Flip overflow dam scouring pit revetment

Abstract

A flip bucket overflow dam scour pit revetment comprises a spillway, an overflow dam, a flip bucket, a dam side retaining wall, a downstream revetment, a scour pit, a river channel accumulation body and a scour pit revetment, the scour pit revetment is located between the dam side retaining wall and the downstream revetment in the river direction, and the scour pit revetment is located on the side edge of the scour pit on the downstream portion of the overflow dam in the transverse river direction; and the foundation surface of the scour pit revetment is lower than the maximum depth of the scour pit. According to the flip overflow dam scouring pit revetment provided by the utility model, the stability of the revetment can be improved, the energy of flushing water flow can be effectively reduced, and the flushing to the revetment is reduced.

Description

Technical Field

[0001] The utility model relates to a bank protection, in particular to a bank protection for a diversion rolling dam. Background Art

[0002] A rolling dam is a low-height water-retaining structure with a low overflow weir. Its main function is to raise the upstream water level and retain sediment. It is often used as a water-taking structure for rural agricultural irrigation. A rolling dam often has a simple control gate at the main river channel and uses wooden boards to block water. When the water flow in the river is not large, the water flows out from the gate hole of the rolling dam. In order to prevent scouring at the toe of the dam, a rolling dam often has a sill. When the water level rises, the flood can overflow freely through the sill to the downstream. Since the height of the rolling dam is not large, the landing point of the sill is not far from the toe of the dam.

[0003] When flash floods break out, the scouring pits often cause the collapse of the revetments on both sides when they reach a certain depth. In addition, the pebbles caused by flash floods often accumulate downstream of the scouring pits of the rolling dam, causing the downstream riverbed to rise. The river water discharged through the spillway of the main river channel of the rolling dam often has a diverted flow, which fluctuates and spreads to both sides, further hollowing out the slope toes of the revetments on both sides, endangering the safety of the revetments. Once the revetments on both sides of the rolling dam collapse, it will directly endanger the safety of buildings within the collapse range. When the revetments on both sides of the rolling dam collapse during the flash flood period, the floods may directly engulf the surrounding farmland and cause economic losses. Therefore, the anti-scouring and stable safety of the revetments of the scouring pits of the diverted rolling dam are extremely important.

[0004] The existing revetments on both sides of the diversion rolling dam are usually built with mortar-stone concrete, the revetment wall is flush with the two sides of the rolling dam, and there are few energy dissipation structures. The diversion and backflow directly scour the slope foot of the revetment, and the embankment foot is easily hollowed out, thus endangering the safety of the revetment. Summary of the invention

[0005] The technical problem to be solved by the utility model is to provide a diversion rolling dam scouring pit bank protection, which can resist scouring and ensure the stability of the bank protection.

[0006] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0007] A scouring pit revetment for a rolling dam comprises a spillway, an overflow dam, a sill, a dam side retaining wall, a downstream revetment, a scouring pit, a river channel accumulation body and a scouring pit revetment. The scouring pit revetment is located between the dam side retaining wall and the downstream revetment in the downstream direction, and is located on the side of the scouring pit downstream of the rolling dam in the cross-river direction; the construction base surface of the scouring pit revetment is lower than the maximum depth of the scouring pit.

[0008] The scouring pit revetment is in an outwardly protruding arc shape as a whole, and comprises an inner chord-shaped column, a middle arc-shaped column and an outer arc-shaped column.

[0009] The bottom elevation of the scour pit revetment is 0.5m below the maximum depth of the scour pit.

[0010] The top elevation of the inner chord-shaped column is 0.5 m below the multi-year average water level.

[0011] The top of the middle arc column is an inclined surface. The side of the middle arc column close to the outer arc column is high and the elevation is the multi-year average water level. The side of the middle arc column close to the inner chord-shaped column is low and the elevation is set to 0.5m below the multi-year average water level.

[0012] A first force dissipation pier is arranged on the top of the middle arc-shaped column, and the first force dissipation piers are radially spaced along the arc-shaped surface of the middle arc-shaped column.

[0013] The inner side surface of the outer arc-shaped column is provided with a second energy dissipation pier, and the second energy dissipation pier is arranged at intervals within the range from the upper end of the middle arc-shaped column to 1 / 3 of the height of the revetment top.

[0014] A temporary bridge is built on the top of the outer arc-shaped column, and the temporary bridge shields the cavities on the tops of the inner chord-shaped column and the middle arc-shaped column.

[0015] The utility model provides a diversion rolling dam pit protection, which has the following technical effects:

[0016] 1) By setting the scouring pit revetment on the side of the blasting area, and the foundation surface of the scouring pit revetment is deeper than the maximum depth of the scouring pit, it is beneficial to the stability of the revetment.

[0017] 2) By setting the middle and upper part of the scouring pit revetment as an arc-shaped structure with a force dissipation pier, the energy of the broken water flow can be effectively reduced, reducing the scouring of the revetment.

[0018] 3) By rationally designing the thickness of the inner chord column, the middle arc column and the outer arc column, the total thickness of the scouring pit revetment is only 1 times the thickness of the retaining wall. The top temporary bridge is directly connected to the upstream dam side retaining wall and the downstream revetment, shielding the lower energy dissipation cavity, with little impact on surrounding facilities and land. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0020] Figure 1 It is a structural schematic diagram of the utility model.

[0021] Figure 2 It is a schematic diagram of the explosion of the flushing pit bank protection in the utility model.

[0022] In the figure: spillway 1, overflow dam 2, cantilever 3, dam side retaining wall 4, downstream revetment 5, scouring pit 6, river channel accumulation body 7, scouring pit revetment 8, inner chord-shaped column 81, middle arc-shaped column 82, outer arc-shaped column 83, first energy dissipation pier 84, second energy dissipation pier 85, temporary bridge 86. DETAILED DESCRIPTION

[0023] like Figure 1 and2 As shown, a scouring pit revetment of a diversion rolling dam includes a spillway 1, an overflow dam 2, a diversion bank 3, a dam side retaining wall 4, a downstream revetment 5, a scouring pit 6, a river channel accumulation body 7 and a scouring pit revetment 8. The scouring pit revetment 8 is located between the dam side retaining wall 4 and the downstream revetment 5 in the downstream direction of the river, and the scouring pit revetment 8 is located on the side of the scouring pit 6 downstream of the rolling dam in the cross-river direction. The scouring pit revetment 8 includes an inner chord-shaped column 81, a middle arc-shaped column 82 and an outer arc-shaped column 83.

[0024] The water flow ejected through the overflow dam 2 and the sill 3 scours the downstream river channel to form a scouring pit 6. When the scouring pit 6 reaches a certain depth, the revetment beside the scouring pit often collapses. Only when the foundation surface of the scouring pit revetment is lower than the maximum scouring pit depth can the revetment collapse caused by the scouring pit in the air be effectively prevented. Only when the scouring pit revetment 8 is built outside the range of the ejected water flow of the overflow dam 2 and the sill 3 can the revetment not be hit by the water flow. Therefore, the scouring pit revetment 8 is arranged on the side of the scouring pit 6 of the rolling dam in the horizontal river direction. The bottom elevations of the inner chord-shaped column 81, the middle arc-shaped column 82, and the outer arc-shaped column 83 are 0.5m below the maximum depth of the scouring pit 6, which is beneficial to the stability of the revetment.

[0025] The water flowing down the spillway 1 will generate a folding flow to both sides of the river channel under the obstruction of the river channel accumulation body 7. The water surface around the scouring pit 6 downstream of the overflow dam 2 presents an arc-shaped backflow, which continuously washes the scouring pit revetment 8. The energy of the arc-shaped folding flow is mainly concentrated within 0.5m below the water surface. When the scouring pit revetment 8 is washed to a certain amount, it is easy to collapse. In order to adapt to the arc-shaped characteristics and energy distribution characteristics of the folding backflow, the middle and upper parts of the scouring pit revetment 8 are made into an arc-shaped structure and energy dissipation measures are set.

[0026] According to the characteristics of river water level operation, when a major flood occurs, the dam surface diversion flow and the spillway flow go straight downstream and there is not necessarily any diverted water flow. Therefore, energy dissipation is divided into the energy dissipation of diverted water flow under common water levels and the energy dissipation of diverted water flow during general floods.

[0027] In view of the energy dissipation of the diverted water flow under common water levels, the diverted water flow is mainly within the range of 0.5m below the water surface, and the top elevation of the inner chord-shaped column 81 is set to 0.5m below the multi-year average water level. The top elevation of the middle arc-shaped column 82 is set to an inclined surface, with the side close to the outer arc-shaped column 83 being high and the elevation being the multi-year average water level, and the side close to the inner chord-shaped column 81 being low and the elevation being set to 0.5m below the multi-year average water level. The first energy dissipation pier 84 is set at the top of the middle arc-shaped column 82. The first energy dissipation pier 84 is a column with a side length of 25cm and a height of 40cm, arranged along the arc radial direction with a spacing of 40cm.

[0028] During a general flood, the flood level can only reach the multi-year average water level to 1 / 3 of the revetment top and below. In order to dissipate the energy of the water flow during a general flood, a second energy dissipation pier 85 is set on the inner side of the outer arc column 83. The second energy dissipation pier 85 is a column with a side length of 25 cm and a height of 40 cm. It is evenly spaced from above the middle arc column 82 to 1 / 3 of the height of the revetment top, with a spacing of 40 cm.

[0029] In order to reduce the impact of the scouring pit revetment 8 on surrounding facilities and land, the total width of the scouring pit revetment 8 in the transverse direction of the river needs to be reduced as much as possible. The chord thickness of the inner chord-shaped column 81 and the thickness of the middle arc-shaped column 82 are both half of the thickness of the dam side retaining wall, and the thickness of the outer arc-shaped column 83 is the thickness of the dam side retaining wall.

[0030] In order to facilitate the pedestrian requirements of the dam side retaining wall and the downstream revetment and to cover the top cavities of the inner chord-shaped column 81 and the middle arc-shaped column 82 and the force dissipation pier, a temporary bridge 86 can be built on the top of the scouring pit revetment 8. The temporary bridge 86 is 0.3m thick.

Claims

1. A scouring pit bank protection for a diverting water rolling dam, comprising a spillway (1), an overflow dam (2), a diverting bank (3), a dam side retaining wall (4), a downstream bank protection (5), a scouring pit (6), a river channel accumulation body (7) and a scouring pit bank protection (8), characterized in that: The scouring pit revetment (8) is located between the dam side retaining wall (4) and the downstream revetment (5) in the downstream direction of the river, and is located on the side of the scouring pit (6) downstream of the rolling dam in the cross-river direction; the foundation surface of the scouring pit revetment (8) is lower than the maximum depth of the scouring pit (6).

2. The diversion rolling dam scouring pit bank protection according to claim 1 is characterized by: The scouring pit revetment (8) is in the shape of an arc protruding outward as a whole, and comprises an inner chord-shaped column (81), a middle arc-shaped column (82) and an outer arc-shaped column (83).

3. The diversion rolling dam scouring pit bank protection according to claim 2 is characterized by: The bottom elevation of the scouring pit revetment (8) is 0.5 m below the maximum depth of the scouring pit (6).

4. The diversion rolling dam scouring pit bank protection according to claim 2 is characterized by: The top elevation of the inner chord-shaped column (81) is 0.5 m below the multi-year average water level.

5. The diversion rolling dam scouring pit bank protection according to claim 2 is characterized by: The top of the middle arc column (82) is an inclined surface. The side of the middle arc column (82) close to the outer arc column (83) is high and its elevation is the multi-year average water level. The side of the middle arc column (82) close to the inner chord-shaped column (81) is low and its elevation is set to be 0.5 m below the multi-year average water level.

6. The diversion rolling dam scouring pit bank protection according to claim 2, characterized in that: A first force dissipation pier (84) is provided on the top of the middle arc-shaped column (82), and the first force dissipation piers (84) are radially spaced along the arc-shaped surface of the middle arc-shaped column (82).

7. The diversion rolling dam scouring pit bank protection according to claim 2 is characterized by: The inner side surface of the outer arc-shaped column (83) is provided with a second energy dissipation pier (85), and the second energy dissipation pier (85) is arranged at intervals within the range from the upper end of the middle arc-shaped column (82) to 1 / 3 of the height of the revetment top.

8. The diversion rolling dam scouring pit bank protection according to claim 2 is characterized by: A temporary bridge (86) is built on the top of the outer arc-shaped column (83), and the temporary bridge (86) shields the top cavities of the inner chord-shaped column (81) and the middle arc-shaped column (82).

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