选取陕西省子长县原状马兰黄土为研究对象，通过瞬态脱水和吸水(TWRI)试验方法，结合Van Genuchten(1980)土-水特征曲线模型和Mualem(1976)水力传导函数模型对土样的水-力作用参数进行反演计算，并绘制土-水特征曲线。试验结果表明，土样在不同脱湿和吸湿路径状态下的土-水特征曲线具有明显的回滞效应，其中，脱湿路径的进气值与饱和体积含水量分别为26 kPa和48%，不同干湿路径下与孔径分布有关的参数变化较小。为验证TWRI试验结果的正确性，针对同一个土样，采用2 Bar体积压力板仪对其基质吸力和体积含水量的关系进行稳态试验。对比以上2种方法的试验结果，可见瞬态脱水和吸水试验方法在低吸力范围内(0~300 kPa)的试验结果与压力板仪试验结果吻合较好，且具有试验周期短，测试吸力范围大的特点。
Abstract
A transient water release and imbibitions(TWRI) method together with Van Genuchten(1980) soil-water characteristic curve models and Mualem(1976) hydraulic conductivity function model was used for the inversion calculation of soil water-force parameters and the soil water characteristic curve(SWCC). The Malan loess at Zichang County in Shaanxi Province was selected as research object. Test results showed that the SWCC of soil samples under different drying and wetting states had apparent hysteresis effect. The air-entry value and saturated volumetric water content under drying state was 26 kPa and 48% respectively. Parameters related to pore size distribution changed slightly under different drying and wetting states. In order to verify the TWRI test results, steady-state test was carried out on the same soil sample using the volume 2 Bar pressure plate apparatus to study the relationship between their matrix suction and volumetric water content. By comparing the test results, it’s found that the test results of TWRI agrees well with that of pressure plate apparatus under low suction (0-300kPa). It has short test time and wide test range of matric suction.
关键词
非饱和马兰黄土 /
土-水特征曲线 /
瞬态脱水和吸水(TWRI)试验方法 /
体积压力板仪
Key words
unsaturated Malan loess /
soil-water characteristic curve /
transient water release and imbibitions(TWRI) method /
volume pressure plate
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 吴剑敏,李广信,王成华. 非饱和土基质吸力对基坑支护计算的影响[J]. 工业建筑,2003,33(7):6-10.(WU Jian-min,LI Guang-xin,WANG Cheng-hua. Effect of Matrix Suction of Unsaturated Soil on the Estimation of the Load Internal Force on Supporting Structure for Deep Excavation[J]. Industrial Construction,2003,33(7):6-10.(in Chinese))
[2] BARBOUR S L. Nineteenth Canadian Geotechnical Colloquium: The Soil-Water Characteristic Curve: A Historical Perspective[J]. Canadian Geotechnical Journal,1998,35(5): 873-894.
[3] BROOKS R H,COREY A T. Properties of Porous Media Affecting Fluid Flow[J]. Irrigation and Draining Division,ASCE,1896,92(2): 61-88.
[4] VAN GENUCHTEN M T. A Close-Form Equation for Predicting the Hydraulic Conductivity of Unsaturated Soils[J]. Soil Science Society of America Journal,1980,44(5): 892-898.
[5] TYLER S W,WHEATCRAFT S W. Fractal Process in Soil Water Retention[J]. Water Resources Research,1990,26(5): 1047-1054.
[6] FREDLUND D G. 非饱和土土力学[M]. 陈仲颐译. 北京:中国建筑工业出版社,1997.(FREDLUND D G. Unsaturated Soil Mechanics[M]. Translated by CHEN Zhong-yi. Beijing:China Architecture and Building Press,1997.(in Chinese))
[7] WAYLLACE A,LU N. A Transient Water Release and Imbibitions Method for Rapidly Measuring Wetting and Drying Soil Water Retention and Hydraulic Conductivity Function[J]. Geotechnical Testing Journal,2012,35(1):1-15.
[8] 李志清,李 涛,胡瑞林,等. 非饱和土土水特征曲线测试与预测[J]. 工程地质学报,2007,15(5):700-707.(LI Zhi-qing,LI Tao,HU Rui-lin,et al. Methods for Testing and Predicting of SWCC in Unsaturated Soil Mechanics[J]. Journal of Engineering Geology,2007,15(5):700-707.(in Chinese))
[9] XU Y F,SUN D A. Determination of Expansive Soil Strength Using a Fractal Model[J]. Fractals,2001,9(1): 51-61.
[10]胡 波,肖元清,王 钊. 土-水特征曲线方程参数和拟合效果研究[J]. 三峡大学学报(自然科学版),2005,27(1):30- 33.(HU Bo,XIAO Yuan-qing,WANG Zhao. Study on Soil-Water Characteristic Curve Equations Parameters and Fitting Effect[J]. Journal of China Three Gorges University (Natural Sciences),2005,27(1):30-33.(in Chinese))
[11]FREDLUND D G.,RAHARDJO H. Soil Mechanics for Unsaturated Soils[M]. New York:John Wiley and Sons Inc., 1993.
[12]FAYER M J,SIMMONS C S. Modified Soil-Water Retention Functions for All Matric Suctions[J]. Water Resource Research,1995,31(5):1233-1238.
[13]吴元莉,项 伟,赵 冬. 非饱和马兰黄土土-水特征曲线研究[J]. 安全与环境工程,2011,18(4):39-42.(WU Yuan-li,XIANG Wei,ZHAO Dong. Research on Soil-Water Characteristic Curve of Unsaturated Malan Loess[J]. Safety and Environmental Engineering,2011,18(4):39-42.(in Chinese))
基金
国家自然科学基金资助项目(41202199)
PDF(1395 KB)
