Sustainable Overhead Line Equipment foundations with optimised shape and backfilling

TY - JOUR

T1 - Sustainable Overhead Line Equipment foundations with optimised shape and backfilling

AU - Brown, Michael

AU - Davidson, Craig

AU - Shepherd, Charlie

AU - Flint, Stuart

AU - Mbisike, Stephen

N1 - © 2025 Emerald Publishing Limited

PY - 2026/2/12

Y1 - 2026/2/12

N2 - This study investigates methods to enhance the tensile capacity and optimise the design of concrete pad and column foundations for overhead line equipment (OLE) towers, aiming to reduce environmental impact and costs. Using FEA and centrifuge modelling, the research explores the effects of chamfering the pad's upper edge and varying the density of the material used to backfill the excavation. A 30-40° chamfered edge on the pad can increase tensile capacity by up to 40% at low embedment ratios compared to standard square-edged pads, shifting the failure surface origin from the pad top to bottom. Backfill density above the foundation was shown to influence the failure mechanisms. When the backfill is less dense than the native soil, vertical failure surfaces form. Conversely, when both backfill and native soil relative densities are 60% or higher, transitional shear planes emerge. When the backfill’s relative density exceeded that of the native soil, an increase in uplift capacity was observed. Sloping the backfill sides to 25°, allowed the failure surface to develop at the soil’s dilation angle, independent of excavation effects. These findings offer practical strategies to improve foundation efficiency and sustainability in overhead line infrastructure projects.

AB - This study investigates methods to enhance the tensile capacity and optimise the design of concrete pad and column foundations for overhead line equipment (OLE) towers, aiming to reduce environmental impact and costs. Using FEA and centrifuge modelling, the research explores the effects of chamfering the pad's upper edge and varying the density of the material used to backfill the excavation. A 30-40° chamfered edge on the pad can increase tensile capacity by up to 40% at low embedment ratios compared to standard square-edged pads, shifting the failure surface origin from the pad top to bottom. Backfill density above the foundation was shown to influence the failure mechanisms. When the backfill is less dense than the native soil, vertical failure surfaces form. Conversely, when both backfill and native soil relative densities are 60% or higher, transitional shear planes emerge. When the backfill’s relative density exceeded that of the native soil, an increase in uplift capacity was observed. Sloping the backfill sides to 25°, allowed the failure surface to develop at the soil’s dilation angle, independent of excavation effects. These findings offer practical strategies to improve foundation efficiency and sustainability in overhead line infrastructure projects.

KW - Overhead line

KW - OLE

KW - foundations

KW - SAND

KW - Centrifuge testing

KW - Finite element analysis (FEA)

KW - Geotechnical engineering

KW - Centrifuge modelling

KW - Finite-element modelling

KW - Electrical engineering & distribution

KW - Model tests

U2 - 10.1680/jgeen.25.00151

DO - 10.1680/jgeen.25.00151

M3 - Article

SN - 1353-2618

JO - Proceedings of the Institution of Civil Engineers: Geotechnical Engineering

JF - Proceedings of the Institution of Civil Engineers: Geotechnical Engineering

ER -