Study On Water Erosion And The Engineering Influences For Yalu Freeway Wenwupo Lamaxigou

Because of its special landscape patterns and climate conditions in Wenwupo Lamaxigou, and the region is made up of Xigeda, which has the characteristic of low diagenetic degree, inhomogenous texture and structure, rich in clay mineral, strong compressible, disintegration and softening in water, dehydration xerochase and so on, so that it is easy to form the water erosion phenomenon. In addition, Yalu highway construction in the basin is man-made to accelerate the water erosion in Wenwupo Lamaxigou basin, and it will form a deeper gully, caused slope instability, collapse, landslides, debris flow and other geological disease.The paper firstly analysis the Xigeda stratum of the engineering geological properties, with the laborator research. First, with the hydrometer method and the diffusing agent method to analyse particle size, that the anti scourability in Xigeda stratum is weak, soil loss very easily in the role of water, and it is propitious to generate the water erosion. Secondly, through the formation of Xigeda experimental analysis of the chemical composition and calculated Xigeda CIA in the territories within the quaternary glacial clay, indicated that Xigeda of the anti-weathering ability is weak. Finally, study the Xigeda soil of corrosion resistance stability, and that the value is almost as the loess soil and ancient soil, therefore, we will be able to use some conclusions in loess erosion researchs for the Xigeda soil studies.On the basis of a wide range investigation and in-depth study, using geology and hydraulics knowledge, and combined the geological background conditions in lamaxigou basin, it is summed up lamaxigou basin water erosion of two types: overland flow erosion and channel erosion. In the part of overland flow erosion, studies the erosion elements of overland flow and analysis its impact factors; In the part of channel erosion, first of all, studies the development of four stages of the channel, according to the scene investigation and contrast the characteristics of the channel four stages, it can be assumed the lamaxigou is now in stem ditch stage, finally, analyzed various effect factors of lamaxigou channel erosion.With the United States Universal Soil Loss Equation USLE (universal soil loss equation), in combination of lamaxigou basin of the rainfall, soil characteristics, topography and vegetation factors determine a reasonable factor, establishing of the lamaxigou soil erosion prediction experienced model. With this model it can be calculated the average soil erosion in lamaxigou basin, through quantitative calculation of the average soil loss and soil erosion under the classification criteria, it is determined the extent of soil erosion in lamaxigou as moderate erosion.The paper uses of the average erosion modulus to predict soil and water loss amount during highway construction, using the analogy method to predict soil and water loss amount of project spoil, and initial gained soil loss amount in the construction period. in a certain extent to offer a basis of the preparation of soil and water conservation plans in this basin. Based on the extent of soil erosion of lamaxigou, the paper propose highway construction period for lamaxigou basin soil and water conservation measures.