枇杷沟泥石流基本特征分析与评价

The analysis and evaluation on the basic characteristics of loquat gully debris flow

以枇杷沟地区地质环境为基础,综合多因素分析阐明:枇杷沟泥石流的发生除受地形地貌等因素的影响外,地震过程中受损岩土体为泥石流的发生提供了大量物源,但主控因素为降雨量及降雨强度。在进行大量野外地质工作的基础上,运用数学手段对枇杷沟泥石流特征值进行计算和确定并最终分析表明:地震地质作用与外动力地质作用所形成的崩滑物在粒度和分选上有所区别,对泥石流的容重和流量有所影响;震后灾区泥石流对泥石流沟道有着明显的拓宽效应和"刮铲效应",使泥石流过水断面面积和泥石流平均流速发生显著变化,所以在确定新的参数并得到新的流量值后有必要使用行之有效的计算方法对计算结果进行验证。

Based on loquat gully geological environment,and a comprehensive analysis on multivariate factors,the paper indicates that:in addition to the affect factors of landform,the damaged rocks during earthquake provide a large number of material resources for the occurrence of loquat gully landslides debris flow.However,the main controlling factors are the amount and intensity of rain fall.On the basis of a lot of field geology work,mathematical means,the calculation and identification to loquat gully debris flow have been made and the final analysis shows that the slump matters caused by geological actions of earthquakes and exogenic geological formation have differences in size and sorting,have an impact on the bulk density and flow of debris flow.After the earthquakes,the debris flow in disaster place has a clear broadening effect in flow channel and 'ploughing and erosion effect',which causes significant changes on debris flow cross section area and average velocity.Thereafter,it is necessary to use an effective method of calculation to calculate and verity the results after identifying the new parameters and the new flow rate value.