黄土区工程堆积体水蚀测算模型坡度因子研究

Study on slope factor of water erosion model for engineering piles in the Loess Area

生产建设项目形成大量的弃土弃渣,即工程堆积体,坡度陡峻,物质组成复杂,土体多含石砾,且较为松散,具有区别于自然坡地独特的侵蚀机理与水土流失规律。通过对野外工程堆积体的下垫面进行概化,采用室内人工模拟降雨试验,对黄土区坡度在15°~35°条件下的工程堆积体地形坡度因子S值进行了修订。在明确定义我国工程堆积体标准径流小区和坡度因子的基础上,建立了黄土区工程堆积体地形坡度因子的幂函数和三角函数关系式,得到了坡度在15°~35°之间的坡度因子S值的查算表,并建立了土石体类型条件下坡度因子Si与纯土体类型条件下坡度因子So和石砾含量Pi之间的线性关系式,以期为黄土区工程堆积体水蚀测算模型的建立提供科学依据。

Waste soils and residues induced by construction projects,namely engineering piles,are characterized by steep slope,complex substance composition,massive gravels and loose structure. An engineering pile has unique erosion mechanism and special soil and water loss processes that significantly differ from natural slopes. By generalizing underlying surface of engineering piles in loess area,the slope steepness factor S on indoor simulated engineering piles was studied through artificial rainfall experiments with slopes between 15° to35°. The results show that the standard plot and slope steepness factor adopted in the water erosion model for various engineering piles in China have been defined. A check spreadsheet of the S values for slopes between15° to 35° has been established using power and trigonometric equations of slope steepness factor for engineering piles in loess area. A significant linear correlation has been found between the slope steepness factor Siof soil-rock piles and the slope steepness factor Soof pure soil and gravel content Pi.