【摘要】 岩质边坡爆破振动的高程放大效应是边坡上振动速度传播规律的重要研究内容之一。基于岩质边坡爆破振动高程响应机制的理论分析以及边坡开挖爆破振动的数值模拟与实例分析,研究边坡爆破振动速度的高程放大效应。结果表明,边坡爆破振动速度的高程放大效应是在一定的条件下产生的,受爆破振动荷载特性及边坡坡形等因素的影响。爆破振动荷载作用下,边坡坡面不同高程台阶岩体结构的自振主频率处于爆破振动荷载主频带范围内,台阶部位岩体结构的振动响应会产生"鞭梢效应",导致台阶部位岩体振动速度放大。在边坡坡形骤变、坡度增大时,边坡上一级台阶岩体的振动速度可大于下一级台阶岩体的振动速度,产生显著的振动速度高程放大效应。坡形相近的条件下,台阶坡脚处的振动速度随高程的增加逐渐减小,不出现振动速度高程放大效应。"鞭梢效应"影响下,边坡台阶边沿的振动速度较大,但应力、应变较同高程台阶坡脚处的小,边沿部位的振动速度不适宜评价边坡的稳定性。更多还原

【Abstract】 Elevation amplification effect of blasting vibration is an important study content of vibration propagation law on rock slope.Based on the theoretical analysis of elevation response mechanism on rock slope,numerical simulation of blasting vibration induced by slope excavation and measured data analysis,the blasting vibration elevation amplification effect has been studied.The results indicate that the blasting vibration elevation amplification effect occurs under some conditions and it is affected by factors such as the property of blasting vibration and the slope form.Under the blasting load,when the natural frequencies of different slope benches correspond with the main frequency band of blast load,the"whiplash effects" are caused in rock structures of the slope benches and the vibrations are amplified.While slope form changes rapidly and slope gradient increase,the vibration velocity of higher slope bench may be larger than that of lower slope bench,which generates significant elevation amplification effect of vibration.Under the similar slope form,the vibration velocity at the toe of slope bench decreases with the increase of the elevation and the elevation amplification effect of vibration is not caused.Under the"whiplash effect",the vibration velocity at the edge of the slope bench is bigger than that at the toe of slope bench on the same elevation;but the stress and strain are smaller.So the vibration velocities at the edge of the slope bench are not appropriate for evaluating the stability of rock slope.更多还原