SCEC Project Details
SCEC Award Number | 17157 | View PDF | |||||
Proposal Category | Individual Proposal (Integration and Theory) | ||||||
Proposal Title | Thermal Pressurization in Dilatant Granular Materials: Investigations on Strength Evolution and Strain Localization | ||||||
Investigator(s) |
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Other Participants | |||||||
SCEC Priorities | 3c, 3d, 3f | SCEC Groups | FARM, CS, Geology | ||||
Report Due Date | 11/30/2018 | Date Report Submitted | 11/14/2019 |
Project Abstract |
The scientific objective of this proposal is to make progress towards quantitatively addressing the following question: How does dilatancy interplay with shear heating to control pore fluid pressure evolution in sheared fluid infiltrated gouge layers? Thermal pressurization has been hypothesized to be a principal mechanism for frictional weakening that may hold the keys for interpretation of many seismic observations such as locking depth, ground motion frequency content and apparent fracture energy. This proposal addresses this critical challenge by numerically modeling shear heating in elastic-visco-plastic gouge layers, accounting for inelastic dilatancy, under a wide range of pressure, slip rate and initial preparation conditions. |
Intellectual Merit |
, this proposal introduces a set of novel features that go beyond the state of the art. These include: (1) A rate dependent plasticity model coupled with temperature and pore pressure diffusion resolving deformation throughout the gouge thickness, (2) A quantitative tool for investigating the competing effects of dilatancy and shear heating and their implications for stability of sliding, strength evolution and shear banding, (3) Nucleation and propagation of complex shear bands in extended fault zone models accounting for both thermal and athermal fluid pressurization |
Broader Impacts |
1- Training of 1 PhD student: Xiao Ma who recently graduated and joined Exxon Mobile as a research scientist. 2- One journal publication: Ma, X., & Elbanna, A. E. (2018). Strain Localization in Dry Sheared Fault Gouge: A Compactivity based approach. Phys. Rev. E, 98(2), 022906 |
Exemplary Figure | Figure 2 |