A New Apparatus for Installing Distributed Optical Sensors onto Uniaxial Compression Test Specimens to Measure Full-Field Strain Responses

The uniaxial compressive strength (UCS) test is a key tool used by the geotechnical industry to determine the strength and stiffness behavior of intact rock. A fundamental procedure in the process of these experiments is strain response measurement. The standard method of measuring UCS test strain response is to use discrete strain measuring devices such as extensometers or electric strain gages, or both, at the mid-height of a specimen. However, by using a novel technique of integrating distributed optical strain sensing with UCS testing, a high density full-field strain response of UCS specimens can be measured. This article presents a novel device that can be used as a turnkey solution for installing optical strain sensors to the exterior of UCS specimens for the benefit of measuring full-field specimen strain during UCS testing.