Performance of Ductile Iron Pipes. I: Characterization of External Corrosion Patterns

Abstract

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1061/(ASCE) IS.1943-555X.0000097 Journal of Infrastructure Systems, 19, 1, pp. 108-119, 2012-02-06 Performance of ductile iron pipes. I : characterization of external corrosion patterns Kleiner, Yehuda; Rajani, Balvant; Krys, Dennis

Performance of Ductile Iron Pipes. II: Sampling Scheme and Inferring the Pipe Condition

“…As noted in the conclusions of the Kleiner et al (2013), no compelling evidence was found that soil samples would improve the ability to predict corrosion pit properties in any significant or consistent manner. Consequently, soil properties are not considered in the current discussion of sampling and statistical inference on pipe condition.…”

“…The appropriate underlying population in the current context is that of rings in a pipe, as described in Kleiner et al (2013). Simple random sampling of say, n samples, would entail the selection of n sample rings whose locations are determined randomly (with assumed uniform distribution) along the entire pipe.…”

“…The ultimate goal of the investigation described in Kleiner et al (2013) was to enable a statistical inference on the structural condition of a ductile iron (DI) pipe based on pit geometrical properties, coupled (possibly) with soil properties, both obtained from a few sample rings along the pipe. As noted in the conclusions of the Kleiner et al (2013), no compelling evidence was found that soil samples would improve the ability to predict corrosion pit properties in any significant or consistent manner.…”

“…Consequently, there is a need to strike a balance between accuracy and cost. Additionally, specifically for buried water mains, it is important to determine what should be the sampled pipe ring length (definition of a pipe ring is provided in Kleiner and Rajani, 2013) and if sampling should be completely random or planned to represent the entire pipe length. This paper describes the investigation of various sampling schemes conducted towards the recommendation for the preferred one as well as the manner with which sampling results can be used to make statistical inferences about the condition of the pipe.…”

“…This paper describes the investigation of various sampling schemes conducted towards the recommendation for the preferred one as well as the manner with which sampling results can be used to make statistical inferences about the condition of the pipe. A key assumption is made, namely that Kleiner et al (2013) provide sufficient evidence to support the notion that the righttruncated Gumbel is the underlying distribution for pit-depth maxima in rings, while Weibull is underlying distribution for pit-area and pit-volume in rings.…”