Study On The Regularity Of Inverted Siphon Siltation In A Certain Drainage

Flood drainage inverted siphons play a huge role in drainage and drainage.Due to the frequent occurrence of summer rainy seasons and increased precipitation,the bank slope soil is washed away,carrying a large amount of sediment into the river and into the inverted siphon.As a result,the silt in the pipe gradually increased and continued to accumulate,resulting in poor flood drainage in the inverted siphon tunnel.In this paper,the physical model of a certain flood discharge inverted siphon is tested and researched to further analyze the clogging law in the inverted siphon,and propose corresponding solutions.Mainly carry out the following research:Aiming at the water and sand conditions of the model at the check flow rate of 20.08L/s and the design flow rate of 13.59L/s,the flow velocity changes in the pipe when the flood discharge inverted siphon is in a state of large flow and full pipe is summarized,and combined with the experimental results.The water flow state is compared with the siltation depth in the pipe after the water is stopped.The analysis results show that when the upstream water flow is large,siltation will not occur in the inverted siphon.To this end,the model flow rate was adjusted to the prototype once-in-a-year flow rate or below,and data measurements of the flow velocity,siltation depth,and inlet and outlet water levels in the inverted siphon for flood discharge under different water and sediment conditions were carried out.The results of analysis data show that when the inverted siphon is in a state of dissatisfaction with the pipe,the turbulence of the water flow at the bend of the model pipe and the increase in the cross-sectional area of the horizontal section make the flow velocity at the bend decrease compared with the inlet flow velocity,and the plastic sand is therefore large.The area is deposited in the bend of the inverted siphon and the middle pipe section.When the upstream water flow is increased or the sand content is reduced,the siltation phenomenon of the inverted siphon is obviously weakened,and the location where the siltation is serious is reduced to the bend.At the same time,the inverted siphon that has been silted is increased to wash and silt the upstream water flow to obtain a clear dredging effect.The changes of water and sediment in the downstream drainage channel during the inverted siphon drainage process are studied.The test results show that when the flow rate is 2.04L/s,as the sand content of the inverted siphon outlet increases,the sediment carrying capacity of the water flow in the drainage channel is smaller,which makes the sedimentation depth and area of the channel increase more.For the flow rate 3.05 L /s,the siltation depth of the channel is reduced,and the range is reduced.When the flow is 5.27L/s,the sediment-carrying capacity of the channel flow is greater,and the siltation thickness and range of the plastic sand in the channel are mainly increased at the end of the channel.When the sediment content of the upstream inverted siphon is constant,the siltation depth and water depth of the channel decrease with the increase of the flow.