Browsing by Author "Vargas-Baecheler, Jose"

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    Estimation of Exceedance Probability of Scour on Bridges Using Reliability Principles
    (2021) Contreras-Jara, Manuel; Echaveguren, Tomas; Chamorro, Alondra; Vargas-Baecheler, Jose
    Scour is one of the most relevant causes of bridge collapse. Most existing scour models have been focused on estimating scour depth as input for bridge design. This estimation is mainly deterministic. Parameter uncertainty has been considered to estimate expected scour as well. This framework is suitable for bridge design but has limitations for risk analysis of bridge networks, in which exceedance probabilities are needed. In this paper we use the first-order reliability method to estimate the probability that the actual scour will exceed the design scour, considering the uncertainty in hydraulic and hydrological parameters. The procedure was applied to a case study in Chile using the flood-flow history between 30 and 60 years of eight fluviometric stations. The local, contraction, and general scour were estimated for return periods between 2 and 500 years. The exceedance probability obtained was highly dependent on the uncertainty in annual maximum flow, Froude's number, top width, and riverbed longitudinal slope.
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    Traffic interruption risk induced by cut-slope failure: The rainfall effect
    (2023) Jimenez-Ramos, Gustavo; Echaveguren, Tomas; Vargas-Baecheler, Jose; Chamorro, Alondra
    Shallow landslides in road cut-slopes cause traffic disruptions, especially during rainy seasons. Even when the cut slopes are planned for saturation conditions, the variability and uncertainty of the explanatory variables of slope stability combined with pore pressure variation due to rainfall determine the need to probabilistic model the slope stability, considering the effects of rainfall intensity and duration. It is also necessary to know the magnitude of road platform blockage induced by slope failure, which is especially important for rural roads. This paper proposes a method for evaluating the probability of cut-slope landslides and traffic interruption. For this purpose, first-order reliability analysis and a Monte Carlo simulation were used to analyze various slope and rainfall scenarios. The analysis found 24 failure probability curves that were obtained for slope inclination, rainfall intensity, and rainfall duration. Probability values were obtained to achieve "low", "moderate", and "extensive" damage states in terms of roadway blocked due to slope slides and the relationship between roadway blocking width to slope height.