Study On Restoration Of Reservior Beach Storage Capacity

In the modern society, the reservoir in flood control, power generation, water supply, shipping and so on made a great contribution to the development of human society. Capacity is the most direct security reservoir play all kinds of benefits, however, after reservoir built over rivers, due to a higher level, flow velocity decreases, and inevitably cause of sediment deposition in the reservoir, directly led to the loss of capacity. As the favorable reservoir optimal operation, capacity of the channel does not have the too big change, but extremely difficult to recover after shoal capacity loss, a "dead beach live tank","deposition in a large, flush the line" phenomenon of mechanical dredging and pipe sediment delivery due to the high cost and large quantities, too consumption manpower to wait for a reason to restore the meaning of the reservoir is not big, therefore, explore the effective approach to restore the capacity of the beach, on the loss of the capacity of the beach is very necessary.Based on the generalized capacity of the reservoirs of beach recovery test, the infiltration scour channel dredging, buried pipe hydraulic dredging and buried pipe pressure infiltration dredging capacity of the three different methods of beach recovery mechanism is studied, the main work content and the research results are as follows:(1) using the generalized of sedimentation tank system of which the model test, not only to verify the selected flow and tail water, also after the beach capacity recovery test provides original scour terrain, as the research capacity of the beach recovery mechanism lay a good foundation.(2) flushing tank solution can only rely on the flow drag force make the slots on both sides of the incipient motion, flushing process is slow. Buried pipe pressure infiltration scheme can make the sediment particle starting, but it can’t make silt beach move to main channel and the desilting range is small. The two solutions are cannot make beach capacity of effective recovery.(3) A slot pipe embedded in underwater warp make bottom sediment pressure liquefied sediment method-buried pipe water pressure infiltration. Pressure flow of water through osmosis hole make silt liquefaction and whole starting up, and silt to the high beach on both sides of main channel direction and Angle of repose of sediment above the collapse of the liquefaction, finally formed in the pipe above the triangle sediment cross-section along the pipeline, reach the purpose of blocking river alluvial and beach capacity recovery. (4) Through observation we found:slot tube into the top and bottom hole pressure water, sand beach overall starting up, and then move to the main tank, test the opening desilting is very obvious; Pressure water after entering the hole around the slot tube, near the main channel slope sediment first fall back into the main channel, spread, and then gradually collapse to high slope beach sediment section gradually expanding.(5) Finally to scour topography measurement, found that8mm aperture of slot tube desilting works best, that means penetration hole aperture size is the key factor that influence the effect of beach capacity recovery, opening slot pipe up and down the scour depth around the hole.