Instrumentation for Monitoring the Dynamic and Static Behaviour of Rock Bolts in Tunnels.

Rodger, Albert Alexander; Littlejohn, G S; Xu, Hongli; Holland, D.

doi:10.1680/igeng.1996.28506

Cited by 6 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This has not been practically achievable for multi-metre long reinforcement elements using conventional sensing technologies, such as electrical resistive strain gauges and load cells (e.g. Rodger et al 1996).…”

Section: Introductionmentioning

confidence: 99%

Coaxial load development along grouted plain strand cable bolts determined by distributed fibre optic strain sensing

Forbes,

Vlachopoulos,

Diederichs

2023

Ground Support 2023: Proceedings of the 10th International Conference on Ground Support in Mining

View full text Add to dashboard Cite

This paper is focused on the mobilisation of coaxial load and displacement along grouted plain strand cable bolts during laboratory coaxial pull testing. In comparison to the existing body of work on cable bolts, this research has investigated grouted cable lengths in excess of a metre. As a result, the load distributed along the cable bolts was not uniform during loading and required many discrete sensing locations to be measured. To this end, a high spatial resolution distributed fibre optic strain sensing technology was used to measure a nearly continuous coaxial load distribution along each cable bolt that was tested. Load development length was measured to increase from the loaded end to the free end of the cable with increased coaxial load. The measured load distributions indicated that the predominate anchoring force of cable bolts was the result of frictional resistance at the cable-grout interface and not dilational slip and shearing of grout flutes. Furthermore, this determined that a grouted length in excess of 2.5 m would be required to fail a typical 15.24 mm diameter cable with an unconstrained end (typical loading condition of tie-backs and toe-grouted cables bolts).

show abstract

Section: Introductionmentioning

confidence: 99%

Coaxial load development along grouted plain strand cable bolts determined by distributed fibre optic strain sensing

Forbes,

Vlachopoulos,

Diederichs

2023

Ground Support 2023: Proceedings of the 10th International Conference on Ground Support in Mining

View full text Add to dashboard Cite

show abstract

“…Examples include electrical-resistive strain gauges (e.g. , Farmer 1975;Serbousek and Signer 1987), load cells (e.g., Rodger et al 1996;Mitri 2011), long base-length induction gauges and displacement transducers (e.g., Choquet and Miller 1988;Spearing et al 2013), and inclinometers (e.g., Volkmann 2003). Using these sensing techniques, the support member under study is effectively discretized into a number of discrete (or individual) measurement points or zones depending on the gauge length of the chosen sensor (see Fig.…”

Section: Introductionmentioning

confidence: 99%

The application of distributed optical strain sensing to measure the strain distribution of ground support members

Forbes

Vlachopoulos

Hyett³

2018

FACETS

View full text Add to dashboard Cite

A distributed optical strain-sensing technique is presented as a solution for measuring the strain distribution along ground support members used in tunnelling and mining works. The technique employs a Rayleigh optical frequency domain reflectometry technology, which measures strain at a spatial resolution of 0.65 mm along the length of a standard optical fiber. A rationale for selecting this technology as a potential monitoring technique for ground support elements over alternative commercially available technologies is discussed. The development of a technique to couple optical fiber sensors with rock bolt, umbrella arch, and cable bolt support members is also demonstrated. A robust laboratory investigation of such optically instrumented support members demonstrated the capability of the technique to capture the expected in situ support behaviour in the form of coaxial, lateral, and shear loading arrangements as would be anticipated in the field. Moreover, the microscale data obtained by this optical sensing technique are shown to provide unprecedented insight into the local/micro-scale geomechanistic complexities associated with the bearing capacity of ground support members, especially when compared with data obtained by discrete strain-sensing technologies.Key words: distributed optical strain sensing, ground support, rock bolt, cable bolt, strain measurement, strain profile OPEN ACCESSCitation: Forbes B, Vlachopoulos N, and Hyett AJ. 2018. The application of distributed optical strain sensing to measure the strain distribution of ground support members. FACETS 3: 195-226.

show abstract

Tunnelling in Weak Rock

Vlachopoulos

Forbes

Vazaios

2019

Soft Rock Mechanics and Engineering

View full text Add to dashboard Cite

Instrumentation for Monitoring the Dynamic and Static Behaviour of Rock Bolts in Tunnels.

Cited by 6 publications

References 0 publications

Coaxial load development along grouted plain strand cable bolts determined by distributed fibre optic strain sensing

Coaxial load development along grouted plain strand cable bolts determined by distributed fibre optic strain sensing

The application of distributed optical strain sensing to measure the strain distribution of ground support members

Tunnelling in Weak Rock

Contact Info

Product

Resources

About