Zmiany właściwości gruntu w strefie aktywnej pęcznienia

Abstract

Changes in soil properties in the active-wetting zone of swelling.A b s t r a c t. Swelling is a phenomenon which occurs in high plasticity soils. It is observed immediately after the contact of not fully saturated expansive soil with water. In clays of very small coefficient of permeability, it may be concluded that swelling is a surface phenomenon – water does not need to infiltrate deep into the clay layer for swelling to start. The so-called active-wetting zone may be observed in the soil layer where the swelling process takes place. The soil conditions in the zone change during swelling and consequently result in changes in the soil strength and deformation properties. In the paper the results of swelling pressure tests are presented and analysed. The tests were carried out in oedometers. Based on the test results, the range of the active-wetting zone in the tested samples was analysed, taking into account index properties of tested soils, as well as orientation of tested samples.