Study on Immersion Test and Settlement Deformation of Large Thickness Collapsible Loess Subgrade

According to Zhengzhou-Xi'an high speed railway projects,conducted a 25mdiameter immersion test in typical section(Tongguan and Huayin)of collapse loess which thickness is greater than 25m.the test lasted for 52d,at the same time,collected a large number of undisturbed soil sample,conducted laboratory tests,received a series of loess mechanical parameters.The research indicates that the loess in this area with large deformation after soaking,resulting in a severe subsidence of loess,it belongs self-weight collapsible loess,the study provides treatment and waterproof and drainage measures data for large thickness collapse loess subgrade along the railway,as well as providing theoretical support for the construction of similar loess in other areas.