Location

San Diego, California

Session Start Date

3-26-2001

Session End Date

3-31-2001

Abstract

Numerical simulation of fault rupture propagation through dry soil was performed using the finite difference code FLAC. A Mohr-Coulomb elasto-plastic constitutive model with strain softening was used to simulate soil behavior. The bedrock motion, prescribed at the bottom boundary of the mesh, was based on relevant seismological theories and observations. A total of 42 parametric analyses were performed where the shear strain rate and the plastic shear strain contours were used for localizing the rupture propagation as a shear band. Parametric analyses show that results are sensitive to the assumed soil type and dilatancy angle, but not to the soil layer thickness. Furthermore, it is concluded that: 1) the declination of the fault trace from the straight projection of the fault plane is higher in dilatant soils, 2) a graben is formed in cases of normal faults with relatively shallow dip-slip angle, 3) high values of the dilatancy angle tend to decrease the width of distorted zone on the ground surface and 4) local amplification of ground motion is possible near the fault trace in dense soils, especially in reverse faulting cases.

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

Numerical Simulation of Active Fault Rupture Propagation Through Dry Soil

San Diego, California

Numerical simulation of fault rupture propagation through dry soil was performed using the finite difference code FLAC. A Mohr-Coulomb elasto-plastic constitutive model with strain softening was used to simulate soil behavior. The bedrock motion, prescribed at the bottom boundary of the mesh, was based on relevant seismological theories and observations. A total of 42 parametric analyses were performed where the shear strain rate and the plastic shear strain contours were used for localizing the rupture propagation as a shear band. Parametric analyses show that results are sensitive to the assumed soil type and dilatancy angle, but not to the soil layer thickness. Furthermore, it is concluded that: 1) the declination of the fault trace from the straight projection of the fault plane is higher in dilatant soils, 2) a graben is formed in cases of normal faults with relatively shallow dip-slip angle, 3) high values of the dilatancy angle tend to decrease the width of distorted zone on the ground surface and 4) local amplification of ground motion is possible near the fault trace in dense soils, especially in reverse faulting cases.