Experimental Study On The Seabuckthorn Flexible Dam Response To Various Sediment And Water Flow Conditions

The seabuckthorn plant flexible dam has the function of intercepting channel sediment in soft rock region and showed a significant blocking sand effect In the national capital town of shaanxi province.Flow field experiments were carried out By planted more groups of different dam type of sea buckthorn plant flexible dam,it is to explore the response of the sea buckthorn plant flexible dam with different conditions of sediment and water flow,which is embodied the seabuckthorn plant flexible dam with different conditions of sediment and water for the change of flow and its basic characteristics.The contents including:under the different conditions of sediment and water,the essential features that belong to the water depth,the flow velocity,the sediment concentration and the sediment grain size distribution in the experiments are changing.In this paper,it is discussed that the application of HEC-RAS software simulating the water depth distribution and blocking sand effect of the seabuckthorn plant flexible dam.What is more,the main influence parameters are discussed.Follow achievements are mainly obtained:(1)The trend of the average flow velocity of different layers is roughly same for prototype sand and model sand,embodied in the flow velocity is fastest from the inlet to the front of the dam;In the process of flowing through the flexible dam,the speed of water is cut quickly,and changing until achieving relatively moderate.The trend of flow velocity of different layers is opposite in the middle of flexible dam.(2)The seabuckthorn plant flexible dam has a greatly influence on the bed surface sediment concentration,under the different of sediment and water conditions,based on the flow test of prototype sand and model sand.The changing trend of suspended sediment in water is roughly the same.The effect of the seabuckthorn flexible dam of the model sand will be far less to the prototype sand.(3)Under the condition of flow and planting parameters unchanged,the sediment concentration which is from the flexible dam upside is reduce gradually,that from the middle of the dam body is gradually increasing and that from the dam bottom reduc Large.Gradient changes of slope can affect the sediment concentration in water body,especially for model sand,which is conducive to deposit under the big slope.Under the condition of the slope and planting parameters constant,the smaller the flow,intercepting the better the results.(4)By analyzing the grain size distribution of the test bed surface of the seabuckthorn plant flexible dam and the deposition of grain size distribution of sand samples,found that the suspended sediment particle size distribution of the sea-buckthorn plant flexible dam has a decreasing trend.And the suspended sediment particle size of model sand of the flow is gradually decreasing in the first half part of the dam body,increasing in the middle of the dam body,and gradually decreasing half after the dam.That suggests that seabuckthorn plants have existed strong resistance,forcing falls along the silting in the water.What is more,the seabuckthorn plant flexible dam has a good separation effect for the grain size more than 2.5 um.(5)We simulating water depth distribution and blocking effect of the seabuckthorn flexible dam with the application of HEC-RAS software,the results show that planting parameters have a great influence on the interception effect of the seabuckthorn flexible dam.In addition,the length and density have a greater influence on the interception effect.