水电站建设项目弃渣场岩土侵蚀研究

Study on Rock and Soil Erosion in Dumpling Pile of Hydropower Station Construction Project

弃渣场是水电站建设项目水土流失最敏感的部位之一,弃渣堆积过程破环了原有岩土结构、地形和植被,且堆积坡度大,稳定性差,岩土侵蚀程度剧烈,岩土侵蚀类型多样。以金沙江上游金安桥大型水电站工程弃渣场为例,通过定位观测和调查,对其土壤侵蚀形式及成因进行了分析,测算了弃渣场不同部位的土壤侵蚀模数。结果显示,弃渣场不同部位存在溅蚀、面蚀、沟蚀、沉陷、陷穴、岩土泻溜、滑塌、滑坡等侵蚀形式;弃渣场不同部位无截排水措施的开挖边坡细沟侵蚀带、弃渣堆积平台和运渣道路不均匀面蚀带、有截排水措施和无截排水措施的弃渣堆积边坡水力-重力侵蚀带,其岩土侵蚀模数是原地貌平均侵蚀模数的73、124、186和887倍,而修建截排水措施后弃渣堆积坡面的侵蚀模数是无措施的弃渣堆积坡面的1/7.2倍。

Dumpling pile produced by construction project, shaped a huge man-dumped pile. The pile had diverse types of rock and soil erosion, and suffered extensive rock and soil erosion, because of the formal physiognomy, vegetation, and rock and soil structure destroyed by project, and the special pile form of stable flat alternated with loose slope. The thesis analyzed the form of rock and soil erosion and its causes with investigation and observation in Jinanqiao hydropower station construction project in Jinshajiang upper reaches, and calculated the erosion modules of different erosion zones. The result indicated that the different zones of dumpling pile exist diverse types of rock and soil erosion ,which contained splash erosion, soil surface erosion, gully erosion, hole caving and debris slide, collapse, landslide and slope debris flow, and it＇s erosion modules was 73,124,186, 887 times more than that of formal physiognomy respectively.