Effects Of Blast Loading On Rockbolt Anchorage Structure Near The Working Face In Model Test

Effects of blast loading on rockbolts near the working face are studied in this disertation. It is of great significance for rapid excavation and supporting design of roadway. Dynamic strain signals on rockbolt in model test were acquired to analyze rockbolt deformation in and after balst loading using dynamic signal analyzer. Deformation law is revealed about end-anchored and full grouted rockbolts subjected to balst loading. It is founded that rockbolts are bending after blast excavation. By spectral analysis based on energy, frequency spectrum laws are studied about dynanic strain signals of rockbolt in near field. Frequency spectrums of measured pointes are related to position and ancharage state. By wave function expansion method, dynamic response of anchored structure has been studied subjected to plane harmonic wave and the possible positions of the cracks are obtained. Utilizing displacement potential function of the infinite body under single force, additive axial stress on anchored section is calculated under some prestress. By damage criteria, analysis shows that end-anchored rockbolts neaerby are likely damaged or lose active supporting effect because of blast loading, combined with rockblot deformation and pull-out force measurement in model test and condition of anchored structure in filed test.