Abstract: In order to explore influence of engineering blasting on rockbolt and shotcrete, cement mortar and glass fiber reinforced plastics are used to simulate the rock and rockbolt respectively; and some 2.5 m×1.8 m×2.1 m rockmass models are built. By model test, construction process is simulated according to similarity. Vibration characteristics of rockbolt and shotcrete structures near the explosion source are studied under cut blasting load. Strain waves were obtained from the measured rockbolts at different setting condition. Test results show that: (1) For end-anchored rockbolts, vibration waveforms and deformation pattern are different between the anchoring segment of rockbolts’ middle and the free segment of its tail. And vibration amplitude of anchoring segment is relatively larger than free segment. (2) Without shotcrete and prestress, strain wave on free segment of bolt tail shows better law and lasts longer. (3) Vibration frequency and amplitude of rockbolt decay distinctly with the distance from the working face; but duration of rockbolt slightly increases with the distance. By time-frequency analysis of stains waves basing on wavelet transform, it is found that: (1) For vibration energy of rockbolts close to working face is large; but vibration energy distributes widely and duration is limited. (2) For the more distance rockbolts, although vibration energy is less, vibration energy is more concentrated and vibration lasts more time. The two different vibration energies cause different damage patterns for the rockbolt and shotcrete structure. Tests and practices show that blasting vibration can easily cause damage in shotcrete and failure to rockbolts near the explosion source. Steel fiber concrete has a better anti-dynamic performance and is helpful to shotcrete near explosion source when subjected to blasting. Adjusting the support process is an effective method to decrease blasting effect.

Key words: rockbolt and shotcrete structures, model test, blasting, vibration, stress wave, shotcrete