ZHANG Guoping,WANG Lin,CAO Zijun,et al.Comparative study of different methods for determining the soil water characteristic curve model considering uncertainty[J].,2018,27(04):151-158.[doi:10.13577/j.jnd.2018.0420]





Comparative study of different methods for determining the soil water characteristic curve model considering uncertainty
张国萍 王林 曹子君 李典庆
武汉大学水资源与水电工程科学国家重点实验室, 工程风险与防灾研究所, 湖北 武汉 430072
ZHANG Guoping WANG Lin CAO Zijun LI Dianqing
State Key Laboratory of Water Resources and Hydropower Engineering Science, Institute of Engineering Risk and Disaster Prevention, Wuhan University, Wuhan 430072, China
unsaturated soilsoil-water characteristic curveuncertaintyBayesian approachmodel selection
土水特征曲线(SWCC)描述了非饱和土中体积含水量(或有效饱和度)与压力水头(或基质吸力)之间的关系。SWCC作为非饱和土力学中的基本函数,可用于研究非饱和土的抗剪强度、渗透特性以及变形特性等,在非饱和土力学应用中发挥着重要作用。工程实践中,通常可采用直接试验方法测得SWCC数据。由于直接试验方法条件苛刻且耗时较长,难以获得体积含水量范围内完整的SWCC数据。在有限试验数据条件下,如何更好的选择SWCC模型是一个关键问题。本文系统对比了考虑不确定性条件下解决该问题的3种方法,即贝叶斯模型比选方法(Bayesian)、Akaike information criterion (AIC)识别准则和Bayesian information criterion (BIC)识别准则。首先介绍了上述3种模型比选方法;然后,采用UNSODA数据库中试验数据开展研究,分别从拟合度和罚值2个方面综合比较3种方法在SWCC模型比选过程中的差异。结果表明:给定试验数据条件下,3种方法所确定的最优SWCC模型不尽相同,Bayesian方法在考虑模型罚值的同时更好地反映了试验数据信息,AIC、BIC准则中不同SWCC模型的拟合度可能十分接近,此时模型比选结果受模型罚值影响显著。
Soil water characteristic curve (SWCC) describes the relationship between volumetric water content (or effective saturation) and pressure head (or matric suction) in unsaturated soils. As an essential element of unsaturated soil mechanics, SWCC can be used to study the shear strength, permeability and deformation properties of unsaturated soils, which plays an important role in the application of unsaturated soil mechanics. In engineering practice, SWCC data can be measured directly by direct test methods. Because the direct test method requires high-standard control and time-consuming, it is difficult to obtain complete SWCC data in the volumetric water content range. Under the condition of a limited number of test data, how to select the SWCC model in a rational manner is a key issue. This paper summarizes three methods to solve the problem, namely, Bayesian model selection method (Bayesian), Akaike information criterion (AIC) and Bayesian information criterion (BIC). First, the theoretical background of the three SWCC methods is introduced. Then, the experimental data in the UNSODA database are used to carry out the research. Differences of the three methods in the determination of the SWCC model are compared from two aspects of the fitting degree and the penalty value. Results show that, for a given set of SWCC data, different optimal models can be obtained from the three methods. The optimal model selected by the Bayesian method reasonably reflects information with the consideration of model penalty while the goodness-of-fit of the optimal models obtained from AIC and BIC can be similar so that the model penalty plays key roles in model selection.


[1] Fredlund D G, Rahardjo H, Fredlund M D. Unsaturated Soil Mechanics in Engineering Practice[M]. New Jersey:John Wiley & Sons, Hoboken, 2012.
[2] 赵丽晓. 土水特征曲线的预测模型研究[D]. 南京:河海大学, 2007. ZHAO Lixiao. Research on the Prediction Model of Soil Water Characteristic Curve[D]. Nanjing:Hohai University, 2007. (in Chinese)
[3] Nam S, Gutierrez M,Diplas P, et al. Comparison of testing techniques and models forestablishing the SWCC of riverbank soils[J]. Engineering Geology, 2010, 110(1-2):1-10.
[4] Lu N,Likos W J. Unsaturated soil mechanics[M]. Wiley, 2004.
[5] Van Genuchten M T. A closed-form equation for predicting the hydraulic conductivity of unsaturated soils[J]. Soil Science Society of America Journal, 1980, 44(5):892-898.
[6] Chen J, Hopmans J W, Grismer M E. Parameter estimation of two-fluid capillary pressure-saturation and permeability functions[J]. Advances in Water Resources, 1999, 22(5):479-493.
[7] Ghezzehei T A, Kneafsey T J, Su G W. Correspondence of the Gardner and van Genuchten-Mualem relative permeability function parameters[J]. Water Resources Research, 2007, 43(10):1-7.
[8] Fredlund D G, Xing A. Equations for the soil-water characteristic curve[J]. Canadian Geotechnical Journal, 1994, 31(4):521-532.
[9] 周葆春, 孔令伟, 陈伟, 等. 荆门膨胀土土-水特征曲线特征参数分析与非饱和抗剪强度预测[J]. 岩石力学与工程学报, 2010, 29(5):1052-1059. ZHOU Baochun, KONG Lingwei, CHEN Wei, et al. Analysis of characteristic parameters of soil-water characteristic curve(swcc) and unsaturated shear strength prediction of Jingmen expansive soil[J]. Chinese Journal of Rock Mechanics and Engineering, 2010, 29(5):1052-1059. (in Chinese)
[10] 曹春山, 吴树仁, 潘懋, 等. 工程切坡诱发黄土滑坡成因机制研究[J]. 岩土力学, 2016, 37(4):1049-1060. CAO Chunshan, WU Shuren, PAN Mao, et al. Mechanism research on artificial slope cutting-induced loess landslide[J]. Rock and Soil Mechanics, 2016, 37(4):1049-1060. (in Chinese)
[11] Chiu C F, Yan W M, Yuen K V. Reliability analysis of soil-water characteristics curve and its application to slope stability analysis[J]. Engineering Geology, 2012, 135-136:83-91.
[12] Yuen K V. Recent developments of Bayesian model class selection and applications in civil engineering[J].Structural Safety, 2010, 32(5):338-346.
[13] Yuen K V. Bayesian Methods for Structural Dynamics and Civil Engineering[M]. Singapore:John Wiley & Sons(Asia) Pte Ltd, 2010.
[14] Zhou W H, Yuen K V, Tan F. Estimation of soil-water characteristic curve and relative permeability for granular soils with different initial dry densities[J]. Engineering Geology, 2014, 179:1-9.
[15] Cao Z J, Wang Y, Li D Q. Quantification of prior knowledge in geotechnical site characterization[J]. Engineering Geology, 2016(203):107-116.
[16] Gelman A, Carlin J B, Stern H S, et al. Bayesian Data Analysis[M]. Boca Raton, FL:CRC press, 2014:172-175.
[17] Cao Z J, Wang Y. Bayesian model comparis on and selection of spatial correlation functions for soil parameters[J]. Structural Safety, 2014(49):10-17.
[18] Cao Z J, Wang Y. Bayesian model comparison and characterization of undrained shear strength[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2014, 140(6):1-9(04014018).
[19] Tian M, Li D Q, Cao Z J, et al. Bayesian identification of random field model using indirect test data[J]. Engineering Geology, 2016(210):197-211.
[20] 李典庆, 唐小松, 周创兵. 基于Copula理论的岩土体参数不确定性表征与可靠度分析[M]. 北京:科学出版社, 2014:3-6. LI Dianqing, TANG Xiaosong, ZHOU Chuangbing. Uncertainty Characterization and Reliability Analysis of Rock and Soil Parameters Based on Copula Theory[M]. Beijing:Science Press, 2014. (in Chinese)
[21] Leij F J, Alves W J, van Genuchten M T, et al. The UNSODA unsaturated soil hydraulic data base user’s manual,version 1.0[R]. Cincinnati:U. S. Environmental Protection Agency, 1996.
[22] Sillers W S, Fredlund D G. Statistical assessment of soil-water characteristic curve models for geotechnical engineering[J]. Canadian Geotechnical Journal, 2001(38):1297-1313.


 CHEN Aijun,ZHANG Jiasheng.Analysis of crack development of unsaturated red clay based on linear elasticity mechanics[J].,2013,22(04):198.
 HE Bing-shun,DING Liu-qian,LIU Chang-jun.Research on abnormal seepage and failure mechanism of faced rockfill dam[J].,2009,18(04):141.
 HE Jianqing,LUO Wan,JIANG Xin,et al.Experimental study on soil-water characteristics of red clay with unsaturated high liquid limit[J].,2014,23(04):249.[doi:10.13577/j.jnd.2014.0631]


更新日期/Last Update: 1900-01-01