| Severe soil erosion has brought a very serious impact to the ecological environment, the mechanical composition of sediment affects the settling process of sediment, and then affect the estimate of the amount of soil loss, therefore, soil composition is a extremely critical step to research soil erosion.Moreover, which is also in accordance with soil texture. So the determination of soil mechanical composition, whether the occurrence of the process of soil erosion, or the study of other areas have important practical significance. Currently, the most commonly used method for measuring soil mechanical composition analysis is hydrometer method and the pipette method,but the former poor accuracy, the latter has complicated steps. As a relatively new method,Laser particle size analysis applied to the soil mechanical analysis is still in its exploratory stage.Based on the preliminary test, it provides a method for deriving sediment concentration of a use of filter paper speed. Deposition of sediment has a certain role to clogging of filter paper. By measuring muddy water filtration rate of different size fractions. Sediment concentration and the filtration rate showed good linear relationship, Whereby the function can be constructed to sediment concentration and muddy water filtration rate,aid this function to anti-calculated the muddy sediment concentration, thereby provide a theoretical basis for the study of water erosion. The method scientific and reasonable, experimental procedure is simple, low cost, overcome some shortcomings of traditional measurement methods.Different particle sediment to filter paper speed have a greater impact, whereby the through filter paper, s filtration speed, construction filtration velocity model of different particle sizes of sediment, with the measured data rate of a given model parameters, further estimate size composition of test soil.In this paper, the determination of different soil mechanical composition by hydrometer method, the determination of sandy water sample filtration rate by straight filtration method, then the measurement results were compared between the two, at last inverse soil mechanical composition. The main findings are as follows:Filtration time has a big difference between five different soil, this shows that the different mechanical composition of soil clogging the filter effect of the existence of differences.Sediment settling velocity and particle size is power function regression, settling velocity increases with particle size, and when the particle size is less than 0.5mm, sedimentation rate of growth is relatively slow, when the particle size is larger than 0.5mm, rapid growth of settling velocity.Particle content changes over time can be described by the power function of five different sandy soil water samples, however, each of which is differences exist of difference equations, this suggests that Different mechanical composition of the soil due to the different coarse and fine particle content, its settling velocity is significant difference.Linear regression of different sediment concentration with filtration rate of five different sandy soil water samples, filtration rate decreased with decreasing of sediment concentration, Settlement also is linear regression with filtration rate, the filtration rate increases with the amount of the settlement slowed.Use k of sediment clogging of the filter effect,can be used for anti-gradation sediment grading, therefore, the method is feasible. |
