Wpływ uziarnienia i granic konsystencji na klasyfikację wybranych gruntów spoistych w świetle zmieniających się kryteriów normowych

Abstract

The influence of grain-size and consistency limits on the classification of selected cohesive soils in the light of the changing standard criteria.A b s t r a c t. The paper presents classifications of seven different cohesive soils, based on seven methods suggested by the standards PN-B-02480:1994, PN-B-04481:1988 and PN-EN ISO 14688:2006. Two included macroscopic analysis, three – grain distribution and two other – Atterberg limits. The liquid limits, necessary to determine the soil type according to the Casagrande’s nomogram, were assessed with the use of the Casagrande’s method according to PN-B-04481:1988 and cone penetrometer test according to PKN-CEN ISO/TS 17892-12:2009. The latter one gave lower values, which is consistent with previous studies. The results were additionally evaluated in terms of the activity and swelling potential of the soils. It has been concluded that macroscopic analysis classifies soils in a way similar to the one suggested in the Casagrande's nomogram, which in turn, allows estimation of physical parameters of the cohesive soils. In the Authors’ opinion, these two ways of cohesive soil description are worth using; the necessity of plotting the grain size distribution curves could be limited to some doubtful cases – e.g. when the activity value of soil is required.