 |
 |
The role of curved-surface envelope Mohr-Coulomb model in governing shallow infiltration induced slope failure
M. J. Md. Noor Lecturer, Institute for Infrastructure Engineering and Sustainable Management, Department of Civil Engineering, Universiti Teknologi MARA, 40000 Shah Alam Selangor, Malaysia B.A. Hadi Lecturer, Institute for Infrastructure Engineering and Sustainable Management, Department of Civil Engineering, Universiti Teknologi MARA, 40000 Shah Alam Selangor, Malaysia
| |
|
ABSTRACT |
Shallow rainfall infiltration induced slope failure is a difficult soil behavior to model. It occurs under low stress level. There are two unique soil shear strength characteristics under this stress level which has a strong influence on the failure. They are the steep drop in shear strength when the soil is wetted and when the effective stress approaches zero. Their incorporation is inevitable in order to back analyze the actual failure plane. These soil shear strength characteristics are excellently replicated in curved-surface envelope Mohr-Coulomb soil shear strength model. Its application in a new slope stability equation is aimed to improve the reliability of the output stability factor. Furthermore, the new slope stability equation is able to replicate the actual mechanism of rainfall induced failure which involves the reduction in shear strength and the increase in the disturbing weight when the soil is wetted. Its applicability is tested by conducting back analysis on the 6th December 2008 a slope failure in granitic residual soil at Bukit Antarabangsa, Malaysia. The soil parameters applied in the analysis was deduced from the common parameters reported and basic information obtained from a visit to the site. The progression of infiltration into the soil is incorporated in the analysis by applying the changes in the moisture content and the increasing depth of wetting front. The influence of the microscopic change in the clay content of the soils is substantiated and incorporated in the analysis. The actual failure surfaces have been back analyzed. The result support the applicability of the method for rainfall infiltration induced failure and the technique would be very appropriate to be applied in slope monitoring system for detection of the shallow type of failure.
Keywords: Slope Failure; Infiltration; curved-surface envelope Mohr-Coulomb model; Unsaturated soil; Rainfall.
Get the entire paper (pdf)
Go back to the TOC
