Maintenance in apparent and underwater hydraulic surfaces of concrete structures of dams must be performed combining characteristics of cost, performance, durability, workability of use, application time of the involved materials and compatibility between them and the substrate, slab concrete or reference-concrete (RefC). Also, it is of fundamental importance to evaluate the local and the environmental conditions, such as: solar radiation, temperature, humidity and AbstractFour types of repairing materials are studied as function of either a conventional concrete or a reference-concrete (RefC), these are: polymer-modified cement mortar (PMor), steel fiber concrete (SFco), epoxy mortar (EMor) and silica fume mortar (SFmo), to be applied in hydraulic structures surfaces subjected to a high velocity water flow. Besides the mechanical requests and wearing resistance of hydraulic concrete dam structures, especially the spillway surfaces, the high solar radiation, the environmental temperature and wet and dry cycles, contribute significantly to the reduction of their lifespan. RefC and the SFco were developed based on a usual concrete mixture used in slabs of spillways. The average RefC mixture used was 1: 1.61: 2.99: 0.376, with Pozzolan-modified Portland cement consumption of 425 kg/m 3 . EMor and PMor mixtures followed the information given by the manufacturers and lab experience. Tests on concrete samples were carried out in laboratory simulating normally found environmental situations in order to control the mechanical resistance and the aging imposed conditions, such as solar radiation and humidity. Also, physicochemical characterizing tests were made for all used materials. From the analyzed results, two of them presented a higher performance: the EMor and SFmo. SFco presented good adherence to the RefC and good mechanical performance. However, it also presented apparent metal corrosion in humidity tests, being indicated for use, with caution, as an intermediate layer in underwater repairs. In a general classification, considering all tests, including their field applications, the better performance material systems were EMor-SFmo> SFco> PMor. Keywords: concrete repair, mortar, abrasion, dam, spillway, epoxy mortar, silica fume, steel fiber, concrete modified polymer. de concreto, argamassa, abrasão, erosão, barragem, vertedor, resina epóxi, sílica ativa, fibra de aço, argamassa polimérica. Resumo Quatro tipos de materiais de reparo são estudados em função de um concreto convencional ou concreto-referência (RefC
The frequent interruption of roads in some freeways in Brazil due to slope failure has caused economic losses and potential harm to users. The paper presents data from a monitoring system installed at Serra do Mar in Santa Catarina State, Brazil. The slope monitored is called Morro do Boi and is located on BR-101 south, near the municipality of Itapema. It was stabilised using anchor and flexible metal mesh. Hence, all the pore water pressure measured is due to environmental changes. After approximately sixteen months of readings, it was possible to observe that the suction variation in the unsaturated layers presents a time delay in relation to the rainfall observed in the area. The ground water table presented a variation of about 1.5 m. The analyses of the data allowed establishing a trigger accumulated rainfall that reduces the negative pore water pressure to values below 10 kPa. So far, no significant positive pore water pressure has been observed above the ground water table.
Este artigo apresenta a metodologia empregada para a definição de uma faixa pluviométrica crítica para deflagra- ção de escorregamentos de terra nos taludes rodoviários da rodovia BR-376, no trecho da Serra do Mar Paranaense. A construção do modelo proposto partiu do entendimento e compilação da intensidade e duração tanto de eventos pluviométricos que resultaram em processos instabilizantes na região como daqueles que historicamente não deflagraram danos às encostas. A relação entre pluviometria e ocorrência de escorregamentos proposta representa uma importante ferramenta para criação sistemas de alerta e desenvolvimento de um plano de mitigação de movimentos de terra para o local. Sua aplicação torna-se mais eficiente se associada à estações pluviométricas capazes de processar dados em tempo real, possibilitando assim a emissão de alertas com o objetivo de se tomar decisões em termos de mobilização de equipes, interrupção ou desvio preventivo do tráfego ou controle de velocidade.
Conteúdo disponível em: https://www.ifgoiano.edu.br/periodicos/ Multi-Science Journal W e b s it e d o p e r i ó d i co : h t t p s : // w w w .i f g o i an o. e d u .b r / p e r i o d i c o s/ i n d ex. p h p / mu l t is c ie n c e
Landslides are one of the main causes of death caused by disasters in the world. In this study, methodologies to measure landslide costs and to assess vulnerability are presented, with the objective of applying them to landslide risk analyses. The methodologies were applied in a region of Serra do Mar, which is crossed by a highway. The analyses and mappings were implemented in a Geographic Information System (GIS). Through the application of the methodology that considers both direct and indirect costs in the composition of total cost, it was established how much an m2 of a landslide would cost. The composition of direct costs encompassed the damages related to restoration or construction of the highways, infrastructures, unpaved roads, residential and commercial buildings, vegetal cover and agricultural areas. In indirect costs, the economic losses by victims, highway interdiction, and agricultural area profitability were calculated. In the methodology for vulnerability assessment, bodily injuries, structural damages, and functional disturbances resulted from landslides were analyzed. The risk assessment was performed through the junction of the maps of total cost, vulnerability and susceptibility. The results indicate that indirect costs were predominant in cost composition, corresponding to 87% of total costs, in comparison to 13% of the direct costs, stressing the importance of considering indirect costs in economic measurement studies. As a result, it is possible to conclude that studying landslide consequences as economic parameters supports the increasing need of performing risk quantitative analyses. It is also prudent to add that these studies help decision makers in projects of disaster risk mitigation strategies, by allowing the identification of regions with greater economic impacts in case of landslide occurrence.
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