周期性爆破振动下围岩的损伤累积效应

采用现场测试的方法对岩石巷道爆破近区的振动进行测试，随着掘进工作面的推进，得出了爆破振动沿巷道侧壁的传播衰减规律；利用超声波测试技术对巷道侧壁的损伤规律进行研究，揭示了爆破振动下岩体的损伤累积规律。研究发现：在爆破近区15 m内爆破振动衰减缓慢，之后有一个急剧衰减过程，掘进工作面推进到25 m时，爆破振动衰减到1 cm/s左右。通过比较发现斜线法更适于巷道侧壁的损伤测试，工作面推进到10~20 m时损伤度急剧增长。综合分析爆破振动与声测结果得出：在周期性爆破振动载荷下垂直于测试孔方向的微裂纹得到优先发展，爆破振动的衰减是岩体内部损伤发展的外在表现。

Damage accumulative effect of surrounding rock under periodic blasting vibration

The authors performed vibration test on the rock tunnel near blasting point adopting field test，obtained the spread attenuation law of blasting vibration along the tunnel sidewall with the development of heading face，used ultrasonic testing techniques to study the damage of tunnel sidewall，and revealed the law of cumulative damage of rock mass under blasting vibration.The study find that in the blast near zone within 15 m of blasting vibration decay slowly，and then a sharp attenuation process.When heading face carries out to 25 m，blasting vibration attenuates to 1 cm/s or so.By comparison，the slash testing method is more suitable for damage test of the lateral wall of tunnel.The damage degree increases sharply when the working face advanced to 10-20 m.Comprehensive analysis of blasting vibration and acoustic measurement results，the studies show that the micro cracks perpendicular to the direction of test holes has the priority to develop，and blast vibration attenuation is the outward manifestation of the damage development in the rock.