DBPapers
DOI: 10.5593/sgem2017/12/S02.031

DETERMINATION THE PRECONSOLIDATION PRESSURE OF EEMIAN GYTTJA TAKEN FROM WARSAW CITY TEST SITE, POLAND

M. Bajda, E. E. Malinowska
Sunday 10 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7105-99-5 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 12, 239-246 pp, DOI: 10.5593/sgem2017/12/S02.031

ABSTRACT

The preconsolidation pressure is an important parameter that determines the value of stress history exerted in the past on the subsoil in the geotechnical engineering. The Eemian gyttja is an organic soft soil from the “Zoliborz channel” located in Warsaw. These soils are used as a base construction in the foundation engineering. The laboratory tests that can be used to determinate the preconsolidation pressure, mainly uses the relationship between the stress and void ratio or strain. In practical geotechnical engineering, evaluation of stress history is based on the overconsolidation ratio OCR. The overconsolidation ratio OCR is one of the basic parameters for the geotechnical design of the structure. Determination of this parameter using for example dilatometer tests is usually based on empirical formulas which were established in different countries. Therefore regional geotechnical conditions could have substantially affected on the empirical relationships. The laboratory tests were made in the automatic oedometer and the in situ tests were carried out on the seismic dilatometer test (SDMT). Some methods have been compared. The paper presents results of determination the preconsolidation pressure of Eemian gyttja from the laboratory and in situ tests. The studies have shown that the values of the overconsolidation ratio determinate from the laboratory tests are a little higher than determinate from the in-situ tests.

Keywords: preconsolidation pressure, overconsolidation ratio, Eemian gyttja