藏木水电站基坑开挖梯段爆破试验

Experimental Study of Bench Blasting in Foundation Pit Excavation of Zangmu Hydropower Station

藏木水电站地处西藏海拔高、空气稀薄地区,为确保基坑爆破开挖施工质量,了解爆破对周围非开挖岩体及建筑物的影响范围与程度,掌握爆破质点振动衰减规律,控制爆破规模,降低爆破振动效应,以保证相邻建筑物安全。通过爆破试验确定了最优爆破参数,利用爆破测振仪测得爆破质点振速,根据萨道夫斯基回归公式原理,计算得出符合本项目岩体特性K值与α值,以此指导现场爆破施工,确保了基坑爆破开挖质量及相邻建筑物安全稳定。

Zangmu Hydropower Station is located in the area of high altitude and rarefied air,which may affect the performance of the blasting excavation construction.In order to ensure the quality of the blasting excavation of the foundation pit and to determine the influence scope and degree of the blasting on surrounding rock mass and buildings,experiments are carried out to get the attenuation mechanism of the blasting induced vibration and thus to ensure the safety of adjacent buildings with controlling of the blasting scale and reducing of the blasting vibration effect.Optimal blasting parameters are determined.Then,based on the measured vibration velocities of blasting particles,the characteristic K andαvalues are calculated with Sadov formula and successfully adopted in the in-situ construction.