Location

Arlington, Virginia

Session Start Date

8-11-2008

Session End Date

8-16-2008

Abstract

Two earthquake–triggered violent landslides are studied. The Nikawa, activated by the Mw 7 1995 Kobe Earthquake, and the Higashi–Takezawa, activated by the MJMA 6.8 2004 Niigata-ken Chuetsu earthquake, in Japan. Both landslides involved about 100 m displace-ment of a large wedge of an originally rather mild slope. The surprisingly large and rapid in nature runoff of the soil masses, motivated several researchers to interpret the sliding process. There is still no consensus as to which were the actual causes of those two catastrophic events. The goal of the paper is to study: (i) the landslide triggering and propagation, and (ii) the mechanism of material softening inside the shear band responsible for the accelerating movement of the two slides. To this, a model is utilised considering two mechanically coupled substructures: (a) the accelerating deformable body of the slide, and (b) the rapidly deforming shear band at the base of the slide. It combines features of an extended Savage–Hutter approach, with (a) Mohr–Coulomb failure criteria, and (b) Bouc–Wen hysteretic stress–strain relationship, and exploits the concept of grain crushing–induced instability. The method success-fully interprets the studied landslides.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Sixth Conference

Publisher

Missouri University of Science and Technology

Publication Date

8-11-2008

Document Version

Final Version

Rights

© 2008 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Aug 11th, 12:00 AM Aug 16th, 12:00 AM

Analysis of Two Case Histories of Violent Landslides Triggered by Earthquakes

Arlington, Virginia

Two earthquake–triggered violent landslides are studied. The Nikawa, activated by the Mw 7 1995 Kobe Earthquake, and the Higashi–Takezawa, activated by the MJMA 6.8 2004 Niigata-ken Chuetsu earthquake, in Japan. Both landslides involved about 100 m displace-ment of a large wedge of an originally rather mild slope. The surprisingly large and rapid in nature runoff of the soil masses, motivated several researchers to interpret the sliding process. There is still no consensus as to which were the actual causes of those two catastrophic events. The goal of the paper is to study: (i) the landslide triggering and propagation, and (ii) the mechanism of material softening inside the shear band responsible for the accelerating movement of the two slides. To this, a model is utilised considering two mechanically coupled substructures: (a) the accelerating deformable body of the slide, and (b) the rapidly deforming shear band at the base of the slide. It combines features of an extended Savage–Hutter approach, with (a) Mohr–Coulomb failure criteria, and (b) Bouc–Wen hysteretic stress–strain relationship, and exploits the concept of grain crushing–induced instability. The method success-fully interprets the studied landslides.