earth and RockfillDams, XIXe Conférence Rankine, Géotechnique,vol. XXIX, nO 3.SEED H.B. (1979b), Soil Liquefaction and CyclicMobility Evaluation for Level Ground During Earthquakes,Journal of the Geotechnical Engineering Division,ASCE, vol. CV, nO GT2.SEED H.B. (1981), Earthquake-Resistant Design ofEarth Dams, International Conference on RecentAdvances in Soil Dynamics and Earthquake Engineering,Rolla, Missouri.SERFF N., SEED H.B., MAKDISI F.L, CHANG C.K.(1976), Earthquake Induced Deformations of EarthDams, Report nO EERC 76-4, Earthquake EngineeringResearch Center, University of California, Berke<strong>le</strong>y.SLADEN J.A., D'HOLLANDER R.D., KRAHN J.(1985), The Liquefaction of Sands, a Collapse SurfaceApproach, Canadian Geotechnical Journal, vol. XXII,nO 4.TAKAHASHI M., HIGHT D.W., VAUGHAN P.R.(1980), Effective Stress Changes observed DuringUndrained Cyclic Triaxial Tests on Clay, InternationalSymposium on Soils Under Cyclic and TransientLoading, Swansea.TANIGUCHI E., SASAKI Y. (1985), Back Analysis ofa Landslide due to the Naganoken Seibu Earthquakeof September 14, 1984, Specialty Session on SeismicStability of Slopes, 11th ICSMFE, San Francisco.TERZAGHI K. (1950), Mechanisms of Landslides,The Geological Survey of America, Engineering Geology(Berk<strong>le</strong>y).VAID P.Y., FINN W.D.L. (1979), Static Shear andLiquefaction Potential, Journal of the GeotechnicalEngineering Division, ASCE, vol. CV, nO GT10.VAID P.Y., CHERN J.C. (1983), Effect of StaticShear on Resistance to Liquefaction, Soils and Foundations,vol. XXIII, nO 1.WHITMAN R.V. (1979), Dynamic Behaviour of Soilsand its Application to Civil Engineering Projects,VIe Conférence Panaméricaine de Mécanique des Solset de Travaux de Fondations, vol. l, pp. 59-105.WILSON N.E., GREENWOOD J.R. (1974), PorePressures and Strains after Repeated Loading of SaturatedClay, Canadian Geotechnical Journal, vol. XI,nO 2.WOODS J.H. (1975), Earthquake-Induced Sail Pressureson Structures, Report nO EERL-73-05, EarthquakeEngineering Research Laboratory, CaliforniaInstitute of Technology, Pasadena.WOOD D.M. (1976), Comments on Cyclic Loadingon Clay, First International Conference on Behaviourof Offshore Structures, vol. l, pp. 418-424.YZIQUEL A., LINO M., POST G., TARDIEU B.(1981), Seismic Analysis as a Tooi in the Design ofTwo Earth Dams, Symposium on Advances in GeotechnicalEarthquake Engineering, Saint-Louis, Missouri.ZARRABI K. (1979), Sliding of Gravity Retaining WallDuring Earthquake Considering Vertical Acce<strong>le</strong>rationand Changing Inclination of Failure Surface, S.M. Thesis,Department of Civil Engineering, M.LT., Cambridge,Massachussets.
ésistance au cisail<strong>le</strong>ment dynamiquedynamic shear strengthNote de Pierre LONDEIngénieur-Conseil, Pierre Londe & Associés *Président Honoraire de la Commission Internationa<strong>le</strong> des Grands BarragesRésuméDes essais de cisail<strong>le</strong>ment direct très rapides, faits sous la direction du ProfesseurSkempton, ont montré que la résistance de surfaces précisaillées croissaiten général avec la vitesse de cisail<strong>le</strong>ment. Mais certains silts posent un sérieuxproblème dynamique en manifestant une chute en dessous de la résistance résiduel<strong>le</strong>.Aucune explication n'a encore été avancée.AbstractFast direct shear tests, carried out under the guidance of Professeur Skemptan,have shawn that in genera/ the strength of pre-sheared surfaces increased substantia//yfor fast shear. Hawever same silt-stane disp/ayed a drop be/aw the residua/strength, raising a seriaus prab/em for dynamic design. No exp/anatian has beenprapased thus far.* Tour Horizon - 92806 Puteaux Cedex.