Rodzaje gruntów serii glin zwałowych Warszawy

Abstract

KINDS OF GROUNDS OF BOULDER CLAY SERIES OF WARSAW Summary Grounds containing over 50 per cent of sand fraction, and having sand grains of more than 0,05 mm in diameter are main constituents (over 84 per cent) of boulder clay series in Warsaw. According to the frequency of determinations, there are: sandy boulder clays, clayey sands and heavy sandy boulder clays. Apparent error arising when determining the kind of ground of boulder clay series by means of macroscopic analyse is, in relation to the granulometric analyse (sieve and areometric analyse), relatively small, and frequently does not exceed ± l per cent, exceptionally reaching up to 6 per cent. The arithmetic mean of absolute values of apparent errors does not exceed 1,5 per cent. It results of this that the well performed macroscopic analyse is of great importance in geological-engineering investigations, Particularly in regional researches, and in study on preliminary works in projecting the constructions.