Supervisorer: Lars Pilgaard Mikkelsen, DTU Vindenergi - Charlie Chunlin Li, NTNU Norway
Eksaminator: Ulrik Borg, Fiberline
Titel: Performance of fully grouted GFRP rock bolt in combined pull and shear
Glass Fiber Reinforced Polymer (GFRP) rock bolts is gaining attention, as an alternative to steel bolts, for permanent rock support. GFRP holds many advantages for this purpose, including light weight, lower environmental impact and excellent durability characteristics. However, the shear strength of GFRP rock bolts is significantly lower than the tensile strength, which raises a concern in combined loading condition. The report has through several experiments defined important parameters and evaluated the performance of a GFRP rock bolt in a combined loading condition. It was found that the strength of the rock bolt at 47° displacement angle was similar to the tensile strength (0°), while in the range of 47°-72° the strength is dropping significantly to a value closer to what was measured in pure shear (90°). Finally an attempt was made, to replicate the obtained results, using numerical modelling. This had limited success, thereby indicating that a more advanced model is required to properly simulate the behaviour of a GFRP rock bolt.