Study On The Soil And Water Conservation Technology Of Expressway In Pisha Sandstone Area

China is one of the most severe countries in the world in soil erosion,and the jin- shan -mong contiguous area of China is the most part in whole country. This sandstone areas is one of the most eco-fragile area with severe soil and water erosion in the west of China.Therefore, how to do well in water and soil conservation in expressway construction of Pisha Rock Area and in improving eco-environment and protecting land resources will be the most important thing in the future.In order to solve the problem why the water and soil erosion in Pisha Rock Area is so serious ,in this paper,a series of preliminary investigations was conducted,a great deal of information was collected , the developing status of this field was known detailedly and the characteristic of Pisha Sandstone was thoroughly studied.After this,let the highway of Dafanpu-Dongsheng an example in this text. Application of Universal Soil-Loss Equation was used in predicting the water and soil erosion mount of Pisha Sandstone. The following conclusion has been achieved by calculation:Erosion background value of engineering site is great; The soil erosion amount of per unit length of highway of Dafanpu-Dongsheng is large; Vegetation recovery significantly reduce soil erosion;Using a simple software Tongji Morning Star SLOPE 1.0 to preliminary calculate the Pisha Sandstone slope of Dadong highway.Come to the following conclusions: All Pisha Sandstone embankment slope are stable slope, can use ecological protection.Greater than 25m of Pisha Sandstone Cut Slopes are instable, take engineering measures to make it instable.less than 6m of the cut slopes are stable, and can be use general ecological protections. Other Soft Rock Cut Slopes that not weathered are stable, Use protection and ecological projects combining protection. 53°～55°is the critical gradient for erosion of expressway embank slope of the Pisha Sandstone Slope, the slope angle of Dafanpu-Dongsheng expressway is between 26.5(?)～53.2(?), The steepest slope approaches the critical gradient for erosion of expressway embank slope, must adopt the project protection. Finally, in the light of the above findings, studied in the area of highway construction of soil and water conservation technology.