SLIDING-BLOCK BACK ANALYSIS OF EARTHQUAKE-INDUCED SLIDES

CONSTANTINE A. STAMATOPOULOS, ELENI G. VELGAKI and SARADA K. SARMA

ABSTRACT: The objective of this article is to propose and evaluate a sliding-block model to deal with very large displacements of slopes when a horizontal earthquake is applied. The slip surface consists of two inclinations on which full shear resistance is mobilized. Internal shearing exists along a sub-plane that intersects the angle between the two sub-planes that form the external slip surface. The ratio of the distance moved along the two external sub-planes depends on the inclination of the internal sub-plane. If there is a water table line, undrained conditions are assumed during motion and total stress analysis is performed. The governing equations of motion are formulated, analytical solutions are obtained for some cases, and back-analysis of four well-documented slides is performed.

Key words: back analysis, critical acceleration, residual soil strength, seismic displacement, slide, sliding-block (IGC: E6/E8)