A New Approach for Classifying the Permanent Deformation Properties of Granular Materials under Cyclic Loading
Gang Liu1, Mingzhi Zhao1, Qiang Luo2
1School of Architecture and Civil Engineering, Xihua University, Chengdu 610039, China.
Materials (Basel, Switzerland)
|March 29, 2023
Summary
Researchers investigated granular material deformation using cyclic triaxial tests. A new method classifies permanent deformation states based on the deformation tendency factor (β), aiding engineering design.
Area of Science:
- Geotechnical Engineering
- Soil Mechanics
- Materials Science
Background:
- Understanding permanent deformation in granular materials is crucial for infrastructure design.
- Existing methods for classifying soil behavior under cyclic loading have limitations.
Purpose of the Study:
- To investigate the permanent deformation properties of granular materials under cyclic stress.
- To develop a new classification approach for permanent deformation states.
Main Methods:
- Performed medium-sized cyclic triaxial tests on granular materials.
- Analyzed the relationship between permanent strain rate (dεp/dN) and loading cycles (N).
- Introduced and utilized the deformation tendency factor (β) for classification.
Main Results:
- A linear correlation between dεp/dN and N was observed for cyclic stress ratios (CSR) < 60%.
- The deformation tendency factor (β) effectively distinguishes between plastic shakedown (β > 1) and plastic creep (0 < β ≤ 1).
- CSR ≥ 60% indicated potential soil collapse and incremental collapse range due to increased dεp/dN.
Conclusions:
- The new approach using the deformation tendency factor (β) provides a robust classification of permanent deformation states.
- This method offers wider applicability and technical guidance for roadway and railway engineering substructures.
- The findings are validated with crushed tuff aggregates and subgrade materials.
Keywords:
deformation tendency factorgranular materialsnegative-power functionpermanent strain ratesteady-state line (SSL)More Related Videos
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