地下厂房开挖爆破地震反应谱特征研究

建筑物在爆破地震作用下的反应是爆破振动和结构动力响应特性共同作用的结果,爆破振动反应谱综合表征了这两方面的影响。结合向家坝水电站地下厂房开挖的爆破振动监测数据,对地下厂房爆破开挖中顶拱层开挖爆破、梯段爆破、保护层开挖爆破及预裂爆破几种不同爆源形式的爆破地震反应谱进行了分析,并与露天梯段爆破以及天然地震的反应谱进行了对比。研究结果表明,地下厂房开挖爆破振动反应谱具有明显放大效应对应的周期值为0.002～0.01s,明显小于露天梯段爆破和天然地震,并且有明显放大效应所对应的周期范围相对要窄得多。

STUDY ON RESPONSE SPECTRUM OF BLASTING VIBRATION INDUCED BY UNDERGROUND POWERHOUSES EXCAVATION

The response of a structure in the blasting earthquake is affected by the blasting vibration and its dynamic response characteristic,which was charactered by response spectrums of blasting vibration.According to monitoring data from excavation of underground powerhouse in Xiangjiaba Hydropower Station,response spectrum of blasting vibration with different forms of explosion source,which included arch blasting,bench blasting,protective layer blasting and presplitting blasting,were analyzed and compared with response spectrums of surface bench blasting and natural earthquake.The results showed that the period of blasting vibration response spectrum with evident amplification effect was 0.002~0.01s in excavation of underground powerhouse,whose value was smaller and range was narrower than surface bench blasting and natural earthquake.