Location

San Diego, California

Session Start Date

3-26-2001

Session End Date

3-31-2001

Abstract

The behaviour of earth slopes under seismic conditions can be effectively studied by evaluating the suffered displacements, which are key parameters in the recent performance design approaches (Pianc/PTCII/WG34, 2001). Different methodologies have been developed to evaluate displacements (Whitman, 1993). Slope instabilities caused by yielding due to seismic inertial forces can be studied by methods based on the well-known model of a rigid block sliding on a plane surface (Newmark 1965). These methodologies utilise accelerometric time histories which allow to take into account the real characteristics of the seismic motion (Simonelli and Viggiani 1995). Displacement analyses are traditionally performed adopting only horizontal accelerograms. The aim of this paper is to evaluate the effects of vertical components of seismic motions. In this case, the critical acceleration depends on the direction of the resulting motion (Sarma 1975, 1999). The analyses have been performed for three major Italian earthquakes. The case of an indefinite slope in dry cohesionless soil has been examined. The results of the analyses have been synthesised in diagrams, which show that the displacement variations induced by vertical accelerations are negligible for the range of displacements values (of the order of centimetres), which are of interest from an engineering point of view.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Meeting Name

Fourth Conference

Publisher

University of Missouri--Rolla

Publication Date

3-26-2001

Document Version

Final Version

Rights

© 2001 University of Missouri--Rolla, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Mar 26th, 12:00 AM Mar 31st, 12:00 AM

Effects of Vertical Seismic Accelerations on Slope Displacements

San Diego, California

The behaviour of earth slopes under seismic conditions can be effectively studied by evaluating the suffered displacements, which are key parameters in the recent performance design approaches (Pianc/PTCII/WG34, 2001). Different methodologies have been developed to evaluate displacements (Whitman, 1993). Slope instabilities caused by yielding due to seismic inertial forces can be studied by methods based on the well-known model of a rigid block sliding on a plane surface (Newmark 1965). These methodologies utilise accelerometric time histories which allow to take into account the real characteristics of the seismic motion (Simonelli and Viggiani 1995). Displacement analyses are traditionally performed adopting only horizontal accelerograms. The aim of this paper is to evaluate the effects of vertical components of seismic motions. In this case, the critical acceleration depends on the direction of the resulting motion (Sarma 1975, 1999). The analyses have been performed for three major Italian earthquakes. The case of an indefinite slope in dry cohesionless soil has been examined. The results of the analyses have been synthesised in diagrams, which show that the displacement variations induced by vertical accelerations are negligible for the range of displacements values (of the order of centimetres), which are of interest from an engineering point of view.