Experimental Study On Erosion And Permeability Of Frost Resistant Vegetation Concrete Ecological Slope Protection

River is an important ecological resource for human survival and development.Under the erosion of rainwater,river slope will produce a lot of soil erosion,damage the environment,and affect the safety and landscape of the river.In China,the river slope protection is mainly hard slope protection,which has poor self purification ability and is not conducive to vegetation growth;Although the hole type concrete slope protection technology has improved the ecology,it will cause uneven settlement under the continuous rain erosion,and cause slope safety problems.As a new type of slope protection material,frost resistant vegetation concrete has a broad prospect in the next step of ecological slope protection.My research group independently developed the frost resistant vegetation concrete,which has been applied in the construction of ecological slope protection project,and the project benefit is remarkable.In this paper,on the basis of the previous research of the research group,the influencing factors of actual working conditions are selected,including slope（1:2.5,1:2.0,1:1.5,1:1.0）,rainfall intensity（20mm/h,30mm/h,40mm/h,50mm/h）and slope condition（Frost resistant vegetation concrete slope protection with grass free loam,frost resistant vegetation concrete slope protection with grass free sandy soil,frost resistant vegetation concrete slope protection with grass sandy soil and frost resistant vegetation concrete slope protection with grass loam）and the orthogonal experiment of three factors and four levels was designed by using these factors.Based on the test data of slope erosion（runoff erosion,infiltration erosion）and permeability（rainfall infiltration,infiltration coefficient）of frost resistant vegetation concrete slope protection,the range and variance analysis were carried out to find out the influence law of slope gradient,rainfall intensity,slope condition and other factors on the performance of frost resistant vegetation concrete slope protection,determine the optimal combination,optimize the slope protection design scheme,and combine with the experimental results The application technology system of frost resistant vegetation concrete ecological river course should be improved.The main conclusions are as follows:（1）The effects of slope gradient,rainfall intensity,slope condition and rainfall duration on the erosion and permeability of frost resistant vegetation concrete slope protection are as follows:When the rainfall intensity and slope condition are constant,with the increase of slope gradient,the runoff erosion of slope protection shows an upward trend,and the infiltration erosion and rainfall infiltration show a downward trend.The infiltration coefficient increases first and then decreases,and reaches the maximum when the slope gradient is 1:2.0;when the slope gradient and slope condition are constant,with the increase of rainfall intensity,the runoff erosion of slope protection increases exponentially,and the infiltration coefficient decreases The rainfall infiltration coefficient first decreased and then increased when the rainfall intensity was 30 When the slope and rainfall intensity are constant,the anti runoff erosion performance of grass loam frost resistant vegetation concrete is the best,the anti infiltration erosion performance of grass sandy soil frost resistant vegetation concrete is the best,and the anti infiltration erosion performance of grass loam frost resistant vegetation concrete is the best.Vegetation coverage can reduce runoff erosion and infiltration erosion,and increase rainfall infiltration.The results show that the variation of runoff erosion rate with rainfall duration depends on the scouring capacity of rainwater;the variation of infiltration erosion rate with rainfall duration depends on the variation of infiltration rate;the infiltration performance of frost resistant vegetation concrete slope protection with grass and grass sandy soil has no obvious change with rainfall duration The permeability of loam frost resistant vegetation concrete slope protection decreased with rainfall time.（2）The optimal combination of slope gradient and slope condition is as follows:The influence order of each factor on runoff erosion is:slope condition>rainfall intensity>slope,the optimal combination is A₁C₄,i.e.slope 1:2.5,and the slope condition is grass loam frost resistant vegetation concrete slope protection;the influence order of each factor on infiltration erosion is:slope condition>slope slope slope>rainfall intensity,and the optimal combination of slope protection design factors is A₄C₃,i.e.slope 1:1.0,and the slope condition is grass sand frost resistant Vegetation concrete slope protection;the influence order of each factor on rainfall infiltration is:slope condition>rainfall intensity>slope gradient,the optimal combination is A₁C₄,that is,slope 1:2.5,slope condition is grass loam frost resistant vegetation concrete slope protection;the influence order of each factor on infiltration coefficient is:slope condition>slope gradient>rainfall intensity,the optimal combination is A₂C₄,that is,slope 1:2.0,slope condition is grass planting Sand frost resistant vegetation concrete slope protection.Through the comprehensive analysis of various factors,when the combination of slope and slope condition is A₂C₄,that is,the slope is 1:2.0,and the slope condition is grass loam frost resistant vegetation concrete slope protection,the overall performance of slope protection is the best,and the runoff erosion is reduced by 98.5%compared with bare slope.（3）Application of frost resistant vegetation concrete ecological slope protection demonstration project:The design scheme of ecological slope protection demonstration project in Shuhe River Basin was optimized.The slope of slope protection project was 1:2.0,and the slope condition was grass loam frost resistant vegetation concrete ecological slope protection.After field testing,compared with the bare slope before construction,the frost resistant vegetation concrete ecological slope protection with 30 mm/h rainfall intensity,slope ratio of1:2.0 and turf maintenance for 7 days can reduce the runoff erosion by about 98.8%,and the infiltration coefficient of slope protection is about 50.6%.The research results provide theoretical support for the popularization and application of frost resistant vegetation concrete ecological slope protection in northern China.