Large-scale model tests on embankment of crude coarse grained saline soil

In Northwest China, there is great deal of crude coarse grained saline soil. If it can be used as embankment fill, full use of local resources will be made and construction cost of highways saved. In order to make the test results more accurately and to reflect the actual working conditions, based on two different chemical analysis tests, experiments of freeze thaw cycles, salt expansion tests under (no) additional load and large-scale immersed tests, large-scale model tests on embankment under freeze thaw cycles are performed. It is shown that the soluble salt obtained by two different test methods (standard method and screening method of 5 mm) is quite different, and the results from the screening method of 5 mm can better guide the construction. With the increase of moisture content, the values of salt expansion and collapsibility gradually increase, and the cumulative characteristics of collapsibility are obvious. The amount of salt expansion for the saline soil under additional covering load is less than 15%, compared with that under no additional load. After several freeze-thaw cycles, the maximum expansion rate of the large-scale embankment model is only 0.44%. The crude coarse grained saline soil can be used for embankment fill.