Four case records are presented of road or railway embankment failures where the bank has been constructed over previously landslipped areas. These records draw attention to the possibility of long-term failure resulting from the existence of the landslip shear surfaces beneath the embankment, even when the bank has been successfully constructed without the development of short-term failures. Evidence is presented which shows that the delayed failure at least in part results from the swelling and consequent reduction of strength of the embankment fill following the development of a perched water table in the crest of the bank. However the final 'trigger' causing failure may be the result of exceptional groundwater conditions following heavy rain.

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Skopek and Ter-Stepanian are to be complimented for their Note on the liquid limit as determined by the two methods in use at present-the method proposed by Casagrande and the Swedish cone method proposed by Vasilev. The two methods give considerably differing results, particularly in case of clays of high plasticity. The present practice may thus lead to errors in interpreting the results of investigations reported by various authors. Moreover, the index of plasticity which depends on the liquid limit is in many cases used as the basis of classifying the clay soils.The Casagrande method is better known and more widely used. The Vasilev procedure has, however, a strong point in giving results which correspond to a definite shearing resistance. As the results obtained by the two methods show a fairly close correlation, either could be used with a subsequent reduction of results to an agreed standard.If we are to speak the same language, the liquid limit problem merits consideration and a definite decision at the next international conference of the International Society for Soil Mechanics and Foundation Engineering.

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