DBPapers
DOI: 10.5593/SGEM2014/B12/S2.030

CONTROL OF SUFFOSION ALONG RIVERBANKS: THE CASE OF THE OLONA RIVER (ITALY)

L. Colombo, V. Francani, P. Gattinoni
Wednesday 1 October 2014 by Libadmin2014

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-08-7 / ISSN 1314-2704, June 19-25, 2014, Book 1, Vol. 2, 227-234 pp

ABSTRACT
Piezometric fluctuations may affect the stability of the riverbanks by determining suffosion, i.e. the removal of fine particles from the soil when the filtration rate is high. Since the suffosion, or underground erosion, can reduce the mechanical properties of the soil and promote its landslide, horizontal drainage systems should be installed nearby riverbanks in order to reduce the piezometric levels fluctuations during the floods of watercourses. The new analytical formulation presented in this paper has allowed to design a drainage system that can increase the slopes stability, reducing suffosion occurring in the riverbanks. A comparison of the results obtained with the new relation and a numerical model has shown a very good agreement, indicating that the new modifications have been sufficiently accurate for using it in a preliminary design of the drainage system. With a simple analytical relation, this study has shown that horizontal drains can be designed to improve the prevention of anomalous suffosion in the riverbanks of Olona River. Additional work is required to develop lower-cost method of installing the drains.

Keywords: analytical solution, horizontal drain, suffosion, piezometric fluctuations