Location

San Diego, California

Session Start Date

3-26-2001

Session End Date

3-31-2001

Abstract

During liquefaction, strength and stiffness degradation in sloping liquefied soil may lead to significant cycle-by-cycle shear strain accumulation. Accuracy in quantifying the magnitude of accumulated permanent shear strain is the key to satisfactory modeling of liquefaction-induced lateral spreading. Commonly used stress-space constitutive models may not be easily calibrated to reproduce the observed magnitudes of permanent shear deformation, since the shear flow phase is often accompanied by a minor change in shear stress magnitude. In a newly developed constitutive model, the observed large post-liquefaction shear-strain accumulation is accomplished by introducing a perfectly plastic zone into a multi-yield surface stress-space framework. After the perfectly plastic strain accumulation phase, the tendency for dilation may result in significant regain in shear stiffness and strength. This aspect of soil behavior is also modeled within the aforementioned constitutive model framework. This new model is integrated in an effective-stress fully coupled two-phase (solid and fluid) Finite Element computer code. In this paper, results of numerical simulations conducted using this computational program are discussed. A one-dimensional version of the program is now available on the Internet for on-line execution (http://casagrande.ucsd.edu).

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

Liquefaction-Induced Lateral Spreading and Dilative Soil Behavior

San Diego, California

During liquefaction, strength and stiffness degradation in sloping liquefied soil may lead to significant cycle-by-cycle shear strain accumulation. Accuracy in quantifying the magnitude of accumulated permanent shear strain is the key to satisfactory modeling of liquefaction-induced lateral spreading. Commonly used stress-space constitutive models may not be easily calibrated to reproduce the observed magnitudes of permanent shear deformation, since the shear flow phase is often accompanied by a minor change in shear stress magnitude. In a newly developed constitutive model, the observed large post-liquefaction shear-strain accumulation is accomplished by introducing a perfectly plastic zone into a multi-yield surface stress-space framework. After the perfectly plastic strain accumulation phase, the tendency for dilation may result in significant regain in shear stiffness and strength. This aspect of soil behavior is also modeled within the aforementioned constitutive model framework. This new model is integrated in an effective-stress fully coupled two-phase (solid and fluid) Finite Element computer code. In this paper, results of numerical simulations conducted using this computational program are discussed. A one-dimensional version of the program is now available on the Internet for on-line execution (http://casagrande.ucsd.edu).