• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.6
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• pp.459-468
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• 2023

In this study, an experiment on pullout capacity was conducted of rock bolts using grouting materials such as cement mortar and resin, which are widely used, and a newly proposed steel pipe friction type rock bolt using elastic restoring force, and the results were compared and analyzed. The experimental results showed that the pullout capacity on the rock bolts with cement mortar under a dry condition (no ground water) was relatively larger than the rock bolts with resin and the steel pipe. Nevertheless, the friction type steel pipe rock bolt to use elastic restoring force is expected to be useful in the field particularly where groundwater exists and it affects the loss and curing of grouting materials such as cement mortar or resin. In addition, it was found to have the advantage of being easy and quick to install.