Floresta e Ambiente
Floresta e Ambiente
Original Article Conservation of Nature

The Effect of Roots on the Shear Strength of Texturally Distinct Soils

Charles Maffra; Rita Sousa; Fabrício Sutili; Rinaldo Pinheiro

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ABSTRACT: The aim of this work was to evaluate the roots influence on the shear strength of a clay soil and a sandy soil. Soil samples with and without roots were collected from experimental plantations of Atlantic Forest native species. The soil samples were then physically characterized and their shear strength tested in a laboratory. The results indicated that the soils’ shear strength and compressive strength were increased by the roots. In the sandy soil, roots influenced the shear strength by increasing the cohesion value (234%), while in the clay soil they influenced the shear strength mainly by increasing the cohesion value (32%) and the internal friction angle (14.4%). This information can ultimately be part of the technical justifications that ratify the use of plants in erosion control and slope stabilization works.


soil bioengineering, geotechnical engineering, rheophyte, soil-root interaction, slope stabilization


Abdullah MN, Osman N, Ali FH. Soil-root shear strength properties of some slope plants. Sains Malaysiana 2011; 40(10): 1065-1073.

Abernethy B, Rutherfurd ID. The distribution and strength of riparian tree roots in relation to riverbank reinforcement. Hydrological Processes 2001; 15(1): 63-79. http://dx.doi.org/10.1002/hyp.152.

Ahmad F, Bateni F, Azmi M. Performance evaluation of silty sand reinforced with fibres. Geotextiles and Geomembranes 2010; 28(1): 93-99. http://dx.doi.org/10.1016/j.geotexmem.2009.09.017.

Ali FH, Osman N. Shear strength of a soil containing vegetation roots. Soil and Foundation 2008; 48(4): 587-596. http://dx.doi.org/10.3208/sandf.48.587.

American Society for Testing and Materials – ASTM. D3080/D3080M: standard method for direct shear test of soils under consolidated drained conditions. West Conshohocken: ASTM; 2011.

Associação Brasileira de Normas Técnicas – ABNT. NBR 11682: estabilidade de taludes. Rio de Janeiro: ABNT; 2009.

Bischetti GB, Chiaradia EA, Simonato T, Speziali B, Vitali B, Vullo P et al. Root strength and root area ratio of forests species in Lombardy (Northern Italy). Plant and Soil 2005; 278(1): 11-22. http://dx.doi.org/10.1007/s11104-005-0605-4.

Coppin NJ, Richards IJ. Use of vegetation in civil engineering. 2nd ed. London: Construction Industry Research and Information Association; 2007.

Eab KH, Likitlersuang S, Takahashi A. Laboratory and modelling investigation of root-reinforced system for slope stabilisation. Soil and Foundation 2015; 55(5): 1270-1281. http://dx.doi.org/10.1016/j.sandf.2015.09.025.

Fiori AP, Carmignani L. Fundamentos de mecânica dos solos e das rochas: aplicações na estabilidade de taludes. 2. ed. Curitiba: UFPR; 2009.

Fredlund DG, Rahardjo H. Soil mechanics for unsaturated soils. New York: John Wiley & Sons; 1993. 544 p. http://dx.doi.org/10.1002/9780470172759.

Gerscovich DMS. Estabilidade de Taludes. 2. ed. São Paulo: Oficina de Textos; 2016.

Graf F, Frei M, Böll A. Effects of vegetation on the angle of internal friction of a moraine. Forest Snow and Landscape Research. 2009; 82(1): 61-77.

Gray DH, Ohashi H. Mechanics of fiber reinforcement in sand. Journal of Geotechnical Engineering 1983; 109(3): 335-353. http://dx.doi.org/10.1061/(ASCE)0733-9410(1983)109:3(335).

Gray DH, Sotir RB. Biotechnical and soil bioengineering slope stabilization: a practical guide for erosion control. 1st ed. New York: Wiley & Sons; 1996.

Greenwood JR. SLIP4EX: a program for routine slope stability analysis to include the effects of vegetation, reinforcement and hydrological changes. Geotechnical and Geological Engineering 2006; 24(3): 449-465. http://dx.doi.org/10.1007/s10706-005-4156-5.

Hejazi SM, Baghulizadeh AR, Nateghi M, Mardani M. Shear modeling of polypropylene-fiber-reinforced soil composite using electrical conductivity contour technique. Journal of Industrial Textiles 2015; 45(1): 133-151. http://dx.doi.org/10.1177/1528083714528014.

Jackson RB, Canadell J, Ehleringer JR, Mooney HA, Sala OE, Schulze ED. A global analysis of root distributions for terrestrial biomes. Oecologia 1996; 108(3): 389-411. http://dx.doi.org/10.1007/BF00333714. PMid:28307854.

Jiang H, Cai Y, Liu J. Engineering properties of soils reinforced by short discrete polypropylene fiber. Journal of Materials in Civil Engineering 2010; 22(12): 1315-1322. http://dx.doi.org/10.1061/(ASCE)MT.1943-5533.0000129.

Kar RK, Pradhan PK, Naik A. Effect of randomly distributed coir fibers on strength characteristics of cohesive soil. The Electronic Journal of Geotechnical Engineering 2014; 19: 1567-1583.

Kumar R, Kanaujia VK, Chandra D. Engineering behavior of fibre-reinforced pond ash and silty sand. Geosynthetics International 1999; 6(6): 509-518. http://dx.doi.org/10.1680/gein.6.0162.

Li J, Tang C, Wang D, Pei X, Shi B. Effect of discrete fibre reinforcement on soil tensile strength. Journal of Rock Mechanics and Geotechnical Engineering 2014; 6(2): 133-137. http://dx.doi.org/10.1016/j.jrmge.2014.01.003.

Liang T, Knappett JA, Bengough AG, Ke YX. Small-scale modelling of plant root systems using 3D printing, with applications to investigate the role of vegetation on earthquake-induced landslides. Landslides 2017; 14(5): 1747-1765. http://dx.doi.org/10.1007/s10346-017-0802-2.

Mattia C, Bischetti GB, Gentile F. Biotechnical characteristics of root systems of typical Mediterranean species. Plant and Soil 2005; 278(1): 23-32. http://dx.doi.org/10.1007/s11104-005-7930-5.

Moradi M, Hamidi A, Tavakoli Mehrjardi G. Shear strength of fiber-reinforced clay sands. Journal of Engineering Geology 2017; 10(4): 3767-3792. http://dx.doi.org/10.18869/acadpub.jeg.10.4.3767.

Morgan RPC, Rickson RJ. Slope stabilization and erosion control: a bioengineering approach. London: E & FN SPON; 1995. 274 p. http://dx.doi.org/10.4324/9780203362136.

Operstein V, Frydman S. The influence of vegetation on soil strength. Ground Improvement 2000; 4(2): 81-89. http://dx.doi.org/10.1680/grim.2000.4.2.81.

Prabakar J, Sridhar RS. Effect of random inclusion of sisal fibre on strength behavior of soil. Construction & Building Materials 2002; 16(2): 123-131. http://dx.doi.org/10.1016/S0950-0618(02)00008-9.

Pradhan PK, Kar RK, Naik A. Effect of random inclusion of polypropylene fibers on strength characteristics of cohesive soil. Geotechnical and Geological Engineering 2012; 30(1): 15-25. http://dx.doi.org/10.1007/s10706-011-9445-6.

Preti F, Giadrossich F. Root reinforcement and slope bioengineering stabilization by Spanish Broom (Spartium junceum L.). Hydrology and Earth System Sciences 2009; 13(9): 1713-1726. http://dx.doi.org/10.5194/hess-13-1713-2009.

Qu J, Li C, Liu B, Chen X, Li M, Yao Z. Effect of random inclusion of wheat straw fibers on shear strength characteristics of Shanghai cohesive soil. Geotechnical and Geological Engineering 2013; 31(2): 511-518. http://dx.doi.org/10.1007/s10706-012-9604-4.

Schmidt KM, Roering JJ, Stock JD, Dietrich WE, Montgomery DR, Schaub T. The variability of root cohesion as an influence on shallow landslide susceptibility in the Oregon Coast Range. Canadian Geotechnical Journal 2001; 38(5): 995-1024. http://dx.doi.org/10.1139/t01-031.

Schwarz M, Preti F, Giadrossich F, Lehmann P, Or D. Quantifying the role of vegetation in slope stability: a case study in Tuscany (Italy). Ecological Engineering 2010; 36(3): 285-291. http://dx.doi.org/10.1016/j.ecoleng.2009.06.014.

Shewbridge SE, Sitar N. Deformation characteristics of reinforced sand in direct shear. Journal of Geotechnical Engineering 1989; 115(8): 1134-1147. http://dx.doi.org/10.1061/(ASCE)0733-9410(1989)115:8(1134).

Silva RB, Dias MS Jr, Santos FL, Franz CAB. . Resistência ao cisalhamento de um Latossolo sob diferentes uso e manejo. Revista Brasileira de Ciência do Solo 2004; 28(1): 165-173. http://dx.doi.org/10.1590/S0100-06832004000100016.

Soundara B, Senthil Kumar KP. Effect of fibers on properties of clay. International Journal of Engineering and Applied Sciences 2015; 2(5): 123-128.

Stokes A, Norris JE, Van Beek LPH, Bogaard T, Cammeraat E, Mickovski SB et al. How vegetation reinforces soil on slopes. In: Norris JE, Stokes A, Mickovski SB, Cammeraat E, Van Beek R, Nicoll BC et al., editors. Slope stability and erosion control: ecotechnological solutions. Dordrecht: Springer; 2008. http://dx.doi.org/10.1007/978-1-4020-6676-4_4.

Veylon G, Ghestem M, Stokes A, Bernard A. Quantification of mechanical and hydric components of soil reinforcement by plant roots. Canadian Geotechnical Journal 2015; 52(11): 1-11. http://dx.doi.org/10.1139/cgj-2014-0090.

Waldron LJ. Shear resistance of root-permeated homogeneous and stratified soil. Soil Science Society of America Journal 1977; 41(5): 843-849. http://dx.doi.org/10.2136/sssaj1977.03615995004100050005x.

Wu TH. Root reinforcement of soil: review of analytical models, test results, and applications to design. Canadian Geotechnical Journal 2013; 50(3): 259-274. http://dx.doi.org/10.1139/cgj-2012-0160.

Wu TH, Kokesh CM, Trenner BR, Fox PJ. Use of live poles for stabilization of a shallow slope failure. Journal of Geotechnical and Geoenvironmental Engineering 2014; 140(10): 1-13. http://dx.doi.org/10.1061/(ASCE)GT.1943-5606.0001161.

Wu TH, McKinnell WP 3rd, Swanston DN. Strength of tree roots and landslides on Prince of Wales Island, Alaska. Canadian Geotechnical Journal. 1979; 16(1): 19-33. http://dx.doi.org/10.1139/t79-003.

Wu TH, McOmber RM, Erb RT, Beal PE. Study of soil-root interaction. Journal of Geotechnical Engineering 1988; 114(12): 1351-1375. http://dx.doi.org/10.1061/(ASCE)0733-9410(1988)114:12(1351).

Wu TH, Watson A. In-situ shear tests of soil blocks with roots. Canadian Geotechnical Journal 1998; 35(4): 579-590. http://dx.doi.org/10.1139/t98-027.

Yetimoglu T, Salbas O. A study on shear strength of sands reinforced with randomly distributed discrete fibers. Geotextiles and Geomembranes 2003; 21(2): 103-110. http://dx.doi.org/10.1016/S0266-1144(03)00003-7.

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