Collapse test studies on coarse grain sulfite saline soil as an embankment fill material

Abstract

For the construction of roads in coarse-grained saline soil areas, coarse-grained sulfite saline soil is often used as an embankment fill material because of the limited choice of local embankment fillers. Because the NaCl in coarse-grained sulfite saline soil dissolves easily in water, when coarse-grained sulfite saline soils are used as embankment fillers, it can easily cause embankment collapse deformation when it meets water. The main objective of this study was to clarify the collapsibility properties of coarse-grained sulfite soils as embankment fillers; the relevant parameters concerning coarse-grained sulfite soils as embankment fillers were provided for embankment engineering. First, through the artificial preparation of typical coarse-grained sulfite saline soils, collapse tests under different salt contents, different initial moisture contents, different initial compaction degrees, and different particle gradations were carried out. Second, natural coarse-grained sulfite saline soils were selected to carry out the collapse tests, and the results were compared with the results of the above-mentioned collapse tests. The results showed that the higher the sulfite content in coarse-grained soil was, the greater the amount of collapse was. A larger embankment compaction degree had a good inhibitory effect on the collapse deformation. The collapsibility of coarse sulfite soils was less relatively when the soil water content was between 100% and 133% of the optimum water content, the compaction degree was 93%, and the soluble salt content was less than 2%. For coarse-grained sulfite saline soil, the larger the proportion of coarse particle was, the smaller the collapsibility ratio was.