工程堆积体坡面砾石分布及含量概化

为室内试验中更好地模拟工程堆积体,利用图像分析法和经典统计学方法对6大典型水蚀区的368座工程堆积体中粒径D1cm的坡面砾石的分布和含量进行概化分析,得到工程堆积体下垫面上中下坡位砾石含量的概化区间。结果表明:工程堆积体坡面各粒径砾石含量大多服从正态分布,且山区和平原丘陵区之间的砾石总含量有显著性差异。工程堆积体坡面砾石重力分选作用明显,且随着砾石粒径的增加,分选程度增大。在室内进行工程堆积体下垫面设计时,山区堆积体的砾石总含量宜设置在50%~60%,其中,细粒砾石含量宜设置在20%~30%,中粒砾石含量宜设置在10%~15%,粗粒砾石和巨粒砾石含量宜设置为10%,堆积体上中下坡位坡面砾石含量配比宜设置为1∶1.3∶1.5;平原丘陵区的砾石总含量宜设置在15%~20%,其中细粒砾石、中粒砾石、粗粒砾石、巨粒砾石含量分别宜设置为5%~10%,3%~7%,2%~5%,2%~3%,堆积体上中下坡位坡面砾石含量配比宜设置为1∶1.5∶2.5。

Generalization Study on Distribution and Content of Gravel on Engineering Accumulation Slope

In order to get a better simulation of engineering accumulation in indoor experiment,image analysis and classical statistics methods were used to generalize the distribution and content of gravel with diameter ＞ 1 cm on 368 engineering accumulation slopes,which were located in six water erosion regions.The generalized content intervals of gravel was obtained on different slope positions.Results showed as follows:Most gravel of different particle diameters obeyed normal distribution and there was a significant differency in the contents of gravel in mountain areas and in plain-hilly areas.The gravity separation effects of gravel were obvious,and the bigger the gravel was,the greater the effects were.In mountain areas,it was appropriate to set the total amount of gravel between 50％～60％ when designing the spoil underlying surface for laboratory rainfall simulation;the content of fine gravel,medium gravel,coarse and macrosome gravel were set in 20％～30％,10％～15％,and 10％ respectively;the content of gravel on top,middle and bottom slope of engineering accumulation are suggested to be 1 ∶ 1.3 ∶ 1.5.In hilly and plain areas,it was appropriate to set the total amount of gravel between 15％～20％,in while the fine gravel,medium gravel,coarse gravel and macrosome gravel accounted for 5％～10％,3％～7％,2％～5％ and 2％～3％ respectively.The optimized proportion of gravel on top,middle and bottom slope of engineering accumulation was 1 ∶ 1.5 ∶ 2.5.