عنوان مقاله [English]
Collapsible soils are one of the problematic soils, as they exhibit good stability in dry conditions but undergo sudden and significant settle-ments upon water entry. The surrounding layers of collapsible soil can be either permeable or impermeable, but the existing devices for determining the collapse potential lack the ability to model the drain-age conditions around the collapsible soil layer. In this study, an ap-paratus capable of modeling drainage conditions was constructed. A collapsible soil was made in laboratory, and its collapse potential was determined using single and double oedometer tests as well as the constructed apparatus. The results show that drainage conditions are an influential factor on the behavior of collapsible soils. The col-lapse potential obtained from this apparatus is lower than the col-lapse potential obtained from the oedometer test. The comparison of the two conditions with drainage and without drainage in two point and wide water distributions shows that in both water distributions, the collapse potential is higher in the condition with drainage than in the condition without drainage. For example, in the point distribution, the collapse potential with drainage is 27.7% higher than the without drainage, while in the wide distribution, it is 19.5%higher.