A curved overflow weir structure for bank spillway

Abstract

The present invention discloses a curved overflow weir structure of a bank spillway, comprising an overflow weir, an outer guide wall extending and arranged according to the terrain near the bank, and an inner guide wall close to the riverbed. The axis of the overflow weir adopts an asymmetric curve, and the inner guide wall adopts an arc arrangement. The overflow weir body is offset to one side of the riverbed to increase the overflow front length of the overflow weir body. When discharging flood water, the flood water passes through the overflow weir smoothly into the chute. The weir body is offset to one side of the riverbed, and its discharge front is longer than that of the traditional straight weir, which can not only ensure the design discharge flow, but also avoid the lateral flow and circulation problems caused by the side weir, and at the same time avoid the increase in engineering volume caused by the increase in the scale of the spillway. The present invention simplifies the structural type of the overflow weir, reduces its construction difficulty, reduces the engineering volume and engineering investment, and obtains good social and economic benefits.

Description

Technical Field

[0001] The invention relates to a flood discharge facility in a water conservancy and hydropower project, in particular to a curved overflow weir structure of a bank spillway. Background Art

[0002] The shore spillway in water conservancy and hydropower projects includes overflow weirs, chutes and energy dissipation facilities. Overflow weirs usually adopt practical weirs, wide crest weirs and hump weirs. The layout of the shore overflow channel usually adopts the positive trough type and the side trough type. The axis of the trough of the positive trough spillway is orthogonal to the axis of the overflow weir, and the direction of the water flow over the weir is parallel to the axis of the trough; the water flow over the weir of the side trough spillway is nearly perpendicular to the axis of the trough. The flow coefficient of the positive weir is slightly larger, and the water flow conditions behind the weir are better; the side weir is prone to circulation and bypass flow behind the weir, especially for low weirs and low head conditions; the combination of the positive weir and the side weir will cause stress concentration at the junction of the weir body, the weir body structure is complex, and the flow pattern behind the weir is turbulent. The use of a curved overflow weir can adapt well to the terrain and geological conditions, increase the discharge capacity without increasing the scale of the spillway, and alleviate the flow pattern of the water behind the weir. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a curved overflow weir structure of a bank spillway, which can ensure the flow capacity and adjust the flow state for a water conservancy hub with a restricted discharge front, and is economical and practical.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a curved overflow weir structure of a shore spillway, including an overflow weir, an outer guide wall extending along the terrain near the shore, and an inner guide wall close to the riverbed, the axis of the overflow weir adopts an asymmetric curve, the inner guide wall is arranged in an arc, the overflow weir body is offset to one side of the riverbed, the overflow front length of the overflow weir body is increased, and the flood passes through the overflow weir smoothly into the chute during flood discharge.

[0005] The overflow weir is a practical weir, a broad-top weir or a hump weir.

[0006] The axis of the overflow weir is an asymmetric curve, which is an arc shape, a parabola shape or an ellipse shape.

[0007] The angle α between the axis of the chute and the center line of the overflow weir is between 15° and 45°.

[0008] The inner guide wall is in an arc shape, the arc center of the inner guide wall is on the extension line of the overflow weir curve center, and the upstream extension section L of the inner guide wall is 1 to 2 times the weir height.

[0009] The beneficial effects of the present invention are as follows: without increasing the width of the spillway, the overflow weir is arranged by an asymmetric curve, the overflow weir arrangement is optimized according to local conditions, only the axial direction and the front length of the overflow weir are changed, the discharge capacity of the overflow weir is effectively increased, and the flow state behind the weir is smoothly transitioned, which can not only ensure the downstream design flow rate, but also avoid the lateral flow and circulation problems caused by the side weir, simplify the overflow weir structure, reduce the construction difficulty, reduce the engineering volume, and reduce the engineering investment at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a plan view schematic diagram of the curved overflow weir structure of the bank spillway of the present invention.

[0011] Figure 2 It is a schematic diagram of the AA section of the curved overflow weir structure of the bank spillway of the present invention.

[0012] In the figure: 1—overflow weir; 2—outer guide wall; 3—inner guide wall; 4—sluice; 5—sluice axis; 6—center line of overflow weir; L—extension length of inner guide wall; α—angle between center line of overflow weir and axis of sluice. DETAILED DESCRIPTION

[0013] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0014] like Figure 1-2 As shown, the curved overflow weir structure of the bank spillway of the present invention comprises an overflow weir 1, an outer guide wall 2 extending and arranged according to the terrain near the bank, and an inner guide wall 3 close to the riverbed. The axis of the overflow weir 1 adopts an asymmetric curve, and the inner guide wall 3 adopts an arc arrangement. The overflow weir body is offset to one side of the riverbed to increase the overflow front length of the overflow weir body. When discharging flood water, the flood passes through the overflow weir 1 smoothly into the chute 4.

[0015] The overflow weir 1 is a practical weir, a broad-top weir or a hump weir.

[0016] The axis of the overflow weir is an asymmetric curve, which is an arc shape, a parabola shape or an ellipse shape.

[0017] The angle α between the axis 5 of the chute and the center line 6 of the overflow weir is between 15° and 45°.

[0018] The inner guide wall 3 is in an arc shape, the arc center of the inner guide wall is on the extension line of the overflow weir curve center, and the upstream extension section L of the inner guide wall 3 is 1 to 2 times the weir height.

[0019] A small reservoir hub project, the dam is a homogeneous earth dam, the maximum dam height is 39m, an open single-hole spillway is used to discharge flood, the water head above the weir is 3.4m, and the verified flood discharge is 201m 3 / s, the design flood discharge is 91m3 / s. The spillway is limited by the terrain, with a limited width and a steep slope on the left. If the positive weir is used, the weir height is low, the head difference is small, and the flow coefficient is small. If the designed discharge flow is met, the width of the spillway will inevitably increase, resulting in an increase in the spillway excavation volume, an increase in the slope, and an increase in project investment. If the side weir is used, in order to meet the designed discharge flow, the overflow front will increase too long, and the flow pattern of the water behind the weir will be turbulent, which is prone to turbulent circulation problems. If the positive weir and the side weir are combined, the stress is concentrated at the junction of the weir body, the weir body structure is complex, and the flow pattern of the water behind the weir is more turbulent.

[0020] The overflow weir of the present invention is adopted. The weir body is directly arranged in the reservoir area, and a low practical weir type with an asymmetrical curve arrangement is set in the spillway. A longer overflow weir can be arranged within a limited width. The right arc guide wall adjusts the flow pattern of the inlet water flow. The flow pattern of the water flow behind the weir is stable at low and high water levels, and finally enters the chute smoothly. The present invention has some changes in the engineering structure type and water flow pattern, making the design engineering economical, reasonable, beautiful and practical.

[0021] The embodiments described above are only used to illustrate the technical ideas and features of the present invention, and their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. The patent scope of the present invention cannot be limited only by this embodiment, that is, any equivalent changes or modifications made to the spirit disclosed by the present invention still fall within the patent scope of the present invention.

Claims

1. A curved overflow weir structure of a bank spillway, comprising an overflow weir (1), an outer guide wall (2) extending along the topography near the bank, and an inner guide wall (3) near the riverbed, characterized in that: The axis of the overflow weir (1) adopts an asymmetric curve, the inner guide wall (3) adopts an arc arrangement, the overflow weir body is offset to one side of the riverbed, the overflow front length of the overflow weir body is increased, and when discharging flood water, the flood water passes through the overflow weir (1) and enters the chute (4) smoothly. The angle α between the axis (5) of the chute and the center line (6) of the overflow weir is between 15° and 45°. The inner guide wall (3) is in an arc shape, the center of the arc of the inner guide wall is on the extension line of the center of the overflow weir curve, and the upstream extension section L of the inner guide wall (3) is 1 to 2 times the height of the weir.

2. The curved overflow weir structure of the bank spillway according to claim 1, characterized in that: The overflow weir (1) is a practical weir, a broad-top weir or a hump weir.

3. The curved overflow weir structure of the bank spillway according to claim 1, characterized in that: The axis of the overflow weir is an asymmetric curve, which is an arc shape, a parabola shape or an ellipse shape.

Images