Comparative assessment of 1g and centrifuge uplift tests on steel grillage foundations

TY - GEN

T1 - Comparative assessment of 1g and centrifuge uplift tests on steel grillage foundations

AU - Shepherd, Charlie

AU - Brown, Michael

AU - Davidson, Craig

AU - Beckett, Christopher

AU - Flint, Stuart

N1 - Conference code: 5th

PY - 2024/10

Y1 - 2024/10

N2 - Steel grillages, as an alternative to concrete foundations for overhead lines, offer construction advantages in remote and challenging terrains, such as those present in Scotland. Their non-concrete nature allows for transportation to the site and pre-fabrication using low-ground pressure vehicles or helicopters, eliminating the need for haul roads and removing concrete curing times, thereby accelerating construction. This paper compares the response of 1g and centrifuge uplift tests on steel grillage foundations, demonstrating ultimate uplift capacity comparable to a solid plate. However, they are subject to reduced stiffness with increasing grille-to-grille spacing, which is critical when assessing against displacement design criteria. The paper also explores the scaling of uplift displacement and the influence of particle size on stiffness by comparing two different particle sizes in both 1g and centrifuge testing. In 1g testing, two particle sizes were used: D 50 of 0.13 mm (sand) and 4 mm (gravel). Centrifuge testing at 28g employed D 50 sizes of 0.13 mm and 0.19 mm (sands/gravel substitute).

AB - Steel grillages, as an alternative to concrete foundations for overhead lines, offer construction advantages in remote and challenging terrains, such as those present in Scotland. Their non-concrete nature allows for transportation to the site and pre-fabrication using low-ground pressure vehicles or helicopters, eliminating the need for haul roads and removing concrete curing times, thereby accelerating construction. This paper compares the response of 1g and centrifuge uplift tests on steel grillage foundations, demonstrating ultimate uplift capacity comparable to a solid plate. However, they are subject to reduced stiffness with increasing grille-to-grille spacing, which is critical when assessing against displacement design criteria. The paper also explores the scaling of uplift displacement and the influence of particle size on stiffness by comparing two different particle sizes in both 1g and centrifuge testing. In 1g testing, two particle sizes were used: D 50 of 0.13 mm (sand) and 4 mm (gravel). Centrifuge testing at 28g employed D 50 sizes of 0.13 mm and 0.19 mm (sands/gravel substitute).

KW - Grillage

KW - Over head lines

KW - Sand

KW - Uplift

KW - Foundation

U2 - 10.53243/ECPMG2024-73

DO - 10.53243/ECPMG2024-73

M3 - Conference contribution

BT - Proceedings of the 5th ECPMG 2024

A2 - Cabrera, Miguel Angel

A2 - van Eekelen, Suzanne J.M.

A2 - Bezuijen, Adam

PB - International Society for Soil Mechanics and Geotechnical Engineering

T2 - ECPMG 2024

Y2 - 2 October 2024 through 4 October 2024

ER -