A field trial of a reusable, hollow, cast-in-situ pile

Abstract

This is the accepted version of the paper.This version of the publication may differ from the final published version. Permanent repository link Number of words in main text and tables:5138 words Number of figures: figures AbstractThis paper describes the concept and field testing of a 1200mm diameter x 30m deep hollow cast in situ rotary bored pile foundation. The aim of the foundation is to allow large diameter piles to be constructed using less concrete than in an equivalent conventional solid pile and with a view to allowing reuse at a later date. Reuse is made possible because the hollow core of the pile allows access for inspection after demolition of an existing structure. The new piles may also allow modification to enhance load capacity by augering through the base and extending their length. In addition, the piles are better suited than conventional piles for use as 'energy piles' to allow environmentally friendly heating and cooling. The geotechnical performance of the hollow test pile was comparable with a conventional solid pile constructed during the same trial. Details of construction are given including lessons learned.• A list of notations, defining all of the symbols used.•

Distributed fibre-optic monitoring of an Osterberg-cell pile test in London

“…Traditional conventional instrumentation includes vibrating-wire strain gauges (VWSGs), electrical-resistance strain gauges, axial load cells and extensometers (Bond et al, 1991;Lehane et al, 1993;McNamara et al, 2014). Recent advances have made use of the interaction of laser pulses in fibre optics (FOs), through techniques such as fibre Bragg gratings (Kersey & Morey, 1993;Lee et al, 2004;Liu & Zhang, 2012;Doherty et al, 2015) and distributed Brillouin optical time-domain reflectometry (BOTDR) (Cheung et al, 2010;Mohamad et al, 2011;Hauswirth et al, 2014;Klar et al, 2014;Kechavarzi et al, 2016;Acikgoz et al, 2017) to obtain larger datasets.…”

Distributed fiber optic monitoring of a CFA pile with a central reinforcement bar bundle

“…On the other hand, in practice, it has been found that there are still some uncertainties about the interpretation of test results due to the limitations of instrumentation. Conventional instrumentation includes electric resistance and vibrating wire strain gauges, accelerometers, axial load cells, and extensometers [2][3][4][5][6][7]. Recent advances make use of fiber optic sensors (FOS), based on either Rayleigh, Raman, and Brillouin scattering or Bragg diffraction, as an alternative to traditional instruments in piles [8].…”

Influence of geometry on the bearing capacity of sheet piled foundations

“…Significant efforts have been made to increase foundation solution sustainability, including the recent development and trialling of hollow piles (McNamara et al 2014) which benefit from a significantly reduced volume of concrete.…”