The Influence of Rib Spacing and Borehole Diameter on the Axial Response of Fully Cemented Rebar Rock Bolts Using Distributed Fiber Optic Sensors

ABSTRACT: Rock bolts are often utilized to provide support to excavations. To better understand bond performance numerous investigations have been conducted. Due to practical and technological limitations, an in-depth investigation (at the geo-mechanical micro scale) of the load transfer and continuous stress distribution along a fully grouted rock bolt has been challenging. The advent and application of Distributed Fiber Optic Sensors (DOS) has led to a methodology (developed by the authors) capable of providing a continuous strain profile for structural members. This paper summarizes the innovative methodology that has been employed for a series of laboratory axial pullout tests in order to determine the effects of rib spacing and borehole diameter on the geo-mechanical response of fully cement grouted rebar rock bolts within simulated rock masses. The results of the research will augment the current body of literature, while also improving rock bolt development, design and implementation.