1. Lect., Dept. of Civ. and Envir. Engrg., Imperial Coll. of Sci., Technol. and Medicine, London, U.K. SW7 2BU.
2. Prof. of Analytical Soil Mech. and Head of the Soil Mech. Sect., Dept. of Civ. and Envir. Engrg., Imperial Coll. of Sci., Technol. and Medicine, London, U.K.
3. Michael Barclay Partnership, 105–109 The Strand, London, U.K., WC2R 0AA; former MS Student, Dept. of Civ. and Envir. Engrg., Imperial Coll. of Sci., Technol. and Medicine, London, U.K.