危岩破坏激振信号概率统计特征研究

Probabilistic and statistic characteristics of excitation signals during rupture of perilous rock

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。

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 releases energy to spread to the surrounding and produce an excitation effect.The excitation signal is reasonable to be characterized by an excitation acceleration.For the falling perilous rock,its probabilistic and statistical features were analyzed through an indoor model test.The results showed that the energy released during rupture of perilous rock has point load characteristics and a certain autocorrelation;the probability density of the excitation signal reveals a single peak type and a quasi-normal distribution, the peak intensity in the horizontal direction is greater than that in the vertical direction;at the moment for perilous rock to rupture,the closer the distance from the excitation source,the greater the average value,the valid value and the standard deviation of the excitation signal,especially,the measuring value in the vertical direction is greater than that in the horizontal direction;the completeness of the interface between perilous rock blocks significantly affect excitation signal transmission effect,the better the completeness,the greater the peaks of the statistical characteristics and the probability density of the excitation signal,and the longer the time of the excitation signal decay.The study was meaningful to the model test of excitation effect during rupture of perilous rock under similar conditions.