Effect of Improvement of Collapsible Soils with Bitumen Emulsions on Collapsibility Rate for Varying Degrees of Saturation

Abdul Kareem E. Zainal

doi:10.3759/joge.v3i1.3750

Abstract

Collapsible soils are one of many problematic soils in Iraq. Many foundation failure problems that occurred in Iraq are associated with percolation of water; the change in the degree of saturation can affect the stability of these soils and may encounter large volumetric change. A series of tests conducted on collapsible soil using oedometer apparatus and the settlement–time curves are determined accurately, then each test is determined to a different degree of saturation through two ways inundation—one of the top of the soil simulating infiltration condition, and the other way is from the bottom which simulate capillary water rise. These results were used to predict the rapid volume change (collapse) for the soil with time (collapsibility rate). The results of volume change (settlement) with suction control was performed in a standard oedometer device for the natural dry density of collapsible soils for varying degree of saturation after the inundation, without applying any loads. The same tests were conducted after improvement of top surface only as one case; and the top and bottom surfaces of soil sample as another case of bitumen emulsions. The comparison of the results obtained from the experimental tests with and without improving the surface of soil sample was presented in graphical forms. Keywords: Collapsible soil, matric suction, collapsibility rate, degree of saturation