Geomechanics and Engineering

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Investigation of slope reinforcement with drilled shafts in colluvium soils

  • Lia, An-Jui (Department of Civil and Construction Engineering, National Taiwan University of Science and Technology) ;
  • Wang, Wei-Chien (Department of Civil and Construction Engineering, National Taiwan University of Science and Technology) ;
  • Lin, Horn-Da (Department of Civil and Construction Engineering, National Taiwan University of Science and Technology)
  • Received : 2021.05.03
  • Accepted : 2022.09.18
  • Published : 2022.10.10
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Abstract

In Taiwan, an efficient approach for enhancing the stability of colluvium slopes is the drilled shaft method. For slopes with drilled shafts, the soil arching effect is one of the primary factors influencing slope stability and intertwines to the failure mechanism of the pile-soil system. In this study, the contribution of soil arching effect to slope stability is evaluated using the FEM software (Plaxis 3D) with the built-in strength reduction technique. The result indicates the depth of the failure surface is influenced by the S/D ratio (the distance to the diameter of piles), which can reflect the contribution of the soil arching effect to soil stability. When α (rock inclination angles)=β (slope angles) is considered and the S/D ratio=4, the failure surface of the slope is not significantly influenced by the piles. Overall, the soil arching effect is more significant on α=β, especially for the steep slopes. Additionally, the soil arching effect has been included in the proposed stability charts. The proposed charts were validated through two case studies, including that of the well-known Woo-Wan-Chai field in Taiwan. The differences in safety factor (FoS) values between the referenced literature and this study was approximately 4.9%.

Keywords

Acknowledgement

The authors thank Land Engineering Consultants Co., Ltd. for providing information and investigation reports on the Woo-Wan-Chai case. The financial support provided by the Ministry of Science and Technology, Taiwan, is also gratefully acknowledged.

References

  1. Ashour, M. and Ardalan, H. (2012), "Analysis of pile stabilized slopes based on soil-pile interaction", Comput. Geotech., 39, 85-97. https://doi.org/10.1016/j.compgeo.2011.09.001.
  2. Ausilio, E., Conte, E. and Dente, G. (2001), "Stability analysis of slopes reinforced with piles", Comput. Geotech., 28, 591-611. https://doi.org/10.1016/S0266-352X(01)00013-1.
  3. Bell, J.M. (1966), "Dimensionless parameters for homogeneous earth slopes", J. Soil Mech. Found. Div., 92(5), 51-65. https://doi.org/10.1061/JSFEAQ.0000910
  4. Boulfoul, K., Hammoud, F. and Abbeche, K. (2020), "Numerical study on the optimal position of a pile for stabilization purpose of a slope", Geomech. Eng., 21(5), 401-411. http://doi.org/10.12989/gae.2020.21.5.401.
  5. Brinkgreve, R.B.J., Swolfs, W.M. and Engin, E. (2016), PLAXIS 3D 2016-User Manual, Delft, The Netherlands.
  6. Bryan, A.M. and Brian, B.S. (2014), "Pile group settlement estimation: Suitability of nonlinear interaction factors", Int. J. Geomech., 13(3). https://doi.org/10.1061/(ASCE)GM.1943-5622.0000395.
  7. Cai, F. and Ugai, K. (2000), "Numerical analysis of the stability of a slope reinforced with piles", Soil. Found., 40(1), 73-84. https://doi.org/10.3208/sandf.40.73.
  8. Chen, C.Y. and Martin, G.R. (2002), "Soil-structure interaction for landslide stabilizing piles", Comput. Geotech., 29, 363-386. https://doi.org/10.1016/S0266-352X(01)00035-0.
  9. Cho, G.C. (2016), "Geotechnical engineering for sustainable development", Proceedings of the 2016 World Congress on Advances in Civil, Environmental and Materials Research (ACEM16), Jeju, Korea, August.
  10. Chow, Y.K. (1996), "Analysis of piles used for slope stabilization", Int. J. Numer. Anal. Meth. Geomech., 20(9), 635-646. https://doi.org/10.1002/(SICI)1096-9853(199609)20:9<635::AID-NAG839>3.0.CO,2-X.
  11. Dao, T.P.T. (2011), "Validation of PLAXIS embedded piles for lateral loading", Master Thesis, Delft University of Technology, The Netherlands.
  12. Deng, D.P., Li, L. and Zhao, L.H. (2019), "Stability analysis of slopes under groundwater seepage and application of charts for optimization of drainage design", Geomech. Eng., 17(2), 181-194. https://doi.org/10.12989/gae.2019.17.2.181.
  13. Design Code (2019), Design Specifications for Concrete Structures, Construction and Planning Agency Ministry of the Interior, Taiwan.
  14. Donald, I.B. and Giam, S.K. (1988), "Application of the nodal displacement method to slope stability analysis", Proceedings of the 5th Australia-New Zealand Conference on Geomechanics. Sydney, Australia.
  15. Gholampour, A. and Johari, A. (2019), "Reliability-based analysis of braced excavation in unsaturated soils considering conditional spatial variability", Comput. Geotech., 115, 103163. https://doi.org/10.1016/j.compgeo.2019.103163.
  16. Griffiths, D.V. and Lane, P.A. (1999), "Slope stability by finite elements", Geotechnique, 49(3), 387-403. https://doi.org/10.1680/geot.1999.49.3.387.
  17. Hassiotis, S., Chameau, J.L. and Gunaratne, M. (1997), "Design method for stabilization of slopes with piles", J. Geotech. Geoenviron. Eng., 123(4), 314-323. https://doi.org/10.1061/(ASCE)1090-0241(1997)123:4(314).
  18. Holtz, R.D., Kovacs, W.D. and Sheahan, T.C. (2010), An Introduction to Geotechnical Engineering, 2nd Edition, Upper Saddle River, NJ, Pearson Prentice-Hall.
  19. Hou, C., Zhang, T., Sun, Z., Dias, D., and Li, J. (2019), "Discretization technique for stability analysis of complex slopes", Geomech. Eng., 17(3), 227-236. http://doi.org/10.12989/gae.2019.17.3.227.
  20. Hu, X., Zhou, C., Xu, C, Liu, D., Wu, S. and Li, L. (2019), "Model tests of the response of landslide-stabilizing piles to piles with different stiffness", Landslid., 16, 2187-2200. https://doi.org/10.1007/s10346-019-01233-4.
  21. Ito, T. and Matsui, T. (1975), "Methods to estimate lateral force acting on stabilizing piles", Soil. Found., 15(4), 43-59. https://doi.org/10.3208/sandf1972.15.4_43.
  22. Jalili, J. and Moosavi, M. (2019), "Evaluation of the truncated soldier pile behavior in an anchored deep excavation case study by the aid of 3d and 2d finite element analyses", J. GeoEng., 14(3), 191-202. http://doi.org/10.6310/jog.201909_14(3).7.
  23. Jeng, C.J. and Su, D.Z. (2016), "Characteristics of ground motion and threshold values for colluvium slope displacement induced by heavy rainfall: a case study in northern Taiwan", Nat. Hazard. Earth Syst Sci., 16, 1309-1321. https://doi.org/10.5194/nhess-16-1309-2016.
  24. Johari, A. and Kalantari, A.R. (2021), "System reliability analysis of soldier-piled excavation in unsaturated soil by combining random finite element and sequential compounding methods", Bull. Eng. Geol. Environ., 80, 2585-2507. https://doi.org/10.1007/s10064-020-02022-3.
  25. Johari, A., Hajivand, A.K. and Binesh, S. (2020), "System reliability analysis of soil nail wall using random finite element method", Bull. Eng. Geol. Environ., 79, 2777-2798. https://doi.org/10.1007/s10064-020-01740-y.
  26. Kim, Y.H. and Jeong, S.S. (2011), "Analysis of soil resistance on laterally loaded piles based on 3D soil-pile interaction", Comput. Geotech., 38, 248-257. https://doi.org/10.1016/j.compgeo.2010.12.001.
  27. Land Engineering Consultants Co., Ltd. (2006), "Fieldwork report of Woo-wan-chai landslide area, 28km+900-31 km+500, Province Road 18", Report to Fifth District, Directorate General Highway, Taiwan. (in Chinese)
  28. Lee, C.Y., Hull, T.S. and Poulos, H.G. (1995), "Simplified pile-slope stability analysis", Comput. Geotech., 17, 1-16. https://doi.org/10.1016/0266-352X(95)91300-S.
  29. Lee, D.H, Lai, M.H., Wu, J.H., Chi, Y.Y., Ko, W.T. and Lee, B.L. (2013), "Slope management criteria for Alishan Highway based on database of heavy rainfall-induced slope failures", Eng. Geol., 162, 97-107. https://doi.org/10.1016/j.enggeo.2013.04.012.
  30. Li, L. and Liang, R.Y. (2014), "Reliability-based design for slopes reinforced with a row of drilled shafts", Int. J. Numer. Anal. Meth. Geomech., 38, 202-220. https://doi.org/10.1002/nag.2220.
  31. Li, X., Pei, X., Gutierrez, M. and He, S. (2012), "Optimal location of piles in slope stabilization by limit analysis", Acta Geotechnica, 7, 253-259. https://doi.org/10.1007/s11440-012-0170-y.
  32. Liang, R.Y. and Yamin, M. (2010), "Three-dimensional finite element study of arching behavior in slope/drilled shafts system", Int. J. Numer. Anal. Meth. Geomech., 34, 1157-1168. https://doi.org/10.1002/nag.851.
  33. Liang, R.Y. and Zeng, S. (2002), "Numerical study of soil arching mechanism in drilled shafts for slope stabilization", Soil. Found., 42(2), 83-92. https://doi.org/10.3208/sandf.42.2_83.
  34. Likitlersuang, S., Pholkainuwatra, P., Chompoorat, T., Keawsawasvong, S. (2018), "Numerical modelling of rail way embankment for high-speed train constructed on soft soil", J. Geoeng., 13(3), 149-159. http://doi.org/10.6310/jog.201809_13(3).6.
  35. Lin, D.G., Chen, W.H. and Wang, S.H. (2015), "Three-dimensional numerical analyses of the mechanical behaviors of retaining shear piles stabilized slope", J. Chin. Soil Water Conserv., 46(4), 205-212. (in Chinese)
  36. Lin, H.D., Li, A.J. and Wang, W.C. (2019), "Investigation of load transfer factor of slope with drilled shaft", Proceedings, 16th Asian Regional Conference on Soil Mechanics and Geotechnical Engineering, Taipei.
  37. Lin, H.D., Tjuar, R. and Dang, H.P. (2013), "Analyses of drilled shaft effects on stabilizing the soil slope", 1st Taiwan-Kazakhstan Joint Workshop in Geotechnical Engineering, Taipei, Taiwan.
  38. Lin, H.D., Wang, W.C. and Li, A.J. (2020), "Investigation of dilatancy angle effects on slope stability using the 3D finite element method strength reduction technique", Comput. Geotech., 118, 103295. https://doi.org/10.1016/j.compgeo.2019.103295.
  39. Michalowski, R.L. (2002), "Stability charts for uniform slopes", J. Geotech. Geoenviron. Eng., 128(4), 351-355. https://doi.org/10.1061/(ASCE)1090-0241(2002)128:4(351).
  40. Michalowski, R.L. (2010), "Limit analysis and stability charts for 3D slope failures", J. Geotech. Geoenviron. Eng., 136(4), 583-593. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000251.
  41. Nakamura, H. (1984), "Design of rigid dowel piles for landslide control", 4th International Symposium on Landslides, 2, 149-154.
  42. Neeraj, C.R., and Thiyyakkandi, S. (2020), "Estimation of lateral pile resistance incorporating soil arching in pile-stabilized slopes", Geomech. Eng., 23(5), 481-491. http://doi.org/10.12989/gae.2020.23.5.481.
  43. Ng, C.W.W. and Zhang, L.M. (2001), "Three-dimensional analysis of performance of laterally loaded sleeved piles in sloping ground", J. Geotech. Geoenviron. Eng., 127(6), 499-509. https://doi.org/10.1061/(ASCE)1090-0241(2001)127:6(499).
  44. Poulos, H.G. (1995), "Design of reinforcing piles to increase slope stability", Can. Geotech. J., 32, 808-818. https://doi.org/10.1139/t95-078.
  45. Qi, S., Vanapalli, S.K., Yang, S.G., Zhou, J.W., and Lu, G.D. (2019), "Stability analysis of an unsaturated expansive soil slope subjected to rainfall infiltration", Geomech. Eng., 19(1), 1-9. http://doi.org/10.12989/gae.2019.19.1.001.
  46. Ramanandan, S., and Dodagoudar, G.R. (2020), "Reliability analysis of slopes stabilized with piles using response surface method", Geomech. Eng., 21(6), 513-525. http://doi.org/10.12989/gae.2020.21.6.513.
  47. Sahoo, P.P., Shukla, S.K. and Ganesh, R. (2020), "Taylor's slope stability chart for combined effects of horizontal and vertical seismic coefficients", Geotechnique, 70(9), 835-838. https://doi.org/10.1680/jgeot.17.P.222.
  48. Shou, K., Chen, Y. and Liu, H. (2009), "Hazard analysis of Li-shan landslide in Taiwan", Geomorphology, 103, 143-153. https://doi.org/10.1016/j.geomorph.2007.09.017.
  49. Stewart, D.P. (1992), "Lateral loading of piled bridge abutments due to embankment construction", Ph.D. Dissertation, University of Western Australia.
  50. Stewart, D.P., Jewell, R.J. and Randolph, M.F. (1994), "Design of piled bridge abutments on soft clay for loading from lateral soil movements", Geotechnique, 44(2), 277-296. https://doi.org/10.1680/geot.1994.44.2.277.
  51. Taylor, D.W. (1937), "Stability of earth slopes", J. Boston Soc. Civil Eng., 24(3), 197-246.
  52. Tschuchnigg, F., Schweiger, H.F. and Sloan, S.W. (2015), "Slope stability analysis by means of finite element limit analysis and finite element strength reduction techniques. Part I: Numerical studies considering non-associated plasticity", Comput. Geotech., 70, 78-189. https://doi.org/10.1016/j.compgeo.2015.06.018.
  53. Wang, D.L. and Yen, B.C. (1974), "Soil arching in slopes", J. Geotech. Eng., 104(4), 493-496. https://doi.org/10.1061/AJGEB6.0000005.
  54. Wei, W.B. and Cheng, Y.M. (2009), "Strength reduction analysis for slope reinforced with one row of piles", Comput. Geotech., 36, 1176-1185. https://doi.org/10.1016/j.compgeo.2009.05.004.
  55. Yang, K.H., Uzuoka, R., Thuo, J.N., Lin, G.L. and Nakia, Y.T. (2017), "Coupled hydro-mechanical analysis of two unstable unsaturated slopes subject to rainfall infiltration", Eng. Geol., 216, 13-30. https://doi.org/10.1016/j.enggeo.2016.11.006.
  56. Ye, S.H., Zhao, Z.F. and Zhu, Y.P. (2020), "Dynamic response analysis of loess slope reinforced by frame anchors based on numerical simulation and shaking table test", J. GeoEng., 15(2), 89-101. http://doi.org/10.6310/jog.202006_15(2).3.
  57. Zhang, Y., Hu, X., Tannant, D.D., Zhang, G. and Tan, F. (2018), "Field monitoring and deformation characteristics of a landslide with piles in the Three Gorges Reservoir area", Landslid., 15, 581-592. https://doi.org/10.1007/s10346-018-0945-9.
  58. Zhong, Z., Yong, R., Tang, H., Li, C. and Du, S. (2020), "Experimental studies on the interaction mechanism of landslide stabilizing piles and sandwich-type bedrock", Landslid., 18, 1369-1386. https://doi.org/10.1007/s10346-020-01570-9.
  59. Zienkiewicz, O.C., Humpheson, C. and Lewis, R.W. (1975), "Associated and non-associated visco-plasticity and plasticity in soil mechanics", Geotechnique, 25(4), 671-689. https://doi.org/10.1680/geot.1975.25.4.671.