DBPapers
DOI: 10.5593/SGEM2015/B12/S2.084

SETTLEMENT PREDICTION FOR BUILDINGS FOUNDED ON PLIOCENE CLAYS FROM THE TERRITORY OF SOFIA CITY

V.I. Kostov, A. Bozhinova-Haapanen
Friday 7 August 2015 by Libadmin2015

References: 15th International Multidisciplinary Scientific GeoConference SGEM 2015, www.sgem.org, SGEM2015 Conference Proceedings, ISBN 978-619-7105-32-2 / ISSN 1314-2704, June 18-24, 2015, Book1 Vol. 2, 633-640 pp

ABSTRACT
The geological conditions on the territory of Sofia City down to a depth of 30 m is represented by Quaternary and Pliocene deposits: clays, sandy clays and silty clays interlayered with sand and gravel beds. The subsoil on which buildings are founded is composed mainly of Pliocene clays. For the purposes of geotechnical engineering those deposits are subdivided into two complexes which differ in terms of visual features, structure and properties: yellowish-brown and bluish-green.
A series of geological explorations on the city territory have resulted in establishing the common properties of the bluish-green Pliocene clays, viz. strong structural bonds, high void ratio, low dry density, high modulus of deformation.
This study deals with the strain characteristics of bluish-green clays from the subsoil on which a building in Sofia is founded. Laboratory studies, Menard pressuremeter tests and SPT have been performed as part of the geotechnical investigation. The results on the strain characteristics of the Pliocene clays, obtained by different methods, have been analyzed. The settlement of the particular building has been determined by EN 1997 and by the “limited bed thickness” model.
Based on the calculations and analysis made it was found that the results obtained on the settlement determined by the limited bed thickness model correspond to measured settlements of buildings on the city territory.

Keywords: geological conditions, subsoil, strain characteristics, settlement, pressuremeter, penetrometer