Unfortunately the research activiti

Unfortunately the research activities in soil mechanics had one undesirable psychological effect. They diverted the attention of many investigators and teachers from the manifold limitations imposed by nature on the application of mathematics to problems in earthwork engineering. As a consequence. more and more emphasis has been placed on refinements in sampling and testing and on those very few problems that can be solved with accuracy. Yet, accurate solutions can be obtained only if the soil strata are practically homogeneous and continuous in horizontal directions. Furthermore, since the investiga- tions leading to accurate solutions involve highly special- ized methods of sampling and testing, they are justified only in exceptional cases. On the overwhelming majority of jobs no more than an approximate forecast is needed. and if such a forecast cannot be made by simple means it cannot be made at all. If it is not possible to make an approximate forecast, the behavior of the soil must be observed during construction, and the design may subse- quently have to be modified in accordance with the findings.These facts cannot be ignored without defying the purpose of soil mechanics. They goverm the treatment of the subject in this book.