Wpływ struktury na skurczalność gruntów spoistych

In this paper structural factors affecting shrinkage phenomena are discussed. 78 soil samples were tested including: neogene (mio-pliocene) clays, glaciall tills, clayey alluvial soils, bentonite, illitic clay and kaolinite. Comparison of destructed soils (remoulded samples) and undisturbed soils (NNS) was made. Analysis of shrinkage curves showed that the most hydrophilic clays and well graded soils have the lowest void ratio and shrinkage limit. Shrinkage curves of silty and sandy soils are relatively plane with poorly differentiated shrinkage stages. For mio-pliocene clays, shrinkage curves of remoulded samples are similar to the undisturbed ones. Both series of samples yielded similar final void ratio and shrinkage limit values. For alluvial soils and glacial tills, remoulded samples yielded lower void ratio and higher shrinkage limit values than NNS samples. The results obtained showed that the soil fabric (natural preserved versus disturbed) does not influence shrinkage of mio-pliocene clays while affects significantly shrinkage of alluvial soils and glacial tills. The statistical analysis revealed that there was no correlation between shrinkage limit and clay content or plastic index. A linear relationship was found between shrinkage limit and void ratio for clays as well as the remoulded samples.