GCL shear strength evaluation - a new test method / Avaliação da resistência ao cisalhamento em GCLs - uma nova metodologia de ensaio

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

GCLs (Geosynthetic Clay Liners) are geosynthetic products used to compose flux control barriers in geotechnical and environmental works. The mechanical properties of GCLs have to be investigated in short and long term. Among its mechanical parameters, GCL internal shear strength plays an important role in the stability of slopes of geotechnical works. The main component of a GCL, the bentonite, when hydrated, presents very low shear strength. This work presents the development of a new index test method that aims cheaply and quickly to estimate the shear strength of GCLs - the CTM method (modified shear-tensile test). The main innovation of the proposed method is the U-shape grip that imposes a state of deformation close to that observed in field works. Two series of tests were performed in which a careful selection of samples and specimens were done. This aimed to minimize variation effects, inherent to the GCL production, on the obtained results. The first series was carried out to correlate results from the CTM tests to other two index tests: peel test and shear-tensile test. The results showed a good correlation between CTM and the other test results. The second series of tests was planned to improve CTM test method in order to get even better results than peel or shear-tensile tests, apart from correlating its results to results of direct shear test. Comparisons of results show very good agreement what justifies the use of the cheaper and quicker CTM method.

ASSUNTO(S)

gcl gcl ensaios-índice resistência ao cisalhamento shear strength index tests

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