Re-appraisal of Terzaghi’s Soil Mechanics

In his recent biography of Terzaghi, Goodman (1999, p 213) has described Terzaghi and Peck's difficulties in writing 'Soil Mechanics in Engineering Practice' which, published in (1948), quickly established itself as a main pillar of geotechnical education. He quotes a judgement they formed on Donald Taylor’s (1948) book ‘Fundamentals of Soil Mechanics’ as a ‘theoretical and esoteric portrayal of soils’. But when Taylor’s book was published it won praise from academics. Students read it and used his interlocking equations (1 and 2 below) to develop an alternative to the normal soil mechanics theory taught by Coulomb, Rankine, Mohr and Terzaghi. Both theories fit data of peak strengths of soil. The alternative theory also fits data of other phenomena. This Lecture will re-appraise the normal soil mechanics theory by contrasting it with the alternative theory.