【摘要】 汶川地震触发了大量崩塌滑坡灾害。这些规模差异巨大的现象之间,能量及空间是否存在着确定的分布规律?巨型崩滑和小规模坍塌是否遵从不同的形成机理?这些都是亟待解决的基本科学问题。作者在自组织临界状态(SOC)的概念框架下,通过震区典型路段考察,发现位于地震Ⅸ度区的崩滑工点,崩滑方量及崩滑体深度,与崩滑工点数目之间存在着良好的负幂律关系,地震Ⅹ度区也体现出有类似特征;拟静力模拟地震的沙堆离心模型实验表明,模型底板倾斜1.5°时,崩塌的动力学特性可以用幂律描述,底板倾斜达到3°时服从正态分布;元胞自动机模型数值模拟表明,随扰动强度增加沙堆模型动力学特性的演变是渐进的。从而从整体理论上对上述问题提出新的解释:处于青壮年期的山地斜坡系统具有SOC的内禀基本属性;存在一个地震强度阈值,在此之下地震触发的崩滑规模与出现频率之间的分布规律可用幂律描述,巨型崩滑灾害和小规模坍塌现象遵从同一形成机理。全新的认识可望为地震触发崩塌滑坡灾势评估提供普适性的概型并建立应用框架。更多还原

【Abstract】 In the conceptual framework of self-organized criticality(SOC),and by investigating the typical slopes in Ⅸ seismic zone of Wenchuan earthquake,the negative power-law relationship of landslides between volume and number,as well as between depth and number was found.Furthermore,landslides also demonstrated the similar characteristics in Ⅹ seismic zone of Wenchuan earthquake.Based on the principle of quasi-static theory,the sandpile model centrifugation tests repeated the dynamic behavior of slope under seismic disturbances,and the dynamical characteristics of landslips can be showed with negative power distribution law when the model box floor tilted 1.5°,but showed normal distribution when 3.0°,and the cellular automaton models revealed the dynamical mechanism of the evolution of sand-pile model with the changes of disturbance intensity by numerical simulation.It was suggested that the slope system in younger or maturity age has the basic properties of intrinsic SOC.There is a seismic intensity threshold,the distribution law between size and frequency of landslides triggered by earthquake can be described under the threshold,and both the huge-scale and small-scale landslides disasters comply with the same formation mechanism.更多还原