稻秸秆加筋土生态护坡室内降雨冲刷试验研究

Study on Rain Erosion Test of the Indoor Slope Protected by Rice Straw Reinforced Soil

针对湖南省某高速公路花岗岩残积土粗颗粒含量多,遇水易崩解,极易形成坡面冲蚀的特点,提出采用稻秸秆加筋土对坡体表面进行生态防护。通过室内边坡模型的降雨冲刷试验探讨了不同稻秸秆加筋土厚度与不同稻秸秆掺和比例的防护机理与效果,可知降雨冲刷作用下坡面破坏是从雨滴溅蚀开始的,而后是重力、摩擦力和坡面径流推力等对土颗粒的搬运作用,进而对坡面形成冲蚀;稻秸秆加筋土防护层受雨水溅蚀程度要小,泥沙冲刷量少,防护效果较好;稻秸秆掺和比例为0. 3%、防护层厚度为5 cm下的稻秸秆加筋土层防护效果最佳。室内试验结果可为同类工程研究与实际工程应用提供借鉴或参考。

According to expressway granite residual soil with charactors of large amount of coarse particle content,easy disintegration in water,easy to form the characteristics of slope surface erosion,the use of rice straw reinforced soil was put out for ecological protection of slope surface.The protection mechanism and effect of different rice straw reinforced soil thickness and different ratios of rice straw mixing were explored through the rainfall scouring test of the indoor slope model.It can be seen that the slope damage caused by rainfall erosion was started from raindrop splashing,then,gravity,friction,and runoff thrust on the slope surface acted on the transport of soil particles,which in turn eroded the slope surface;the protective layer of rice straw-reinforced soil is less affected by rainwater splashing,less erosion of sediment,and better protective effect.The best protective effect of rice straw reinforced soil layer were 0.3%rice straw ratio and 5 cm thickness of protective layer.It can provide reference for similar engineering research and practical engineering applications.