Standard penetration test State-of-the-art report
Ivan K. Nixon
Abstract
Important developments have taken place since ESOPT 1974 both with respect to the test method as well as the interpretation of the results. The considerable amount of research into the method being undertaken in the USA and Japan is reviewed against the new European Standard for the test. Japan has raised an objection to the specified rod size. Driving techniques have been closely examined in the search for a more precise standard in the USA. In reviewing the correlations with the various soil parameters particular attention is given to large scale laboratory experiments on the relationship between SPT N value, overburden pressure and relative density in sands that has emphasised the need for consideration of the other factors involved. Outline descriptions are given of eleven new methods for estimating settlement in granular soils and the results of a comparative study between eighteen methods. The test is important for estimating the danger of liquefaction and statistical methods are being suggested. Examples are included for compaction control by SPT. Besides its application in soils the test is widely used in Britain when investigating weak rocks and techniques have been proposed to aid pile design.