【摘要】 汶川地震后,极震区产生了大量的崩滑堆积体、震裂岩体及震动松弛覆盖层,极震区震后泥石流物源的产生及汇集方式发生了极大的变化,但缺乏震后特殊条件下动储量的计算方法。在实际调查统计"5·12"极震区安县高川乡多条泥石沟物源的基础上,总结了极震区震后泥石流的形成过程及启动方式。分析得出,震后泥石流物源量与沟域面积、高程放大效应、断层运动方式、地质岩性条件及地形条件等因素有关,其中沟域面积、沟顶高程及沟道与发震断裂的距离为主控影响因子。在此基础上,提出了"地震高程指数放大经验模型";通过多元统计拟合法首次得出了震后泥石流动储量与流域面积、高差的计算关系,并通过地震距离修正得出极震区震后泥石流的动储量计算公式,为震后泥石流动储量估算及工程治理提供参考。更多还原

【Abstract】 After the Wenchuan earthquake,a great deal of slumping mass,shattered rock and the soil with loose surface were formed. The formation and accumulation way of the post-seismic provenance of debris flows in the meizoseismal area had a great changes,it is still lack of methods to calculate dynamic reserves in special conditions after earthquakes. On the basis of the field work of investigating and counting provenance features of several debris flows gullies in Gaochuan Village,An County in Sichuan Province,the meizoseimal area of Wenchuan earthquake,we summarized in this essay the formation process and start methods of post-seismic debris flows in the meizoseimal area.Through analysis,we also drawn the conclusion that the provenance amount of debris flows after the earthquake is related to the gully’s area,elevation amplification effect,movement pattern of fault,geological lithology and topography,and the gully’s area,the elevation of the gully top and the distance between the gully and seismogenic fault are key factors. Under that condition,we propose the ‘empirical model on seismic elevation index amplification’. And this is the first time through multivariate statistics fitting method to figure out the calculation relationships of post-seismic dynamic reserves of debris flows with the drainage area and the altitude difference. We also obtain formula about dynamic reserves of debris flow through the seismic distance modification. It provides a refevence to estimation of post-seismic dynamic reserves of debris flowss and engineering prevention and control.更多还原