Studying the Bond Performance of Full-Grouting Rock Bolts Based on the Variable Controlling Method

Abstract

This paper studied the bond performance of full-grouting rock bolts with a theoretical analysis. The variable controlling method was used to study the effect of parameters on the load-carrying force of bars. The results showed that when the bar diameter grew from 15 mm to 25 mm, the maximum force of the bars rose from 194 kN to 349 kN, growing by 80%. As for the stiffness, it grew by 108%. Moreover, when the elastic modulus grew from 50 GPa to 200 GPa, the maximum force rose from 229 kN to 269 kN, only growing by 17%. As for the stiffness, it grew by 100%. When the grouting length increased from 2 m to 3 m, the maximum force rose from 269 kN to 364 kN, growing by 35%. However, the grouting length had almost no effect on the stiffness. Lastly, for the bond slip when the bond strength was reached, when it grew from 1 mm to 3 mm, the maximum force dropped from 281 kN to 258 kN, dropping by 8%. As for the stiffness, it dropped by 44%. This paper is conducive to enriching the base of knowledge.