基于Goodman单元的顺层边坡爆破动力响应数值模拟

为了研究爆炸荷载作用下顺层边坡岩体的动力响应,采用数值模拟的方法对边坡坡面及岩体内部质点振速、应力场的分布规律进行分析,采用Goodman单元模拟岩体内部软弱结构面.结果表明：边坡台阶处坡形的变化会导致质点振速和应力值波动明显,台阶突出部位"鞭梢效应"显著,但质点振速与应力并非在边坡坡面的同一位置达到峰值,因此将质点峰值振速或应力值作为评价边坡稳定性的单一指标并不合理;岩体内部质点的动力响应规律主要与介质阻尼、结构面以及边坡形状等因素有关,结构面的存在会造成爆炸应力波的反射叠加,质点振速和应力值在结构面之前也有一定程度的放大;边坡自由面对应力波的反射叠加效应不应忽视.

Numerical Simulation of Dynamic Response Law of Bedding Slope Blasting Based on Goodman Element

To study the dynamic response of bedding slope rock under blasting load, numerical simulation method is used to analyze the propagation law of velocity and stress field of the slope. Goodman unit is used to simulate the relative slip of rock masses on both sides of the structural plane. The results show that the change of the slope shape at the step of the slope will cause the vibration velocity and stress value of the particle to fluctuate significantly, and the "whiplash effect" of the protruding part of the slope step is obvious, but the vibration velocity and stress do not reach the peak at the same part of the slope. Therefore, it is unreasonable to use the peak vibration velocity or stress value as the single index to evaluate the stability of the slope. The dynamic response of the internal mass of the rock mass is mainly related to the factors such as medium damping, structural plane and slope shape. The existence of the internal structural plane will cause the reflection of the explosion stress wave to be superimposed, and the vibration velocity and stress value of the particle point will also be enlarged to some extent before the structural surface. The reflection superposition effect of stress wave on the free surface should not be ignored