| 引用本文: | 康鑫睿,李宏波,田军仓,等.季冻区渠基盐渍土冻胀和盐分迁移试验研究[J].灌溉排水学报,2025,44(2):83-92. |
| KANG Xinrui,LI Hongbo,TIAN Juncang,et al.季冻区渠基盐渍土冻胀和盐分迁移试验研究[J].灌溉排水学报,2025,44(2):83-92. |
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| 摘要: |
| 【目的】盐渍土作为渠道地基，在季节冻土区对渠道衬砌易造成严重的冻胀和盐腐蚀破坏，为明确固化前后盐渍土的冻胀和盐分迁移问题开展试验研究。【方法】设计了5组固化前后盐渍土的室内冻融循环试验，分别以5种压实系数（0.855、0.879、0.903、0.927和0.952），3种含水率（10%、14%和18%）作为控制条件，探究了固化前后盐渍土在冻融循环条件下冻胀力、冻胀量和盐分迁移量的变化规律。【结果】冻融循环中固化前后盐渍土试样的冻胀力均会出现明显的波动现象，冻胀力波动的温度区间在-10~0 ℃；固化盐渍土在同深度处的最大冻胀力和最大冻胀量较盐渍土有明显衰减，冻胀力衰减达65.0%、冻胀量衰减达41.8%；固化前后盐渍土试样的盐分迁移量随深度增加均呈减小趋势，同深度处固化盐渍土的盐分迁移量明显小于盐渍土；随着压实系数的增加，固化前后盐渍土的冻胀力、冻胀量和盐分迁移量均呈先增后减的变化趋势。【结论】固化盐渍土较盐渍土在抗冻性和抑制盐分迁移特性方面均有明显提高。建立了固化前后盐渍土最大冻胀力、最大冻胀量与压实系数、冻融循环次数间的关系模型以及盐分迁移量与深度间的关系模型，通过关系模型得出对于小型渠道盐渍土地基的压实系数在0.85~0.90较佳，中、大型渠道在0.94以上较为合适。 |
| 关键词: 盐渍土；冻融循环；冻胀力；冻胀量；盐分迁移 |
| DOI：10.13522/j.cnki.ggps.2024108 |
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| Reducing frost heave and salt migration in saline soil foundations of channels in seasonal frozen regions using solidification |
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KANG Xinrui, LI Hongbo, TIAN Juncang, ZHANG Zhe, WANG Zi
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1. College of Civil and Hydraulic Engineering, Ningxia University, Yinchuan 750021, China;
2. Ningxia Research Center of Technology on Water-saving Irrigation and Water Resources Regulation, Yinchuan 750021, China;
3. Engineering Research Center for Efficient Utilization of Water Resources in Modern Agriculture in Arid Regions, Yinchuan 750021, China
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| Abstract: |
| 【Objective】Saline soils in seasonal frozen regions are often used as channel foundations but are prone to frost heave and salt migration, which can compromise structural stability. The objective of this paper is to investigate the efficacy of soil solidification in improving frost resistance and mitigating salt migration, and provide insights for improving engineering design in cold regions. 【Method】Freeze -thaw cycle tests were conducted on saline soil with and without solidification in laboratory. There were five test sets, with the compaction coefficient varying from 0.855 to 0.952 and soil moisture content ranging from 10% to 18%. Key parameters, including frost heave force, frost heave volume, and salt migration were measured during the experiment.【Result】① Both solidified and non-solidified saline soils exhibited significant fluctuation in the frost heave force for temperature in the range of -10 to 0 ℃. Solidification reduced the frost heave force by up to 65.0% compared to non-solidified soil. ②Solidification reduced the frost heave volume by 41.8% at the same soil depth, compared with non-solidification. ③Salt migration decreased with increasing soil depth in both solidified and non-solidified soils. However, significantly slower migration was observed in solidified soils. ④ With the increase in compaction coefficient, the frost heave force, frost heave volume, and salt migration initially increased, followed by a decline, after the increase exceeded a threshold. 【Conclusion】Soil solidification significantly improved the frost resistance and reduced salt migration in saline soils. An empirical model was developed to estimate the maximum frost heave force and volume based on compaction coefficient and the number of freeze-thaw cycles, as well as salt migration as a function of soil depth. Our findings suggest that a compaction coefficient in the range of 0.85-0.90 is optimal for small-scale channel foundations, while a compaction coefficient exceeding 0.94 is recommended for medium to large-sized channels. |
| Key words: saline soil; freeze-thaw cycle; frost heave force; frost heave volume; salt migration |
