龙滩水电站地下厂房开挖爆破震动衰减规律研究

RESEARCH ON THE BLASTING VIBRATION VELOCITY ATTENUATION LAW IN THE EXCAVATION OF LONGTAN UNDERGROUND POWERHOUSE

在地下厂房开挖支护过程中，爆破震动控制直接影响到高边墙的稳定及岩锚粱结构安全。本文根据龙滩水电站地下厂房Ⅲ～Ⅶ层开挖爆破震动监测数据，采用统计分析方法，经二元回归计算得到主厂房岩石高边墙、岩锚吊车梁以及已喷护岩石边墙、锚索（杆）墩（头）等防护目标的爆破振速衰减规律经验公式。结果表明，地下厂房开挖过程诱发的爆破震动沿高程H方向总体没有放大现象，但衰减较为缓慢或很缓慢，这为地下厂房工程开挖爆破施工提供了理论依据。

The control of blasting vibration in the excavation of underground powerhouse is the key factor influencing the construction safety of underground powerhouse. Based on the monitoring data of blasting vibration in the excavation of Ⅲ- Ⅳ layers of Longtan hydropower project underground powerhouse, the paper obtained the empirical formula for the attenuation law of blasting velocity by adopting the statistic analysis method accompanied with the duality regression analysis, which involved some protected objects, such as the high side walls and crane beam anchored on rock of main power house, side walls with shotcrete and anchor mound. The results showed that the deep-hole blasting induced vibration gave no evidences of vibration-amplifying effect along the high side walls, and the attenuation of the vibration velocity was relatively slow or very slow. The results obtained offered theoretical foundation for the similar blasting works in excavation of underground powerhouse.