Abstract: The salt resolving slump characteristics of sodic saline soil in the western part of Jilin Province are the main engineering problem of lining-free channels in the connectivity of rivers and lakes in the region. This study of salt resolving slump characteristics of sodic saline soil can provide the basis for problem solving. By taking the saline soil area passing through a planning channel in Qian’an as the research object, through the indoor dissolution test on undisturbed soil, the variation law of the salt resolving slump coefficient of sodic saline soil with the pressure load and the relationship between the salt resolving slump coefficient and the soil above 150 cm were obtained. The results are as follows: Under the pressure of 200 kPa, sodic soil produced the largest amount of slump deformation when it first encountered water, and the salt resolving slump coefficient was the largest; with the pressure increased, the salt resolving slump coefficient decreased. The soil with a depth of less than 30 cm and more than 120 cm was not collapsible, and the sodic saline soil with a depth of 30-120 cm was slightly collapsible. The soil with a depth of 30 cm or more acted as a salt accumulation layer, the high concentration of exchangeable sodium made the soil particles coalesced, the void ratio low, the soil moisture infiltration blocked, the seepage effect weak, and the salt not easy to dissolve and lose. The sodic saline soil with a depth of 30-120 cm had slight disintegration. The difference of physical and chemical properties between the upper and lower layers is one of the causes of the slump of saline soil, which is also the key area of channel regulation.

Key words: sodic saline soil, subsurface erosion, salt resolving slump