On characteristics of K0 value and shear behaviour of loess using triaxial test
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View abstract on PubMed
Summary
This summary is machine-generated.This study investigates the coefficient of lateral earth pressure at-rest (K<sub>0</sub>) in compacted loess. Results show K<sub>0</sub> values range from 0.28 to 0.53, influencing undrained shear behavior and revealing contractive responses.
Area Of Science
- Geotechnical Engineering
- Soil Mechanics
- Earth Science
Background
- Limited data exists on the coefficient of lateral earth pressure at-rest (K<sub>0</sub>) for loess soils compared to conventional soils like sand and clay.
- Understanding K<sub>0</sub> is crucial for predicting the in-situ stress state and subsequent soil behavior.
Purpose Of The Study
- To experimentally investigate the coefficient of lateral earth pressure at-rest (K<sub>0</sub>) in compacted loess.
- To analyze the impact of K<sub>0</sub> consolidation on the undrained shear behavior of loess.
- To determine the relationship between K<sub>0</sub>, packing density, and clay content in compacted loess.
Main Methods
- Utilized a K<sub>0</sub> consolidation module within a triaxial system with unique feedback control to achieve the K<sub>0</sub> stress state.
- Monitored deviatoric stress (q) increase against volumetric strain (ε<sub>v</sub>) equaling axial strain (ε<sub>a</sub>) during K<sub>0</sub> consolidation.
- Conducted undrained shear tests on K<sub>0</sub> consolidated loess samples to observe stress path and quantify collapsibility.
Main Results
- Determined K<sub>0</sub> values for compacted loess ranging from 0.28 to 0.53, influenced by packing density and clay content.
- Observed a decrease in K<sub>0</sub> during consolidation for loosely compacted samples, but not for dense samples.
- All specimens exhibited contractive behavior in the stress path (q-p') diagram, with K<sub>0</sub> consolidated samples showing higher collapsibility index (I<sub>c</sub>) than isotropic ones.
Conclusions
- The initial stress state significantly impacts the shear behavior of compacted loess.
- K<sub>0</sub> values are sensitive to the physical properties of loess, specifically density and clay content.
- K<sub>0</sub> consolidation leads to increased contractive response and collapsibility in loess shear behavior.
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