基于FLAC^(3D)的岩质边坡爆破动力响应规律研究

Study on dynamic response laws of rock slope blasting based on FLAC^(3D)

边坡的动力稳定一直以来都是岩土工程及地震工程重点研究的问题。利用FLAC^(3D)数值计算方法,对爆破作用下岩质边坡振动速度、位移、应力等进行模拟,并在与实测爆破振动峰值进行对比验证的基础上,分析边坡的动力响应规律。结果表明:地震波具有极强的方向性,主要朝施加荷载的正向传播;在边坡坡面和坡脚处因应力波在边坡自由面反射容易产生一定区域的振动加强场;应力的响应特征上,无论是拉应力还是压应力其最大值均出现在坡脚附近,在实际的边坡爆破开挖过程中,对边坡的坡面尤其是坡脚处应该加强保护措施。研究成果对岩质边坡开挖设计及施工具有一定的参考价值。

The dynamic stability of slope has always been the focus of geotechnical engineering and seismic engineering. In this paper, FLAC3 D numerical calculation method is used to simulate the vibration velocity, displacement and stress of rocky slope under blasting action. And on the basis of comparing and verifying the peak value of blasting vibration, the dynamic response laws of rocky slope was analyzed. The results show that the seismic wave has a strong directionality and propagates mainly to the positive direction of the applied load. On the slope surface and at the foot of the slope, it is easy to produce the vibration strengthening field in a certain area due to the reflection of the force wave on the free surface of the slope. The maximum value of stress, whether tensile stress or compressive stress, appears near the slope foot. In the actual blasting excavation, the slope surface should be protected, especially the slope foot. The research results have certain reference for the construction design of rocky slope excavation.