Water and Energy Abstracts
Year : 2004, Volume : 14, Issue : 1
First page : ( 47) Last page : ( 47)
Print ISSN : 0021-1672.

135. Assessing the Likelihood of Concentrated Leaks Leading to Failure in Concrete Faced Rockfill Dams

Southcott P.H., Herweynen R., Fell R.

(ANCOLD Bulletin No. 124, pp. 17–28).

Abstract

Hydro Tasmania is in the process of undertaking a Portfolio Risk Assessment of its 54 referable dams, of which 14 are concrete faced rockfill dams. One of the potential failure modes identified during the study so far is a concentrated leak developing in the face slab or joints of the slab, leading to failure of the dam. Current methodologies for assessment of piping failures through embankment dams are considered inadequate for this failure mode. This paper discusses an event three methodology developed from the work of Foster and Fell (1999) and Foster et al (2001) to address this failure mode. The key aspect of this method is identifying the factors that influence the likelihood of initiating a concentrated leak through the perimetric, vertical and crest wall joints and through the face slab concrete. It is concluded that for the vast majority of well designed and constructed concrete faced rockfill dams that a concentrated leak leading to failure is very unlikely.

Top

Keywords

Risk assessment, Concrete faced rockfill, Leak, Failure, Piping failures, Tree methodology, Crest.

Top