Soil Slip Versus Flow Failure in Rain-infiltrated Slopes: Using Principles of Geomechanical Stability to Enhance Spatially Distributed Models for Shallow Landslides

Project: Research project

Description

Intellectual Merits: Rainfall-induced landslides are processes that affect hillslope geomorphology
and landscape evolution, as well as major natural hazards. Although it is widely accepted that shallow soil veneers fail in different ways (e.g., localized slips, chaotic liquefaction, etc.), these mechanisms depends heavily on local geomorphic features and soil properties. Current physical models cannot capture the richness of their responses, as they postulate frictional failure as the only form of mechanical instability. Engineering mechanics theories (e.g., the theory of soil liquefaction) could provide new insights, but in order to capture the complex processes taking place during rain infiltration (e.g., changes in the properties of soils, fluid-skeleton interactions, pore-collapse, fluid pressurization, etc.) require an extension to partially saturated conditions. Insights from the recent work of the PI on the stability of partially saturated media can bridge this gap and provides exciting opportunities for understanding the dichotomy between slip failure and flow instability in geomorphic settings. For this purpose, we propose a unified approach for capturing localized slip and/or chaotic liquefaction for both fully- and partially-saturated states. This endeavor can be crucial to understand natural hazards, as it will allow one to locate unstable masses and associate them with precise post-failure scenarios. In addition, it provides a unique possibility for integrating spatially distributed models with the emerging area of multi-physical geomechanical modeling, a vibrant research domain that aims at capturing the mutual feedbacks between the stress-strain response of geological materials and the surrounding physical conditions (e.g., wetting/drying cycles, thermal fluctuations, chemical degradation, etc.). Objectives and Methods: The proposal describes a research plan aimed at formulating a new generation of spatially distributed models for landslide triggering analyses. The work will build on the extensive expertise of the PI in formulating stability criteria for geological media and linking them to the prediction of natural hazards. The project will benefit from an international collaboration with the Applied Geomorphology group led by Dr. Crosta at the University of Milan-Bicocca. This initiative will offer a unique opportunity to the PI for challenging his theories against extensive data sets for large areas.
StatusFinished
Effective start/end date9/1/137/31/17

Funding

  • National Science Foundation (CMMI-1324834)

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natural hazard
liquefaction
landslide
geomorphology
wetting-drying cycle
saturated medium
soil
fluid
shallow soil
landscape evolution
hillslope
skeleton
mechanics
soil property
infiltration
engineering
rainfall
prediction
modeling
rain