Optimization of impact pile driving using optical fiber Bragg-grating measurements

Buckley, R. M. , McAdam, R. A., Byrne, B. W., Doherty, J. P., Jardine, R. J., Kontoe, S. and Randolph, M. F. (2020) Optimization of impact pile driving using optical fiber Bragg-grating measurements. Journal of Geotechnical and Geoenvironmental Engineering, 146(9), 04020082. (doi: 10.1061/(ASCE)GT.1943-5606.0002293)

Abstract

This paper reports the use of optical fiber Bragg-grating (FBG) sensors to monitor the stress waves generated below ground during pile driving, combined with measurements using conventional pile driving analyzer (PDA) sensors mounted at the pile head. Fourteen tubular steel piles with a diameter of 508 mm and embedded length-to-diameter ratios of 6∶20 were impact driven at an established chalk test site in Kent, United Kingdom. The pile shafts were instrumented with multiple FBG strain gauges and pile head PDA sensors, which monitored the piles’ responses under each hammer blow. A high-frequency (5 kHz) fiber optic interrogator allowed a previously unseen resolution of the stress wave propagation along the pile. Estimates of the base soil resistances to driving and distributions of shaft shear resistances were found through signal matching that compared the time series of pile head PDA measurements and FBG strains measured below the ground surface. Numerical solutions of the one-dimensional wave equation were optimized by taking account of the data from multiple FBG gauges, leading to significant advantages that have potential for widespread application in cases where high-resolution strain measurement

• Item Type: Articles
• Additional Information: The ALPACA project was funded by the Engineering and Physical Science Research Council (EPSRC) through Grant No. EP/ P033091/1.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Buckley, Dr Roisin
• Authors: Buckley, R. M., McAdam, R. A., Byrne, B. W., Doherty, J. P., Jardine, R. J., Kontoe, S., and Randolph, M. F.
• College/School: College of Science and Engineering > School of Engineering > Infrastructure and Environment
• Journal Name: Journal of Geotechnical and Geoenvironmental Engineering
• Publisher: American Society of Civil Engineers
• ISSN: 1090-0241
• ISSN (Online): 1943-5606
• Published Online: 29 June 2020
• Copyright Holders: Copyright © 2020 ASCE
• First Published: First published in Journal of Geotechnical and Geoenvironmental Engineering 146(9): 04020082
• Publisher Policy: Reproduced under a Creative Commons License