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Dynamic pore-pressure fluctuations in rapidly shearing granular materials
Science (New York, N.Y.)
|November 10, 1989
Summary
Dynamic pore pressures in granular materials can momentarily eliminate grain contact stresses during shear. These pressure fluctuations propagate, potentially influencing shear zone development and material behavior.
Area of Science:
- Geophysics
- Material Science
- Fluid Dynamics
Background:
- Understanding granular material behavior under stress is crucial in fields like geotechnical engineering and seismology.
- Pore pressure dynamics significantly influence the mechanical response of saturated granular systems.
Purpose of the Study:
- To investigate the dynamic behavior of intergranular pore pressures during rapid shear deformation.
- To determine the conditions under which pore water can support all stresses in granular materials.
Main Methods:
- Experimental analysis of water-saturated granular materials undergoing steady shear deformation.
- Monitoring of intergranular pore pressures and grain-contact stresses during deformation.
Main Results:
- Observed dynamic fluctuations in pore pressures during shear.
- Identified instances where pore water supported all normal and shear stresses, causing transient zero grain-contact stresses.
- Documented the outward propagation of pore pressure fluctuations from the shear zone.
Conclusions:
- Intergranular pore pressure fluctuations are a key mechanism in the dynamic response of shear-deforming granular materials.
- The propagation of these fluctuations can alter stress distribution in surrounding areas and potentially lead to shear zone expansion.
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