The Writers are in total agreement with the main theme of the Paper, namely that the factors affecting compressibility and penetration resistance of sands are not homologous and therefore, in general, it is not possible to assess compressibility from
correlations with penetration resistance. The errors are particularly large if the sand has a stress or cyclic strain history. This was also the main thrust of the paper by Lambrechts & Leonards (1978), which has been fully confirmed by extensive
tests conducted in recent years in Italy by Jamiolkowski and his co-workers (Jamiolkowski, Ladd, Germaine & Lancellota, 1985). In spite of this general agreement, there are some specific items in the Paper that warrant further discussion.