Anti-collapse self-adaptive anti-scouring energy dissipation earth and rockfill dam and energy dissipation method

Abstract

The dam comprises a dam body, the top of the dam body is provided with a water retaining body extending in the transverse direction, the water retaining body is provided with a drainage hole with a valve, the downstream of the dam body is provided with lateral drainage ditches located on the two sides of the dam face, and the lateral drainage ditches are arranged in the dam face. A flexible energy dissipation layer is arranged on the dam face between the lateral drainage ditches, a longitudinal drainage ditch located in the center of the dam face and a net-shaped drainage ditch distributed along the dam face are arranged on the flexible energy dissipation layer, and the bottom outlet ends of the longitudinal drainage ditch, the net-shaped drainage ditch and the lateral drainage ditches are all connected with a stilling pool. According to the method, by comprehensively applying the modes of combining the characteristics of protective structure materials, the energy dissipation principle, the overtopping flood discharge capacity of the earth and rockfill dam and the like, the deformation coordination between the structure materials is improved, and meanwhile safety protection and safety operation of overtopping but not collapsing or overtopping and slow collapsing of small and medium-sized reservoir dam bodies are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of dam protection, and in particular to an anti-collapse-adaptive anti-scour energy dissipation earth-rock dam and an energy dissipation method. Background Art

[0002] Earth-rock dams (including face-plate dams and core-wall dams, the former uses concrete face-plates to block water, and the latter uses core-walls to block water) are built with homogeneous soil or soil-rock mixtures. They are highly discrete and have poor erosion resistance. Under extreme rainfall conditions, super-standard floods lead to insufficient flood discharge capacity of earth-rock dams and weak erosion resistance of downstream dam bodies, which can easily lead to overtopping and dam failure risks. In recent years, earth-rock dam failures caused by extreme weather, dam design defects and aging have occurred frequently, seriously affecting people's lives and property safety. In particular, for small and medium-sized earth-rock dams, affected by the construction age and construction technology level, it is questionable whether some old dam bodies can operate safely after being affected by extreme rainfall.

[0003] Since the 1950s, more than 3,000 reservoir dams have collapsed in my country, of which more than 90% are earth-rock dams. More than 50% of the dam failures were caused by reservoir water overflow. The most common cause of earth-rock dam overtopping is the formation and development of "steep slopes", such as Figure 1 As shown in the figure, the flow velocity at the bottom of the downstream dam body is high, which will form a corresponding scouring pit and cause upstream scouring on both sides of the dam body. With the continuous scouring of the overtopping water flow and the upstream scouring of the scouring pit flow direction, the downstream dam body gradually loses support at the bottom, and eventually the overtopping dam collapse is caused by the breakage of the upstream panel or the collapse of the dam body. This process lasts for a short time, but has a high degree of damage and a wide range of damage.

[0004] The problem of preventing and mitigating the collapse of earth-rock dams can be improved by increasing the emptying speed of the reservoir, improving the anti-scouring performance of the downstream dam materials, and accelerating the drainage capacity. Patent CN 118390457 A provides an emergency rescue device and early warning method for earth-rock dams, that is, adding a blocking unit in the middle of the dam body, and then adding enclosure units along the length of the dam to improve the flood discharge capacity of the earth-rock dam. This method is feasible for preventing or mitigating the collapse of small dams with short-term rainfall or slow rise in reservoir water level. However, in the case of heavy rainfall or rapid rise in water level, the enclosure unit is easily washed away by water pressure, and the downstream dam surface is still subject to the danger of being washed away and traced back to the source, resulting in dam collapse. In addition, this structure has poor adaptability to earth-rock dam materials. In the case of uneven deformation, the entire device is easily destroyed, causing the downstream dam body to be damaged due to infiltration, affecting the structural reliability and normal use. Summary of the invention

[0005] In order to solve the problems of scouring and scouring damage to the downstream dam body caused by the overtopping water flow under the action of super-standard floods in existing earth-rock dams, as well as the seepage damage caused by uneven settlement deformation caused by the difference in performance of the existing structural form and dam body materials, the present invention provides an earth-rock dam anti-break-up-adaptive anti-scouring energy dissipation structure, and also provides an energy dissipation method, which can specifically adopt the following technical solutions: The anti-break-up and self-adaptive anti-scour energy dissipation earth-rock dam described in the present invention comprises a dam body, a water retaining body extending laterally is arranged on the top of the dam body, a drainage hole with a valve is arranged on the water retaining body, lateral drainage ditches located on both sides of the dam surface are arranged downstream of the dam body, a flexible energy dissipation layer is arranged on the dam surface between the lateral drainage ditches, a longitudinal drainage ditch located in the center of the dam surface and a mesh drainage ditch arranged along the dam surface are arranged on the flexible energy dissipation layer, and the bottom outlet ends of the longitudinal drainage ditch, the mesh drainage ditch and the lateral drainage ditch are all connected to the energy dissipation pool.

[0006] The water retaining body is a prefabricated concrete part, the height of which is determined according to the flood discharge level, and the length of which is equal to the top of the dam body.

[0007] A foldable metal water retaining plate is arranged on the top of the water retaining body.

[0008] There are multiple drainage holes, which are evenly spaced and arranged in a single row in the extending direction of the water retaining body, and the drainage holes are arranged one by one corresponding to the top entrances of the mesh drainage ditch and the longitudinal drainage ditch.

[0009] The lateral drainage ditch is a concrete structure, and its strength is equivalent to the deformation modulus of the downstream material of the dam body.

[0010] The flexible energy dissipation layer is made of a flexible waterproof material having a deformation modulus equivalent to that of the downstream material of the dam body.

[0011] The mesh drainage ditch includes a plurality of regular hexagonal units which are equal in size and interconnected.

[0012] The side surfaces of the mesh drainage ditch are connected with the longitudinal drainage ditch and the lateral drainage ditch.

[0013] The edge of the flexible energy dissipation layer and the dam body are filled with anti-seepage sealant, and the connection between the longitudinal drainage ditch, the mesh drainage ditch, the lateral drainage ditch and the energy dissipation pool is provided with a reinforcement layer.

[0014] The energy dissipation method of the anti-break-adaptive anti-scour energy dissipation earth-rock dam described in the present invention includes: when extremely heavy rainfall produces a flood that exceeds the flood control level of the earth-rock dam, the valve of the drainage hole is opened to allow the flood to pass through the drainage hole along the longitudinal drainage ditch, the mesh drainage ditch and the lateral drainage ditch to flow to the energy dissipation pool.

[0015] The present invention provides an earth-rock dam type that can adapt to the deformation of the dam body and the anti-scouring and energy dissipation form, which effectively solves the scouring and source scouring damage of the downstream dam body by the overtopping water flow under the action of super-standard floods in the existing earth-rock dam, and at the same time provides an emergency prevention and rescue method for earth-rock dams in the case of extreme heavy rainfall. It combines the characteristics of protective structural materials, the principle of energy dissipation, and the overtopping flood discharge capacity of earth-rock dams. While improving the deformation coordination between structural materials, it ensures the safety protection and safe operation of small and medium-sized reservoir dams (core wall dams and panel dams) that are flooded but not collapsed or flooded but slowly collapsed. In addition, the present invention can also be applied to the silt dams on the Loess Plateau in my country, which can effectively improve the soil and water conservation capacity of the plateau area. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the "steep slope" phenomenon that occurs in existing earth-rock dams.

[0017] Figure 2 It is a structural schematic diagram of the earth-rock dam in Example 1.

[0018] Figure 3 yes Figure 2 Top view of the .

[0019] Figure 4 yes Figure 3 Enlarged view of part A.

[0020] Figure 5 It is a structural schematic diagram of the earth-rock dam in Example 2. DETAILED DESCRIPTION

[0021] The following is a detailed description of an embodiment of the present invention in conjunction with the accompanying drawings. This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific working process are given, but the protection scope of the present invention is not limited to the following embodiment.

[0022] Embodiment 1: like Figure 2-4 As shown, the anti-break-adaptive anti-scour energy dissipation earth-rock dam described in the present invention includes a dam body 1 composed of rockfill materials, and a water retaining body 2 extending laterally is arranged at the top near the downstream. The water retaining body 2 is a prefabricated concrete part, and the height is determined according to the flood discharge level, and the length is equal to the top of the dam body 1. If the structural performance of the dam body 1 allows, the water retaining height can be appropriately increased. For example, a foldable metal water retaining plate 3 can be installed on the top of the water retaining body 2. When an excessive flood comes, the metal water retaining plate 3 can be opened to increase the water retaining level of the dam body 1. The water retaining body 2 is also provided with a drainage hole 4 with a valve. The drainage holes 4 are multiple and are evenly spaced in a single row in the extension direction of the water retaining body 2. When flood discharge is required, the valve is opened to allow water to flow through the drainage hole 4 and be discharged to the downstream of the dam body 1.

[0023] Lateral drainage ditches 5 are arranged on both sides of the dam surface downstream of the dam body 1, and a flexible energy dissipation layer 6 is arranged on the dam surface between the lateral drainage ditches 5. A longitudinal drainage ditch 7 located in the center of the dam surface and a mesh drainage ditch 8 arranged along the dam surface are arranged on the flexible energy dissipation layer 6. The main body of the mesh drainage ditch 8 is composed of a plurality of equal-sized, interconnected regular hexagonal units, and the top entrance of the mesh drainage ditch 8, the top entrance of the longitudinal drainage ditch 7 and the drainage hole 4 are arranged one by one, the side of the mesh drainage ditch 8 is connected with the longitudinal drainage ditch 7 and the lateral drainage ditch 5, and the bottom outlet ends of the mesh drainage ditch 8, the longitudinal drainage ditch 7 and the lateral drainage ditch 5 are connected with the energy dissipation pool 9.

[0024] The above-mentioned lateral drainage ditch 5 is a concrete structure, and its strength is equivalent to the deformation modulus of the rockfill material downstream of the dam body 1. The flexible energy dissipation layer 6 is made of a flexible waterproof material (such as silica gel, etc.) that is equivalent to the deformation modulus of the rockfill material downstream of the dam body. The mesh drainage ditches 8 on the flexible energy dissipation layer 6 are interconnected. In addition to increasing the function of the entire downstream dam body drainage channel, the most important thing is to disperse the scouring and upstream scouring of the dam body bottom by high-speed water flow caused by extreme rainfall (after the water flows into the bottom, the reaction force of the bottom structure scours the bottom sides and the upper dam body) by extending the water flow distance and constantly changing the water flow direction, that is, to play an energy dissipation role. The longitudinal drainage ditch 7 on the flexible energy dissipation layer 6 and the lateral drainage ditches 5 on both sides of the dam body 1 are mainly used to increase the drainage capacity of the downstream dam body under the action of super-standard floods.

[0025] In order to prevent leakage, an anti-seepage sealant is filled between the edge of the flexible energy dissipation layer 6 and the dam body 1. At the same time, a reinforcement layer is provided at the connection between the longitudinal drainage ditch 7, the mesh drainage ditch 8, the lateral drainage ditch 5 and the energy dissipation pool 9 to improve the strength of the connection part and reduce the uneven settlement damage caused by the deformation difference of the connection part.

[0026] Through the above-mentioned anti-break-adaptive anti-scour energy dissipation earth-rock dam, the present invention can adopt the following method for energy dissipation and drainage. That is: in the case of extremely heavy rainfall, when the flood water level exceeds the flood control level of the earth-rock dam, open the valve of the drainage hole 4 on the water retaining body 2, so that the flood can pass through the drainage hole 4 and quickly drain along the longitudinal drainage ditch 7, the mesh drainage ditch 8 and the lateral drainage ditch 5 to the downstream energy dissipation pool 9. The above-mentioned drainage method can improve the adaptive deformation and anti-scour ability of the downstream dam surface, while dissipating the energy of the upstream overflow water flow, reducing the harm of the downstream dam body's rapid flow rate to the source of the dam body. It can meet the anti-scour and flood discharge level of small and medium-sized reservoir dams when experiencing super-standard flood overflow, improve the dam body's anti-break or slow-break ability, and protect the lives and property of downstream residents.

[0027] Embodiment 2: Compared with Example 1, the only difference is that a gravel / clay core wall 10 (see Figure 5 ), and no concrete panel is provided upstream of the dam surface, and the rest is the same as in Example 1.

[0028] It should be noted that, in the description of the present invention, terms indicating orientation or positional relationships, such as "front", "rear", "left", "right", "vertical", "horizontal", "inside", "outside", etc., are based on the orientation or positional relationships shown in the drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

Claims

1. A collapse-proof and adaptive anti-scour energy dissipation earth-rock dam, characterized by: It includes a dam body, a water retaining body extending laterally is arranged on the top of the dam body, a drainage hole with a valve is arranged on the water retaining body, lateral drainage ditches are arranged on both sides of the dam surface downstream of the dam body, a flexible energy dissipation layer is arranged on the dam surface between the lateral drainage ditches, a longitudinal drainage ditch located in the center of the dam surface and a mesh drainage ditch arranged along the dam surface are arranged on the flexible energy dissipation layer, and the bottom outlet ends of the longitudinal drainage ditch, the mesh drainage ditch and the lateral drainage ditch are all connected to the energy dissipation pool.

2. The collapse-proof and adaptive anti-scour energy dissipation earth-rock dam according to claim 1 is characterized in that: The water retaining body is a prefabricated concrete part, the height of which is determined according to the flood discharge level, and the length of which is equal to the top of the dam body.

3. The collapse-proof and adaptive anti-scour energy dissipation earth-rock dam according to claim 1 is characterized in that: A foldable metal water retaining plate is arranged on the top of the water retaining body.

4. The collapse-proof and adaptive anti-scour energy dissipation earth-rock dam according to claim 1 is characterized in that: There are multiple drainage holes, which are evenly spaced and arranged in a single row in the extending direction of the water retaining body, and the drainage holes are arranged one by one corresponding to the top entrances of the mesh drainage ditch and the longitudinal drainage ditch.

5. The collapse-proof and adaptive anti-scour energy dissipation earth-rock dam according to claim 1 is characterized in that: The lateral drainage ditch is a concrete structure, and its strength is equivalent to the deformation modulus of the downstream material of the dam body.

6. The collapse-proof and adaptive anti-scour energy dissipation earth-rock dam according to claim 1 is characterized in that: The flexible energy dissipation layer is made of a flexible waterproof material having a deformation modulus equivalent to that of the downstream material of the dam body.

7. The collapse-proof and adaptive anti-scour energy dissipation earth-rock dam according to claim 1 is characterized in that: The mesh drainage ditch includes a plurality of regular hexagonal units which are equal in size and interconnected.

8. The collapse-proof and self-adaptive anti-scour energy dissipation earth-rock dam according to claim 1 is characterized in that: The side surfaces of the mesh drainage ditch are connected with the longitudinal drainage ditch and the lateral drainage ditch.

9. The collapse-proof and adaptive anti-scour energy dissipation earth-rock dam according to claim 1 is characterized in that: The edge of the flexible energy dissipation layer and the dam body are filled with anti-seepage sealant, and the connection between the longitudinal drainage ditch, the mesh drainage ditch, the lateral drainage ditch and the energy dissipation pool is provided with a reinforcement layer.

10. The energy dissipation method for a collapse-resistant and self-adaptive anti-scour energy dissipation earth-rock dam according to any one of claims 1 to 9, characterized in that: When extremely heavy rainfall produces floods that exceed the flood control level of the earth-rock dam, the valve of the drainage hole is opened to allow the flood to flow through the drainage hole along the longitudinal drainage ditch, mesh drainage ditch and lateral drainage ditch to the energy dissipation pool.

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