Static and dynamic pullout test of cable bolts in laboratory scale

As a typical secondary roof-supporting system of mines and tunnels, cable bolts are subjected to static and dynamic loading conditions caused by seismic and mining extraction activities. On the other hand, as mining depth increases, stress concentrations around the openings increases, and subsequently, the probability of sudden energy release in form of rock bursts increases. In this laboratory study, a new pullout testing apparatus has been introduced, which is capable of axial pullout testing of tendons in both static and dynamic loading conditions. Several static and dynamic pullout tests were undertaken in laboratory scale to compare the response of cable bolts to different pullout rates from ۱ mm/min to ۹ m/s. Nine-strand Sumo cable bolt, as one of the common cable bolt in Australian mines, was selected for this study. Results of the tests revealed that geometery of the cable bolt can significantly change their response to the pullout load. Ultimate pullout load with bulbed cable bolts was ۱.۵ times higher than the pullout load of unbulbed cable bolts.

کلیدواژه ها:

Pullout.Cable bolting.Rockburst.Coalburst.Axial loading