Research on the Simulated Rainfall Experiment for the Soil Erosion by the Project Spoil

Liu Xiaoqiang(Southwest Forestry College,Kunming,Yunnan Province,China 650224)

Project Spoil,Soil Erosion,Soil Shearing Strength,Artificial Simulation Rainfall

On the basis on measurement of gradation composition and water content of waste spoil,it is used the 14.10 Pocket Vane Tester Type of triple shearing instrument to measure the shearing strength of the soil at the experimental area.Using the method of artificial simulation rainfall,the research was conducted to the soil erosion features on the original landform,newly accumulated soil and waste spoil for one year,respectively.The result shows that i) the producing runoff time at the protected landform is one hour later than that of at the waste spoil area.The sediment production at the waste spoil area reached 0.927 kg,2.06 times of that of at the original landform area;ii) during the field rainfall,the runoff production volume at the waste spoil area is 1.21 times of that of at the original landform area,with the runoff coefficient of 0.12 and 0.62 at the original landform area and the waste spoil area respectively.The sediment production volume at the waste spoil area is far more than that of at the original landform area.The initial sediment concentration at the original landform area is less than that of at the waste spoil area,which is 24kg/m3 and 145 kg/m3 respectively,and would be increased following with the increase of the sediment production volume.And iii) With the increase of the spoil accumulation time,the shearing strength also increased continuously,which resulted in the decrease of the fine spoil content while the increase of the water content.