Geo-Congress 2020
A Mathematical Model for Shear Strength Prediction of Vetiver Rooted Soil
Publication: Geo-Congress 2020: Engineering, Monitoring, and Management of Geotechnical Infrastructure (GSP 316)
ABSTRACT
The role of vegetation in the stability of slopes has expanded recognition in the last few decades. Performance of plants in stabilizing slopes is closely linked to the variation of the shear strength of root-reinforced soils. Vetiver grass (locally known as binna or binna shoba) is mostly available in Bangladesh. An attempt has been made in this study to develop a mathematical model for predicting the shear strength contribution by root of vetiver rooted soil. The mean tensile strength of matured vetiver root was found to be 27 MPa. The shear strength parameters of vetiver rooted soil were determined by in situ shear strength tests. Tests were conducted in the field on 9 block samples under same normal load at same soil depth using a special device developed in the study. Additional shear strength for rooted soil was determined by comparing with bare sample. The obtained relationship between the additional shear strength provided by roots (Δs) and the tensile strength of roots per unit area of soils (tR) is approximately linear. Based on the experimental observation, a mathematical model (Δs=5.14tR) was developed to predict the additional shear strength of soil-root system. This simple, straightforward model will provide a convenient mean for stability analysis of vegetated slopes.
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ACKNOWLEDGEMENT
The authors acknowledge the infrastructural and financial support received from Bangladesh University of Engineering and Technology (BUET), Dhaka, Bangladesh for carrying out the research work.
REFERENCES
Badhon, F.F. (2018). “Development of a mathematical model for quantifying the effect of root reinforcement on shear strength of soil” M.Sc. Engg. Thesis, Department of Civil Engineering, Bangladesh University of Engineering and Technology, Dhaka-1000, Bangladesh.
Badhon, F.F., Islam, M.S. and Al-Hussaini, T.M. (2019). “Study of root-reinforcement effect on shear strength parameters of soil obtained by direct shear tests”, Proceedings, International Conference on Disaster Risk Mitigation, Dhaka, Bangladesh, January 12-14, 2019
Cammeraat, E., Beek, R.V., and Kooijman, A. (2005). “Vegetation succession and its consequences for slope stability in SE Spain,” Plant and Soil, vol. 278, pp. 135-147.
Coppin, N.J. and Richards, I.G. (1990). "Use of vegetation in civil engineering", Construction Industry Research and Information Association, Butterworths, London.
Das, S.C. and Tanak, N. (2009) “The Effectiveness of Vetiver Grass in Controlling Water Borne Erosion in Bangladesh”. The 11th International Summer Symposium, JSCE, Tokyo, Japan, pp.69-72.
Fan, C. and Su, C. (2008). “Role of roots in the shear strength of root-reinforced soils with high moisture content”. Ecological Engineering vol. 33, pp. 157-166.
Gray, D.H. and Leiser, A.T. (1982). “Biotechnical Slope Protection and Erosion Control”. New York, Van Nostrand Reinhold.
Greenway, D.R. (1987). “Vegetation and slope stability, In: Slope stability”, edited by M.F. Anderson and Richards, K.S., New York: Wiley.
Hengchaovanich, D. (1998). “Vetiver grass for slope stabilization and erosion control” Tech. Bull. No. 1998/2, PRVN/ORDPB, Bangkok, Thailand.
Islam, M.S., Arif, M.Z.U., Badhon, F.F., Mallik, S., and Islam, T. (2016). “Investigation of Vetiver Root Growth in Sandy Soil,” in BUET-ANWAR ISPAT 1st Bangladesh Civil Engineering SUMMIT, Dhaka, Bangladesh.
Islam, M.A. (2018) “Measures for landslide prevention in chittagong hill tracts of bangladesh.” M.Sc. Eng. Thesis, Dept. of Civil Eng., Bangladesh University of Engineering and Technology (BUET).
Islam, M.S. and Arifuzzaman. (2010). “In situ shear strength of Vetiver rooted soil”, Bangladesh Geotechnical Conference 2010: Natural Hazards and Countermeasures in Geotechnical Engineering Dhaka, Bangladesh, pp. 274-279.
Islam, M.S. and Badhon, F.F. (2017). “Sandy slope stabilization using vegetation”, Proceedings, International Conference on Disaster Risk Mitigation, Dhaka, Bangladesh, September 23-24, 2017
Islam, M.S. and Islam, M.A. (2018). “Reduction of landslide risk and water-logging using vegetation”, International Conference on Civil and Environmental Engineering (ICCEE2018), Kuala Lumpur, Malaysia, Paper No. 197.
Islam, M.S., Arifuzzaman and Nasrin, S. (2010). “In situ shear strength of vetiver grass rooted soil,” in Bangladesh Geotechnical Conference: Natural Hazards and Counter Measures in Geotechnical Engineering, Dhaka, Bangladesh.
Operstein, V., Frydman, S. (2000). The influence of vegetation on soil strength. Ground Improve, vol. 4, pp. 81–89.
Tosi, M. (2007). “Root tensile strength relationships and their slope stability implications of three shrub species in the Northern Apennines (Italy)”. Geomorphology 87:268–283
Voottipruex, P., Bergado, D., Mairaeng, W., Chucheepsakul, S., and Modmoltin, C. (2008). “Soil Reinforcement with combination roots system: a case study of vetiver grass and acacia mangium wild,” Lowland Technology International, vol. 10, no. 2, pp. 56-67.
Waldron, L.J. (1977). “The shear resistance of root-permeated homogeneous and stratified soil”. Soil Science Society of American Proceedings 41: 834-849.
Waldron, L.J. and Dakessian, S. (1981). “Soil reinforcement by roots: calculation of increased soil shear strength from root properties”. Soil Science, vol. 132, no.6, pp. 427–435.
Wu, T.H. (1976). “Investigation of landslides on Prince of Wales, Island”. Alaska Geotechnical Engineering Report No. 5, Department of Civil Engineering, Ohio State University, Columbus OH, 94 pp.
Wu, T.H. and Watson, A. (1998). “In situ shear tests of soil blocks with roots”. Canadian. Geotechnical Journal vol. 35, no.4 pp.579–590.
Wu, T.H., McKinell, W.P. and Swaston, D.N. (1979). “Strength of tree roots and landslides on Prince of Wales Island, Alaska”. Canadian Geotechnical Journal vol. 16 no. 1; pp. 19-33.
Information & Authors
Information
Published In
Geo-Congress 2020: Engineering, Monitoring, and Management of Geotechnical Infrastructure (GSP 316)
Pages: 96 - 105
Editors: James P. Hambleton, Ph.D., Northwestern University, Roman Makhnenko, Ph.D., University of Illinois at Urbana-Champaign, and Aaron S. Budge, Ph.D., Minnesota State University, Mankato
ISBN (Online): 978-0-7844-8279-7
Copyright
© 2020 American Society of Civil Engineers.
History
Published online: Feb 21, 2020
ASCE Technical Topics:
- Ecosystems
- Engineering fundamentals
- Environmental engineering
- Field tests
- Geomechanics
- Geotechnical engineering
- Material mechanics
- Material properties
- Materials engineering
- Mathematical models
- Mathematics
- Models (by type)
- Shear strength
- Soil dynamics
- Soil mechanics
- Soil properties
- Soil stabilization
- Soil strength
- Strength of materials
- Tensile strength
- Tests (by type)
- Vegetation
Authors
Metrics & Citations
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