TITLE:
Applying Empirical Methods to Assess the Internal Stability of Embankment Dam Cores of Glacial Till
AUTHORS:
Hans Rönnqvist, Peter Viklander
KEYWORDS:
Internal Stability, Internal Erosion, Cores, Glacial Tills, Embankment Dams
JOURNAL NAME:
Geomaterials,
Vol.5 No.1,
December
23,
2014
ABSTRACT: This paper presents a
database of glacial till gradations that are compiled from laboratory internal
stability tests from the literature and from core soils of existing dams, some
of which have experienced internal erosion. The potential internal instability of
these gradations is assessed using empirical methods. Two approaches of
evaluation are used: the Kenney-Lau method, which analyzes the shape of the
gradation curve; and the Burenkova method, which uses factors of uniformity of
the slope of the gradation. Although they include some uncertainties in terms
of soils with fines, these methods, which are primarily developed from
laboratory studies of sand and gravels, are used in engineering practice to
evaluate widely graded soils that include fines, such as glacial tills. This
study evaluates the glacial till gradations of the database using these
approaches and discusses their applicability and relative predictive success.
This study indicates that both the Kenney-Lau method and the Burenkova method
have merit, but a closer analysis indicates that the Kenney-Lau approach has
relatively better predictive ability based on the glacial till gradations
analyzed in this study.