Slope Stability Analysis after Decline of Water Level at the River Meander Considering Strain and Monte-Carlo Probabilistic Method

Authors

1 Assist. Prof., Dept. of Water Engin., College of Agricultural Sciences, University of Guilan, Rasht, Iran

2 Graduated M.Sc. of Water Structures, Dept. of Water Engin., University of Guilan, Rasht, Iran

Abstract

While investigating the stability of slopes at the rivers, uncertainty of soil shear strength parameters and their spatial variations affect the accuracy of results. Nowadays, probabilistic analyses are adopted to understand the probability of slope stability as the complementary methods. Throughout the current research on the meanders in Shalmanrood river of Guilan, the probabilistic analysis using Monte-Carlo method was carried out after field and laboratory studies on the soil. Accordingly, the pore pressure and strain under unsteady condition were modeled using finite element method. Then the slope stability was evaluated combining Monte-Carlo and limit equilibrium methods and compared with other researches’ results. The results showed that at meandering section 2 (the highest curvature), pore water pressure was dissipated in low rate after decline of the water level at the river. Additionally, results of strain analysis demonstrated that at the water elevations lower than normal level, swelling and compression occurred in meanders with slight and high curvatures, respectively. The probabilistic analysis with Monte-Carlo method applying Ordinary Slice method approximated the probability of slope failure within a bigger time span, as compared to Morgenstern-Price method. Meanwhile by decrease of the water level in river, the probability density function (PDF) of the safety factor showed a descending trend within 9.6 hours. In meander with the maximum curvature (section 2), a bigger temporal variations were observed in the position of PDF of safety factor, as compared to the minimum curvature (section 4).

Keywords

References

Burman A, Acharya SP, Sahay RR and Maity D, 2015. A comparative study of slope stability analysis using traditional limit equilibrium method and finite element method. Asian Journal of Civil Engineering 16 (4): 467-492.
Esmaili Varaki M, Zamani A and Kazemi Rad M, 1391. Numerical simulation of different alternatives of river modification in meandering rivers. Pp. 164-173. Proceedings of the Eleventh Iranian Hydraulic Conference. 6-8 November, Urmia, Iran. 
Fredlund DG and Krahn J, 1977. Comparison of slope stability methods of analysis. Canadian Geotechnical Journal 14 (3): 429-439.
Gibson W, 2011.Probabilistic methods for slope analysis and design. Australian Geomechanics 46 (3):1-12.
Kok ST and Kim HB, Noorzaie J, Jaafar MS and Gue SS, 2009. A review of basic soil constitutive models for geotechnical application. Electronic Journal of Geotechnical Engineering 14:1-18.
Parker C, Simon AR, Thorne R, 2008. The effects of variability in bank material properties on riverbank stability: Goodwin Creek, Mississippi. Geomorphology 101:533-543.
Pirestani MR, Sadatmoosavi Anari SA and Salehi Neishaboori SA, 1391. Numerical simulation of flow pattern on develoment amount of meandering river. Journal of Water Resources Engineering 5(12):1-18.
Rahbar D and Mahboobi Ardakani A, 1392. Evaluation of slope stability using discrete deformation analysis DDA method. Pp. 18-26. Proceedings of the Seventeenth National Civil Engineering Conference. 7-8 May, Zahedan, Iran.
Wang Y, Zhao T and Cao Z, 2015. Site specific probability distribution of geotechnical properties. Computers and Geotechnics 70: 159-168.
Zahiri A, Amini R and Kordi H., 1391. Numerical simulation of velocity lateral distribution in meandering compound channels.Journal of Water and Soil Conservation 19(3): 201-218.
Zhang G and Zhang JM, 2007. Simplified method of stability evaluation for strain-softening slopes. Journal of Mechanics Research Communication 34(5-6): 444-450.
Water and Soil Science
Volume 28, Issue 2
May 2018
Pages 1-13

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