非饱和土路基中水分的迁移不仅以液态形式发生,同时也会以气态形式发生,水汽的耦合迁移作用会在路基长期运营过程中对路基的长期稳定性及服役性能造成严重影响。因此,开展了针对典型非饱和土路基的电阻率测试及水汽迁移试验,研究了初始含水率和初始压实度对电阻率的影响,揭示了水汽迁移过程中非饱和土路基的电阻率变化规律,建立了电阻率-含水率模型。研究结果表明:随着含水率、压实度的增加,黏性土的电阻率均减小,呈指数特征,且电阻率对含水率这一影响因素更为敏感。随着迁移时间增加,土体顶部电阻率越来越小,土体底部电阻率越来越大。不同初始含水率试验,初始含水率增大,顶部土壤电阻率衰减率先增大后减小。不同压实度试验,压实度越大,土体顶部电阻率降低程度越小。电阻率-含水率模型计算结果与试验数据较吻合,模型拟合程度良好。
Abstract
In unsaturated soil roadbeds, water migration occurs not only in liquid form but also in gas form. The coupled migration of water vapor can severely impact the long-term stability and service performance of the roadbed throughout its service life. We conducted resistivity tests and water vapor migration tests on representative unsaturated soil roadbeds to investigate the effects of initial water content and initial degree of compaction on resistivity. The aim was to uncover the resistivity variation pattern of unsaturated soil roadbeds during water vapor migration and establish a water content-resistivity model. The results indicate that the resistivity of clayey soil decreases exponentially with an increase in water content and compaction degree. Resistivity is more sensitive to changes in water content. Furthermore, as migration time increases, the resistivity decreases at the top of the soil while increasing at the bottom. Higher initial water content initially intensifies resistivity attenuation at the top of the soil, followed by a subsequent decrease. As for different compaction tests, greater compaction results in a smaller decrease in resistivity at the top of the soil. The calculated results from the resistivity-water content model align well with the experimental data, exhibiting a good model fit.
关键词
非饱和路基 /
水汽迁移 /
电阻率 /
含水率 /
压实度
Key words
unsaturated roadbed /
water vapor migration /
resistivity /
moisture content /
degree of compaction
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 罗 汀, 陈 含, 姚仰平, 等. 锅盖效应水分迁移规律分析[J]. 工业建筑, 2016, 46(9): 6-9.
[2] 王悦月, 毛雪松, 李汶霖. 水分迁移引起千枚岩填筑路基回弹模量衰变对路面结构力学特性的影响[J]. 科学技术与工程, 2019, 19(12): 344-352.
[3] 姚仰平, 王 琳, 王乃东, 等. 锅盖效应的形成机制及其防治[J]. 工业建筑, 2016, 46(9): 1-5.
[4] 张 升, 贺佐跃, 滕继东, 等. 非饱和土水汽迁移与相变: 两类“锅盖效应”的试验研究[J]. 岩土工程学报, 2017, 39(5): 961-968.
[5] 李彦龙,王 俊,王铁行.温度梯度作用下非饱和土水分迁移研究[J].岩土力学,2016,37(10):2839-2844.
[6] 王铁行, 王娟娟, 张龙党. 冻结作用下非饱和黄土水分迁移试验研究[J]. 西安建筑科技大学学报(自然科学版), 2012, 44(1): 7-13, 71.
[7] 李 杨, 王 清, 王坛华. 长春地区季节冻土水分迁移实验研究[J]. 科学技术与工程, 2017, 17(35): 307-311.
[8] 龚晓南, 焦 丹, 李 瑛. 粘性土的电阻计算模型[J]. 沈阳工业大学学报, 2011, 33(2): 213-218.
[9] 李瑞珂, 车爱兰, 冯少孔. 基于电测法的路基土物理性质室内测试方法研究[J]. 工程地质学报, 2020, 28(1): 51-59.
[10]储 亚,查甫生,刘松玉,等.基于电阻率法的膨胀土膨胀性评价研究[J].岩土力学,2017,38(1):157-164.
[11]付 伟,汪 稔.饱和粉质黏土反复冻融电阻率及变形特性试验研究[J].岩土力学,2010,31(3):769-774.
[12]杨更社, 高宇璠, 田俊峰, 等. 冻融循环对黄土电阻率及水分迁移影响的试验研究[J]. 科学技术与工程, 2016, 16(35): 267-272.
[13]YUAN G,CHE A,TANG H. Evaluation of Soil Damage Degree under Freeze-Thaw Cycles through Electrical Measurements[J]. Engineering Geology,2021,293:106297.
[14]陈议城, 黄 翔, 陈学军, 等. Cu2+污染红黏土抗剪强度与电阻率关系研究[J]. 长江科学院院报, 2021, 38(3): 121-127, 136.
[15]李文忠, 肖国强, 孙卫民, 等. 长江堤防土电阻率测试及其与含水率和密实度的相关性研究[J]. 长江科学院院报, 2019, 36(10): 131-134.
[16]姚仰平, 王 琳. 影响锅盖效应因素的研究[J]. 岩土工程学报, 2018, 40(8): 1373-1382.
[17]NEYAMADPOUR A. Detection of Subsurface Cracking Depth Using Electrical Resistivity Tomography: A Case Study in Masjed-Soleiman, Iran[J]. Construction and Building Materials, 2018, 191: 1103-1108.
[18]AYODELE A L, PAMUKCU S, SHRESTHA R A, et al. Electrochemical Soil Stabilization and Verification[J]. Geotechnical and Geological Engineering, 2018, 36(2): 1283-1293.
[19]ZHOU Z, XING K, YANG H, et al. Damage Mechanism of Soil-Rock Mixture after Freeze-Thaw Cycles[J]. Journal of Central South University, 2019, 26(1): 13-24.
[20]NGUYEN T T H, CUI Y J, FERBER V, et al. Effect of Freeze-Thaw Cycles on Mechanical Strength of Lime-treated Fine-grained Soils[J]. Transportation Geotechnics, 2019, 21: 100281.
基金
国家自然科学基金项目(42077262,42077261,41672312)
PDF(1585 KB)
