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Title: DEM study of fabric features governing undrained post-liquefaction shear deformation of sand

In an effort to study undrained post-liquefaction shear deformation of sand, the discrete element method (DEM) is adopted to conduct undrained cyclic biaxial compression simulations on granular assemblies consisting of 2D circular particles. The simulations are able to successfully reproduce the generation and eventual saturation of shear strain through the series of liquefaction states that the material experiences during cyclic loading after the initial liquefaction. Also, DEM simulations with different deviatoric stress amplitudes and initial mean effective stresses on samples with different void ratios and loading histories are carried out to investigate the relationship between various mechanics- or fabric-related variables and post-liquefaction shear strain development. It is found that well-known metrics such as deviatoric stress amplitude, initial mean effective stress, void ratio, contact normal fabric anisotropy intensity, and coordination number, are not adequately correlated to the observed shear strain development and, therefore, could not possibly be used for its prediction. A new fabric entity, namely the Mean Neighboring Particle Distance (MNPD), is introduced to reflect the space arrangement of particles. It is found that the MNPD has an extremely strong and definitive relationship with the post-liquefaction shear strain development, showing MNPD’s potential role as a parameter governing post-liquefaction behavior ofmore » sand.« less
Authors:
 [1] ;  [2] ;  [1] ;  [3]
  1. Tsinghua Univ., Beijing (China). Department of Hydraulic Engineering
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Atmospheric, Earth, and Energy Division
  3. Univ. of California, Davis, CA (United States). Department of Civil and Environmental Engineering; National Technical University of Athens (Greece). Department of Mechanics, School of Applied Mathematical and Physical Sciences
Publication Date:
OSTI Identifier:
1328542
Report Number(s):
LLNL-JRNL-681216
Journal ID: ISSN 1861-1125
Grant/Contract Number:
AC52-07NA27344
Type:
Published Article
Journal Name:
Acta Geotechnica
Additional Journal Information:
Journal Volume: 11; Journal Issue: 6; Journal ID: ISSN 1861-1125
Publisher:
Springer
Research Org:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; 58 GEOSCIENCES; DEM; Fabric; Sand liquefaction; Shear deformation; Undrained cyclic biaxial