Estudo tens?o-deforma??o da barragem de Irap?.

A barragem da Usina Hidrel?trica de Irap?, localizada no rio Jequitinhonha, ? uma das maiores do mundo. A previs?o de recalques e de tens?es durante o per?odo construtivo ? extremamente importante, tanto no acompanhamento da constru??o do aterro quanto no que concerne ? valida??o do modelo te?rico, ou mesmo calibra??o deste, principalmente de seus par?metros. Com esses prop?sitos, foram efetuadas an?lises de tens?o-deforma??o da barragem utilizando o m?todo dos elementos finitos, largamente utilizado no campo da engenharia. Uma vez que o escopo do trabalho n?o contemplou estudos de estabilidade por tens?o deforma??o, as an?lises foram desenvolvidas por modelo linear el?stico. No sentido de sofisticar a an?lise linear el?stica e aproxim?-la mais das condi??es de campo, foi implementado uma variante deste modelo atrav?s do uso de m?dulos de elasticidade crescentes com o n?vel de tens?o. A ferramenta num?rica utilizada tamb?m propiciou representar de forma mais fiel a constru??o da barragem atrav?s de etapas definidas no programa, objetivando a obten??o de valores de tens?o e deforma??o, nos diversos pontos do aterro. Os valores obtidos nas simula??es num?ricas foram razoavelmente validados perante os resultados da instrumenta??o disponibilizada na estrutura.The dam at Irap? Hydroelectric Plant, located on Jequitinhonha river, is one of the highest in the world of its type. The forecast of settlements and stresses during construction is extremely important in monitoring the progress of the embankment, as well as in what it concerns the validation of the theoretical model, or even its calibration. With these purposes, analyses of stress-deformation of the dam were performed using the finite element method, widely used in the field of the engineering. As the study did not contemplate stress-strain analyses associated with stability analyses, it was adopted a linear elastic model. In order to improve the linear elastic analyses and obtain a better compatibility with field instrumentation data, a variant of the same model was employed, which used several moduli of elasticity that increase in relation to the stress level. The numerical model used also provided a more accurate representation of the construction of the dam, using steps that were defined in the program. The objective was to obtain stress and deformation values in several points of the embankment. The values supplied by the models were reasonable validated by instrumentation installed in the structure