Open AccessHigh resolution monitoring of strain fields in concrete during hydraulic fracturing processes
Author(s) -
Rongzhang Chen,
Mohamed Zaghloul,
Aidong Yan,
Shuo Li,
Guanyi Lu,
Brandon C. Ames,
Navid Zolfaghari,
Andrew P. Bunger,
Mingjun Li,
Kevin P. Chen
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.003894
Subject(s) - reflectometry , materials science , optical fiber , distributed acoustic sensing , hydraulic fracturing , optics , fiber optic sensor , image resolution , rayleigh scattering , fiber , geology , geotechnical engineering , time domain , composite material , computer science , physics , computer vision
We present a distributed fiber optic sensing scheme to image 3D strain fields inside concrete blocks during laboratory-scale hydraulic fracturing. Strain fields were measured by optical fibers embedded during casting of the concrete blocks. The axial strain profile along the optical fiber was interrogated by the in-fiber Rayleigh backscattering with 1-cm spatial resolution using optical frequency domain reflectometry (OFDR). The 3D strain fields inside the cubes under various driving pressures and pumping schedules were measured and used to characterize the location, shape, and growth rate of the hydraulic fractures. The fiber optic sensor detection method presented in this paper provides scientists and engineers an unique laboratory tool to understand the hydraulic fracturing processes via internal, 3D strain measurements with the potential to ascertain mechanisms related to crack growth and its associated damage of the surrounding material as well as poromechanically-coupled mechanisms driven by fluid diffusion from the crack into the permeable matrix of concrete specimens.