Variability of small scale model reinforced concrete and implications for geotechnical centrifuge testing

TY - GEN

T1 - Variability of small scale model reinforced concrete and implications for geotechnical centrifuge testing

AU - Knappett, Jonathan

AU - Brown, Michael

AU - Shields, Lauren

AU - Al-Defae, Asad H.

AU - Loli, Marianna

PY - 2018/10/24

Y1 - 2018/10/24

N2 - There are soil-structure interaction problems for which it is important to model both the relative soil-structure stiffness and strength. Examples from the earthquake engineering field include the design of resilient rocking-isolated foundations and the seismic stabilisation of slopes using piling. In both cases the aim is to ensure a preferred failure mode happens first in the soil instead of the structure i.e. controlled bearing failure of the foundation or soil yielding around piles. A recently developed model reinforced concrete for centrifuge testing can simulate stiffness and strength simultaneously, but suffers from variability in the material properties, as does the full-scale material. This paper presents a series of element tests on the variability of model reinforced concrete elements representative of large square monolithic bridge piers and slender square piles. Coefficients of variation for various material and element properties have been determined and shown to be similar to typical values for full-scale reinforced concrete elements obtained from the literature. It is also demonstrated that curing time beyond 28 days does not substantially affect strength and variability and that models of different absolute volume can be produced without inducing detrimental size effects. The results are used to discuss the selection of mean design strengths for model structural elements in centrifuge experiments using a quantitative statistical approach where there are competing structural and soil failure modes.

AB - There are soil-structure interaction problems for which it is important to model both the relative soil-structure stiffness and strength. Examples from the earthquake engineering field include the design of resilient rocking-isolated foundations and the seismic stabilisation of slopes using piling. In both cases the aim is to ensure a preferred failure mode happens first in the soil instead of the structure i.e. controlled bearing failure of the foundation or soil yielding around piles. A recently developed model reinforced concrete for centrifuge testing can simulate stiffness and strength simultaneously, but suffers from variability in the material properties, as does the full-scale material. This paper presents a series of element tests on the variability of model reinforced concrete elements representative of large square monolithic bridge piers and slender square piles. Coefficients of variation for various material and element properties have been determined and shown to be similar to typical values for full-scale reinforced concrete elements obtained from the literature. It is also demonstrated that curing time beyond 28 days does not substantially affect strength and variability and that models of different absolute volume can be produced without inducing detrimental size effects. The results are used to discuss the selection of mean design strengths for model structural elements in centrifuge experiments using a quantitative statistical approach where there are competing structural and soil failure modes.

KW - model concrete

KW - geotechnical centrifuge

KW - Scaling

UR - https://www.crcpress.com/Physical-Modelling-in-Geotechnics-Proceedings-of-the-9th-International/McNamara-Divall-Goodey-Taylor-Stallebrass-Panchal/p/book/9781138559752

U2 - 10.1201/9780429438646

DO - 10.1201/9780429438646

M3 - Conference contribution

SN - 9781138559752

SP - 241

EP - 246

BT - Physical Modelling in Geotechnics

A2 - McNamara, Andrew

A2 - Divall, Sam

A2 - Goodey, Richard

A2 - Taylor, Neil

A2 - Stallebrass, Sarah

A2 - Panchal, Jignasha

PB - CRC Press-Taylor & Francis Group

T2 - 9th Int. Conf. on Physical Modelling in Geotechnics 2018

Y2 - 17 July 2018 through 20 July 2018

ER -