Qualidade de amostras “indeformadas” em solos não coesivos recolhidas com procedimentos avançados
DOI:
https://doi.org/10.14195/2184-8394_153_3Palabras clave:
Qualidade de amostragem, Dames & Moore, Gel-Push, velocidade de ondas distorcionaisResumen
Ao longo da última década, as técnicas de amostragem de solos têm evoluído no sentido de reduzirem o atrito na interface entre o amostrador e o solo, minimizando as perturbações e obtendo amostras de alta qualidade para caracterização laboratorial. No âmbito de um projeto de investigação focado no estudo da liquefação em Portugal (LIQ2PROEARTH) e um europeu mais global (LIQUEFACT), foi implementado um campo experimental nas zonas de Benavente e Vila Franca de Xira, no qual foram realizados diversos ensaios in situ (SPT, CPTu, DMT), com medição de ondas sísmicas (SCPTu e SDMT) em locais onde foram recolhidas amostras indeformadas. O presente trabalho apresenta a experiência com amostradores especialmente adaptados a condições difíceis, Dames & Moore e Gel-Push, em depósitos aluvionares granulares com suscetibilidade à liquefação. Os procedimentos de manuseamento e transporte adotados são descritos e o desempenho de cada metodologia é avaliada em termos de integridade material e estrutural. Assim, recorre-se a um método que permite comparar as velocidades das ondas distorcionais obtidas tanto em campo como em laboratório, aqui com recurso a bender elements. Ambos os amostradores mostraram ser competentes na extração de amostras de areias e areias siltosas soltas de elevada qualidade.
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