Performance Monitoring of a Secant-Piled Wall Using Distributed Fiber Optic Strain Sensing
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 137, Issue 12
Abstract
An optical fiber strain-sensing technique, on the basis of Brillouin optical time domain reflectometry (BOTDR), was used to monitor the performance of a secant pile wall subjected to multiple props during construction of an adjacent basement in London. Details of the installation of sensors and data processing are described. Distributed strain profiles were obtained by deriving strain measurements from optical fibers installed on opposite sides of the pile to allow monitoring of both axial and lateral movements along the pile. Methods for analyzing the thermal strain and temperature compensation are also presented. Measurements obtained from the BOTDR were found to be in good agreement with inclinometer data from the adjacent piles. The relative merits of the two different techniques are discussed.
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Acknowledgments
The writers would like to thank the assistance provided Dr. Assaf Klar and Dr. Eduard Vorster (former members of Cambridge Geotechnical Research Group) during the fiber optic installation process. The writers would like to acknowledge in particular the support provided by Mr. Jim Mackey of McGee Group Ltd and Arup Geotechnics in supporting this work.
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Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 137 • Issue 12 • December 2011
Pages: 1236 - 1243
Copyright
© 2011 American Society of Civil Engineers.
History
Received: May 25, 2010
Accepted: Mar 16, 2011
Published online: Mar 17, 2011
Published in print: Dec 1, 2011
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