Estudo em laboratório e em campo de colunas granulares encamisadas com geossintéticos

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

The construction of embankments on soft soils is a common challenge to be faced by geotechnical engineers. Several techniques have been developed to improve the performance of such works and the use of geosynthetics for the stabilisation of the soft soil or embankment reinforcement has been increasingly employed. The use of granular columns is also a traditional solution for the stabilisation of embankments on soft soils and more recently the use of geosynthetic encased granular columns has gained increasingly acceptance. This thesis aimed to study the behaviour of geosynthetic encased granular columns constructed with different materials. To accomplish that, field and laboratory tests were carried out, as well as numerical analysis using the finite element method. The tests in the field consisted of loading tests on sand, gravel and soil-cement columns, with and without geosynthetic casing. Woven geotextile casings were used for the sand and soil-cement columns, whereas geogrid casings was used for the gravel columns. Strain-gauges devices were installed in the columns to assess column deformation during the tests. The laboratory tests were carried out on large granular column specimens (0.3m diameter, 0.45m high), and internal measurements of column strains were also made. Back-analysis of laboratory and field tests results were also conducted using a finite element code. The field tests showed that the presence of the geosynthetic casing increased the load capacity of the sand and gravel columns. The performance of the gravel columns was affected by breakage of the gravel particles during the tests. This breakage was also confirmed in laboratory tests. The laboratory test results confirmed the increase on column load capacity due to the use of geosynthetic casing and the predictions by the numerical analysis were consistent with the results obtained in the laboratory and field tests.

ASSUNTO(S)

encamisadas colunas granulares ensaios de laboratório outros

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