The paper examines the mechanism of pile installation by vertical jet fluidization in saturated sand in order to define the constitutive parameters that control installation geometry and pile depth of embedment. A series of laboratory model tests representative of offshore torpedo piles was carried out using downwardly directed vertical water jets in both medium and dense sands. Measurements from model tests at three different scales indicate that the geometry of fluidized cavities is not influenced by the initial density of the sand and that the perturbed zone is constrained to a distance of about two pile diameters from the pile centerline during pile installation. Following the laws of dimensional analysis, an expression for the embedment of fluidized piles is derived and shows that penetration depth is a function of pile weight and geometry, fluidized water jet flow rate and velocity, as well as the soil and fluid properties. Penetration is shown to increase with increasing flow rate and pile weight and decreasing soil relative density. Although the results have to be validated by tests at larger scales to prove compatibility with the full-scale behavior, model tests indicate maximum embedment depth of the order of 50 times the pile diameter.

No abstract

A incorporação de dados meteorológicos em pesquisas envolvendo o estudo de acidentes é considerada como essencial quando se objetiva analisar o comportamento de acidentes rodoviários. Neste contexto, o presente trabalho pretendeu explorar a existência de correlação entre ocorrência de acidentes rodoviários e condições climáticas, em específico a precipitação diária, num trecho selecionado da Rodovia BR- 376 (Paraná, Brasil). Uma análise de correspondência múltipla (ACM) foi aplicada (software Statigraphics) para determinar a relação existente entre as características dos acidentes e a precipitação. A ACM permitiu a criação de um mapa perceptual, agrupando as variáveis consideradas semelhantes de acordo com o método, o qual evidenciou que a intensidade da chuva não foi um fator significativo para alterar as características dos acidentes. Entretanto, a ocorrência de precipitação mostrou-se como uma circunstância condicionante. Com respeito à segurança da rodovia, a pesquisa indica aplicações práticas que podem ser aplicadas pelas agências de tráfego, como a implementação de sinalização de tráfego e educacional em pontos específicos da rodovia.

No abstract

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.