基于爆破振动监测的岩石边坡开挖损伤区预测

 通过对白鹤滩水电站左岸834.0～770.0 m高程坝肩槽边坡爆破开挖振动监测和爆破损伤的声波检测，分析第一～六梯段的振动衰减规律，并通过回归分析建立不同爆心距处质点峰值振动速度与损伤深度的关系，并利用此关系和爆破振动监测结果对第七梯段的损伤深度进行预测。结果表明，当边坡岩性较为均一，且坡体上无较大结构面发育时，在一定距离处边坡预裂爆破振动峰值与保留岩体的损伤深度之间的相关性良好；采用预裂爆破振动衰减规律与保留岩体损伤深度之间的关系预测下一梯段损伤范围的方法简便可行，可大大降低大面积边坡损伤声波检测的工程量。考虑到地质条件、开挖造成的地貌改变等因素，为进一步提高预测精度，需要增加其它因素作为回归要素，或者增加部分关键部位的声波检测，对预测结果进行修正补充。

Predicting the damage zone of rock slopes under blasting excavation based on vibration monitoring

Vibration monitoring and acoustic detecting to rock slopes under blasting excavation at the altitude of 834.0–770.0 m on the left bank abutment slot of Baihetan hydropower project were carried out and the vibration attenuation of the first to the sixth bench was analyzed. The relationships between the peak particle velocity(PPV) and the damage depth at different distances to the blast center were obtained with the method of regression analysis. These relationships were applied to predict the damage depth of the seventh bench using the results of vibration monitoring. When the lithology of the slope was uniform and there was no large structural plane in the rock mass，the PPV at certain distance to the slope had a high correlation with damage depth. Predicting the damage zone using the correlations between vibration attenuation of pre-splitting blasting and damage depth of reserved rock mass was simple and convenient，thus greatly reducing the massive acoustic detection workload of rock slopes. Taking the geological conditions and physiognomy changes induced by excavation into consideration，other factors needed to be involved in regression analysis or acoustic detection points of key positions are supplemented to promote the prediction accuracy of damage depth.