Earth-rock embankment / dam capable of overtopping and overflowing and design, construction and operation method of earth-rock embankment / dam

Abstract

The invention discloses an overtopping and overflowing earth and rockfill dam and a design, construction and operation method thereof. The overtopping and overflowing earth and rockfill dam comprises an earth and rockfill dam body, and an anti-scouring structure layer is arranged on the downstream face and / or the dam top of the earth and rockfill dam body; the anti-scouring structure layer adopts a net-hanging sprayed concrete layer or a reinforced concrete layer or a fiber concrete layer; the anti-scouring structure layer is arranged on the earth and rockfill dam, so that the safety risk of dam break and collapse of the earth and rockfill dam is eliminated, the reservoir capacity does not need to be emptied in advance for flood control in the flood season, the reservoir can be prevented from running at low water level throughout the year due to insufficient water storage, the flood control pressure is reduced, and the benefit-making reservoir capacity is greatly expanded; benefits such as agricultural irrigation, water supply and power generation are fully exerted, and high-quality development of the water conservancy career is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of water conservancy engineering, and in particular to an earth-rock embankment / dam capable of overflowing and a design, construction and operation method thereof. Background Art

[0002] Traditional earth-rock dams do not allow overtopping and overflowing, because once the flood water level exceeds the top of the dam, the scouring of the water flow will quickly destroy the dam structure, carry away soil and stone particles, and lead to serious consequences such as dam collapse and embankment collapse. Based on the above reasons, in order to prevent the dam from overtopping and overflowing, after entering the flood season every year, it is often mandatory for each reservoir management unit to vacate the storage capacity in advance to prevent floods. Sometimes, when the storage capacity is emptied, the rain does not fall, or the rainfall is very small, resulting in insufficient water storage in the reservoir in the later stage, and long-term low water level operation, which to a certain extent wastes the beneficial storage capacity. Despite this (emptying the storage capacity in advance), there is still a safety hazard of overtopping and dam collapse when dealing with extreme floods. Therefore, it is of great practical significance to develop a new type of earth-rock dam that can allow overtopping and overflow while ensuring the stability and safety of the dam body.

[0003] Most of the existing reservoir dams are earth dams, and almost all of the existing embankments are earth embankments. Since earth dams (embankments) use natural construction materials and local materials, the construction cost is relatively low. However, although the earth has a certain density after rolling and compaction, its ability to resist water scouring is weak. If it overflows, it is easy to cause dam collapse and embankment collapse; the panel rockfill dam is a rockfill dam with a rockfill body as a supporting structure and a concrete panel cast on its upstream surface as an anti-seepage structure. Most of this type of dam uses natural building materials and has a low construction cost. Because the back surface of the panel rockfill dam is a "granular" structure, it still does not have sufficient anti-scouring ability, so overflow is prohibited during operation; the concrete gravity dam refers to a dam with a dam body cast in concrete. This type of dam uses concrete as a building material, and its construction cost is relatively high. Most high dams use this type of dam. The concrete dam has good integrity. Theoretically, its back water surface has a certain ability to resist scour and can withstand overtopping. However, influenced by traditional concepts and based on the pursuit of absolute safety, overtopping operation is still not considered during the design stage, and relevant measures are not designed under the "overtopping" condition. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides an earth-rock embankment / dam capable of overflowing and a design, construction and operation method thereof, the purpose of which is to allow overflowing operation during the flood season or in the event of a severe flood, thereby preventing dam collapse and improving the ability to defend against floods, while ensuring the safety of the embankment.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: an earth-rock embankment / dam capable of overflowing, comprising: an earth-rock dam, an anti-scour structural layer is arranged on the back water surface and / or the dam top of the earth-rock dam.

[0006] Furthermore, the anti-scour structural layer adopts a mesh shotcrete layer or a reinforced concrete layer or a fiber concrete layer.

[0007] Furthermore, a plurality of anchor rods for reinforcing the anti-scour structural layer are provided on the earth-rock dam.

[0008] Furthermore, the anti-scour structure layer arranged on the back water surface is provided with drainage holes.

[0009] Furthermore, a greening spraying layer is arranged on the anti-scour structural layer arranged on the back water surface.

[0010] A design method for an earth-rock embankment / dam capable of overflowing is applied to an earth-rock embankment / dam capable of overflowing. The construction of an earth-rock dam capable of overflowing includes both the reconstruction of an existing earth-rock dam and the construction of a new earth-rock dam, and includes the following steps:

[0011] The specific process of the existing earth-rock dam reconstruction design is as follows:

[0012] Step 1.1: Conduct safety assessment of existing earth-rock dams;

[0013] Step 1.2: Re-determine the dam crest elevation and normal water storage level parameters based on the historical data of the existing earth-rock dam;

[0014] Step 1.3: Determine whether the spillway gate of the existing earth-rock dam should be raised and whether the existing earth-rock dam should be reinforced according to Step 1.1 and Step 1.2;

[0015] Step 1.4: Determine the material type, thickness and physical and mechanical parameters of the anti-scour structural layer according to steps 1.1 to 1.3;

[0016] Step 1.5: According to the material type, thickness and physical and mechanical parameters determined in step 1.4, an anti-scour structural layer and a greening spraying layer are laid on the backwater surface of the existing earth-rock dam to complete the reconstruction design of the existing earth-rock dam;

[0017] The specific process of designing a new earth-rock dam is as follows:

[0018] Step 2.1: Determine the characteristic parameters of the new earth-rock dam based on the survey data;

[0019] Step 2.2: Determine the material type, thickness and physical and mechanical parameters of the anti-scour structural layer according to step 2.1;

[0020] Step 2.3: Based on the characteristic parameters determined in step 2.1 and the material type, thickness and physical and mechanical parameters determined in step 2.2, the anti-scour structural layer and greening spraying layer on the back surface of the earth-rock dam are designed to complete the design of the new earth-rock dam.

[0021] Furthermore, it is determined whether to lay an anti-scour structural layer on the water-facing surface and the dam top according to the filling material, size and geological conditions of the dam body.

[0022] A construction method of an earth-rock embankment / dam capable of overflowing, which uses an earth-rock embankment / dam capable of overflowing, and the specific construction process of laying an anti-scour structural layer is as follows:

[0023] First carry out anchor construction;

[0024] After the anchor rod construction is completed, the mesh sprayed concrete layer or reinforced concrete layer or fiber concrete layer is constructed on the backwater surface;

[0025] Drill drainage holes on the constructed mesh shotcrete layer, reinforced concrete layer or fiber concrete layer;

[0026] Finally, the greening layer is sprayed on the mesh shotcrete layer, reinforced concrete layer or fiber concrete layer.

[0027] A method for operating an earth-rock embankment / dam capable of overflowing, which refers to an earth-rock embankment / dam capable of overflowing. The earth-rock dam capable of overflowing does not overflow under normal circumstances, operates according to the normal water storage level determined in step 1.2 or step 2.1 all year round, and overflows during the flood season when the flood standard is extremely high.

[0028] Compared with the existing technology, the present invention has the following beneficial effects: the present invention eliminates the safety risk of dam collapse and embankment collapse by arranging an anti-scouring structural layer on the earth-rock dam, and there is no need to vacate the reservoir capacity in advance for flood prevention during the flood season. It can avoid the reservoir from operating at a low water level all year round due to insufficient water storage, thereby reducing the pressure of flood prevention, greatly expanding the beneficial reservoir capacity, ensuring the full realization of the benefits of agricultural irrigation, water supply, power generation, etc., and promoting the high-quality development of water conservancy. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0030] In the figure, 1. earth-rock dam; 2. back water surface; 3. front water surface; 4. dam top; 5. anti-scour structural layer; 6. anchor rod; 7. greening spraying layer; 8. drainage hole; 9. wave-breaking wall. DETAILED DESCRIPTION

[0031] like Figure 1As shown, the present invention provides a technical solution: an earth-rock embankment / dam capable of overflowing, comprising: an earth-rock dam 1; an anti-scouring structural layer 5 is arranged on the earth-rock dam 1; the anti-scouring structural layer 5 of the present application is also applicable to earth-rock embankments.

[0032] The present invention eliminates the safety risk of dam collapse by arranging an anti-scour structural layer 5 on the earth-rock dam 1, and there is no need to vacate the reservoir capacity in advance for flood prevention during the flood season. It can avoid the reservoir from operating at a low water level all year round due to insufficient water storage, thereby reducing the pressure of flood prevention, greatly expanding the beneficial reservoir capacity, ensuring the full realization of the benefits of agricultural irrigation, water supply, power generation, etc., and promoting the high-quality development of water conservancy.

[0033] The back surface 2 of the earth-rock dam 1 is provided with an anti-scour structural layer 5; the front surface 3 and the dam top 4 of the earth-rock dam 1 may or may not be provided with an anti-scour structural layer 5.

[0034] The anti-scour structural layer 5 can be a mesh shotcrete layer, a reinforced concrete layer, a fiber concrete layer, or other anti-scour structural layers. By setting the anti-scour structural layer 5 on the earth-rock dam 1, it can prevent water flow from dispersing and carrying away earth and rock particles in the dam body, causing dam collapse.

[0035] The earth-rock dam 1 is provided with a plurality of anchor rods 6 for reinforcing the anti-scour structural layer 5 .

[0036] A wave-breaking wall 9 is provided at the dam top 4 at the water-facing surface 3 .

[0037] The anti-scour structure layer 5 disposed on the back water surface 2 is provided with a plurality of drainage holes 8 .

[0038] Wherein, a greening spraying layer 7 is arranged on the anti-scour structural layer 5 arranged on the back water surface 2 .

[0039] A design method for an earth-rock embankment / dam capable of overflowing, and construction of an earth-rock dam capable of overflowing, including both reconstruction of an existing earth-rock dam and construction of a new earth-rock dam, respectively comprising the following steps:

[0040] The specific process of the existing earth-rock dam reconstruction design is as follows:

[0041] Step 1.1: Conduct safety assessment of existing earth-rock dams.

[0042] Step 1.2: Re-determine the dam crest elevation, normal water storage level and other parameters based on the historical data of existing earth-rock dams (catchment area, hydrological parameters, inundation range).

[0043] Among them, whether the original wave-breaking wall will be demolished or transformed into a sub-dam is determined based on parameters such as the dam top elevation and normal water storage level.

[0044] Step 1.3: According to Step 1.1 and Step 1.2, determine whether the spillway gate of the existing earth-rock dam should be raised and whether the existing earth-rock dam should be reinforced.

[0045] Step 1.4: Determine the material type, thickness and physical and mechanical parameters of the anti-scour structural layer according to Steps 1.1 to 1.3. Determine whether several anchor rods need to be laid according to geological conditions and dam height parameters to prevent the structural layer from floating or sliding.

[0046] Step S1.5: According to the material type, thickness and physical and mechanical parameters determined in step 1.4, an anti-scour structural layer and a greening spraying layer are laid on the backwater surface of the existing earth-rock dam to complete the renovation design of the existing earth-rock dam.

[0047] The specific process of designing a new earth-rock dam is as follows:

[0048] Step 2.1: Determine the characteristic parameters of the new earth-rock dam (dam crest elevation, normal water storage level, spillway bottom elevation, gate size, etc.) based on the survey data.

[0049] Step 2.2: Determine the material type, thickness and physical and mechanical parameters of the anti-scour structural layer according to step 2.1.

[0050] Among them, whether it is necessary to lay a number of anchor rods to prevent the anti-scour structure layer from floating or sliding can be determined based on geological conditions, dam height and other parameters.

[0051] Step 2.3: Based on the characteristic parameters determined in step 2.1 and the material type, thickness and physical and mechanical parameters determined in step 2.2, the anti-scour structural layer and greening spraying layer on the back surface of the earth-rock dam are designed to complete the design of the new earth-rock dam.

[0052] Among them, it can be chosen whether to lay an anti-scour structural layer on the water-facing surface and the dam top according to the situation.

[0053] A method for constructing an earth-rock embankment / dam capable of overflowing, comprising: laying an anti-scour structural layer; the specific construction process is as follows:

[0054] Carry out anchor construction first.

[0055] After the anchor rod construction is completed, the mesh shotcrete layer, reinforced concrete layer or fiber concrete layer is constructed on the back water surface (the shotcrete process should be used preferentially).

[0056] Drain holes are drilled on the constructed mesh shotcrete layer, reinforced concrete layer or fiber concrete layer.

[0057] Finally, the greening layer is sprayed on the mesh shotcrete layer, reinforced concrete layer or fiber concrete layer.

[0058] A method for operating an earth-rock embankment / dam capable of overflowing. Compared with existing earth-rock dams, the present invention further improves the water storage level. The earth-rock dam capable of overflowing does not overflow under normal circumstances, and operates at the normal water storage level determined in step 1.2 or step 2.1 all year round. When the flood standard is extremely high during the flood season, it can overflow.

[0059] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An earth-rock embankment / dam capable of overflowing, characterized in that: include: An earth-rock dam (1) is provided with an anti-scour structural layer (5) on the backwater surface (2) and / or the dam top (4) of the earth-rock dam (1).

2. The earth-rock embankment / dam capable of overflowing according to claim 1, characterized in that: The anti-scour structural layer (5) is a mesh sprayed concrete layer or a reinforced concrete layer or a fiber concrete layer.

3. The earth-rock embankment / dam capable of overflowing according to claim 1, characterized in that: A plurality of anchor rods (6) for reinforcing the anti-scour structural layer (5) are arranged on the earth-rock dam (1).

4. The earth-rock embankment / dam capable of overflowing according to claim 1, characterized in that: The anti-scour structural layer (5) arranged on the back water surface (2) is provided with drainage holes (8).

5. The earth-rock embankment / dam capable of overflowing according to claim 1, characterized in that: A greening spraying layer (7) is arranged on the anti-scour structural layer (5) arranged on the back surface (2).

6. A design method for an earth-rock embankment / dam capable of overflowing, applied to the earth-rock embankment / dam capable of overflowing as claimed in any one of claims 1 to 5, characterized in that: The construction of an earth-rock dam with overflowing capacity includes both the reconstruction of existing earth-rock dams and the construction of new earth-rock dams, which include the following steps: The specific process of the reconstruction design of existing earth-rock dam is as follows: Step 1.1: Conduct safety assessment of existing earth-rock dams; Step 1.2: Re-determine the dam crest elevation and normal water storage level parameters based on the historical data of the existing earth-rock dam; Step 1.3: Determine whether the spillway gate of the existing earth-rock dam should be raised and whether the existing earth-rock dam should be reinforced according to Step 1.1 and Step 1.2; Step 1.4: Determine the material type, thickness and physical and mechanical parameters of the anti-scour structural layer according to steps 1.1 to 1.3; Step 1.5: According to the material type, thickness and physical and mechanical parameters determined in step 1.4, an anti-scour structural layer and a greening spraying layer are laid on the backwater surface of the existing earth-rock dam to complete the reconstruction design of the existing earth-rock dam; The specific process of designing a new earth-rock dam is as follows: Step 2.1: Determine the characteristic parameters of the new earth-rock dam based on the survey data; Step 2.2: Determine the material type, thickness and physical and mechanical parameters of the anti-scour structural layer according to step 2.1; Step 2.3: Based on the characteristic parameters determined in step 2.1 and the material type, thickness and physical and mechanical parameters determined in step 2.2, the anti-scour structural layer and greening spraying layer on the back surface of the earth-rock dam are designed to complete the design of the new earth-rock dam.

7. A method for designing an earth-rock embankment / dam capable of overflowing according to claim 6, characterized in that: Whether to lay an anti-scour structural layer on the water-facing surface and dam top should be determined based on the dam body filling material, size and geological conditions.

8. A method for constructing an earth-rock embankment / dam capable of overflowing, referring to the earth-rock embankment / dam capable of overflowing as claimed in any one of claims 1 to 5, characterized in that: The specific construction process of laying the anti-scour structural layer is as follows: First carry out anchor construction; After the anchor rod construction is completed, the mesh sprayed concrete layer or reinforced concrete layer or fiber concrete layer is constructed on the backwater surface; Drill drainage holes on the constructed mesh shotcrete layer, reinforced concrete layer or fiber concrete layer; Finally, the greening layer is sprayed on the mesh shotcrete layer, reinforced concrete layer or fiber concrete layer.

9. A method for operating an earth-rock embankment / dam capable of overflowing, referring to the earth-rock embankment / dam capable of overflowing as claimed in any one of claims 1 to 5, characterized in that: The earth-rock dam capable of overflowing does not overflow under normal circumstances, and operates according to the normal water storage level determined in step 1.2 or step 2.1 all year round. It overflows during the flood season when the flood standard is extremely high.

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