Los Diques Tailings Storage Facility: Construction Quality Assurance

摘要

Recent catastrophic failures of tailings dams highlight the relevance of a proper governance framework for tailings storage facilities (TSF's) to ensure the implementation and verification of controls, in order to minimize risk over the full life of the facility. In this regard, construction is recognized as a progressive process during the life cycle of most TSF's, requiring robust management of controls to assure tailings dam safety.This article presents the construction quality assurance (CQA) developed during the first phase of Los Diques TSF1, focusing on the role of the Engineer of Record onsite (EoR onsite) as a part of the governance framework established by the Owner. It also addresses its relevance for the effective CQA of an Owner self-perform (OSP) tailings rockfill dam, using mine waste rock directly from the Candelaria open pit.In effect, the OSP construction allowed to increase the efficiency and to reduce the footprint of the project. In addition, the role of the EoR onsite described in this article, proved to be a key part of the success of this construction scheme, fulfilling the approved design requirements and permit commitments related to the tailings dam.Los Diques downstream constructed rockfill dam design considers a maximum final height of 160 m (first construction phase of 60 m height) and a total tailings storage capacity of approximately 600 Mt (up to 75 ktpd of whole tailings deposited with a solid concentration by weight about 50%).