Abstract
This paper shows the results of the numerical modelling of water flow and ion propagation occurring in a test field of KCl wells installed in a landslide of the southern Italian Apennines. Preliminarily, oedometer and direct shear tests on specimens exposed to KCl were carried out in laboratory; ion diffusion and related time-dependent increase in residual shear strength were modelled by a commercial FEM code. Then, the processes occurring in the test field were analysed. The specific discharge profile q(z) along the well height in steady-state conditions and the transient water level restoring h(t) after a rapid drawdown were observed, monitored and modelled. For an axisymmetric domain, a permeability distribution interpreting both q(z) and h(t) in each borehole was determined. Thus, a 3D model of the entire test field was calibrated in MODFLOW-3D FDM code. The results of the experimental/numerical analysis show that, under natural hydraulic potentials, ion propagation from the wells is governed by water flow along a narrow band surrounding the slip surface, much more permeable than the soil above and beneath. Two years after the beginning of the experimentation, the increase in pore ion concentration is noticeable in the monitoring verticals, 5 m far from the KCl wells.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Di Maio, C., Vassallo, R., Vallario, M., Pascale, F., Sdao, F.: Structure and kinematics of a landslide in a complex clayey formation of the Italian southern Apennines. Eng. Geol. 116, 311–322 (2010)
Di Maio, C., Vassallo, R., Vallario, M., Calcaterra, S., Gambino, P.: Surface and deep displacements evaluated by GPS and inclinometers in a clayey slope. In: Proceedings of the 2nd World Landslide Forum, Rome, Italy 2011, vol. 2, pp. 265–271 (2011)
Calcaterra, S., Cesi, C., Di Maio, C., Gambino, P., Merli, K., Vallario, M., Vassallo, R.: Surface displacements of two landslides evaluated by GPS and inclinometer systems: a case study in southern Apennines, Italy. Nat. Hazards. 61, 257–266 (2012)
Vassallo, R., Di Maio, C., Comegna, L., Picarelli, L.: Some considerations on the mechanics of a large earthslide in stiff clays. In: Eberhardt, E., Froese, C., Turner, K., Leroueil, S. (eds.) Landslides and Engineered Slopes: Protecting Society through Improved Understanding, pp. 963–968. Taylor & Francis Group, London (2012)
Di Maio, C., Vassallo, R., Scaringi, G., De Rosa, J., Pontolillo, D.M., Grimaldi, G.M.: Monitoring and analysis of an earthflow in tectonized clay shales and study of a remedial intervention by KCl wells. RIG. 51(3), 48–63 (2017)
Vassallo, R., Grimaldi, G.M., Di Maio, C.: Pore water pressures induced by historical rain series in a clayey landslide: 3D modeling. Landslides. 12, 731–744 (2015)
Vassallo, R., Doglioni, A., Grimaldi, G.M., Di Maio, C., Simeone, V.: Relationships between rain and displacements of an active earthflow: a data-driven approach by EPRMOGA. Nat. Hazards. 81, 1467–1482 (2016)
Rosenqvist, I.T.: Investigations in the clay-electrolyte-water system. Norw. Geotech. Inst. Publ. 9, 3–120 (1955)
Torrance, J.K.: Chemistry, sensitivity and quick-clay landslide amelioration. In: L’Heureux, J.-S., et al. (eds.) Landslides in Sensitive Clays—From Geosciences to Risk Management, pp. 15–24. Springer, Dordrecht (2014)
Helle, T.E., Nordal, S., Aagaard, P., Lied, O.K.: Long-term effect of potassium chloride treatment on improving the soil behavior of highly sensitive clay— Ulvensplitten, Norway. Can. Geotech. J. 53(3), 410–422 (2016)
Helle, T.E., Aagaard, P.: Predicting required time stabilising quick clays by potassium chloride. Environ. Geotech. 5(1), 1–47 (2018)
Di Maio, C.: Exposure of bentonite to salt solution: osmotic and mechanical effects. Géotechnique. 46(4), 695–707 (1996)
Li, Y.-H., Gregory, S.: Diffusion of ions in sea water and in deep-sea sediments. Geochim. Cosmochim. Acta. 38(5), 703–714 (1974)
Di Maio, C., Scaringi, G.: Shear displacements induced by decrease in pore solution concentration on a pre-existing slip surface. Eng. Geol. 200, 1–9 (2016)
Mitchell, J.K., Soga, K.: Fundamentals of Soil Behavior, 3rd edn. Wiley, New York (2005)
Gajo, A., Loret, B.: Transient analysis of ionic replacements in elastic-plastic expansive clay. Int. J. Solid Struct. 41, 7493–7531 (2004)
Gelhar, L.W., Welty, C., Rehfeldt, K.R.: A critical review of data on field-scale dispersion in aquifers. Water Resour. Res. 28(7), 1955–1974 (1992)
Acknowledgments
This research is funded by the Italian Ministry of Education, University and Research (PRIN 2015: Innovative Monitoring and design strategies for sustainable landslide risk mitigation).
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2018 Springer Nature Switzerland AG
About this paper
Cite this paper
Grimaldi, G.M., Pontolillo, D.M., De Rosa, J., Rizzo, E., Di Maio, C. (2018). Modelling Water Flow and Ion Transport in Clay Soils: The Case of KCl Wells in the Head of an Earthflow. In: Giovine, P., Mariano, P., Mortara, G. (eds) Micro to MACRO Mathematical Modelling in Soil Mechanics. Trends in Mathematics. Birkhäuser, Cham. https://doi.org/10.1007/978-3-319-99474-1_16
Download citation
DOI: https://doi.org/10.1007/978-3-319-99474-1_16
Published:
Publisher Name: Birkhäuser, Cham
Print ISBN: 978-3-319-99473-4
Online ISBN: 978-3-319-99474-1
eBook Packages: Mathematics and StatisticsMathematics and Statistics (R0)