THE SWELL-SHRINK PROPERTIES OF INTACT AND DISTURBED CLAYEY AND MARLY SOILS: THE DISTURBANCE EFFECT

The occurrence of droughts in recent decades has prompted researchers to pay closer attention to soil shrinkage.It is no longer appropriate to assume that surface soils in temperate countries are always saturated.When using traditional geotechnical identifications for soil classification based on swelling and shrinkage, the soil density is not consistently considered as a crucial parameter, nor is the state of the soil (intact or disturbed) or the degree of soil cementation.This article highlights the importance of studying the soil in its intact state to accurately represent its behavior on-site.The microstructure of undisturbed soil differs from that of disturbed soil and governs its macroscopic behavior.The method and level of soil disturbance have an impact on the results, depending on whether the focus is on shrinkage or swelling behavior and cementation.This research demonstrates that disturbed samples of clayey soils (Romainville green clay) exhibit lower shrinkage amplitude than intact clayey soil samples, whereas disturbed marly soil samples (Argenteuil blue marl) show the opposite trend.Furthermore, depending on the disturbance method, the swelling amplitude of intact soil samples may be higher or lower than that of disturbed soil samples.The results indicate that conducting a swelling test on Wdisturbed samples and a shrinkage test on C-disturbed samples allows us to assess more closely the behavior of intact soil samples.In conclusion, recommendations for a more accurate assessment of the swelling-shrinkage potential of any given soil are provided, considering the test method and the level of disturbance of the sample.