The Investigation and 3D Numerical Simulation of Herb Roots in Reinforcing Soil and Stabilizing Slope

다국어 초록 (Multilingual Abstract)

This paper investigated and simulated the mechanical effect of root reinforcing soil and stabilizing slope. The unconfined compression test was used to investigate the reinforcement soil behavior of herb roots. This paper used the 3D finite element to quantify the mechanical effect of the herb root for slope’s stability in terms of the safety factor. The soil was simulated by an elasticplastic model, and the root was simulated by a linear elastic model. Results show that using the Root Content (RC) to estimate the additional cohesion cr of Setaria sphacelata and Orchardgrass was a simple and reliable method. Lateral fine roots can play a more significant role in reinforcing soils and slopes. Compared to various slope angles, the steep slope was less stable. The slope existed a slope angle threshold αthr. When the slope angle α was smaller than αthr, the herb root system can improve the stability of slope. The α existed an optimal angle αopt for the root system. When α = αopt and α < αthr, the herb roots can exert its maximum stabilization capacity. Moreover, we can select herb species with lateral fine roots and more roots in deeper soil layer. Results can better estimate the cr for the herb of lateral fine roots and select the herb and the slope’s geometry in the engineering.

참고문헌 (Reference)

1 Donald Kleinfelder, "Unconfined Compressive Strength of Some Streambank Soils with Herbaceous Roots" Soil Science Society of America 56 (56): 1920-1925, 1992

2 Chao-Bo Zhang, "Triaxial compression test of soil–root composites to evaluate influence of roots on soil shear strength" Elsevier BV 36 (36): 19-26, 2010

3 Zhun Mao, "Three-dimensional modelling of slope stability in heterogeneous montane forest ecosystems" Elsevier BV 273 (273): 11-22, 2014

4 K.M. Schmidt, "The variability of root cohesion as an influence on shallow landslide susceptibility in the Oregon Coast Range" Canadian Science Publishing 38 (38): 995-1024, 2001

5 G.T. Tengbeh, "The effect of grass roots on shear strength variations with moisture content" Elsevier BV 6 (6): 287-295, 1993

6 E. Comino, "The effect of Poaceae roots on the shear strength of soils in the Italian alpine environment" Elsevier BV 106 (106): 194-201, 2010

7 L. J. Waldron, "The Shear Resistance of Root-Permeated Homogeneous and Stratified Soil1" Soil Science Society of America 41 (41): 843-849, 1977

8 Marie Genet, "The Influence of Cellulose Content on Tensile Strength in Tree Roots" Springer Nature 278 (278): 1-9, 2005

9 Natasha Pollen, "Temporal and spatial variability in root reinforcement of streambanks: Accounting for soil shear strength and moisture" Elsevier BV 69 (69): 197-205, 2007

10 Tien H. Wu, "Strength of tree roots and landslides on Prince of Wales Island, Alaska" Canadian Science Publishing 16 (16): 19-33, 1979

11 Chia-Cheng Fan, "Spatial distribution of plant root forces in root-permeated soils subject to shear" Elsevier BV 156 : 1-15, 2016

12 Ali, F. H., "Soil-roots composite: Correlation between shear strength and some plant properties" Engineering Village 12D : 2007

13 L. J. WALDRON, "Soil reinforcement by roots:Calculation of increased soil shear resistance from root properties" Ovid Technologies (Wolters Kluwer Health) 132 (132): 427-435, 1981

14 Nomessi Kuma Kokutse, "Slope stability and vegetation: Conceptual and numerical investigation of mechanical effects" Elsevier BV 86 : 146-153, 2016

15 Slobodan B. Mickovski, "Simulation of direct shear tests on rooted and non-rooted soil using finite element analysis" Elsevier BV 37 (37): 1523-1532, 2011

16 B Zhang, "Shear strength of surface soil as affected by soil bulk density and soil water content" Elsevier BV 59 (59): 97-106, 2001

17 M. Schwarz, "Root-soil mechanical interactions during pullout and failure of root bundles" American Geophysical Union (AGU) 115 (115): 701-719, 2010

18 Gian Battista Bischetti, "Root Strength and Root Area Ratio of Forest Species in Lombardy (Northern Italy)" Springer Nature 278 (278): 11-22, 2005

19 Chia-Cheng Fan, "Role of roots in the shear strength of root-reinforced soils with high moisture content" Elsevier BV 33 (33): 157-166, 2008

20 Mohammad S. Islam, "Reinforcing effect of vetiver (Vetiveria zizanioides) root in geotechnical structures - experiments and analyses" Techno-Press 5 (5): 313-329, 2013

21 Andrew Simon, "Quantifying the mechanical and hydrologic effects of riparian vegetation on streambank stability" Wiley 27 (27): 527-546, 2002

22 Ehsan Abdi, "Quantifying the effects of root reinforcement of Persian Ironwood (Parrotia persica) on slope stability; A case study: Hillslope of Hyrcanian forests, northern Iran" Elsevier BV 36 (36): 1409-1416, 2010

23 M. Bordoni, "Quantifying the contribution of grapevine roots to soil mechanical reinforcement in an area susceptible to shallow landslides" Elsevier BV 163 : 195-206, 2016

24 Joseph F. Labuz, "Mohr–Coulomb Failure Criterion" Springer Nature 45 (45): 975-979, 2012

25 Robert E. Thomas, "Modeling root-reinforcement with a fiber-bundle model and Monte Carlo simulation" Elsevier BV 36 (36): 47-61, 2010

26 Guillermo Tardío, "Method for synchronisation of soil and root behaviour for assessment of stability of vegetated slopes" Elsevier BV 82 : 222-230, 2015

27 Donald H. Gray, "Mechanics of Fiber Reinforcement in Sand" American Society of Civil Engineers (ASCE) 109 (109): 335-353, 1983

28 Warrey K. Wray, "Measuring Engineering Properties of Soil" ASME International 108 (108): 378-, 1986

29 Chia-Cheng Fan, "Influence of the spatial layout of vegetation on the stability of slopes" Springer Nature 377 (377): 83-95, 2014

30 Nuno Cristelo, "Influence of discrete fibre reinforcement on the uniaxial compression response and seismic wave velocity of a cement-stabilised sandy-clay" Elsevier BV 43 (43): 1-13, 2015

31 Yang, Y., "In-situ measurement and model prediction of fixing soil capabilities for three industrial biogas crops roots" 31 (31): 1103-1110, 2016

32 G. Gyssels, "Impact of plant roots on the resistance of soils to erosion by water: a review" SAGE Publications 29 (29): 189-217, 2016

33 Matsui, T., "Finite element slope stability analysis by shear strength reduction technique" 32 (32): 59-70, 1992

34 차경섭, "Evaluation of Slope Stability with Topography and Slope Stability Analysis Method" 대한토목학회 15 (15): 251-256, 2011

35 Natasha Pollen, "Estimating the mechanical effects of riparian vegetation on stream bank stability using a fiber bundle model" American Geophysical Union (AGU) 41 (41): 226-244, 2005

36 M. Fattet, "Effects of vegetation type on soil resistance to erosion: Relationship between aggregate stability and shear strength" Elsevier BV 87 (87): 60-69, 2011

37 Rickli, C., "Effects of forests on shallow landslides - Case studies in Switzerland" 82 : 33-44, 2009

38 Li, "Effectiveness of plant roots in the Loess Plateau to improve soil erosion resistance" 36 (36): 935-938, 1991

39 Jinnan Ji, "Effect of spatial variation of tree root characteristics on slope stability. A case study on Black Locust (Robinia pseudoacacia) and Arborvitae (Platycladus orientalis) stands on the Loess Plateau, China" Elsevier BV 92 (92): 139-154, 2012

40 Alexia Stokes, "Desirable plant root traits for protecting natural and engineered slopes against landslides" Springer Nature 324 (324): 1-30, 2009

41 Timon Rabczuk, "A simple and robust three-dimensional cracking-particle method without enrichment" Elsevier BV 199 (199): 2437-2455, 2010

42 Lionel Dupuy, "A Numerical Investigation into the Influence of Soil Type and Root Architecture on Tree Anchorage" Springer Nature 278 (278): 119-134, 2005

43 Hang Lin, "A Dimensionless Parameter Determining Slip Surfaces in Homogeneous Slopes" 대한토목학회 18 (18): 470-474, 2014

44 André Guy Tranquille Temgoua, "A 3D model applied to analyze the mechanical stability of real-world forested hillslopes prone to landslides" Elsevier BV 106 : 609-619, 2017

45 Der-Guey Lin, "3-D numerical investigations into the shear strength of the soil–root system of Makino bamboo and its effect on slope stability" Elsevier BV 36 (36): 992-1006, 2010