Effect of freeze-thaw cycles on collapsibility of loess under different moisture contents

Loess is usually used as the main building materials for road subgrade. The collapsibility can be greatly eliminated after compaction of collapsible loess, and it can satisfy the requirements of whole intensity and stability of road subgrade. However, a lot of disasters such as differential settlement and collapse occur after the road subgrade of loess has been used for several years in seasonally frozen soil zone. In order to analyze the influence of various levels of moisture contents on collapsibility of loess under freeze-thaw cycles, deformation and collapsibility of collapsible loess are studied under different freeze-thaw cycles in laboratory. The test results indicate that the remolded loess at every level of moisture content still has secondary collapsibility after freeze-thaw cycles. The soil structure with higher moisture content is damaged earlier than that with lower moisture content under freeze-thaw cycles. When the dry density is certain, the larger the net amount of deformation with low soil moisture content after freeze-thaw cycles is, the smaller the collapsible coefficient is, and vice versa.