Location

San Diego, California

Session Start Date

3-26-2001

Session End Date

3-31-2001

Abstract

One of the most severe landslides triggered by the 1995 Hyogoken-Nambu earthquake was the Nikawa landslide. The seismic ground motion generated excessive pore pressure inside the portion of the slope mass that was below the water table. Data from standard penetration tests suggested that, in spite of the significant percentage of fines in the sand and its slight overconsolidation due to the fluctuation of the water table, the slope material had potential of liquefaction under seismic loading. The objective of the present study was to investigate the consistency between observations and the results of analysis methods for this slope failure. The methods of analysis were the conventional method of slices for static and pseudo-static computations, the Newmark method, and numerical modeling using the finite differences program FLAC. The constitutive behavior of the sand in FLAC analyses was represented by a modified Mohr-Coulomb model incorporating the equation proposed by Martin, Finn and Seed (1975) for the volumetric strain increments due to cyclic loading. Using this formulation, it is possible to simulate the pore pressure build-up due to dynamic loading in the portion of the sand layer located below the water table. Results are discussed and compared with observations.

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

Analytical Study of the Nikawa Landslide

San Diego, California

One of the most severe landslides triggered by the 1995 Hyogoken-Nambu earthquake was the Nikawa landslide. The seismic ground motion generated excessive pore pressure inside the portion of the slope mass that was below the water table. Data from standard penetration tests suggested that, in spite of the significant percentage of fines in the sand and its slight overconsolidation due to the fluctuation of the water table, the slope material had potential of liquefaction under seismic loading. The objective of the present study was to investigate the consistency between observations and the results of analysis methods for this slope failure. The methods of analysis were the conventional method of slices for static and pseudo-static computations, the Newmark method, and numerical modeling using the finite differences program FLAC. The constitutive behavior of the sand in FLAC analyses was represented by a modified Mohr-Coulomb model incorporating the equation proposed by Martin, Finn and Seed (1975) for the volumetric strain increments due to cyclic loading. Using this formulation, it is possible to simulate the pore pressure build-up due to dynamic loading in the portion of the sand layer located below the water table. Results are discussed and compared with observations.