Assessing the Difference in Measuring Bolt Stress: A Comparison of Two Optical Fiber Sensing Techniques

Figure 4

Photographs of the installation of a bolt pull-out test system. Installation of (a) resin grouting materials, (b) bolt encapsulated optical fiber sensors, and (c) hollow jack together with a pressure gauge. (d) A bolt pull-out test system after installation.

(a)

(b)

(c)

(d)