Instability of sand under generalized stress conditions

• Main Author: Zhang, Bo
• Other Authors: Chu Jian
• Format: Theses and Dissertations
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Civil engineering::Geotechnical
• Online Access: http://hdl.handle.net/10356/51188
• Institution: Nanyang Technological University

The instability behavior of sand can cause landslides, debris flow where large plastic strain are generated rapidly due to the inability of soil element to sustain a given load or stress. The thesis deals with systematical study of the instability of sand under generalized stress conditions, includes both axisymmetric and plane strain conditions. Firstly, a comprehensive experiment program was carried out to study the behavior of sand under triaxial and plane strain conditions. The drained and undrained behaviors of sand under both compression and extension conditions had been investigated. In additional, instability tests on extension side were carried out. The experimental program was carried out in both triaxial and plane strain conditions. The results showed that the instability behaviors under extension side are different from compression side. Finally, a bounding surface plasticity constitutive model proposed by Manzari and Dafalias (2004) was adopted to validate the experimental results. The model was used to predict instability conditions under generalized stress conditions.