Abstract: The engineering properties of loess soils are characterized by their regional and location specific. In order to study the influence of the cement content on the mechanical properties of the collapsible loess in the western Henan Province, extensive laboratory tests were performed on treated collapsible loess soil samples. The test items are: Atterberg Limits, collapsible soil compression tests, unconfined compression tests with various cement content and curing ages. The results indicate that, the mixing of cement into the collapsible loess soils could change the grain size distribution of the soil so that the physical properties of the loess soils could be improved; then, the mixing of cement could significantly reduce the collapsibility of the loess soils. With the increasing of the cement content in the soil and curing age, the unconfined compressive strength of the modified loess has an obvious increase and the sensitivity to the water has significantly decreased. It is suggested that, due to the collapsibility and water sensitivities of the collapsible loess, a cement content of 4% should be applied in the loess soils for embankment and subgrade soils. 

Key words: collapsible loess, plasticity index, unconfined compressive strength