土石坝背坡植被抗冲蚀能力试验研究

摘要

The scouring resistance of the back slope of earth-rockfill dam covered by vegetation of different type,height and density is investigated by using flume experiment.It is concluded that vegetation can enhance the scouring resistance from two aspects:retaining soil by stems and leaves,reinforcing soil by roots.Different types of vegetation have different physical properties.Higher vegetation stem means that the vegetation roots will be more developed,the protection layer on the back slope will be thicker,hence the capacity of retaining and reinforcing soil will be stronger.Similarly,higher vegetation density means that the vegetation roots will be denser,and the coverage on back slope will be wider,thus,the capacity of retaining and reinforcing soil will also be stronger.By analyzing the experiment results,it's found that Bermuda Grass collected from the area adjacent to Bashimu dock in Ruian,Zhejiang Province has strong scouring resistance.%基于水槽试验,探求不同种类、高度、密度植被防护条件下,土石坝背坡的抗冲蚀能力.研究发现,植被主要从茎叶护土和根系固土两方面增强土石坝背坡的抗冲蚀能力.不同种类植被的物理性状差别较大,植被株高越高,土石坝背坡形成毯状保护层越厚实,根系也越发达,护土和固土能力都更好,其抗冲能力亦越强;植被密度越高,土石坝背坡的覆盖度越高,根系密度也越高,护土和固土能力同样会增强,其抗冲能力亦越强.通过多组试验成果的对比分析,采自浙江瑞安八十亩码头附近的狗牙根抗冲蚀能力最好.