Modelagem determinístico-estocástica da dinâmica de sedimentos em reservatórios de água e de rejeitos de mineração

• Autor(a) principal: Laquini, João Paulo
• Data de Publicação: 2009
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/812
• topic: Sedimentação; Adensamento; Reservatório; Monte Carlo; Sedimentation; Densification; Reservoirs; Monte Carlo; CNPQ::ENGENHARIAS::ENGENHARIA CIVIL::GEOTECNICA

Sediments transported by rivers accumulate into water reservoirs, reducing their water storage capacity and prejudicing their operation. Tailing reservoirs, however, are built to store waste of mining processes. No matter what is the reservoir function, it is fundamental to estimate the sediment deposition along time. Therefore, a quasi-tridimensional deterministic mathematical model was developed to represent the physical phenomena involved on the sediment filling process in a reservoir: transport, deposition erosion and consolidation of sediments. The model considers the grain-size distribution of the inflow and deposited sediments. Through a network channel delineation, the model allows simulating the sediment inflow contribution from tributaries entering any place along the reservoir. The hydrodynamics model is solved by the Preissmann scheme and the double-sweep algorithm, through an incremental-iterative scheme. The sediment model is solved by an implicit finite difference scheme and a direct-coupled method. The finite strain consolidation model is also solved with an implicit finite difference scheme in time and an iterative procedure and then it is coupled to the hydrodynamics and sediment models. The stochastic character of the silting up of reservoirs is simulated through the Monte Carlo and the Latin hypercube sampling methods. The developed model was implemented in a computer program named SimSed. A water reservoir is deterministically simulated, showing that the model predicts successfully the silting up. The filling of a bauxite red mud tailing reservoir is analyzed by the model, which satisfactorily calculates the process. Finally, another water reservoir was analyzed by the Monte Carlo xix method, providing answers that were satisfactorily analyzed by the stochastic model.