为了更好地了解顺层岩质边坡爆破开挖时振动速度的传播规律以及坡体的损伤程度,以云南省普宣高速公路顺层边坡爆破开挖为工程背景,利用声波测试结合监测点振动速度的方法,获取坡体不同深度的声速变化及不同位置的振动速度,分析不同药量下单次和多次爆破的坡体损伤范围以及振动速度的衰减规律。研究表明,爆破区任意点的振动速度与损伤深度存在对应关系:对单次爆破,振动速度与损伤深度呈线性关系,而对多次爆破,振动速度与损伤深度呈非线性关系;以声速降低率10%作为损伤界限,并作为爆破控制时,单次爆破对应的临界振动速度为11.54cm/s,损伤半径为5.57m;,基于首次爆破的多次爆破临界振动速度为24.20cm/s,最大损伤半径为7.56m,并由萨道夫基公式得到2种方式的最大起爆药量。
In order to understand the law of vibration propagation and the damage degree of the bedding rock slope during blasting excavation, we studied the bedding slope in Puli-Xuanwei Expressway in Yunnan Province as an example. By applying acoustic tests in combination with the monitoring vi- bration and sound velocities under different depths of the rock mass, we obtained the vibration velocities at different locations after blasting, and analyzed the damage range as well as the propagation and attenuation law of the vibration wave measured of different explosive doses. The results show that the vibration velocity at any point of the blasting area exhibits a corresponding relationship with the dam- age depth of the slope. It exhibits a linear relation for single explosion and a presents non-linear relation for repeated explosion. Assuming a decrease of 10% in the sound velocity as the damage limit and the control value of blasting, the critical velocity corresponding to single explosion is 11.54 cm/s, the damage radius is 5.57 m, and the critical velocity corresponding to repeated explosion is 24.20 cm/s, the damage radius is 7.56 m. The largest explosive dose is deduced by two ways mentioned above according to the Sadaovsk Formula.