Best Practices for Road Weather Management Version 2.0
Title:
Triggering Mechanisms for the Garvin Landslide
Abstract:
Shallow landslides in natural occurring stiff clay deposits in highway road cuts are generally associated with longterm slope behavior and performance, and being triggered by heavy rainfall events. This paper investigates a slope failure in which the triggering mechanisms are much more complicated. The landslide occurs within a period of 42 months and 16 days from the end of the cut slope excavation. The overall climate has been dryer than normal over the past five years, yet numerous rainfall events happened during the 42 month and 16 day period. The site was investigated through surface surveys, continuously sampled auger and SPT borings, in-situ shear tests and stability analyses. The clay slope can be characterized as a stiff, very high plasticity, mottled, structured, and expansive clay. Backcalculated shear strengths approach a fully softened state, and are close to the residual shear strength. This analysis was based on the best fit slope stability of the failed slope geometry. The paper looks into the effect that soil suction has on reducing the mobilized shear strength at the time of failure, through a case history. Equations and assumptions developed in recent research were utililized to show the effect of soil suction on an infinite slope element.
Source(s):
86th Transportation Research Board (TRB) Annual Meeting, Oklahoma Department of Transportation. For an electronic copy of this resource, please direct your request to WeatherFeedback@dot.gov.
Date: 2007
Author:
Clarke, Nevels
Keywords:
Rain
Precipitation
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