循环爆破振动下边坡变形累积效应研究

Study on Cumulative Effect of Slope Deformation Under Cyclic Blasting Vibration

为了研究循环爆破下边坡受到的累积动载作用,对白马铁矿及及坪采场东帮边坡进行了现场爆破振动监测,并通过FLAC3D软件进行了循环加载模拟计算。研究结果表明:边坡在水平径向、水平切向、竖直方向3个方向的振动速度先增大后减小,整体呈下降趋势,且峰值速度出现在水平径向方向;随着爆破次数增加,边坡水平方向上的最大位移由7.89mm增大到8.05mm,对应的剪应变由7.44×10^(-4)增大到7.88×10^(-4);边坡的累积变形量与爆破振动次数之间成正相关变化关系。推导出了水平位移量X与爆破次数n之间的关系表达式。通过数值模拟方法可推算出生产爆破强度下的安全爆破次数阈值,从而指导矿山的安全生产。

In order to study the cumulative dynamic load of the slope under cyclic blasting,the on-site blasting vibration monitoring was carried out on the eastern slope of the Jijiping mining site in Baima Iron Mine,and the cyclic loading simulation calculation was carried out by FLAC3D software.The results show that the vibration velocity of the slope in the horizontal radial,horizontal tangential and vertical directions increases first and then decreases,and the overall trend is downward,and the peak velocity appears in the horizontal radial direction.With the increase of blasting times,the maximum displacement in the horizontal direction of the slope increases from 7.89 mm to 8.05 mm,and the corresponding shear strain increases from 7.44×10^(-4)to 7.88×10^(-4).There is a positive correlation between the cumulative deformation of the slope and the number of blasting vibrations.The expression of the relationship between the horizontal displacement X and the blasting times n is deduced.Through the numerical simulation method,the threshold value of safe blasting times under the production blasting intensity can be calculated,so as to guide the safe production of the mine.