An up-and-down staggered concrete dam structure and a construction method thereof

Abstract

This invention discloses a staggered concrete dam structure and its construction method, belonging to the field of water conservancy and hydropower engineering technology. The structure includes a gravity dam body, comprising alternating layers of rockfill concrete and normal concrete arranged vertically from bottom to top to form a staggered layered composite structure. The gravity dam body has a normal concrete cushion layer at the bottom and a normal concrete top layer at the top. An upstream normal concrete anti-seepage layer is provided on the water-facing side, and a downstream normal concrete surface layer is provided on the backwater side. This design effectively controls the overall heat of hydration of the dam, simplifies temperature control measures, and reduces overall costs, while fully ensuring the anti-seepage and shear resistance performance between dam layers, achieving a balanced optimization of cost reduction, efficiency improvement, and project safety.

Description

Technical Field

[0001] This invention relates to an alternating vertical concrete dam structure and its construction method, belonging to the field of water conservancy and hydropower engineering technology. Background Technology

[0002] Conventional concrete dams, as the traditional mainstream dam type, are widely used in water conservancy projects due to their advantages such as high strength, durability, reliable interlayer bonding, and excellent seepage resistance. However, their high consumption of cementitious materials and high construction costs are prominent problems, and they require complex cooling water pipe systems for temperature stress control, leading to extended construction cycles and limited overall benefits. The team led by Jin Feng at Tsinghua University innovatively proposed rock-filled concrete (RFC) dam construction technology. Through a composite structure of "large rockfill blocks + high self-compacting concrete," it significantly reduces the amount of cementitious materials used, effectively controls adiabatic temperature rise, and typically eliminates the need for cooling water pipes, resulting in significant advantages such as improved construction efficiency and reduced overall costs. However, during the construction of rock-filled concrete, the surface is easily contaminated by impurities such as medium-sized stone chips and stone powder generated during rockfill operations, making the interlayer bonding quality a weak link in construction control and causing significant leakage problems.

[0003] Therefore, there is an urgent need for a new type of concrete dam structure and its construction method. This solution should simultaneously achieve: effective control of the overall hydration heat of the dam, simplified temperature control measures without the need for cooling water pipes, and full guarantee of the interlayer impermeability and shear resistance of the dam, so as to further optimize the construction efficiency and engineering safety of concrete dams. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a staggered concrete dam structure and its construction method.

[0005] This invention is achieved through the following technical solution: A staggered concrete dam structure includes a gravity dam body, wherein the gravity dam body comprises alternating layers of rockfill concrete and normal concrete arranged vertically from bottom to top to form a staggered layered composite structure. The gravity dam body has a normal concrete cushion layer at the bottom and a normal concrete dam top layer at the top. The upstream side has a normal concrete upstream anti-seepage layer and the downstream side has a normal concrete downstream surface layer.

[0006] The bottom and top layers of the gravity dam body are both made of riprap concrete.

[0007] The height of the riprap concrete layer is h1 = 1.5m to 3m, and the weight ratio of the cementitious material in the riprap concrete is 5% to 8%. The height of the normal concrete layer is h2 = 0.5m to 1.5m, and the weight ratio of the cementitious material in the normal concrete is 12% to 15%.

[0008] The thickness of the upstream impermeable layer of the normal concrete is d1=0.5m~1.0m, and its material properties are improved by 2 levels of impermeability and 1 level of strength compared with the normal concrete layer. The thickness of the downstream surface layer of the normal concrete is d2=0.5m~1.0m, and its material properties are improved by 1 level of impermeability compared with the normal concrete layer. The material properties of the normal concrete cushion layer are improved by 1 or 2 levels of impermeability compared to the normal concrete layer, and the strength grade is improved by 1 level. The material properties of the top layer of the conventional concrete dam are improved by one strength grade compared to the conventional concrete layer.

[0009] The normal concrete layer and the adjacent riprap concrete layer below it are formed by erecting the formwork and then pouring the entire layer together.

[0010] The proposed gravity dam body first The height of the riprap concrete layer in each pouring unit Normal concrete layer pouring height And it must meet the constraint condition: total temperature rise of the casting unit <Permissible temperature rise .

[0011] The gravity dam body Allowable temperature rise per casting unit Combining the engineering grade of the concrete dam and the first The external temperature environment during the pouring of each pouring unit is determined and the value is taken within the range of 20℃~25℃.

[0012] The gravity dam body Total temperature rise of each pouring unit The following formula is used for calculation: , In the formula, For the first The thermal temperature rise of the riprap concrete layer in each casting unit is expressed in °C. For the first The adiabatic temperature rise of the normal concrete layer in each pouring unit is expressed in °C. For the first The heat dissipation coefficient of the riprap concrete layer in each casting unit is dimensionless. For the first The heat dissipation coefficient of the normal concrete layer of each pouring unit is dimensionless. For the first The cross-sectional area of ​​the riprap concrete layer in each cast-in-place unit is expressed in m². 2 ; For the first The cross-sectional area of ​​the normal concrete layer of each pouring unit, in m². 2 ; Among them, the The thermal temperature rise of the riprap concrete layer in each pouring unit The calculation formula is as follows: , In the formula, The accumulated heat of cement hydration in the riprap concrete layer is expressed in kJ / kg. This refers to the amount of cement and fly ash used as binders in the riprap concrete layer, expressed in kg / m³. 3 ; The percentage of fly ash content in the riprap concrete layer is dimensionless. The specific heat of the riprap concrete layer is expressed in kJ / (kg•℃). This refers to the density of the riprap concrete layer, expressed in kg / m³. 3 ; No. The adiabatic temperature rise of the normal concrete layer in each pouring unit The calculation formula is as follows: , In the formula, The accumulated heat of cement hydration in a normal concrete layer is expressed in kJ / kg. This refers to the amount of cement and fly ash used as binders in a normal concrete layer, expressed in kg / m³. 3 ; The percentage of fly ash content in normal concrete layers is dimensionless. The specific heat of the normal concrete layer is expressed in kJ / (kg•℃). The density of the normal concrete layer is expressed in kg / m³. 3 ; No. Cross-sectional area of ​​the riprap concrete layer in each pouring unit The calculation formula is as follows: , In the formula, For the first The cross-sectional width of each casting unit is in meters. For the first The cross-sectional height of the riprap concrete layer in each casting unit is in meters. No. The cross-sectional area of ​​the normal concrete layer of each pouring unit The calculation formula is as follows: In the formula, For the first The cross-sectional height of the normal concrete layer of each pouring unit is in meters. The thickness of the upstream impermeable layer of normal concrete is expressed in meters (m). The thickness of the downstream surface layer of normal concrete is expressed in meters (m). It is the reciprocal of the slope ratio of the downstream face of the gravity dam, and is dimensionless. After integrating the above formulas, the first gravity dam body Total temperature rise of each pouring unit The calculation formula is as follows: .

[0013] The first Heat dissipation coefficient of the riprap concrete layer in each pouring unit The value is taken in the range of 0.7 to 1.0. Heat dissipation coefficient of the normal concrete layer in each pouring unit It takes values ​​in the range of 0.6 to 0.9; When the downstream face of the gravity dam is designed as a stepped slope, its first The cross-sectional area of ​​the normal concrete layer of each pouring unit The calculation formula is as follows: , Based on this, the integrated first Total temperature rise of each pouring unit The calculation formula is as follows: .

[0014] A construction method for an alternating vertical concrete dam structure includes the following steps: Step 1: Construction Preparation: Begin preparing for construction. The first pouring unit is to formulate the first... The cross-sectional height of the riprap concrete layer in each pouring unit , No. The cross-sectional height of the normal concrete layer of each pouring unit Then calculate the first Total temperature rise of each pouring unit ; if Then draft a new one. , ;if Then start the first The pouring work of each pouring unit; Step 2: Pouring the riprap concrete layer: Based on the planned cross-sectional height of the riprap concrete layer... Erect the riprap concrete formwork; roughen and chisel the surface of the space enclosed by the riprap concrete formwork that will come into contact with the riprap concrete; after the surface treatment is qualified, spread the slow-setting cement mortar on the roughened and chiseled surface; start the riprap operation and ensure that the riprap quality meets the requirements; pour the self-compacting concrete, and remove the riprap concrete formwork after the concrete strength reaches the demolding design requirements. Step 3: Pouring the normal concrete layer: According to the planned... The cross-sectional height of the normal concrete layer of each pouring unit The thickness of the upstream impermeable layer of normal concrete should be reserved upstream of the riprap concrete layer. Erect the normal concrete formwork at the designated location, and reserve the thickness of the downstream surface layer of normal concrete downstream of the riprap concrete layer. The normal concrete formwork is erected at the designated location, and the vertical height of the normal concrete formwork upstream and downstream of the riprap concrete layer is the same. + ; Roughen and chip the surface of the space enclosed by the normal concrete formwork that will come into contact with the normal concrete; After the surface treatment is qualified, spread ordinary cement mortar on the roughened and chipped surface; Complete the concrete pouring work of the normal concrete layer, the upstream anti-seepage layer of the normal concrete and the downstream surface layer of the normal concrete in sections; After the concrete strength reaches the demolding design requirements, remove the normal concrete formwork. Step 4: Repeat steps 1 to 3, completing the construction of each pouring unit from bottom to top. Finally, construct the top layer of the normal concrete dam on the upstream anti-seepage layer of the normal concrete, the downstream surface layer of the normal concrete, and the top of the gravity dam body.

[0015] The beneficial effects of this invention are as follows: The innovative use of a dam structure with alternating layers of riprap concrete and conventional concrete offers dual advantages over traditional dam types. Firstly, compared to traditional conventional concrete dams, this structure significantly reduces the overall amount of cementitious materials used, effectively controlling the overall hydration heat generation at the source. This simplifies temperature control measures considerably, eliminating the need for complex temperature control systems such as additional cooling water pipes, reducing construction complexity, and lowering the overall cost of the dam. Secondly, compared to traditional riprap concrete dams, this alternating structure increases the amount of cementitious materials used at the interlayer joints, and the bond between the upstream impermeable layer and the conventional concrete layer is stronger, improving the interlayer impermeability and shear strength of the dam. Therefore, this invention effectively controls the overall hydration heat of the dam, simplifies temperature control measures, and reduces overall cost while fully ensuring the interlayer impermeability and shear strength of the dam, achieving a balanced optimization of cost reduction, efficiency improvement, and engineering safety. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the cross-sectional structure of the staggered concrete dam structure of the present invention; Figure 2 The first of the present invention The first pouring unit and the first Assembly drawing of each casting unit; Figure 3 This is a schematic diagram of the cross-sectional structure of a staggered concrete dam structure when the downstream face of the gravity dam body of the present invention is designed as a stepped slope. Figure 4 When the downstream face of the gravity dam body of the present invention is designed as a stepped slope, the first The first pouring unit and the first Assembly drawing of each casting unit; Figure 5 This is a flowchart illustrating the construction process of the present invention.

[0017] In the diagram: 1-Rockfill concrete layer, 2-Normal concrete layer, 5-Normal concrete foundation layer, 6-Upstream seepage prevention layer of normal concrete, 7-Downstream surface layer of normal concrete, 8-Top layer of normal concrete dam, 31-Rockfill concrete formwork, 32-Normal concrete formwork, 41-Retarded cement mortar, 42-Ordinary cement mortar. Detailed Implementation

[0018] The technical solution of the present invention is further described below, but the scope of protection is not limited to what is described.

[0019] like Figures 1 to 5 As shown, the present invention discloses an alternating vertical concrete dam structure, comprising a gravity dam body. The gravity dam body includes alternating layers of rockfill concrete 1 and normal concrete 2 arranged vertically from bottom to top to form an alternating layered composite structure. The gravity dam body has a normal concrete cushion layer 5 at the bottom, a normal concrete dam top layer 8 at the top, an upstream normal concrete anti-seepage layer 6 on the water-facing side, and a downstream normal concrete surface layer 7 on the backwater side.

[0020] Specifically, since the amount of cementitious material used in the riprap concrete layer 1 is relatively small, it will result in a lower heat of hydration release, while the amount of cementitious material used in the normal concrete layer 2 is relatively large, resulting in a higher heat of hydration release. Therefore, the gravity dam body adopts a structure in which the riprap concrete layer 1 and the normal concrete layer 2 are alternately stacked from bottom to top in the vertical direction. This can effectively neutralize the heat of hydration released by the normal concrete layer 2 during the hardening process through the riprap concrete layer 1, thereby effectively controlling the overall heat of hydration of the dam, simplifying temperature control measures, and eliminating the need for cooling water pipes.

[0021] The bottom and top layers of the gravity dam body are both made of riprap concrete 1.

[0022] The height of the riprap concrete layer 1 is h1 = 1.5m to 3m, and the weight percentage of the cementitious material in the riprap concrete is 5% to 8%. The height of the normal concrete layer 2 is h2 = 0.5m to 1.5m, and the weight ratio of the cementitious material in the normal concrete is 12% to 15%.

[0023] Specifically, since the weight ratio of cementitious material in the rockfill concrete layer 1 is 5% to 8%, and the weight ratio of cementitious material in the normal concrete layer 2 is 12% to 15%, when the gravity dam body adopts a layered composite structure with alternating rockfill concrete layer 1 and normal concrete layer 2, the overall weight ratio of cementitious material at the interface between rockfill concrete layer 1 and normal concrete layer 2 can be increased to 9% to 12%, thus improving the interlayer bonding quality assurance rate of the gravity dam body compared to traditional rockfill concrete dams.

[0024] The thickness of the upstream impermeable layer 6 of the normal concrete is d1=0.5m~1.0m, and its material properties are improved by 2 levels of impermeability and 1 level of strength compared with the normal concrete layer 2. The thickness of the downstream surface layer 7 of the normal concrete is d2=0.5m~1.0m, and its material properties are improved by 1 level of impermeability compared with the normal concrete layer 2. The material properties of the normal concrete cushion layer 5 are improved by 1 or 2 levels of impermeability compared to the normal concrete layer 2, and the strength level is improved by 1 level. The material properties of the top layer 8 of the normal concrete dam are one grade higher in strength than those of the normal concrete layer 2.

[0025] The normal concrete layer 2 and the adjacent riprap concrete layer 1 below it are formed by the upstream anti-seepage layer 6 and the downstream surface layer 7 of the normal concrete after the formwork is erected and the entire section is poured.

[0026] Specifically, since the upstream impermeable layer 6 of the normal concrete upstream of the riprap concrete layer 1 is integrally cast with the interface height of the riprap concrete layer 1 and the normal concrete layer 2, this casting method can significantly improve the impermeability of the upstream impermeable layer 6 of the normal concrete, thereby enhancing the overall impermeability of the interlayer at the interface between the riprap concrete layer 1 and the normal concrete layer 2.

[0027] The proposed gravity dam body first The height of the rubble concrete layer of each pouring unit is 1. 2. Normal concrete layer pouring height And it must meet the constraint condition: total temperature rise of the casting unit <Permissible temperature rise .

[0028] The gravity dam body Allowable temperature rise per casting unit Combining the engineering grade of the concrete dam and the first The external temperature environment during the pouring of each pouring unit is determined and the value is taken within the range of 20℃~25℃.

[0029] The gravity dam body Total temperature rise of each pouring unit The following formula is used for calculation: , In the formula, For the first The adiabatic temperature rise of the riprap concrete layer in each casting unit is expressed in °C. For the first The adiabatic temperature rise of the normal concrete layer in each pouring unit is expressed in °C. For the first The heat dissipation coefficient of the riprap concrete layer in each casting unit is dimensionless. For the first The heat dissipation coefficient of the normal concrete layer in each pouring unit is dimensionless. For the first The cross-sectional area of ​​the riprap concrete layer in each casting unit is expressed in m². 2 ; For the first The cross-sectional area of ​​the normal concrete layer of each pouring unit is 2 m². 2 ; Among them, the The thermal temperature rise of the riprap concrete layer in each pouring unit is 1. The calculation formula is as follows: , In the formula, The cumulative heat of cement hydration in the riprap concrete layer 1 is expressed in kJ / kg. The cement and fly ash binder content for the riprap concrete layer 1 is given in kg / m³. 3 ; The percentage of fly ash content in the riprap concrete layer 1 is dimensionless. The specific heat of the riprap concrete layer 1 is expressed in kJ / (kg•℃). The density of the riprap concrete layer is expressed in kg / m³. 3 ; acceptable =2450kg / m 3 .

[0030] No. The normal concrete layer of each pouring unit experiences two adiabatic temperature rises. The calculation formula is as follows: , In the formula, The accumulated heat of cement hydration in normal concrete layer 2 is expressed in kJ / kg. The amount of cement and fly ash used as binders in the normal concrete layer 2 is expressed in kg / m². 3 ; The percentage of fly ash content in the normal concrete layer 2 is dimensionless. The specific heat of the normal concrete layer is expressed in kJ / (kg•℃). The density of the normal concrete layer is 2 kg / m³. 3 ; acceptable =2400kg / m 3 .

[0031] No. The cross-sectional area of ​​the riprap concrete layer in each casting unit is 1. The calculation formula is as follows: , In the formula, For the first The cross-sectional width of each casting unit is in meters. For the first The cross-sectional height of the riprap concrete layer in each casting unit is shown in meters. No. The cross-sectional area of ​​the normal concrete layer of each pouring unit is 2. The calculation formula is as follows: In the formula, For the first The cross-sectional height of the normal concrete layer in each pouring unit is shown in meters. The thickness of the upstream impermeable layer 6 of the normal concrete is in meters (m). The thickness of the downstream surface layer 7 of the normal concrete is given in meters. It is the reciprocal of the slope ratio of the downstream face of the gravity dam, and is dimensionless. After integrating the above formulas, the first gravity dam body Total temperature rise of each pouring unit The calculation formula is as follows: .

[0032] Specifically, for the first The heat dissipation coefficient of the riprap concrete layer in each pouring unit is 1. When the project employs a variety of temperature control measures (such as frequent water curing and pre-cooling of concrete aggregates), and the length of the pouring section along the dam axis is relatively short, this... Take the lower value; conversely, if the temperature control measures adopted in the project are relatively simple, or if the length of the pouring section along the dam axis is relatively long, then... Take the higher value. For the first... The heat dissipation coefficient of the normal concrete layer in each pouring unit is 2. When the project employs a variety of temperature control measures (such as frequent water curing and pre-cooling of concrete aggregates), and the length of the pouring section along the dam axis is relatively short, this... Take the lower value; conversely, if the temperature control measures adopted in the project are relatively simple, or if the length of the pouring section along the dam axis is relatively long, then... Take the higher value.

[0033] The first The heat dissipation coefficient of the riprap concrete layer in each pouring unit is 1. The value is taken in the range of 0.7 to 1.0. The heat dissipation coefficient of the normal concrete layer in each pouring unit is 2. It takes values ​​in the range of 0.6 to 0.9; When the downstream face of the gravity dam is designed as a stepped slope, its first The cross-sectional area of ​​the normal concrete layer of each pouring unit is 2. The calculation formula is as follows: , Based on this, the integrated first Total temperature rise of each pouring unit The calculation formula is as follows: .

[0034] Specifically, for the downstream face of a gravity dam where the appearance is not a primary concern, a stepped slope design can be adopted.

[0035] Specifically, the third pouring unit of the gravity dam in a small reservoir project is planned to... =2m、 =1m, =32m、 =1m、 =0.5m, m=0.75, calculate S 1i =64m 2 S 2i =37.63m 2 For the riprap concrete layer 1, Q1 = 300 kJ / kg and W1 = 150 kg / m³. 3Given p1=25%, c1=0.96kJ / (kg•℃), and ρ1=2450kg / m3, calculate T. 1i =15.54℃; For normal concrete layer 2, Q2=300kJ / kg, W2=320kg / m 3 , p2=20%, c2=0.96kJ / (kg·℃), ρ2=2400kg / m 3 T is calculated 2i =35.41℃; temperature control measures only involve conventional watering and curing; the pouring area is moderate along the dam axis, therefore k is taken. 1i =0.9、k 2i =0.8, T is calculated. i =19.29℃<T 允 =20℃, which meets the temperature control requirements.

[0036] Alternatively, if the downstream slope of the dam in this project is a stepped slope, the remaining parameters are the same as in the above embodiment, and S is calculated. 1i =64m 2 S 2i =36.5m 2 The final calculated value of T is... i =19.23℃<T 允 =20℃, which also meets the temperature control requirements.

[0037] A construction method for an alternating vertical concrete dam structure includes the following steps: Step 1: Construction Preparation: Begin preparing for construction. The first pouring unit is to formulate the first... The cross-sectional height of the riprap concrete layer in each casting unit is 1. , No. The cross-sectional height of the normal concrete layer in each pouring unit is 2. Then calculate the first Total temperature rise of each pouring unit ; if Then draft a new one. , ;if Then start the first The pouring work of each pouring unit; Step 2: Pouring of the riprap concrete layer 1: Based on the planned cross-sectional height of the riprap concrete layer 1... Erect the riprap concrete formwork 31; roughen and chisel the surface of the space enclosed by the riprap concrete formwork 31 that will come into contact with the riprap concrete; after the surface treatment is qualified, spread the slow-setting cement mortar 41 on the roughened and chiseled surface; start the riprap operation and ensure that the riprap quality meets the requirements; pour self-compacting concrete, and remove the riprap concrete formwork 31 after the concrete strength reaches the demolding design requirements. Step 3, Pouring of the second layer of normal concrete: According to the planned... The cross-sectional height of the normal concrete layer in each pouring unit is 2. A thickness of 6 for the upstream impermeable layer of normal concrete is reserved upstream of the riprap concrete layer 1. Erect the normal concrete formwork 32 at the location, and reserve a normal concrete downstream surface layer 7 thickness downstream of the riprap concrete layer 1. The normal concrete formwork 32 is erected at the location, and the vertical height of the normal concrete formwork 32 upstream and downstream of the riprap concrete layer 1 is the same. + ; Roughen and chip the surface of the space enclosed by the normal concrete formwork 32 that will come into contact with the normal concrete; After the surface treatment is qualified, spread ordinary cement mortar 42 on the roughened and chipped surface; Complete the concrete pouring work of normal concrete layer 2, upstream anti-seepage layer 6 of normal concrete and downstream surface layer 7 of normal concrete in sections; After the concrete strength reaches the demolding design requirements, remove the normal concrete formwork 32. Step 4: Repeat steps 1 to 3, and complete the construction of each pouring unit from bottom to top. Finally, construct the top layer of normal concrete dam 8 on the upstream anti-seepage layer 6 of normal concrete, the downstream surface layer 7 of normal concrete, and the top of the gravity dam body.

Claims

1. A staggered concrete dam structure, characterized in that: The dam body includes a gravity dam body comprising alternating layers of rockfill concrete (1) and normal concrete (2) arranged vertically from bottom to top to form a layered composite structure. The gravity dam body has a normal concrete cushion layer (5) at the bottom, a normal concrete dam top layer (8) at the top, an upstream normal concrete anti-seepage layer (6) on the water-facing side, and a downstream normal concrete surface layer (7) on the back side.

2. The staggered concrete dam structure as described in claim 1, characterized in that: The bottom and top layers of the gravity dam body are both made of riprap concrete (1).

3. The staggered concrete dam structure as described in claim 1, characterized in that: The height of the riprap concrete layer (1) is h1 = 1.5m to 3m, and the weight ratio of the cementitious material in the riprap concrete is 5% to 8%. The height of the normal concrete layer (2) is h2=0.5m~1.5m, and the weight ratio of the cementitious material in the normal concrete is 12%~15%.

4. The staggered concrete dam structure as described in claim 1, characterized in that: The thickness of the upstream impermeable layer (6) of the normal concrete is d1=0.5m~1.0m, and its material properties are improved by 2 levels of impermeability and 1 level of strength compared with the normal concrete layer (2). The thickness of the downstream surface layer (7) of the normal concrete is d2=0.5m~1.0m, and its material properties are improved by 1 level of impermeability compared with the normal concrete layer (2). The material properties of the normal concrete cushion layer (5) are improved by 1 or 2 levels of impermeability compared to the normal concrete layer (2), and the strength level is improved by 1 level. The material properties of the top layer (8) of the normal concrete dam are improved by one strength grade compared with the normal concrete layer (2).

5. The staggered concrete dam structure as described in claim 1, characterized in that: The normal concrete layer (2) and the adjacent riprap concrete layer (1) above and below it are formed by the upstream anti-seepage layer (6) and the downstream surface layer (7) of the normal concrete layer after the formwork is erected and the entire section is poured.

6. The staggered concrete dam structure as described in claim 1, characterized in that: The proposed gravity dam body first The height of the riprap concrete layer (1) of each pouring unit 1. Normal concrete layer (2) pouring height And it must meet the constraint condition: total temperature rise of the casting unit <Permissible temperature rise .

7. The staggered concrete dam structure as described in claim 6, characterized in that: The gravity dam body Allowable temperature rise per casting unit Combining the engineering grade of the concrete dam and the first The external temperature environment during the pouring of each pouring unit is determined and the value is taken within the range of 20℃~25℃.

8. The staggered concrete dam structure as described in claim 6, characterized in that: The gravity dam body Total temperature rise of each pouring unit The following formula is used for calculation: ， In the formula, For the first (1) Adiabatic temperature rise of the riprap concrete layer of each casting unit, in °C; For the first The adiabatic temperature rise of the normal concrete layer (2) of each pouring unit, in °C; For the first Heat dissipation coefficient of the riprap concrete layer of each casting unit (1), dimensionless; For the first Heat dissipation coefficient of normal concrete layer (2) of each pouring unit, dimensionless; For the first Cross-sectional area of ​​the riprap concrete layer (1) of each cast-in-place unit, in m² 2 ; For the first Cross-sectional area of ​​the normal concrete layer (2) of each pouring unit, in m² 2 ; Among them, the (1) Insulation temperature rise of the concrete layer of the cast-in-place unit (1) The calculation formula is as follows: ， In the formula, The cumulative heat of cement hydration for the riprap concrete layer (1) is expressed in kJ / kg. The amount of cement and fly ash used as binders for the riprap concrete layer (1) is expressed in kg / m³. 3 ; The percentage of fly ash content in the riprap concrete layer (1) is dimensionless. The specific heat of the riprap concrete layer (1) is expressed in kJ / (kg•℃). The density of the riprap concrete layer (1) is expressed in kg / m³. 3 ; No. (2) Adiabatic temperature rise of the normal concrete layer of each pouring unit The calculation formula is as follows: ， In the formula, The accumulated heat of cement hydration in the normal concrete layer (2) is expressed in kJ / kg. The amount of cement and fly ash used as binders for the normal concrete layer (2) is expressed in kg / m³. 3 ; The percentage of fly ash content in the normal concrete layer (2) is dimensionless; The specific heat of the normal concrete layer (2) is expressed in kJ / (kg•℃). The density of the normal concrete layer (2) is expressed in kg / m³. 3 ; No. Cross-sectional area of ​​the riprap concrete layer of each casting unit (1) The calculation formula is as follows: ， In the formula, For the first The cross-sectional width of each casting unit is in meters. For the first The cross-sectional height of the riprap concrete layer (1) of each cast-in-place unit is in meters; No. Cross-sectional area of ​​the normal concrete layer (2) of each pouring unit The calculation formula is as follows: In the formula, For the first The cross-sectional height of the normal concrete layer (2) of each casting unit, in meters; The thickness of the upstream impermeable layer (6) of the normal concrete is in meters; The thickness of the downstream surface layer (7) of the normal concrete is given in meters. It is the reciprocal of the slope ratio of the downstream face of the gravity dam, and is dimensionless. After integrating the above formulas, the first gravity dam body Total temperature rise of each pouring unit The calculation formula is as follows: 。 9. The staggered concrete dam structure as described in claim 8, characterized in that: The first Heat dissipation coefficient of each cast-in-place riprap concrete layer (1) The value is taken in the range of 0.7 to 1.

0. Heat dissipation coefficient of normal concrete layer in each pouring unit (2) It takes values ​​in the range of 0.6 to 0.9; When the downstream face of the gravity dam is designed as a stepped slope, its first Cross-sectional area of ​​the normal concrete layer (2) of each pouring unit The calculation formula is as follows: ， Based on this, the integrated first Total temperature rise of each pouring unit The calculation formula is as follows: 。 10. A construction method for a staggered concrete dam structure as described in claim 8, characterized in that: Includes the following steps: Step 1: Construction Preparation: Begin preparing for construction. The first pouring unit is to formulate the first... The cross-sectional height of the riprap concrete layer in each casting unit (1) , No. Cross-sectional height of the normal concrete layer (2) of each casting unit Then calculate the first Total temperature rise of each pouring unit ; if Then draft a new one. , ;if Then start the first The pouring work of each pouring unit; Step 2, Pouring of the riprap concrete layer (1): Based on the planned cross-sectional height of the riprap concrete layer (1) Erect the riprap concrete formwork (31); roughen and chisel the surface of the space enclosed by the riprap concrete formwork (31) that will come into contact with the riprap concrete; after the surface treatment is qualified, spread the slow-setting cement mortar (41) on the roughened and chiseled surface; start the riprap operation and ensure that the riprap quality meets the requirements; pour self-compacting concrete, and remove the riprap concrete formwork (31) after the concrete strength reaches the demolding design requirements. Step 3, Normal Concrete Layer (2) Pouring: According to the planned... Cross-sectional height of the normal concrete layer (2) of each casting unit A thickness of 6mm for the upstream impermeable layer of normal concrete is reserved upstream of the riprap concrete layer (1). Erect the normal concrete formwork (32) at the location, and reserve the thickness of the downstream surface layer (7) of the normal concrete downstream of the riprap concrete layer (1). The normal concrete formwork (32) is erected at the location, and the normal concrete formwork (32) upstream and downstream of the riprap concrete layer (1) is at the same height in the vertical direction. + ; Roughen and chip the surface of the space enclosed by the normal concrete formwork (32) that will come into contact with the normal concrete; After the surface treatment is qualified, spread ordinary cement mortar (42) on the roughened and chipped surface; Complete the concrete pouring work of the normal concrete layer (2), the upstream anti-seepage layer (6) of the normal concrete and the downstream surface layer (7) of the normal concrete in sections. After the concrete strength reaches the demolding design requirements, remove the normal concrete formwork (32). Step 4: Repeat steps 1 to 3 to complete the construction of each pouring unit from bottom to top. Finally, construct the top layer of normal concrete dam (8) on the upstream anti-seepage layer (6) of normal concrete, the downstream surface layer (7) of normal concrete, and the top of gravity dam body.

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