Reliability-based design optimization of a concrete dam

• Autor(a) principal: Siacara,Adrian Torrico
• Data de Publicação: 2022
• Outros Autores: Pellizzer,Giovanni Pais, Beck,André Teófilo, Futai,Marcos Massao
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Revista IBRACON de Estruturas e Materiais
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1983-41952022000500205
• topic: reliability-based design optimization; concrete dam; reliability index; dam design; single-loop approach

abstract: Performance and safety of geotechnical structures are affected by uncertainties. Yet, the design of dams is nowadays still made using deterministic methods and design codes. Dam optimization in a deterministic setting may lead to compromised safety margins. In this setting, Reliability-Based Design Optimization (RBDO) appears as an alternative, allowing one to optimize dam performance, but respecting specified reliability constraints. In this paper, we employ an efficient and accurate Single-Loop Approach (SLA) in the RBDO of a concrete dam. Considering dam equilibrium reliability constraints, we find the optimal dam base and optimal placement of drainage galleries, for different dam heights and different target reliability index ( β T). We show how the governing failure mode changes for each optimal solution: for large β T, sliding limit state is the active constraint; for smaller β T values, the eccentricity limit state function is found to be the active constraint for the optimum dam. We also investigate how the importance of random parameters change for each optimum solution: for large β T and failure controlled by sliding, the cohesion and friction angle along dam base interface with foundation rock are the most relevant uncertain parameters for dam equilibrium. For smaller β T with failure controlled by eccentricity, the more relevant uncertain geotechnical parameters are the base length of the dam, the specific weight of concrete, and the coefficient of drainage gallery inefficiency.