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Hydraulic Response of an Internally Stable Gap-Graded Soil Under Variable Hydraulic Loading: A Coupled DEM-Monte Carlo Approach

  • Sandun M. Dassanayake
  • Ahmad MousaEmail author
Conference paper
Part of the Sustainable Civil Infrastructures book series (SUCI)

Abstract

Seepage-induced fines migration, referred to as suffusion, conceivably degrades the hydraulic performance of soil masses subjected to water flow. Suffusion susceptibility of the soil (i.e. internal instability) is empirically evaluated using the grain size distribution (GSD) with little emphasis on the permeation process of fines (i.e. mobile fines) in the matrix. Upon experiencing different hydraulic gradient histories, the mobile fines can detach (unclog) or filtrate (clog) in the pore space of the load bearing soil skeleton (i.e. primary fabric). Moreover, clogging and unclogging phenomena are instrumental to temporally altering the hydraulic responses, mainly the hydraulic conductivity (K) and critical hydraulic gradient required to initiate internal erosion of the soil. Therefore, real-time predictions of the hydraulic response of the soil can reveal the initiation and progression of suffusion. This study attempts to forecast the hydraulic response of the soil by quantifying the statistical distribution of K values under mobile fines contents (fc). To this end, the discrete element method (DEM) has been employed to estimate the void ratio distribution of the primary fabric. The statistical Monte Carlo simulations have been performed using the Kozeny-Carman equation and the void ratio distribution to estimate the statistical distribution of K values. A set of pilot-scale experiments were conducted on internally stable gap-graded soil subjected to stepwise hydraulic loading histories to allow validation for the numerical results. Based on the measured pore pressure distribution parallel to the seepage path, the possible clogging and filtration of fines were inferred, and the K variations were estimated. The change in GSD of the soil after testing was used as a measure for the mobile fines fraction. An average of 6–8% mass loss (from the fine fraction) was observed over a 45-min duration of the controlled-head flows. The experimentally observed K (1–3 × 10−4 m/s) and fc ranges fall well within the non-parametric bounds of the predicted K and fc (<10%) ranges.

Keywords

Temporal suffusion DEM Statistical techniques Fines migration Inverse modeling 

References

  1. Bianchi, F., Wittel, F.K., Thielmann, M., Trtik, P., Herrmann, H.J.: Tomographic study of internal erosion of particle flows in porous media. Transp. Porous Media 122(1), 169–184 (2018)CrossRefGoogle Scholar
  2. Calamak, M., Melih Yanmaz, A., Kentel, E.: Probabilistic evaluation of the effects of uncertainty in transient seepage parameters. J. Geotech. Geoenviron. Eng. 143(9), 06017009 (2017)CrossRefGoogle Scholar
  3. Chang, C.S., Wang, J.Y., Ge, L.: Modeling of minimum void ratio for sand–silt mixtures. Eng. Geol. 196, 293–304 (2015)CrossRefGoogle Scholar
  4. Chang, D.S., Zhang, L.M.: Extended internal stability criteria for soils under seepage. Soils Found. 53(4), 569–583 (2013)CrossRefGoogle Scholar
  5. Chapuis, R.P.: Predicting the saturated hydraulic conductivity of soils: a review. Bull. Eng. Geol. Environ. 71(3), 401–434 (2012)CrossRefGoogle Scholar
  6. Dassanayake, S.M., Mousa, A.: Probabilistic stability evaluation for wildlife-damaged earth dams: a Bayesian approach. Georisk Assess. Manage. Risk Eng. Syst. Geohazards 1–15 (2018)Google Scholar
  7. Dassanayake, S.M., Mousa, A., Kong, D.: Voids distribution of pavement filters under permeating fines: a DEM approach coupled with statistical inference. In: 4th International Conference on Civil Engineering and Materials Science, Bangkok, Thailand (2019)Google Scholar
  8. Fannin, R.J., Slangen, P.: On the distinct phenomena of suffusion and suffosion. Géotechnique Lett. 4(4), 289–294 (2014)CrossRefGoogle Scholar
  9. Fell, R., Wan, C.F., Cyganiewicz, J., Foster, M.: Time for development of internal erosion and piping in embankment dams. J. Geotech. Geoenviron. Eng. 129(4), 307–314 (2003)CrossRefGoogle Scholar
  10. Indraratna, B., Israr, J., Li, M.: Inception of geohydraulic failures in granular soils-an experimental and theoretical treatment (2018)CrossRefGoogle Scholar
  11. Langroudi, M.F., Soroush, A., Shourijeh, P.T., Shafipour, R.: Stress transmission in internally unstable gap-graded soils using discrete element modeling. Powder Technol. 247, 161–171 (2013)CrossRefGoogle Scholar
  12. MATLAB (2019). www.mathworks.com
  13. Marot, D., Rochim, A., Nguyen, H.H., Bendahmane, F., Sibille, L.: Assessing the susceptibility of gap-graded soils to internal erosion: proposition of a new experimental methodology. Nat. Hazards 83(1), 365–388 (2016)CrossRefGoogle Scholar
  14. Rasheed, A.K., Dassanayake, S.M., Mousa, A.: Suffusion susceptibility in gap-graded granular soils under variable hydraulic loading. In: Fifteenth International Conference on Structural and Geotechnical Engineering, Cairo (2018)Google Scholar
  15. Staudt, F., Mullarney, J.C., Pilditch, C.A., Huhn, K.: The role of grain-size ratio in the mobility of mixed granular beds. Geomorphology 278, 314–328 (2017)CrossRefGoogle Scholar
  16. Yang, J., Wei, L.M., Dai, B.B.: State variables for silty sands: global void ratio or skeleton void ratio? Soils Found. 55(1), 99–111 (2015)CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2020

Authors and Affiliations

  1. 1.School of EngineeringMonash University MalaysiaBandar SunwayMalaysia

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