Extended Residual-State Creep Test and Its Application for Landslide Stability Assessment

Area of Science:

• Geotechnical Engineering
• Earthquake Engineering
• Soil Mechanics

Background:

• Landslides pose significant risks, often initiated by long-term precipitation and water infiltration.
• Understanding soil and rock creep behavior is crucial for predicting landslide reactivation.
• Residual strength is a critical parameter in assessing the stability of slopes.

Purpose of the Study:

• To introduce a novel residual-state creep test for geomaterials.
• To investigate the creep behavior of clayey soil under varying shear stress conditions.
• To develop a model for predicting critical or failure times in reactivated landslides.

Main Methods:

• Development and application of a residual-state creep test.
• Analysis of primary, secondary, and tertiary creep behavior under different shear stress levels.
• Modeling of limit state development using a contact model (Blair's body).
• Estimation of time to unlimited creep conditions.

Main Results:

• The tested clayey material (Kobe, Japan) exhibits tertiary creep exclusively above residual strength.
• Primary and secondary creep were observed at shear stresses at or below residual strength.
• A predictive model for critical or failure time was successfully developed and applied.

Conclusions:

• The developed residual-state creep test provides valuable insights into landslide behavior.
• The findings enable more accurate prediction of landslide initiation and failure.
• The study offers a framework for determining optimal timing for landslide safety interventions.