DBPapers
DOI: 10.5593/SGEM2014/B12/S2.123

THE USE OF MOHR’S THEORY OF LIMIT STRESS STATE FOR EVALUATION OF SEISMIC SOIL PRESSURE ON RETAINING WALLS

M. Vrabie, B. Teodoru, S. Baetu
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, 963-970 pp

ABSTRACT
The retaining walls located in seismic areas are loaded, during earthquakes, by supplementary forces of dynamic nature. In order to evaluate the dynamic active pressure, respectively of the dynamic passive strength, the most frequently is used the pseudo-static method Mononobe-Okabe. In the present paper are done some developments, systematisations and specifications to the use of Mohr’s theory of limit stress state in order to determine the active and passive earth pressure on gravity retaining walls. It starts from the Rankine hypothesis, according to which the pressures on the surface elements, parallel to the free surface of the soil, have vertical direction. As an effect of the horizontal seismic acceleration, in the soil appear inertial forces which are combining with the vertical pressures, generating in this way normal and shearing stresses on the parallel planes with the soil surface behind the retaining wall. Using the intrinsic curve appropriate to the slip plane and the stresses from this plane, can be obtained the limit Mohr’s circles and, than the active and passive pressures generated by the earthquake on the retaining wall. The algorithm for solving can be graphical, but can be analytical too. It permits the determination of the slip plane position and also of magnitude for principal normal and shearing stresses in the points of this plane, in which the stress state is limit.

Keywords: seismic active pressure; slip plane; limit stress state; Mohr’s circle; intrinsic curve