生产建设项目弃土堆置体下垫面仿真模拟标准化参数

Standardization Parameter for Spoilbank Underlying Surface Simulation of Development Construction Project

室内模拟降雨实验是进行生产建设项目人为弃土水土流失特征研究的重要方法。为了使实验下垫面设计更加科学合理,实验结果应用范围更加广泛,通过对陕西关中平原区和秦巴山区各类生产建设项目弃土堆置体的实地调查,结合室内实验,运用经典统计学有关原理对堆置体的坡度、坡长、坡面物质组成进行统计分析。结果表明:秦巴山区生产建设项目弃土堆置体在不同坡面位置上,块石和土壤结构体的含量均明显大于关中平原区;两研究区内细粒土含量极少且均未超过2%;块石和土壤结构体重力分选作用明显,D<10mm的坡面物质在不同坡位的含量数据变化较小且无明显规律;因此在室内进行下垫面仿真设计时,对D<10mm的坡面组成物质可不考虑坡面位置的差异性。两研究区内弃土堆置体坡度多集中在26°～35°之间,贡献率分别为90.2%和88.8%;弃土堆置体坡长多集中在2～8m之间,贡献率分别为100.0%和79.4%。因此,在室内进行下垫面仿真设计时应重点对上述坡度、坡长范围进行实验测试。

Laboratory rainfall simulation is an important method for studying erosion characteristics of spoilbanks in development construction projects.In order to provide a scientific foundation for the design of the spoilbank underlying surface in laboratory rainfall simulation,authors firstly investigate development construction project spoilbank in Guanzhong plain and Qinba mountain area,Shaanxi province.The theory of statistics was applied to analyze gradient,length of slope,composition of slope surface.The results showed as follows： The percentages of stones and soil aggregates at different position of spoilbank slopes in Qinba mountain area were higher than spoilbank in Guanzhong plain;the percentages of fine-grained soil both in two studied areas were less than 2%;stones and soil aggregates＇ gravity separation effects were obvious;the percentages of material（particle diameter10 mm） at different position of spoilbank slopes didn＇t obviously change.Therefore,percentages of material（particle diameter10 mm） at different position of spoilbank slopes can＇t be considered during the design of the spoil underlying surface for laboratory rainfall simulation.The gradient of spoilbank were between 26° and 35° in two studied areas with contribution rate 90.2% and 88.8% respectively;slope length of spoilbank were between 2 m and 8 m with contribution rate 100.0% and 79.4% respectively.Therefore,ranges of gradient and length were mainly considered during design experiment of the spoilbank underlying surface in laboratory rainfall simulation.