| The dumped along the slope spoilbank is a common type of accumulation type of production and construction projects. It generally exists in the tunnel excavation of railway and highway construction, mountain development projects implement. Dregs dumped down along the hillside slope surface or the ditch. Accumulation of this type has characteristics of steep slope, loose cover, and complex composition of the material surface. It easily lead to soil erosion and geological disasters compared to the original geomorphological conditions. Common field stacked body according to the slope poured divided into two categories: 1. Slope gully stacked body, such stacked bodies has large amount of dregs, it is usually directly dumped on the slope gully whit thick layer. 2. Slope stacked body, this kind of stacked body has relatively small amount of dregs, it is dumped down from the top of a slope and forms a stack shape which top is thick and toe is thin. In this paper, two types of stacked body, which exist in the field, were set as our study objects. And we used indoor simulated rainfall and simulated upper buss method to study stacked bodies with different gravel contents or different gradients, and we explored the soil erosion accumulating calculation model about these types of stacked bodies, hoping to provide a scientific basis for the establishment of production and construction projects of soil erosion calculation model. Draw the following conclusions:Form one: Research conclusions for slope gully dumped stack body(1) Relationship between runoff producing time of slope gully dumped stack body and the upper part runoff amount, gravel content, the slope: runoff producing time and upper part runoff amount was significant negative correlated. With the increasing of the upper part runoff amount, runoff producing time is shortened; With the increasing content of gravel, runoff producing time showed an increasing trend; With the increasing of slope, runoff producing time showed a decreasing trend.(2) Relationship between runoff rate of slope gully dumped stack body and the upper part runoff amount, gravel content, the slope: Within 54 min after the runoff exist, under the same gravel content conditions, the average runoff rate and the upper part runoff amount was significant positive correlated. the average runoff rate decreased with increasing of gravel content, and increased with the increasing of slope.(3) Relationship between runoff rate of slope gully dumped stack body and time: Within 54 min after the runoff exist, runoff rate increased with the increase of upper part runoff amount. With the development of gully erosion, edge erosion gully collapse constantly. This hindered runoff transport to the lower slope and made constant runoff rate fluctuations. The larger upper part runoff amount, the faster gully erosion developed, and resulted in larger runoff rate fluctuation range. With time extended, runoff rate of stacked body increased and tend to be stable at last.(4) Relationship between erosion rate of slope gully dumped stack body and the upper part runoff amount, gravel content, the slope: Erosion rate of slope gully dumped stack body was significant power function with upper part runoff amount. With the increase of gravel content, the erosion rate showed a decreasing trend. And with the slope increased erosion rate showed an increasing trend(5) Under the situation that the upper part runoff amount was 10 L/min, gravel content was 60%, slope was 30°, the average erosion rate was significantly larger than that of other combination of factors under the same gravel content condition. With increase of gravel content and the slope, mixed erosion of slope gully dumped stack body increased, as speculated, 60% of gravel content, 30° of slope, 10 L/min of the runoff amount was the critical value when mixed erosion appeared.(6) The erosion amount calculation model in per unit area is: A=1.194Q1.612′(S/25°)0.977 ′(0.908-0.256′Di)。Form two: Research conclusions for slope dumped stack body(7) Relationship between runoff producing time of slope dumped stack body and the rainfall intensity, gravel content, the slope: runoff producing time of slope dumped stack body is significant negative correlated with the rainfall intensity. And runoff producing time shows an increasing trend with gravel content increasing.(8) The runoff rate of slope dumped stack body has significant linear relationship with rainfall intensity. With the continuation of rainfall time, the runoff rate shows an increasing trend and then tends to be stable. At 2.5 mm / min rain intensity conditions, runoff rate fluctuates significantly. The lager gravel content, he smaller runoff rate fluctuations.(9) The erosion rate of slope dumped stack body is significantly associated with both gravel content and rainfall intensity. The erosion rate is mainly dominated by the rainfall intensity. The stronger rain, the larger fluctuate range of erosion rate. Under the same conditions gravel content, There is a significant power function relationship between the average erosion rate and rainfall intensity.(10) There is a significant linear function relationship between erosion modulus of slope dumped stack body and gravel content. And there is a significant power function relationship between erosion modulus of slope dumped stack body and rainfall intensity. The erosion amount calculation model in per unit area is: A=0.0662P1.6266′(1.543-1.895′Di) ′(S/25°)1.352。... |
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