As the main driving force of pollutant migration and the movement of water, vapour and heat, water movement in vadose zone is of very important significance to the “four water” transformation, groundwater source, water resources development and utilization, ecological protection, and human’s production and life. Nevertheless, it is still controversial whether centrifugal simulation can be applied to researching the water migration in vadose zone. In this paper, the feasibility of applying centrifugal simulation to researching water migration in vadose zone is investigated via establishing one-dimensional theoretical and numerical models and verification by four sets of data. Results demonstrate that: (1)numerical model could well reproduce the water migration process presented in the literature, matching well with experimental data; (2) the analysis of materials conservation error show that the quality of the numerical simulation results can be guaranteed to be excellent when the time step and space step are small enough; (3) it is feasible to apply centrifugal simulation technology to researching the water migration in vadose zone; (4) the uneven distribution of acceleration in the centrifugal simulation would result in the lag of water migration at the bottom of the model behind that of the prototype, which, however, can be alleviated by using higher centrifugal acceleration.
Key words
vadose zone /
water migration /
centrifugal simulation /
soil contamination /
feasibility
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
References
[1] 周 训,胡伏生,何江涛,等.地下水科学概论[M]. 北京:地质出版社,2009.
[2] 商 洁.巴丹吉林沙漠腹地包气带水分运移研究[D].北京:中国地质大学(北京),2014.
[3] 喻立珊.非饱和带溶质迁移离心实验的数值模拟研究[D].北京:北京大学,2015.
[4] 赵雅琼.非饱和带土壤水分特征曲线的测定与预测[D].西安:长安大学,2015.
[5] 刘小军,闫玉闯,罗 扬.非饱和黄土水分迁移规律及迁移量的试验研究[J].西安建筑科技大学学报(自然科学版),2015,47(1):56-61.
[6] 喻立珊,曹国亮,许 模,等.离心实验在污染物迁移研究中的应用[J].地球科学进展,2014,29(2):227-237.
[7] 包承纲.我国岩土离心模拟技术的应用与发展[J].长江科学院院报,2013,30(11):55-66.
[8] KUMAR P R. Scaling Laws and Experimental Modelling of Contaminant Transport Mechanism Through Soils in a Geotechnical Centrifuge [J]. Geotechnical and Geological Engineering, 2007, 25(5):581-590.
[9] 林 明.国内土工离心机及专用试验装置研制的新进展[J].长江科学院院报,2012,29(4):80-84.
[10]TIMMS W, HENDRY M J, MUISE J, et al. Coupling Centrifuge Modeling and Laser Ablation Inductively Coupled Plasma Mass Spectrometry to Determine Contaminant Retardation in Clays[J]. Environmental Science & Technology, 2009, 43(4):1153-1159.
[11]张建红,吕 禾,王文成.铜离子在非饱和土中迁移的离心模型试验研究[J].岩土力学,2006,27(11):1885-1890.
[12]张建红,胡黎明.重金属离子和LNAPLs在非饱和土中的运移规律研究[J].岩土工程学报,2006,28(2): 276-280.
[13]詹良通,曾 兴,李育超,等.高水头条件下氯离子击穿高岭土衬垫的离心模型试验研究[J].长江科学院院报,2012,29(2):83-89.
[14]张建红,劳敏慈,胡黎明.非饱和土中水分迁移及污染物扩散的离心模拟[J].岩土工程学报,2002,24(5):622-625.
[15]GOFORTH G F E.Technical Feasibility of Centrifugal Techniques for Evaluating Hazardous Waste Migration[D].Gainesville: University of Florida, 1986.
[16]POULOSE A, NAIR S R, SINGH D N. Centrifuge Modeling of Moisture Migration in Silty Soils[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2000, 126(8):748-752.
[17]MITCHELL R J. The Eleventh Annual RM Hardy Keynote Address, 1997: Centrifugation in Geoenvironmental Practice and Education [J]. Canadian Geotechnical Journal, 1998, 35(4):630-640.
[18]MITCHELL R J. Matrix Suction and Diffusive Transport in Centrifuge Models[J]. Canadian Geotechnical Journal, 1994, 31(3):357-363.
[19]SINGH D N, KURIYAN S J. Estimation of Hydraulic Conductivity of Unsaturated Soils Using a Geotechnical Centrifuge [J]. Canadian Geotechnical Journal, 2002, 39(3):684-694.
[20]MCCARTNEY J S, ZORNBERG J G. Centrifuge Permeameter for Unsaturated Soils. II: Measurement of the Hydraulic Characteristics of an Unsaturated Clay[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2010, 136(8):1064-1076.
[21]ZADEH K S. A Mass-conservative Switching Algorithm for Modeling Fluid Flow in Variably Saturated Porous Media [J]. Journal of Computational Physics, 2011, 230:664-679.
[22]VAN GENUCHTEN M T. A Closed-form Equation for Predicting the Hydraulic Conductivity of Un-saturated Soils[J]. Soil Science Society of America Journal, 1980, 44(5):892-898.
[23]GARDNER W. Some Steady-state Solutions of the Unsaturated Moisture Flow Equation with Application to Evaporation from a Water Table[J]. Soil Science, 1958, 85(4):228-232.
[24]MUALEM Y. A New Model for Predicting the Hydraulic Conductivity of Unsaturated Porous Media[J]. Water Resources Research, 1976, 12(3):513-522.
[25]KIRKHAM J. Manipulation of Soil Nitrogen to Increase Efficiency of Mintuber Seed Production in Tasmania[D]. Tasmania: University of Tasmania, 2010.
[26]NIMMO J R, RUBIN J, HAMMERMEISTER D P. Unsaturated Flow in a Centrifugal Field: Measurement of Hydraulic Conductivity and Testing of Darcy’s Law [J]. Water Resources Research, 1987, 23(1):124-134.
[27]NAKAJIMA H, STADLER A T. Centrifuge Modeling of One-step Outflow Tests for Unsaturated Parameter Estimations [J]. Hydrology and Earth System Sciences, 2006, 10(5):715-729.
[28]ŠIMUNEK J, NIMMO J R. Estimating Soil Hydraulic Parameters from Transient Flow Experiments in a Centrifuge Using Parameter Optimization Technique[J]. Water Resources Research, 2005, 41(4):297-303.
PDF(2357 KB)
