不同供给源下的粗粒土水盐迁移特性分析

为探究不同供给源下的粗粒土水盐迁移时空分布特性,根据新疆盐渍土地区的实际工况,选择氯盐为研究对象,掺配3种不同细粒掺量的粗粒土,开展不同压实度与不同供给源组合的粗粒土水盐迁移试验,分析在不同供给源下,细粒掺量与压实度对粗粒土水盐迁移时空分布的影响。结果表明：随着细粒掺量由10%、20%、30%依次递增,水盐迁移趋势逐渐显著；压实度对水盐迁移的影响会因供给源的不同而不同；盐溶液供给源下的水盐迁移速率较小,但迁移高度较高；盐渍土供给源下的水盐前期迁移速率较大,但后期迁移速率有所减小。盐溶液供给源宜选用细粒掺量少的粗粒土进行换填,并尽可能提高压实度；盐渍土供给源的盐渍土部分宜适当降低压实度,换填非盐渍土宜选用细粒掺量为20%左右的粗粒土并提高压实度,由此控制水盐迁移水平。研究成果可为粗粒盐渍土路基结构设计提供一定的理论依据和技术支持。

Analysis of Water and Salt Migration Characteristics of the Coarse-Grained Soil under Different Supply Sources

In order to explore the spatial and temporal distribution characteristics of water and salt migration of coarse grained soil under different supply sources, According to the actual conditions of the saline soil area in Xinjiang, the chlorine salt was chosen as the research object, and three kinds of soils were mixed with different fine-grained contents, the experiment on water and salt migration of coarse-grained soil with different compaction degrees and different supply sources were carried out, the influences and laws of different fine-grained contents and compaction degrees were analyzed under different supply sources by the coarse-grained soil water and salt migration tests. The results demonstrate that the migration trend of water and salt is more significant with the increase of the fine-grained content from 10%, 20%, and 30%. The influence of compaction degree on water-salt migration is varied under different supply sources. For the salt solution supply source, the migration rate of water and salt is smaller, but the migration height is higher. For the saline soil supply source, the early migration rate is larger, but the later migration rate decreases. The salt solution supply source should be replaced with coarse-grained soil of less fine-grained content, and the compaction degree should be improved as much as possible. The saline soil supply source should be reduced the compaction degree appropriately, and the coarse-grained soil with fine-grained content of about 20% should be used to control the level of water and salt migration. The research results provide the theoretical basis and technical support for the subgrade structure design of coarse-grained saline soil.