危岩破坏激振信号概率统计特征研究

具有复杂成生关系的危岩块聚集体是孕发大型及特大型崩塌灾害的基本条件,聚集体内任何一个危岩块的突发性破坏均会释放能量,并向周围传播,产生激振效应,可用激振加速度表征危岩破坏激振信号。针对坠落式危岩,通过室内模型试验,分析了实验条件下危岩破坏激振信号的概率统计特征。分析结果表明,危岩破坏所释放的能量具有点荷载特征,激振信号具有一定的自相关性;激振信号的概率密度呈现单峰型近似正态分布,概率密度水平方向的峰值强度大于竖直方向的峰值强度;危岩破坏瞬间,距离激振源越近,激振信号的均值、有效值和标准差数值越大,且竖直方向的量值大于水平方向的量值;危岩块之间界面的完整性影响着激振信号的传递效果,完整性越好,激振信号的统计特征值及概率密度峰值越大,激振信号衰减用时越长。研究成果对于实施考虑相似条件下危岩破坏激振效应实验研究有积极意义。

Study on probability and statistics characteristics of excitation signal at rupture of perilous rock

The perilous rock aggregates with complex genetic relations are the basic conditions to trigger large and giant collapse disasters, the sudden destruction of any rock block in the aggregates will release energy which spread to the surrounding and produce excitation effect. The excitation signal is reasonable to be characterized by excitation acceleration. For the falling perilous rock, the probability statistical features are analyzed through the indoor model test. The results show that the energy released at rupture of perilous rock has point load characteristics and autocorrelation at a certain extent. The probability density of excitation signal showing a single peak approximates a normal distribution, as well as, the peak intensity in the horizontal is greater than that in the vertical. At the moment for perilous rock to rupture, the closer to excitation source, the average value, the valid value and the standard deviation of excitation signals are greater, especially the measuring value at the vertical direction is greater than that at the horizontal direction. the completeness of the interface between perilous rock blocks significantly affect excitation signal transmission, the peak of the statistical characteristics and the probability density of excitation signal is greater as the completeness gets better, and the transfer effect of the excitation signal is better as the attenuation time gets longer. The study has a positive meaning to make the model test of excitation effect at rupture of perilous rock under similar conditions.