BIG - Branschsamverkan i Grunden

15 december 2016

Blockprovtagare - rapport publicerad

Nu har rapporten som jämför provtagning med blockprovtagare och traditionell kolv publicerats.

Abstract
Block sampling is long seen as the preferred method for sampling soft soils that need to be tested for its mechanical properties (stiness, strength). Its use in soft high plasticity clays, however, is not so well established. The presented experimental programme compares the sample quality of the 50 mm Swedish STII piston sampler against the NTNU mini-block sampler.

The test site has been selected on grounds of consistency and high sensitivity, and samples have been collected from depths ranging from 6 - 10 m below surface level. The results indicate that the mini-block sampler produces superior samples as assessed with the Lunne criteria for sample quality (volume change upon re-loading to in-situ stress).

These findings are corroborated by analyzing the mechanical properties from a wide array of laboratory tests (1D incremental loading, CRS, CAUC and CAUE triaxial tests). The subsequent analysis of a typical settlement problem using model properties derived from the piston samples and the block samples respectively show that these dierences in sample quality lead to signicant differences in calculated response.

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Uppdaterat 2016-12-15

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