Występowanie agregatów w gruntach spoistych i ich wpływ na ocenę niektórych właściwości tych gruntów

Abstract

Occurrence of aggregates in cohesive soils and their influence on evaluation of selected properties.S u m m a r y. The paper presents problems linked with the presence of aggregates in cohesive mineral and organic soils. Aggregates are present in almost all of these soil types. They result from the cooperation of clay particles, soil crystallization, cooperation between clay particles and organic matter as well as such factors as soil loading or drying. Aggregates are to a variable degree resistant to external factors. Most resistant are organic-mineral aggregates, particulary after drying. The presence of aggregates decreases the degree of soil dispersion, and thus their total surface and hydrophility. At the same time the porosity and permeability of aggregate soils increases in comparison to more dispersive soils. Examples of changes in the activity value (coefficient A) for soils are presented according to the results of microaggregate analysis, that is presence of aggregates, in relation to the coefficient calculated with the use of results of granulometric analysis determining the primary granulometric content. In order to evaluate correctly the different parameters determined basing on the correlation with the clay fraction content, a granulometric analysis of the primary clay fraction content as well as microaggregate analysis should be carried out.