Study On K Factor Of Soil Loss Equation Practised In Highway Side Slope Of Hubei Province

The highway construction brings the development and prosperities of the economy, but the expressway construction is closely related to natural ecosystem environment, it will bring the breakage certain extent to the natural ecosystem environment inevitably, among which soil erosion is of most prominent.The soil erosion brought on by the highway engineering construction primarily focuses on construction phase. When starting the works, corresponding water and soil conservation measures are put into application, the new soil erosion is no longer produced generally.The soil erosion during the highway construction phase is closely related to the progress of construction. During the first stage, a great amount of soil is cut or spoiled, the soil erosion mainly occurs at these sensitive spots; during the second stage—road surface construction, the soil erosion mainly takes place in those sensitive areas on side slope and side slope where the revegetation measures are adopted.When the first constriction stage ends, according to the request of the installations for preventing soil loss should be designed, built and put into operation at the same time as the main project corresponding soil conservation measure validly decrease the soil erosion quantity. But during the second construction phase, owing to the length of the road surface construction is so long and it lasts a very long time, while the effect of the corresponding water and soil conservation measures need a very long time to be workable. Therefore, the soil erosion quantity of the highway slope occupies a very big proportion in total amount of the highway soil erosion, and the estimation and conservation of the soil erosion of the highway slope become the priority of the highway water and soil prevention.This thesis is to modify the calculating model of soil erodibility(K factor),one of the most important factors of universal soil loss equation, which is widely used in the prediction of soil loss amount of highway slope in Hubei Province. To get the more accurate calculating model of K fact, so as to use the universal soil loss equation to obtain a much more precise estimation of soil loss amount of highway slope in HubeiProvince.Through setting plots for identifying typical soil types on appropriate highway slopes. It can collect soil samples from plots and conduct chemical and physical experiment on typical soils, and in sequence calculating K values theoretically as expressed by Normal Equation. At the same time, based on the real time precipitation rain-fall data and on-the-spot soil loss amount information, calculate K value. By comparison with theoretical K value to figure out variance and to find out the main soil character parameter. Using MATLAB software, theory of parameter modification is employed to modify parameters in Normal Equation. Eventually, the proper calculating model of K factor the same with the typical slope soil of highway in Hubei Province, is established.