Effect Of Soil And Water Conservation Measures In Heilongjiang Expressway Cutting Slopes

Expressway construction and use is a big development items of basic construction,it's long and broad,the site condition is bad,the influence area and the human factor is very big. Effect of soil and water conservation measures seriously influence the work of soil and water conservation and the environmental protection along the expressway.We select 4 types of soil and water conservation measures and 3 control groups in Yabuli freeway cutting slopes, through the study on rules of vegetation survey and soil physico-chemical properties,the paper comparative analysis the effect of the type places,the results were as follows:1.Data display,the soil erosion is extremely serious,only control groupⅡerosed 1650t/km~2 soil in odd-numbered days rains.Soil and water conservation measures plays the vital role,in which,The runoff of geo-cell measure,3D vegetative cove measure and planting grass measure reduces separately 58.5%,59.3%,50.8%;the silt content reduces 59.4%,50.2% and 44.7%,it indicate that the measures have remarkable effect in soil and water conservation.2.The vegetation coverage fraction of geo-cell measure(96%),3D vegetative cove measure(95.8%),planting grass measure(95.2%),and 6-corner blocks measure(56.6%) are much higher than the mean value of control groups(45.27%).The biomass of 3D vegetative cove measure(1102.2g/m~2),geo-cell measure(817.4g/m~2),planting grass measure(710.2g/m~2) and 6-corner blocks measure(579.2g/m~2) are much higher than the mean value of control groups(378.24g/m~2).This 4 measures provide the good survival environment to the protection vegetation of expressway.The Biomass of Poa pratensis is very big,and it adapt the environment of Heilongjiang,and it enhances the coverage fraction,so Poa pratensis is a vegetation which is fit to the work of soil and water conservation3.Project measures increase the soil porosity,improvement soil structure.In which,the mean unit volume weight value of 3D vegetative cove measure and geo-cell measure is 1.22 g/cm~3,it's less than the mean value of other control groups,the value is 1.39g/cm~3,the non-capillary tube porosity 12.56%,capillary tube porosity 43.81%and gross porosity 56.37%of geo-cell measure are more than the mean value of control groups 7.13%,42.04%and 49.17%, this means the 2 measures are in favor of soil and water conservation,water permeability and ventilation.4.The saturated water capacity value,capillary tube water capacity and field capacity of geo-cell measure and 3D vegetative cove measure are 1.76 times,1.56times and 1.59 times higher than the mean value of control groups,the shows good ability on water-holding capacity. 5.The effect of slope angle on soil physical property is notable,when the angle is 15°, every soil layer has remarkable difference,when the angle is 30°or 45°,the soil physical property is close.Generalized analysis each kind of tentative data,compared with structure of the 4 measures,the results were as follows:geo-cell measure＞vegetative cove measure＞planting grass measure＞6-corner blocks measure.The 6-corner blocks measure a little effect on the conservation,but consider to the construction cost factor and landscaping factor,we suggest to built it less.