汶川强震区泥石流起动模型试验分析

强震使大量松散堆积物堆积于高山峡谷内,由于持续降雨的作用,导致泥石流在汶川灾区频繁发生。降雨强度和物源与泥石流的起动有着密切联系,分析雨强和物源与泥石流起动的相关关系,可得不同雨强下,不同物源区泥石流起动的特征。通过对典型泥石流沟（映秀镇烧火坪侧沟,牛莲花心沟）进行野外样品采集,将两条泥石流沟进行对比室内试验。控制起动坡度,降雨强度与颗粒级配得出不同坡度下泥石流起动的表面流形成流量,起动流量。同时,与非强震区（西昌市琅环乡）的泥石流简单对比,得到强震区泥石流起动的临界条件及雨强,为泥石流的预测和治理提供相应的理论依据。通过大量的试验结果,泥石流起动首先会形成表面流,然后形成冲沟,随着物源区雨强的增加,最终形成大面积松散堆积物失稳,整体起动。泥石流起动与汇水区面积成一定关系。

Strong earthquake debris flow starting mechanism analysis

Strong earthquake makes a lot of loose accumulation in the alpine valleys,due to the continuous rain,mudslides in Wenchuan occurred frequently. The starting of debris flow is related to the rainfall intensity and source closely,analysis of the relation between rainfall intensity and source with mudslides starting,available under different rainfall intensity,different provenance mud-rock flow starting characteristics. Through the typical debris flow ditch（ Yingxiu the shaohuo ping side ditch,Niuxin ditch） for field sample acquisition,the two flow gully comparing indoor test. Control the starting slope,the rainfall intensity and grain size of different slope debris flow starting flow formation on the surface flow,starting flow. At the same time,with the strong earthquake（ Xichang Langhuan township） debris flow simple comparison,get meizoseismal area the critical starting condition of debris flow and rainfall intensity,for the prediction of debris flow and the management to provide the corresponding theoretical basis. Through lots of experiment results,debris flow starting first will form the surface flow,and gully formation,with the increase of provenance rainfall intensity,the final formation of loose debris instability of large area,starting as a whole. Debris flow starting and catchments area are into a certain relationship.