基于代表体元法的根土复合体本构计算与验证

doi:10.16843/j.sswc.2023.02.013

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Abstract [Background] Tree roots can inhibit shallow landslides. Quantitative evaluation of the effect of root reinforcement is a key step for assessing the effectiveness of vegetation in slope stabilization. The traditional calculation method of root-soil composites did not consider the influence of roots on the elastic parameters of root-soil composites. Meanwhile, it is difficult to calculate a slope with a large number of roots. In fact, trees are often planted in a spatial layout of regular planting arrangement on slopes to create plantations; thus, this research treats periodically arranged tree roots and the surrounding soil as a periodic composite.[Methods] The representative volume element (RVE) method was introduced to directly construct the three-dimensional constitutive relation of root-soil composites. The theoretical results obtained by the RVE method were verified by direct shear tests and repeated shear tests with length-varied roots. The roots and soil used in the test were collected in Jixian, Shanxi. The application feasibility of the equivalent mechanical properties of the root-soil composite obtained by the RVE method to evaluate the slope stability was verified by numerical simulation.[Results] The RVE method can be used to accurately evaluate the equivalent elastic properties of root-soil composites, and the improvement rate of the shear elastic modulus is only 0.24% higher than the repeated shear test. The difference for cohesion c and internal friction angle φ is only 2.45 kPa and 3°, respectively. The cohesion calculated by the Wu model is overestimated about 5 times compared to the test results. Compared with the pure soil slope, the safety factor of the vegetated slope with the test data increases by 7.20% and the RVE slope model increases by 9.78%, while the safety factor of the slope with the Wu model increase by 29.33%. The Wu model has the risk of overestimating the slope stability compared with the RVE model.[Conclusions] The RVE method can accurately predict the alterations of the elastic parameters and strength parameters c and φ of the root-soil composite. The strengthening effect of roots on the soil not only improves the cohesion, but also changes the internal friction angle and elastic parameters. RVE method combined with numerical simulation provide new method and technical means to realize the stable calculation of the slope with a large number of roots.

Key words： representative volume element method root reinforcement direct shear test slope stability equivalent mechanical parameters

Received: 22 March 2022

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TU457

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	Articles by authors
	LI Shaoling
	HUANG Jiankun
	JI Jinnan
	CHEN Lihua

Cite this article:

LI Shaoling,HUANG Jiankun,JI Jinnan, et al. Calculation and validation of the constitutive relation for root-soil composite based on representative volume element method[J]. SSWC, 2023, 21(2): 107-116.

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http://journal12.magtechjournal.com/Jweb_stbc/EN/10.16843/j.sswc.2023.02.013 OR http://journal12.magtechjournal.com/Jweb_stbc/EN/Y2023/V21/I2/107

[1]	PHILLIPS C, HALES T, SMITH H, et al. Shallow landslides and vegetation at the catchment scale:A perspective[J].Ecological Engineering, 2021(173):106436.
[2]	田佳, 韩磊, 金学娟, 等. 用有限元法研究降雨对青海云杉林边坡稳定性的影响[J].中国水土保持科学, 2019, 17(6):11. TIAN Jia, HAN Lei, JIN Xuejuan, et al. Effect of rainfall on slope stability of Picea crassifolia forest based on finite element method in Qinghai[J]. Science of Soil and Water Conservation, 2019, 17(6):11.
[3]	MEIJER G J. A generic form of fibre bundle models for root reinforcement of soil[J]. Plant and Soil, 2021(468):45
[4]	LIANG T, KNAPPETT J A, LEUNG A, et al. A critical evaluation of predictive models for rooted soil strength with application to predicting the seismic deformation of rooted slopes[J]. Landslides, 2020, 17(1):93.
[5]	WU T H, MCKINNELL III W P, SWANSTON D N. Strength of tree roots and landslides on Prince of Wales Island, Alaska[J]. Canadian Geotechnical Journal, 1979, 16(1):19.
[6]	POLLEN N, SIMON A. Estimating the mechanical effects of riparian vegetation on stream bank stability using a fiber bundle model[J]. Water Resources Research, 2005, 41(7):226.
[7]	JI Jinnan, MAO Zhun, QU Wenbin, et al. Energy-based fibre bundle model algorithms to predict soil reinforcement by roots[J]. Plant and Soil, 2020, 446(1):307.
[8]	吕春娟, 陈丽华, 陈卫国, 等. 根土复合体的抗剪特性研究[J]. 灌溉排水学报, 2016, 35(3):13. LV Chunjuan, CHEN Lihua, CHEN Weiguo, et al. Study on shear performance of soil-root composite[J]. Journal of Irrigation and Drainage, 2016, 35(3):13.
[9]	ZHU Jinqi, WANG Yunqi, WANG Yujie, et al. How does root biodegradation after plant felling change root reinforcement to soil?[J]. Plant and Soil, 2020, 446(1):211
[10]	及金楠, 田佳, 瞿文斌. 基于连续断裂过程的根系黏聚力Wu氏模型修正系数的确定[J].林业科学, 2017, 53(11):170. JI Jinnan, TIAN Jia, QU Wenbin. Determination of correction coefficients of Wu's model of root cohesion based on successive fracture process[J]. Scientia Silvae Sinicae, 2017, 53(11):170.
[11]	COHEN D, SCHWARZ M. Tree-root control of shallow landslides[J]. Earth Surface Dynamics, 2017, 5(3):451.
[12]	SWITALA B M, WU W J G. Numerical modelling of rainfall-induced instability of vegetated slopes[J].Geotechnique, 2018, 68(6):481.
[13]	黄建坤, 王学林, 及金楠, 等. 基于渐近均匀化理论的黄土高原草本植物固土效果数值分析[J].农业工程学报, 2020, 36(9):168. HUANG Jiankun, WANG Xuelin, JI Jinnan, et al. Numerical simulation of root reinforcement for herbs in Loess Plateau based on asymptotic homogenization theory[J]. Transactions of the CSAE, 2020, 36(9):168.
[14]	陈玉丽, 马勇, 潘飞, 等. 多尺度复合材料力学研究进展[J]. 固体力学学报, 2018, 39(1):1. CHEN Yuli, MA Yong, PAN Fei, et al. Research progress in multi-scale mechanics of composite materials[J]. Chinese Journal of Solid Mechanics, 2018, 39(1):1.
[15]	杨璞, 向志海, 胡夏嵩, 等. 根对土壤加强作用的研究[J]. 清华大学学报:自然科学版, 2009, 49(2):305. YANG Pu, XIANG Zhihai, HU Xiasong, et al. Soil reinforcement by vegetation roots[J]. Journal of Tsinghua University:Science and Technology, 2009, 49(2):305.
[16]	陈丽华, 及金楠, 冀晓东, 等. 林木根系基本力学性质[M]. 北京:科学出版社, 2012:121. CHEN Lihua, JI Jinnan, JI Xiaodong, et al. Mechanics of root-soil[M]. Beijing:Science Press, 2012:121.
[17]	OMAIREY S L, DUNNING P D, SRIRAMULA S. Development of an ABAQUS plugin tool for periodic RVE homogenisation[J]. Engineering with Computers, 2019, 35(2):567.
[18]	瞿文斌, 及金楠, 陈丽华, 等. 黄土高原植物根系增强土体抗剪强度的模型与试验研究[J]. 北京林业大学学报, 2017, 39(12):79. QU Wenbin, JI Jinnan, CHEN Lihua, et al. Research on model and test of reinforcing shear strength by vegetation roots in the Loess Plateau of northern China[J]. Journal of Bejing Forestry Unitersity, 2017, 39(12):79.
[19]	吕庆, 孙红月, 尚岳全. 强度折减有限元法中边坡失稳判据的研究[J].浙江大学学报(工学版), 2008, 42(1):83. LV Qing, SUN Hongyue, SHANG Yuequan. Slope failure criteria of shear strength reduction finite element method[J]. Journal of Zhejiang University (Engineering Science), 2008, 42(1):83.