A method for constructing a hydraulic dam

Abstract

This invention provides a construction method for a hydraulic dam. By partially excavating the dam body to form a groove and using rebar to form a boss, the energy dissipation of the back pipe is achieved through the interlocking of the groove and the fixing performance of the back pipe is improved. An arc-shaped groove and an arc-shaped plate are set at the outlet of the back pipe. The water flow at the outlet of the back pipe flows down through the arc-shaped plate, which can effectively reduce the scouring of the dam body and improve the overall structural stability of the back pipe.

Description

Technical Field

[0001] This invention relates to the field of water conservancy engineering, and specifically to a method for constructing a water conservancy dam. Background Technology

[0002] The dam backpipe, also known as the dam downstream pipe, is a pipe located on the downstream surface of the dam. Because it is located on the downstream surface of the dam, it does not require excavation of the dam body and is easy to maintain. It is a common type of dam pipe, especially for existing concrete dams. When it is necessary to transport water downstream, the dam backpipe can be used as a water conveyance pipe to transport water downstream. For example, when it is necessary to ensure the ecological flow downstream, water can be transported downstream through the dam backpipe to form a siphon structure.

[0003] While the construction of the dam back pipe is simple, extending it directly to the dam toe not only results in excessive pipe length, affecting costs, but more importantly, it increases the difficulty of fixing the pipe and makes it prone to significant deflection, impacting the normal use of the structure. To ensure the dam back pipe's integrity, its length can be reduced, for example, by placing the pipe's outlet at the middle of the downstream surface of the dam. Although this method reduces the pipe's length, the high water flow energy at the pipe's outlet can scour the dam, causing concrete erosion damage and potentially affecting the dam's stability. Summary of the Invention

[0004] This invention addresses the problems of existing technologies by providing a method for constructing hydraulic dams.

[0005] This invention provides a construction method for a hydraulic dam, wherein the dam is a concrete dam, a backpipe is located downstream of the dam, the backpipe is used to discharge water downstream of the dam, and the outlet of the backpipe is located on the downstream surface of the dam; the method is characterized by comprising the following construction steps:

[0006] S1: Clean the downstream surface of the dam body and remove surface debris; excavate a groove at the first position on the downstream surface of the dam body and clean the excavated groove;

[0007] S2: Drill holes on the downstream surface of the dam body below the groove and insert longitudinal steel bars. The diameter of the drill holes is larger than the diameter of the longitudinal steel bars, and the upper end of the longitudinal steel bars extends a certain distance beyond the downstream surface of the dam body. After the longitudinal steel bars are inserted into the drill holes, grout is injected into the drill holes and cured to the design strength.

[0008] S3: Tie transverse steel bars to the longitudinal steel bars. The longitudinal and transverse steel bars are tied and fixed by fasteners. The longitudinal and transverse steel bars are connected to form a steel cage. A formwork is erected outside the steel cage, concrete is poured, and it is cured to the design strength. The poured concrete forms a boss. The side of the boss that connects to the groove is on the same plane as the side of the groove that connects to the boss.

[0009] S4: Process the back tube, which is factory-processed to match the shape of the downstream surface, groove, and boss of the dam body, so that the back tube can be closely attached to the downstream surface, groove, and boss of the dam body; the back tube extends to below the boss and fits against the downstream surface of the dam body below the boss.

[0010] S5: The processed back pipe is transported to the downstream of the dam body and fixed sequentially to the downstream surface, groove, and boss of the dam body, and is made to fit against the surfaces of the downstream surface, groove, and boss of the dam body; after the back pipe is fixed, a U-shaped clamp is installed on the back pipe, and the clamp is provided with fixing parts on both sides of the U-shaped clamp. The fixing parts are used to fix it to the downstream surface, groove, and boss of the dam body. The U-shaped clamp fixes the back pipe to the downstream surface, groove, and boss of the dam body; the outlet of the back pipe is located below the boss.

[0011] S6: A curved groove is formed on the downstream surface of the dam body at the outlet of the back pipe, and the curved groove is connected to the dam toe downstream of the dam body;

[0012] S7: Processing the arc-shaped plate, the arc-shaped plate is processed in the factory; the arc-shaped plate matches the arc-shaped groove and can be tightly fixed in the arc-shaped groove, and both sides of the arc-shaped plate are provided with flanges, and bolt holes are opened on the flanges;

[0013] S8: Transport the arc-shaped plate to the downstream of the dam body and fix it tightly in the arc-shaped groove, so that the flange is tightly fixed to the downstream surface of the dam body. Use fixing bolts to pass through the bolt holes to fix the arc-shaped plate to the downstream surface of the dam body.

[0014] Preferably, the first position is predetermined, and its distance from the back tube outlet shall not be less than 5m; the groove depth shall not be less than 0.3m.

[0015] Preferably, the groove has a trapezoidal cross-section, which is in the same plane as the dam body cross-section, and the length of the groove perpendicular to the groove cross-section is no more than 1.5m.

[0016] Preferably, the cross-section of the boss is a reminder section, the cross-section of the boss is a section in the same plane as the cross-section of the dam body, the length of the boss perpendicular to the cross-section of the groove is not greater than 1.5m, and the side of the boss that connects to the groove is in the same plane as the side of the groove that connects to the boss.

[0017] Preferably, the curved plate can be made of steel.

[0018] Preferably, the wear-resistant pad is provided on the surface of the groove and the boss, the wear-resistant pad has a rough surface, and the back tube is placed on the wear-resistant pad.

[0019] The working principle of this invention is as follows:

[0020] An improvement to the conventional back pipe involves excavating grooves in the dam body and using drilled holes in the dam body to anchor reinforcing bars to fix the boss. The back pipe cooperates with the grooves and bosses. This fixing method has two advantages: first, the cooperation of the grooves and bosses creates turbulence in the water flow, enhancing energy dissipation and reducing water flow capacity; second, the cooperation of the grooves and bosses can improve the overall stress performance of the back pipe, preventing displacement and resulting in a better fixing effect.

[0021] An arc-shaped groove and an arc-shaped plate are installed at the outlet of the back pipe. The arc-shaped plate is fixed to the downstream surface of the dam body. The water flow at the outlet of the back pipe flows directly through the arc-shaped plate to the toe of the dam body instead of directly scouring the dam body. This fixing method can reduce the impact of the back pipe on the dam body, which is extremely beneficial to improving the stability of the dam body. If the arc-shaped plate is damaged, it can be replaced directly. Springs, damping plates and other components can also be installed between the arc-shaped plate and the arc-shaped groove to further improve its energy dissipation effect.

[0022] By utilizing the combination of grooves and protrusions, the original method of directly arranging the back pipe along the dam surface is changed. The grooves and protrusions can form a statically indeterminate force, ensuring the overall structural safety. In addition, the combination of grooves and protrusions realizes turbulence, consumes water flow energy, and the water outlet passes through the arc plate, which does not directly scour the dam body, thus improving the dam's service life.

[0023] The above structure can be used for dam siphon pipe installation or other dams that require equipment back pipes; for scouring caused by the original dam back pipes, the structure and construction method of this invention can be used to repair it, setting grooves and bosses to change the original stress mode, which has high economic benefits.

[0024] The construction method of the dam body back pipe fixing device of the present invention can be applied to the use of siphon pipe when the dam body discharges ecological flow downward. Therefore, it is a construction method of dam body ecological flow back pipe fixing device. It can appropriately raise the height of the dam body back pipe outlet, improve structural stability, and reduce project investment.

[0025] The advantages of this invention are:

[0026] This invention provides a construction method for a hydraulic dam. By partially excavating the dam body to form a groove and using rebar to form a boss, the energy dissipation of the back pipe is achieved through the interlocking of the groove and the fixing performance of the back pipe is improved. An arc-shaped groove and an arc-shaped plate are set at the outlet of the back pipe. The water flow at the outlet of the back pipe flows down through the arc-shaped plate, which can effectively reduce the scouring of the dam body and improve the overall structural stability of the back pipe. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the present invention;

[0028] Figure 2 This is a structural diagram of the groove and the boss;

[0029] Figure 3 This is a schematic diagram of the boss structure;

[0030] Figure 4 This is a schematic diagram of an arc-shaped plate structure. Detailed Implementation

[0031] The following description, based on the accompanying drawings, provides a detailed explanation of the structure defined in this invention.

[0032] This invention provides a construction method for a hydraulic dam, wherein the dam is a concrete dam, a backfill pipe 1 is located downstream of the dam, the backfill pipe 1 is used to discharge water downstream of the dam, and the outlet of the backfill pipe 1 is located on the downstream surface of the dam; the method is characterized by the following construction steps:

[0033] S1: Clean the downstream surface of the dam body and remove surface debris; excavate a groove 2 at the first position on the downstream surface of the dam body and clean the excavated groove 2;

[0034] S2: Drill a hole on the downstream surface of the dam body below the groove 2 and insert a longitudinal steel bar 31. The diameter of the hole is larger than the diameter of the longitudinal steel bar 31, and the upper end of the longitudinal steel bar 31 extends a certain distance from the downstream surface of the dam body. After the longitudinal steel bar 31 is inserted into the hole, grout is injected into the hole and cured to the design strength.

[0035] S3: Bind transverse steel bars 32 to the longitudinal steel bars 31. The longitudinal steel bars 31 and transverse steel bars 32 are bound and fixed by fasteners. The longitudinal steel bars 31 and transverse steel bars 32 are connected to form a steel cage. A formwork is erected outside the steel cage, concrete is poured, and cured to the design strength. The poured concrete forms a boss 3. The side of the boss 3 that connects to the groove 2 is on the same plane as the side of the groove 2 that connects to the boss 3.

[0036] S4: Process the back tube 1. The back tube 1 is factory-processed so that its shape matches the downstream surface of the dam body, the groove 2, and the boss 3, and so that the back tube 1 can be set tightly against the downstream surface of the dam body, the groove 2, and the boss 3; the back tube 1 extends to below the boss 3 and fits against the downstream surface of the dam body below the boss 3.

[0037] S5: The processed back pipe 1 is transported to the downstream of the dam body and fixed sequentially on the downstream surface of the dam body, the groove 2, and the boss 3, and is in contact with the surfaces of the downstream surface of the dam body, the groove 2, and the boss 3; after the back pipe 1 is fixed, a U-shaped clamp is installed on the back pipe 1, and the clamp is provided with fixing parts on both sides of the U-shaped clamp. The fixing parts are used to fix it to the downstream surface of the dam body, the groove 2, and the boss 3. The U-shaped clamp fixes the back pipe 1 to the downstream surface of the dam body, the groove 2, and the boss 3; the outlet of the back pipe 1 is located below the boss 3;

[0038] S6: The downstream surface of the dam body at the outlet of the back pipe 1 is chiseled to form an arc-shaped groove 4, which is connected to the dam toe downstream of the dam body;

[0039] S7: Processing the arc plate 5, the arc plate 5 is processed in the factory; the arc plate 5 matches the arc groove 4 and can be tightly fixed in the arc groove 4, and both sides of the arc plate 5 are provided with flanges 51, and bolt holes 52 are opened on the flanges 51;

[0040] S8: Transport the arc plate 5 to the downstream of the dam body and fix it tightly in the arc groove 4 so that the flange 51 is tightly fixed to the downstream surface of the dam body. Use fixing bolts to pass through the bolt holes 52 to fix the arc plate 5 to the downstream surface of the dam body.

[0041] In the actual construction, the position of the back pipe 1 of the dam body should be measured first to determine its position and dimensions, which will serve as the basis for the design and fabrication of the back pipe 1; for the construction of the groove 2 and the boss 3, their accurate construction positions should be determined by measurement and layout according to the design requirements; as shown in the attached... Figure 2 As shown, the dashed line is the excavation line;

[0042] Preferably, the first position is predetermined, and its distance from the outlet of the back tube 1 shall not be less than 5m; the depth of the groove 2 shall not be less than 0.3m; the first position shall not be too low from the outlet, and shall meet the layout requirements of the back tube 1. If the depth of the groove 2 is too deep, it will make it more difficult to fix the back tube 1.

[0043] Preferably, the cross-section of the groove 2 is trapezoidal, and the cross-section of the groove 2 is in the same plane as the cross-section of the dam body. The length of the groove 2 perpendicular to the cross-section of the groove 2 is no more than 1.5m. The distance from the first position to the outlet, the depth of the groove 2, and the length of the groove 2 perpendicular to the cross-section of the groove 2 should all be reasonably determined according to the size of the dam body and the diameter of the back pipe 1. If conditions permit, they can be determined through hydraulic tests.

[0044] Preferably, the cross-section of the protrusion 3 is a reminder section, and the cross-section of the protrusion 3 is a section that is in the same plane as the cross-section of the dam body. The length of the protrusion 3 perpendicular to the cross-section of the groove 2 is not greater than 1.5m. The side of the protrusion 3 that connects to the groove 2 is in the same plane as the side of the groove 2 that connects to the protrusion 3. The height and length of the protrusion 3 are related to the diameter of the back pipe, and can be determined by hydraulic experiments if conditions permit.

[0045] Preferably, the arc-shaped plate 5 can be made of steel; a rubber pad can be placed under the arc-shaped plate 5 to improve the stress performance of the arc-shaped plate 5 and the arc-shaped groove 4.

[0046] Preferably, the wear-resistant pad is provided on the surface of the groove 2 and the boss 3, and the wear-resistant pad has a rough surface. The back tube 1 is placed on the wear-resistant pad. As an alternative implementation, a local groove is formed in both the groove 2 and the boss 3, and a local protrusion is provided at the corresponding position of the back tube 1. The local protrusion cooperates with the local groove, and the connection and fixation performance is improved by utilizing their convex-concave cooperation.

[0047] The above embodiments are merely preferred embodiments of the present invention. The scope of protection of the present invention should not be considered as limited to the specific forms described in the embodiments. The scope of protection of the present invention also includes equivalent technical means that can be conceived by those skilled in the art based on the concept of the present invention.

Claims

1. A method of constructing a water retaining dam, the dam being a concrete dam, a back pipe being located downstream of the dam, the back pipe being for spillway flow downstream of the dam, the outlet of the back pipe being located at the downstream surface of the dam; characterised in that: The construction method includes the following construction steps: S1: Clean the downstream surface of the dam body and remove surface debris; excavate a groove at the first position on the downstream surface of the dam body and clean the excavated groove; S2: Drill holes on the downstream surface of the dam body below the groove and insert longitudinal steel bars. The diameter of the drill holes is larger than the diameter of the longitudinal steel bars, and the upper end of the longitudinal steel bars extends a certain distance beyond the downstream surface of the dam body. After the longitudinal steel bars are inserted into the drill holes, grout is injected into the drill holes and cured to the design strength. S3: Tie transverse steel bars to the longitudinal steel bars. The longitudinal and transverse steel bars are tied and fixed by fasteners. The longitudinal and transverse steel bars are connected to form a steel cage. A formwork is erected outside the steel cage, concrete is poured, and it is cured to the design strength. The poured concrete forms a boss. The side of the boss that connects to the groove is on the same plane as the side of the groove that connects to the boss. S4: Process the back tube, which is factory-processed to match the shape of the downstream surface, groove, and boss of the dam body, so that the back tube can be closely attached to the downstream surface, groove, and boss of the dam body; the back tube extends to below the boss and fits against the downstream surface of the dam body below the boss. S5: The processed back pipe is transported to the downstream of the dam body and fixed sequentially to the downstream surface, groove, and boss of the dam body, and is made to fit against the surfaces of the downstream surface, groove, and boss of the dam body; after the back pipe is fixed, a U-shaped clamp is installed on the back pipe, and the clamp is provided with fixing parts on both sides of the U-shaped clamp. The fixing parts are used to fix it to the downstream surface, groove, and boss of the dam body. The U-shaped clamp fixes the back pipe to the downstream surface, groove, and boss of the dam body; the outlet of the back pipe is located below the boss. S6: A curved groove is formed on the downstream surface of the dam body at the outlet of the back pipe, and the curved groove is connected to the dam toe downstream of the dam body; S7: Processing the arc-shaped plate, the arc-shaped plate is processed in the factory; the arc-shaped plate matches the arc-shaped groove and can be tightly fixed in the arc-shaped groove, and both sides of the arc-shaped plate are provided with flanges, and bolt holes are opened on the flanges; S8: Transport the arc-shaped plate to the downstream of the dam body and fix it tightly in the arc-shaped groove, so that the flange is tightly fixed to the downstream surface of the dam body. Use fixing bolts to pass through the bolt holes to fix the arc-shaped plate to the downstream surface of the dam body.

2. The method of claim 1, wherein: The first position is predetermined, and its distance from the back tube outlet shall not be less than 5m; the groove depth shall not be less than 0.3m.

3. The method of claim 1, wherein: The groove has a trapezoidal cross-section, which is in the same plane as the dam body cross-section. The length of the groove perpendicular to its cross-section is no more than 1.5m.

4. The method of claim 1, wherein: The curved plate is made of steel.

5. The method of claim 1, wherein: A wear-resistant pad is provided on the surface of the groove and the boss. The wear-resistant pad has a rough surface, and the back tube is placed on the wear-resistant pad.

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