Study on the Strength and Failure Characteristics of Silty Mudstone Using Different Unloading Paths
Jijing Wang1, Hualin Zhang2,3, Shuangxing Qi1
1School of Traffic & Transportation Engineering, Changsha University of Science & Technology, Changsha 410114, China.
Materials (Basel, Switzerland)
|July 29, 2023
Summary
This study examined silty mudstone strength under triaxial unloading. Higher confining pressure generally increased strength and strain, while higher deviatoric stress decreased them, revealing complex failure behaviors.
Area of Science:
- Geotechnical Engineering
- Rock Mechanics
- Soil Mechanics
Background:
- Understanding the mechanical behavior of mudstone is crucial for civil engineering projects.
- Silty mudstone presents unique challenges due to its complex composition.
- Investigating failure characteristics under unloading conditions is vital for stability analysis.
Purpose of the Study:
- To analyze the strength and failure mechanisms of silty mudstone under various triaxial unloading stress paths.
- To determine the influence of confining pressure and deviatoric stress on mudstone's mechanical response during unloading.
- To characterize shear strength variations and failure modes.
Main Methods:
- Triaxial unloading tests were performed on silt-like mudstone specimens.
- Confining pressure and initial deviatoric stress were systematically varied.
- Mohr stress circles were used to analyze shear strength parameters (cohesion and internal friction angle).
Main Results:
- Peak stress, residual stress, and elastic modulus increased with confining pressure but decreased with initial deviatoric stress.
- Strain behaviors showed complex, non-monotonic responses to both confining pressure and deviatoric stress.
- Cohesion and internal friction angle remained relatively stable, with minor variations between unloading paths.
- Failure was attributed to lateral expansion and collapse, with shear failure morphology dominating.
Conclusions:
- Silty mudstone exhibits distinct strength and failure characteristics under triaxial unloading.
- Confining pressure and deviatoric stress significantly influence the mechanical response and failure modes.
- The findings provide valuable data for predicting mudstone behavior in engineering applications.
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