Advertisement

On the Stability of a Fully Instrumented River Embankment Under Transient Conditions

  • C. G. GragnanoEmail author
  • I. Bertolini
  • I. Rocchi
  • G. Gottardi
Conference paper
Part of the Lecture Notes in Civil Engineering book series (LNCE, volume 40)

Abstract

Time-dependent boundary conditions, uncertainties and variability of soil suction and water content of the filling material together with the use of proper retention and strength soil models are crucial aspects to be included for reliable analyses of the actual stability of river embankments. However, due to a typical lack of information in many practical cases, the use of simplistic assumptions on both hydraulic and mechanical response of earth infrastructures to hydrometric water level fluctuation and atmospheric loading is largely diffused, thus providing erroneous conclusions on the effective safety margins towards possible slope instability and collapse. Within this context, site measurements down to relevant depths, combined to an accurate soil characterization under partially saturated conditions, can be extremely useful to evaluate unsaturated variables (i.e. soil water content and suction) under transient flow conditions and hence carry out realistic stability analyses. A comprehensive monitoring system has been therefore designed and installed on a relevant representative section along river Secchia, a right-hand tributary of river Po (Northern Italy). The paper aims at presenting a methodological approach for a sustainable performance assessment of such geotechnical infrastructures, based on the complementary use of laboratory tests, field measurements and numerical analyses.

Keywords

River embankment Slope stability Field monitoring Unsaturated soil Transient flow 

Notes

Acknowledgements

The activities presented in the paper have been carried out within the research project INFRASAFE, funded under the POR FESR 2014-2020 scheme.

References

  1. Bittelli M (2011) Measuring soil water content: a review. HortTechnology 21(3):293–300CrossRefGoogle Scholar
  2. Bicalho KV, Yasmina B, Cui, Yu-Jun (2018) Performance of an instrumented embankment constructed with lime-treated silty clay during four years in the northeast of France. Trans Geotech 17:100–116 Google Scholar
  3. Bordoni M, Meisina C, Valentino R, Lu N, Bittelli M, Chersich S (2015) Hydrological factors affecting rainfall-induced shallow landslides: from the field monitoring to a simplified slope stability analysis. Eng Geol 193:19–37CrossRefGoogle Scholar
  4. Calabresi G, Coleselli F, Danese D, Giani GP, Mancuso C, Montrasio L, Nocilla A, Pagano L, Reali E, Sciotti A (2013) A research study of the hydraulic behaviour of the Po river embankments. Can Geotech J 50(9):947–960CrossRefGoogle Scholar
  5. D’Alpaos L, Brath A, Fioravante V, Gottardi G, Mignosa P Orlandini S. (2014). Relazione tecnico-scientifica sulle cause del collasso dell’argine del fiume Secchia avvenuto il giorno 19 Gennaio 2014 presso la frazione San Matteo. Available online on http://www.regione.emilia-romagna.it
  6. Geo-Slope International Ltd (2012) Seepage modelling with SEEP/W. Geo-Slope International Ltd., Calgary, CanadaGoogle Scholar
  7. Gottardi G, Gragnano CG (2016). On the role of partially saturated soil strength in the stability analysis of a river embankment under steady-state and transient seepage conditions. In: 3rd European Conference on Unsaturated Soils – E-UNSAT 2016, p 9Google Scholar
  8. Gragnano CG, Rocchi I, Moscariello M, Cuomo S, Gottardi, G. (2018). Laboratory measurement of the mechanical and retention properties of a river embankment silty soil in partially saturated condition. In: Proceedings 7th International Conference on Unsaturated Soils – UNSAT 2018, Hong Kong, 3–5 August 2018Google Scholar
  9. Istituto Superiore per la Protezione e la Ricerca Ambientale – ISPRA (2018) Dissesto idrogeologico in Italia: pericolosità e indicatori di rischio. ISPRA, Rapporti 287/2018. Available at http://www.isprambiente.gov.it/it/pubblicazioni/rapporti/dissesto-idrogeologico-in-italia-pericolosita-e-indicatori-di-rischio-edizione-2018
  10. Liang C, Jaska MB, Ostendorf B, Kuo YL (2015) Influence of river level fluctuations and climate on riverbank stability. Comput Geotech 63:83–98CrossRefGoogle Scholar
  11. Matheron, G (1963) Principles of geostatistics. Economic Geol 58:1246–1266Google Scholar
  12. Mualem Y (1976) A new model for predicting the hydraulic conductivity of unsaturated porous media. Water Resour Res 12(3):513–522CrossRefGoogle Scholar
  13. Pirone M, Papa R, Nicotera MV, Urciuoli G (2015) Soil water balance in an unsaturated pyroclastic slope for evaluation of soil hydraulic behaviour and boundary conditions. J Hydrol 528:63–83Google Scholar
  14. Rinaldi M, Casagli N (1999) Stability of streambanks formed in partially saturated soils and effects of negative pore water pressures: the Sieve River (Italy). Geomorphol 26:253–277CrossRefGoogle Scholar
  15. Rinaldi M, Dapporto S, Casagli N (2001) Monitoring and modelling of unsaturated flow and mechanisms of riverbank failure in gravel bedrivers. In: Nolan T. and Thorne C.R. (eds) Gravel Bed Rivers 2000. New Zealand Hydrological Society, New ZealandGoogle Scholar
  16. Robertson PK (2009) Interpretation of cone penetration tests - a unified approach. Can Geotech J 46(11):1337–1355CrossRefGoogle Scholar
  17. Rocchi I, Gragnano, CG, Gottardi, G, Govoni, L, Bittelli, M (2018a). In-situ measurements of soil water content and suction to assess river embankments stability under transient flow conditions. Proceedings 7th International Conference on Unsaturated Soils – UNSAT 2018, Hong Kong, 3–5 August 2018Google Scholar
  18. Rocchi I, Gragnano CG, Govoni L, Mentani A, Bittelli M, Castiglione P, Buzzi O, Gottardi G (2018) A new technique for deep in situ measurements of soil water retention properties. Geotech Res 5(1):1–10CrossRefGoogle Scholar
  19. Toll DG, Lourenço SDN, Mendes J, Gallipoli D, Evans FD, Augarde CE, Cui YJ, Tang AM, Rojas Vidovic JC, Pagano L, Mancuso C, Zingariello C, Tarantino A (2011) Soil suction monitoring for landslides and slopes. Q. J Eng Geology 1 Hydrogeol 44(1):23–33Google Scholar
  20. Van Genuchten MTh (1980) A closed-form equation for predicting hydraulic conductivity of unsaturated soils. Soil Sci Am J 44(5):892–898CrossRefGoogle Scholar
  21. Vanapalli SK, Fredlund DG, Pufahl DE, Clifton AW (1996) Model for the prediction of shear strength with respect to soil suction. Can Geotech J 33(3):379–392CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2020

Authors and Affiliations

  • C. G. Gragnano
    • 1
    Email author
  • I. Bertolini
    • 1
  • I. Rocchi
    • 2
  • G. Gottardi
    • 1
  1. 1.Department of Civil, Chemical, Environmental and Material Engineering DICAMUniversity of BolognaBolognaItaly
  2. 2.Department of Civil EngineeringTechnical University of DenmarkLyngbyDenmark

Personalised recommendations