Fiber Optic Monitoring of Base Grouted Piles

Researchers: Andrew Yeskoo and Kenichi Soga (Cal), Erik Loehr and Andy Boeckmann (University of Missouri), Tom Shantz (Caltrans)

Client/Owner: California Department of Transportation (CALTRANS)

Technologies: Distributed Fiber Optic Sensing

Publications: R. A. Yeskoo and K. Soga. “Fiber Optic Monitoring of Base Grouted Piles.” CALTRANS Report, 2021. (publication pending)

The UC Berkeley team participated in a full-scale field test of different base grouting technologies, using fiber optic sensing to measure strain and temperature development throughout the project. The project included the construction of 13 drilled shafts, base grouting of 12 of the 13, and full-scale load testing of 4 of the shafts. Three different base grout delivery systems were trialed on the project, with the overall goal being to compare the performance of the different methods as well as refine the quality assurance/quality control methods employed during grout delivery. The types of monitoring performed by the UC Berkeley team included distributed fiber optic sensing (DFOS) of temperature development during curing, DFOS for strain monitoring during base grouting and load testing, and point-based Fiber Bragg Grating (FBG) strain monitoring during base grouting and load testing. These results were compared with conventional electronic sensors and showed good agreement throughout the monitoring program.