【摘要】 利用"4·20"芦山地震Ⅶ—Ⅸ度烈度区资料翔实的有利条件,研究不同烈度区地震触发崩塌滑坡的整体分布规律,并基于自组织临界状态理论,从物理角度对其机理进行诠释.实震资料表明:Ⅸ度、Ⅷ度、Ⅶ度烈度区,崩塌滑坡面积与发生频率之间的关系均可用幂律描述,且幂指数b值相近,但随地震烈度的降低,崩塌滑坡密度单调减小;元胞自动机模拟表明:当扰动强度按0.5的比率递减时,沙堆模型的动力学特性基本服从同一幂律分布,雪崩密度呈线性关系减小;振动台沙堆模型物理实验也支持了以上结论.说明规模与发生频率之间的幂律关系是Ⅶ—Ⅸ度烈度区地震触发崩塌滑坡的统一分布规律,灾害点密度的不同是体现它们震害强度差异的主要指标.结论可为地震触发山地灾害危险性区划、地震次生灾害风险评估等提供科学依据.更多还原

【Abstract】 Based on the detailed data of "4·20"Lushan Earthquake from Ⅶ to Ⅸ seismic intensity zone,the distribution law of landslides triggered by earthquakes in different seismic intensity zones was explored. The mechanism is interpreted from a physical point of view. The field data shows that there exists a power-law relationship between the area and frequency of landslides inⅨ、Ⅷ、Ⅶ seismic intensity zones. Exponent b of the power-law in different zones is closed. But with the decline of the seismic intensity,the density of landslides decreases monotonically. The cellular automaton simulation reveals that the dynamical mechanism of sand-pile model is subject to the same power-law distribution,with 0. 5 decline ratio of disturbance intensity. The density of avalanche decreases linearly. Physics experiments with shaking table sandpile model also support above results. It is concluded that the power-law relationship between the scale and frequency is the basic regulation of landslides triggered by earthquakes from Ⅶ to Ⅸ seismic intensity zone. Different densities may serve as a major indicator of various intensities of damage. The research results may be used to provide scientific basis to sketch and assess the mountain disasters triggered by earthquake.更多还原