Archival Document Search Methodology
The archival documents delivered by the client should cover the TSFs and their dams including:
- geotechnical studies
- geological studies
- design reports
- geotechnical analyses and reports
- inspections
- correspondence
- incident descriptions
- dam break analyses
- FIA and GISTM consequence evaluations
- emergency plans
- monitoring equipment and measurements (as applicable)
During the deployment of ORE2_Tailings™, we deliver an analysis of the archival gaps (Takeaway #1).
Semi-automated Discovery Platform
ORE2_Tailings accepts Microsoft Word, PDF, images, and email files as input. It is capable of optical character recognition. After a preliminary read of a sample of the files by experienced analysts, a list of keywords is edited in order to ensure that the language used in the reports is covered. The list contains dam/slope assessment−specific words such as: dam/slope, settlement, fill, buttress, deformation, decant, tower, erosion, piping, liquefaction. The software will search all the documents for those keywords, in singular and plural.
A verification is then performed to see if the list of keywords has deficiencies, such as local language differences or missing archival documents that deal with the missing words.
If we receive new documents, the cycle is repeated until we obtain a satisfactory result and deliver the archival gap analysis constituting Takeaway #1 of the study.
Different languages in the portfolio do not cause great difficulties provided the analysts are fluent in each language, including in orthography (for instance the accents on the letter “e” in French).
We deliver the results in “structured form,” meaning the results are already organized by document/author/themes/search strings.
We then use the structured results in Chapter 3: Portfolio description and Chapter 4: Knowledge base results. These feed the evaluation of the ORE2_Tailings key performance indicators/key risk indicators (KPIs/KRIs) that we use to evaluate the probability of failure pf and the consequences of potential failures.
Portfolio Description
Based on preliminary discussions and the analysis of archival information, this chapter describes the TSF portfolio and each dam or homogeneous section of dam in general terms, such as by activity, status, year of commission, year of end of spigotting (if applicable), history of accidents/incidents and comments on work performed to date.
Knowledge Base Results
This chapter delivers the bulk of the rich-data information we gather using the archival document search methodology in terms of general knowledge.
It includes an annotated qualitative judgement on the available information. This covers the ORE2_Tailings KPIs/KRIs, including general, storage, ancillary water management, tailings lines and traffic, erosion controls, liquefaction, piping and leaching, investigations and geological model, project and construction, as is status, monitoring and inspections and consequences.
Note that two identically design and built dams could have different values because, for instance, one has active erosion on the dam/slope face, and the other has no working inclinometers, etc. Conversely, two different dams can have the same “note” due to very different reasons. That is why we discuss the quality of the dams further and deliver a potential failure causality analysis. The chapter closes with a gap analysis on archival documents (Takeaway #2).
