Face plate self-compacting rock-fill concrete gravity dam and construction method

Abstract

The invention relates to a face plate self-compaction rock-fill concrete gravity dam which comprises an upstream face plate, a foundation concrete layer, an upstream assembly type precast block, a downstream assembly type precast block, a dam belly self-compaction pile body, a dam crest protection layer and a drainage system. A certain gap is reserved in the self-compacting concrete structure of the dam belly portion, the requirement for the mobility of the self-compacting concrete can be lowered, and the effective anti-seepage layer is arranged to ensure the good anti-seepage performance of the whole structure. The invention further relates to a construction method of the panel self-compacting rock-fill concrete gravity dam, which comprises the following steps: mining and selecting materials, warehousing and paving rockfill, pouring self-compacting rock-fill concrete, constructing rock-fill concrete construction joints, constructing a dam crest protection layer, perfecting a drainage system, constructing a panel, partitioning a concrete panel, erecting a reinforcing steel bar, pouring panel concrete and maintaining the panel. And the problems of leakage and template installation are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of rockfill concrete dams, and in particular to a face-plate self-compacting rockfill concrete gravity dam. The present invention also relates to a construction method of the face-plate self-compacting rockfill concrete gravity dam. Background Art

[0002] Self-compacting concrete (SCC), also known as vibration-free concrete, is a concrete that can flow and compact under its own gravity, while achieving good homogeneity and without the need for additional vibration. Due to its high water reduction rate and high water retention, it can be pumped into the warehouse, eliminating the need for manual vibration. Therefore, in the water conservancy and hydropower industry, self-compacting concrete is widely used as a cementing material for blocks in the construction of reservoirs and dams. Compared with traditional concrete, the rockfill concrete formed by self-compacting concrete cementing blocks has the advantages of less comprehensive cement consumption, small hydration temperature rise, and low comprehensive cost, and has been widely used and promoted.

[0003] Although self-compacting concrete has broad application prospects in water conservancy and hydropower projects, there are still some urgent problems to be solved in practical applications. In order to pursue pumpability and fluidity, the self-compacting concrete used in water conservancy projects has a small gradation, and the general particle size is between 5mm and 20mm. Due to the small aggregate particle size, the cement consumption is large, the hydration heat stability is increased, and it is easy to crack and leak; the specified distance between the block and the template must be enough for the anti-seepage layer, but unloading and stacking are more difficult, and the debris generated by the collision of the blocks during unloading cannot be removed. The rockfill concrete is a structure that lacks a continuous gradation of 20mm to 150mm. The gaps in the pile body entering the warehouse are random, and some blocks cannot be filled by self-compacting, resulting in leakage. It is difficult to separate the cementitious materials in the anti-seepage area of ​​the dam that adopts integrated casting from the cementitious materials in the non-anti-seepage area, which makes casting difficult. When the concrete is poured in layers or sections, the joints are not handled properly, and cracks appear between the new and old concrete and the construction joints, which are prone to water leakage. The template reinforcement used in the internal pull formwork construction affects the stacking of stone blocks, and both erecting and dismantling the formwork are more troublesome.

[0004] In response to the anti-seepage and formwork problems of the above-mentioned self-compacting concrete gravity dam, this research team proposed a face-plate self-compacting rockfill concrete gravity dam and its construction method. Summary of the invention

[0005] In order to solve the above-mentioned defects existing in the prior art, the purpose of the present invention is to provide a self-compacting rockfill concrete gravity dam with a panel, in which the anti-seepage and structural load-bearing bodies are divided into zones, so as to realize the construction of the dam belly material of the load-bearing body without using a formwork, while ensuring the anti-seepage reliability of the anti-seepage body.

[0006] In one aspect, the present invention provides a self-compacting rockfill concrete gravity dam with a panel, comprising an upstream panel, a foundation concrete layer, upstream and downstream assembled prefabricated blocks, a self-compacting pile at the dam belly, a dam top protective layer, and a drainage system;

[0007] The upstream panel is made of normal concrete with anti-seepage performance or normal concrete coated with anti-seepage coating. When normal concrete is used as the anti-seepage layer, the thickness gradually increases from the top to the bottom. The specific thickness is determined comprehensively based on the dam body height and water level changes. The thickness should be 1 / 30 to 1 / 60 of the corresponding water head, and the top thickness should not be less than 0.3m to ensure the anti-seepage effect;

[0008] The foundation concrete layer is located at the bottom of the dam body and is made of normal concrete with a thickness of 1 to 3 meters. It provides a stable foundation support for the dam body and serves as a platform and weight for consolidation grouting and curtain grouting, facilitating construction operations.

[0009] The upstream and downstream assembled prefabricated blocks include a first prefabricated block and a second prefabricated block, which are laid in a "one-in-one-in-one" pattern and connected by cement mortar to ensure the tightness and stability between the prefabricated blocks. No formwork is required. When the upstream assembled prefabricated blocks are laid, each layer retreats 4 to 6 cm toward the belly of the dam to form a small offset.

[0010] The self-compacting pile in the dam belly is transported into the warehouse by a tower crane or a dump truck. After being placed with the assistance of manual labor, the gap in the dam belly is filled with pumped self-compacting concrete and poured into shape to improve the overall stability of the dam body.

[0011] The dam top protective layer is located on the top of the dam body and is made of normal concrete or asphalt concrete to protect the dam top from wind and rain erosion and mechanical damage;

[0012] The drainage system includes a drainage network, drainage corridors and drainage holes, which are used to discharge the accumulated water in the dam body to reduce the erosion of the building itself caused by the water flow.

[0013] Furthermore, when the dam height exceeds 50m, anti-cracking steel bars are configured to enhance the anti-cracking performance.

[0014] Furthermore, the upstream and downstream prefabricated blocks have a first prefabricated block size of 400mm×300mm×300mm, and a second prefabricated block size of 600mm×300mm×300mm, which is convenient for “one-by-one” masonry. Drainage holes are reserved inside the prefabricated blocks to facilitate drainage and reduce water pressure, and at the same time facilitate the subsequent casting of steel bar panels.

[0015] The drainage system also includes a water level monitoring device for real-time monitoring of water level changes in the dam body to ensure the effective operation of the drainage system.

[0016] The drainage system is directly connected to the drainage network, drainage corridors and drainage holes by drilling, forming a systematic drainage system, avoiding the problem of mechanical rock pile being easily deformed or bent when entering the warehouse due to pre-buried geotextile blind ditch pipes, and also solving the risk of concrete seeping into the pipe and causing blockage.

[0017] The concrete face plate is used as the anti-seepage structure of the dam, and the self-compacting pile in the belly of the dam is used as the main supporting structure for transferring water loads. The anti-seepage and load-bearing structures are clearly separated. This design allows certain gaps in the load-bearing concrete structure, so that the coarse aggregate of the self-compacting cementing material can be used in the secondary concrete, thereby reducing the amount of cement, reducing the hydration heat, and saving costs. At the same time, the simplified structure allows the stone stacking requirements and concrete pouring requirements to be appropriately relaxed, further simplifying the construction, and the material strength grade can be lowered by one grade than the minimum standard specified in the specification to allow C 90 10, thus greatly reducing investment; the quality of the dam belly rockfill is controlled by easy-to-implement drilling water pressure detection, and its permeability can be allowed to be ≥5 Lu.

[0018] Another object of the present invention is to provide a construction method for a self-compacting rockfill concrete gravity dam, comprising the following steps:

[0019] S10 pouring normal concrete dam foundation cushion: the dam foundation pit is excavated and acceptance is carried out after completion. The normal concrete dam foundation cushion is poured on the dam foundation pit that has passed the acceptance. It ensures that the quality of the foundation pit meets the construction standards and requirements, laying a solid foundation for subsequent projects. This step aims to transition the dam foundation and the dam body, providing stable support for the structure of the entire dam;

[0020] S20 Casting of drainage corridors and surrounding transition layers: On the basis of the dam foundation cushion layer, further cast the drainage corridors and surrounding transition layers, and carry out curtain grouting and drainage hole drilling at the same time to ensure the effective operation of the dam's drainage system and prevent leakage;

[0021] S30 installation of upstream and downstream prefabricated blocks: on the dam foundation cushion layer, a layer of upstream and downstream prefabricated blocks is installed according to the "one Ding and one Shun" masonry method. The prefabricated blocks can not only improve the construction efficiency, but also enhance the overall stability of the dam;

[0022] Construction of the S40 dam belly self-compacting rockfill: The main processes are mining and material selection, rockfill storage and paving, self-compacting rock concrete pouring, construction layer treatment, and finally forming the dam belly rockfill;

[0023] The construction of the self-compacting rockfill body at the dam belly in step S40 specifically includes the following steps:

[0024] S41 Mining and material selection: Choose rough stone, block stone or boulders as stone, with apparent density ≥2550kg / m3 , block thickness ≥ 150mm, choose hard block stones, and choose complete, hard, non-weathering and non-disintegrating stones for rockfill;

[0025] S42 Stone piles are transported directly into the warehouse by dump trucks. If road transportation is not possible, the stones can be hoisted into the warehouse. After unloading, they are piled with the help of small excavators and manual labor. During the piling process, manual labor or small excavators are used to assist in piling to avoid direct contact between the flat surfaces of the stones or with the foundation surface and construction joint surface, so that the concrete can flow into the cavity by gravity.

[0026] S43 self-compacting stone concrete pouring: Use concrete delivery pumps or concrete mixer trucks to transport self-compacting concrete to avoid segregation during transportation;

[0027] S44 Construction surface treatment: After the compressive strength of the cementing material on the stonefill surface reaches 2.5MPa, wash away the scum on the stonefill surface, remove the accumulated water, and roughen the smooth surface of the cementing material.

[0028] S50 repeats steps S30 and S40: according to the design requirements, repeatedly installs the prefabricated blocks and performs the cementing material construction until the dam top height is reached. This process needs to be continuously repeated until the dam reaches the predetermined height and stability requirements;

[0029] S60 Dam top protection layer construction: laying a normal concrete or asphalt concrete protective layer on the dam top to protect the dam top from weathering and erosion. This step is crucial to extending the service life of the dam;

[0030] S70 drainage system construction: The entire drainage network consists of drainage pipes, drainage channels and drainage holes. The excess water is directly guided out and connected to the existing drainage facilities by drilling. Before the construction of the dam top protection layer, a drilling rig is used to drill holes from the top to the drainage gallery with a hole diameter of 75 to 110 mm. The drainage system is improved and debugged to ensure unobstructed drainage. This is one of the important measures to ensure the safe operation of the dam.

[0031] S80 upstream panel construction: including concrete panel segmentation, steel bar erection, panel concrete pouring, and panel maintenance.

[0032] The step S80 of upstream panel construction specifically includes the following steps:

[0033] S81 concrete panel block design: The panel block design needs to consider the deformation characteristics of the dam body and construction conditions. The vertical joint spacing is 12 to 18 meters, which is convenient for construction and quality control.

[0034] S82 Steel bar erection: The panel adopts single-layer bidirectional steel bars, and the steel bars are placed in the middle of the panel section. The reinforcement ratio in each direction is between 0.3% and 0.4%, the horizontal reinforcement ratio is 0.3% to 0.35%, and the vertical reinforcement ratio is 0.35 to 0.4%. In the tensile stress area or the bank peripheral seam and nearby, steel bars with one diameter higher are appropriately arranged to improve the crack resistance of the panel. On both sides of the vertical seam adjacent to the peripheral seam of the high dam, structural steel bars with bent steel bars to resist extrusion are appropriately arranged. However, it should be noted that these steel bars should not affect the installation of water stop and the vibration quality of the concrete nearby. The calculation of the steel bar area is based on the design thickness of the panel concrete;

[0035] S83 panel concrete pouring: Slipform pouring is adopted. The pouring method of the starting plate can be rotation, translation or rotation followed by translation of the slipform, etc. It is completed by the winch on the dam top and the lateral manual hoist. This is an efficient and continuous pouring method. The number of chutes is selected for distribution according to the width of the slipform. If the slipform is 12m wide, two chutes are used. If the slipform is 16m wide, three chutes are used. The tail section of the chute is moved manually to evenly distribute the material. The slump is controlled between 3 and 6cm. The vibrator is vibrated 50cm in front of the slipform to ensure the compactness of the concrete.

[0036] S84 panel maintenance: Maintenance is an important measure to avoid cracks in the panel. Panel maintenance includes insulation and moisture retention. Generally, insulation materials such as straw bags are used to cover the panel to reduce cracks caused by temperature changes. Water is used to keep the panel surface moist to prevent the concrete from cracking due to drying. The maintenance period is at least 90 days or until water is stored.

[0037] The beneficial effects of the present invention are:

[0038] 1. By laying a layer of ordinary concrete cushion with a thickness of about 1 to 3 meters at the bottom of the dam, a solid foundation support is provided for the entire dam body, and it can also be used as a working platform and weighting material for consolidation grouting and curtain grouting operations, which is conducive to the subsequent work; concrete anti-seepage panels are used to solve the anti-seepage problem of the dam, and the anti-seepage panel construction is completed by using the slipform one-time casting technology. There is no need for the design of upper and lower formworks, which not only effectively solves the leakage and formwork installation problems existing in traditional construction methods, but also improves construction efficiency and project quality.

[0039] 2. The self-compacting rockfill in the belly of the dam serves as the main supporting structure for transmitting water loads. The anti-seepage and force-bearing structures are clearly separated. The crack resistance, anti-seepage and durability of the dam body ensure the long-term stable operation of the dam body. The force-bearing structure only needs to meet the load requirements transmitted by the load-bearing panels, etc. Therefore, the requirements for the density and porosity of the materials are relaxed. Quality control is only required through water pressure testing, avoiding the traditional cumbersome pit digging and testing process. The quality of the rockfill in the belly of the dam is controlled by easy-to-implement drilling water pressure testing, and its permeability can be allowed to be ≥5 Lu.

[0040] 3. The design of the present invention allows certain gaps in the load-bearing concrete structure, so that the coarse aggregate of the self-compacting cementing material can be used in the secondary concrete, thereby reducing the amount of cement, reducing the hydration heat, and saving costs. At the same time, the simplified structure can relax the requirements for stone stacking and concrete pouring, further simplifying the construction, and the material strength grade can be higher than the minimum standard specified in the specification, and can be selected up to C 90 10, thereby reducing investment.

[0041] 4. Using prefabricated blocks of different sizes as the outer formwork of the dam body is suitable for ordinary workers to operate, which simplifies the construction steps and is easy to master, helping to greatly improve work efficiency and shorten the construction period; the drainage system is directly connected to the drainage network, drainage corridors and drainage holes by drilling, forming a systematic drainage system, avoiding the problem of mechanical rockfill being easily deformed or bent when entering the warehouse due to the pre-buried blind ditch pipe with geotextile, and also solving the risk of concrete seeping into the pipe and causing blockage. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the structure of a self-compacting rockfill concrete gravity dam with a panel according to Example 1 of the present invention;

[0043] Figure 2 This is a plan view of the upstream surface assembled prefabricated blocks of Example 1 of the present invention;

[0044] Figure 3 This is a plan view of the masonry of the assembled prefabricated blocks on the downstream side of Example 1 of the present invention;

[0045] Figure 4 This is a masonry elevation view of upstream and downstream prefabricated blocks in Example 1 of the present invention.

[0046] Description of reference numerals: 1-upstream panel, 2-foundation concrete layer, 3-upstream and downstream assembled prefabricated blocks, 4-self-compacting pile at the dam belly, 5-dam top protective layer, 6-drainage system, 7-drainage gallery, 8-first prefabricated block, 9-second prefabricated block, B-thickness of upstream panel;

[0047] 1:0.1 and 1:0.75 represent the slope of the dam. DETAILED DESCRIPTION

[0048] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The exemplary embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0049] Example 1

[0050] Please refer to Figure 1, a self-compacting rockfill concrete gravity dam with a panel, comprising an upstream panel, a foundation concrete layer, upstream and downstream assembled prefabricated blocks, a self-compacting pile at the dam belly, a dam top protective layer, and a drainage system;

[0051] The upstream panel is made of normal concrete with anti-seepage performance. The thickness of the anti-seepage layer gradually increases from top to bottom, with a thickness of 1m at the bottom and 0.3m at the top to ensure the anti-seepage effect.

[0052] The foundation concrete layer is located at the bottom of the dam body and is made of normal concrete with a thickness of 1.5m. It provides a stable foundation support for the dam body and serves as a platform and weight for consolidation grouting and curtain grouting, facilitating construction operations.

[0053] The upstream and downstream prefabricated blocks include the first prefabricated block and the second prefabricated block. The size of the first prefabricated block is 400mm×300mm×300mm, and the size of the second prefabricated block is 600mm×300mm×300mm. They are laid in a “one-by-one” manner. Drainage holes are reserved inside the prefabricated blocks to facilitate drainage and reduce water pressure. This is also beneficial to the subsequent reinforcement of the steel panels. They are connected by cement mortar in a building block manner to ensure the tightness and stability between the prefabricated blocks. No formwork is required. When the prefabricated blocks on the upstream side are laid, each layer retreats 5cm toward the belly of the dam to form a small misalignment.

[0054] The self-compacting pile at the dam belly is transported into the bin through a hanging basket, and after artificially assisted shaping, it is pumped into the C 90 10 Concrete is poured to form, and the rockfill fills the gap in the dam belly, improving the overall stability of the dam body; the quality of the rockfill in the dam belly is controlled by drilling water pressure detection, which is easy to implement, and its permeability can be allowed to be ≥5 Lu;

[0055] The dam top protection layer is located on the top of the dam body and is made of normal concrete. It is used to protect the dam top from wind and rain erosion and mechanical damage;

[0056] The drainage system includes drainage pipes, drainage corridors and drainage holes, which are used to discharge the accumulated water in the dam body to reduce the impact of the water flow on the building itself.

[0057] When the dam height exceeds 50m, anti-cracking steel bars are configured to enhance the anti-cracking performance.

[0058] The drainage system also includes a water level monitoring device, which is used to monitor the water level changes in the dam body in real time to ensure the effective operation of the drainage system.

[0059] The drainage system is directly connected to the drainage network, drainage corridors, drainage holes and other facilities by drilling holes to form a systematic drainage system. This avoids the problem of mechanical rock piles being easily deformed or bent when entering the warehouse due to pre-buried geotextile blind ditch pipes. It also solves the risk of concrete seeping into the pipe and causing blockage.

[0060] Example 2

[0061] A self-compacting rockfill concrete gravity dam with a panel, comprising an upstream panel, a foundation concrete layer, upstream and downstream assembled prefabricated blocks, a self-compacting pile at the dam belly, a dam top protective layer, and a drainage system;

[0062] The upstream panel is made of normal concrete coated with anti-seepage paint. The thickness of the anti-seepage layer gradually increases from top to bottom, 0.3m at the top and 1m at the bottom to ensure the anti-seepage effect.

[0063] The foundation concrete layer is located at the bottom of the dam body and is made of normal concrete with a thickness of 1m. It provides a stable foundation support for the dam body and serves as a platform and weight for consolidation grouting and curtain grouting to facilitate construction operations.

[0064] The upstream and downstream prefabricated blocks include the first prefabricated block and the second prefabricated block. The size of the first prefabricated block is 400mm×300mm×300mm, and the size of the second prefabricated block is 600mm×300mm×300mm. They are laid in a “one-by-one” manner. Drainage holes are reserved inside the prefabricated blocks to facilitate drainage and reduce water pressure. This is also beneficial to the subsequent reinforcement of the steel panels. They are connected by cement mortar in a building block manner to ensure the tightness and stability between the prefabricated blocks. No formwork is required. When the prefabricated blocks on the upstream side are laid, each layer retreats 4cm toward the center of the dam to form a small misalignment.

[0065] The self-compacting pile in the belly of the dam is transported into the warehouse by dump trucks. After artificial auxiliary shaping, it is formed by pumping self-compacting concrete. The coarse aggregate is secondary concrete. The pile fills the gap in the belly of the dam and improves the overall stability of the dam. The quality of the rockfill in the belly of the dam is controlled by drilling water pressure detection, which is easy to implement. Its permeability can be allowed to be ≥5 Lu;

[0066] The dam top protection layer is located on the top of the dam body and is made of asphalt concrete. It is used to protect the dam top from wind and rain erosion and mechanical damage;

[0067] The drainage system includes drainage pipes, drainage corridors and drainage holes, which are used to discharge the accumulated water in the dam body to reduce the impact of the water flow on the building itself.

[0068] When the dam height exceeds 50m, anti-cracking steel bars are configured to enhance the anti-cracking performance.

[0069] The drainage system also includes a water level monitoring device, which is used to monitor the water level changes in the dam body in real time to ensure the effective operation of the drainage system.

[0070] The drainage system is directly connected to the drainage network, drainage corridors, drainage holes and other facilities by drilling holes to form a systematic drainage system. This avoids the problem of mechanical rock piles being easily deformed or bent when entering the warehouse due to pre-buried geotextile blind ditch pipes. It also solves the risk of concrete seeping into the pipe and causing blockage.

[0071] Example 3

[0072] The construction method of the self-compacting rockfill concrete gravity dam includes the following steps:

[0073] S10 pouring normal concrete dam foundation cushion: the dam foundation pit is excavated and acceptance is carried out after completion. The normal concrete dam foundation cushion is poured on the dam foundation pit that has passed the acceptance. It ensures that the quality of the foundation pit meets the construction standards and requirements, laying a solid foundation for subsequent projects. This step aims to transition the dam foundation and the dam body, providing stable support for the structure of the entire dam;

[0074] S20 Casting of drainage corridors and surrounding transition layers: On the basis of the dam foundation cushion layer, further cast the drainage corridors and surrounding transition layers, and carry out curtain grouting and drainage hole drilling at the same time to ensure the effective operation of the dam's drainage system and prevent leakage;

[0075] S30 installation of upstream and downstream prefabricated blocks: on the dam foundation cushion layer, a layer of upstream and downstream prefabricated blocks is installed according to the "one Ding and one Shun" masonry method. The prefabricated blocks can not only improve the construction efficiency, but also enhance the overall stability of the dam;

[0076] Construction of the S40 dam belly self-compacting rockfill: The main processes are mining and material selection, rockfill storage and paving, self-compacting rock concrete pouring, construction layer treatment, and finally forming the dam belly rockfill;

[0077] S41 Mining and material selection: Choose rough stone, block stone or boulders as stone, with apparent density ≥2550kg / m 3 , block thickness ≥ 155mm, choose hard block stones, and choose complete, hard, non-weathering, non-disintegration stones for rockfill;

[0078] S42 Stone piles are transported directly into the warehouse by dump trucks. If road transportation is not possible, the stones can be hoisted into the warehouse. After unloading, they are piled with the help of small excavators and manual labor. Manual assistance is used during the piling process to avoid direct contact between the flat surfaces of the stones or with the foundation surface and construction joint surface, so that the concrete can flow into the cavity by gravity.

[0079] S43 self-compacting stone concrete pouring: Use concrete delivery pumps or concrete mixer trucks to transport self-compacting concrete to avoid segregation during transportation;

[0080] S44 Construction surface treatment: After the compressive strength of the cementing material on the rockfill surface reaches 2.5MPa, wash away the scum on the stone masonry surface, remove the accumulated water, and roughen the smooth surface of the cementing material;

[0081] S50 repeats steps S30 and S40: according to the design requirements, repeatedly installs the prefabricated blocks and performs the cementing material construction until the dam top height is reached. This process needs to be continuously repeated until the dam reaches the predetermined height and stability requirements;

[0082] S60 Dam top protection layer construction: laying a normal concrete or asphalt concrete protective layer on the dam top to protect the dam top from weathering and erosion. This step is crucial to extending the service life of the dam;

[0083] S70 drainage system construction: The entire drainage network consists of multiple components such as drainage pipes, drainage channels and drainage holes. The excess water is directly guided out and connected to the existing drainage facilities by drilling. Before the construction of the dam top protection layer, a drilling rig is used to drill holes from the top to the drainage gallery with a hole diameter of 90mm. The drainage system is improved and debugged to ensure unobstructed drainage. This is one of the important measures to ensure the safe operation of the dam.

[0084] S80 upstream panel construction: including concrete panel segmentation, steel bar erection, panel concrete pouring, and panel maintenance;

[0085] S81 concrete panel block design: The panel block design needs to consider the deformation characteristics of the dam body and construction conditions. The vertical joint spacing is 15m, which is convenient for construction and quality control;

[0086] S82 Steel bar erection: The panel adopts single-layer bidirectional steel bars, and the steel bars are placed in the middle of the panel section. The reinforcement ratio in each direction is between 0.33% and 0.38%, with a horizontal reinforcement ratio of 0.33% and a vertical reinforcement ratio of 0.38%. In the tensile stress area or the bank peripheral seam and nearby, steel bars with one diameter higher are appropriately arranged to improve the crack resistance of the panel. On both sides of the vertical seam adjacent to the peripheral seam of the high dam, structural steel bars with bent steel bars to resist extrusion are appropriately arranged. However, it should be noted that these steel bars should not affect the installation of water stop and the vibration quality of the concrete nearby. The calculation of the steel bar area is based on the design thickness of the panel concrete;

[0087] S83 panel concrete pouring: Slipform pouring is adopted. The pouring method of the starting plate can be the rotation of the slipform, which is completed by the winch on the dam top and the lateral manual hoist. This is an efficient and continuous pouring method. The number of chutes is selected for distribution according to the width of the slipform. Two chutes are used for a 12m wide slipform. The tail section of the chute is manually moved for uniform distribution. The slump is controlled at 4.5cm. The vibrator is vibrated 50cm in front of the slipform to ensure the compactness of the concrete.

[0088] S84 panel maintenance: Maintenance is an important measure to avoid cracks in the panel. The maintenance of the panel includes two aspects: insulation and moisture retention. Generally, insulation materials such as straw bags are used to cover the panel to reduce cracks caused by temperature gradients. Water is used to keep the surface of the panel moist to prevent the concrete from cracking due to drying. The maintenance period is 90 days.

[0089] Example 4

[0090] The construction method of the self-compacting rockfill concrete gravity dam includes the following steps:

[0091] S10 pouring normal concrete dam foundation cushion: the dam foundation pit is excavated and acceptance is carried out after completion. The normal concrete dam foundation cushion is poured on the dam foundation pit that has passed the acceptance. It ensures that the quality of the foundation pit meets the construction standards and requirements, laying a solid foundation for subsequent projects. This step aims to transition the dam foundation and the dam body, providing stable support for the structure of the entire dam;

[0092] S20 Casting of drainage corridors and surrounding transition layers: On the basis of the dam foundation cushion layer, further cast the drainage corridors and surrounding transition layers, and carry out curtain grouting and drainage hole drilling at the same time to ensure the effective operation of the dam's drainage system and prevent leakage;

[0093] S30 installation of upstream and downstream prefabricated blocks: on the dam foundation cushion layer, a layer of upstream and downstream prefabricated blocks is installed according to the "one Ding and one Shun" masonry method. The prefabricated blocks can not only improve the construction efficiency, but also enhance the overall stability of the dam;

[0094] Construction of the S40 dam belly self-compacting rockfill: The main processes are mining and material selection, rockfill storage and paving, self-compacting rock concrete pouring, construction layer treatment, and finally forming the dam belly rockfill;

[0095] S41 Mining and material selection: Choose rough stone, block stone or boulders as stone, with apparent density ≥2550kg / m 3 , block thickness ≥ 200mm, choose hard block stones, and choose complete, hard, non-weathering and non-disintegrating stones for rockfill;

[0096] S42 Stone pile into warehouse for paving: The stone pile is directly transported into the warehouse by dump trucks. If road transportation is not available, the stone pile can be hoisted into the warehouse. After unloading, it is piled with the help of small excavators and manual labor. During the paving process, a small excavator is used to assist in the paving to avoid direct contact between the flat surfaces of the stone pile or with the foundation surface and construction joint surface, so that the concrete can flow into the cavity by gravity;

[0097] S43 self-compacting stone concrete pouring: Use concrete delivery pumps or concrete mixer trucks to transport self-compacting concrete to avoid segregation during transportation;

[0098] S44 Construction surface treatment: After the compressive strength of the cementing material on the rockfill surface reaches 2.5MPa, wash away the scum on the stone masonry surface, remove the accumulated water, and roughen the smooth surface of the cementing material;

[0099] S50 repeats steps S30 and S40: according to the design requirements, repeatedly installs the prefabricated blocks and performs the cementing material construction until the dam top height is reached. This process needs to be continuously repeated until the dam reaches the predetermined height and stability requirements;

[0100] S60 Dam top protection layer construction: laying a normal concrete or asphalt concrete protective layer on the dam top to protect the dam top from weathering and erosion. This step is crucial to extending the service life of the dam;

[0101] S70 drainage system construction: The entire drainage network consists of multiple components such as drainage pipes, drainage channels and drainage holes. The excess water is directly guided out and connected to the existing drainage facilities by drilling. Before the construction of the dam top protection layer, a drilling rig is used to drill holes from the top to the drainage gallery with a hole diameter of 75mm. The drainage system is improved and debugged to ensure unobstructed drainage. This is one of the important measures to ensure the safe operation of the dam.

[0102] S80 upstream panel construction: including concrete panel segmentation, steel bar erection, panel concrete pouring, and panel maintenance;

[0103] S81 concrete panel block design: The panel block design needs to consider the deformation characteristics of the dam body and construction conditions. The vertical joint spacing is 18m, which is convenient for construction and quality control;

[0104] S82 Steel bar erection: The panel adopts single-layer bidirectional steel bars, and the steel bars are placed in the middle of the panel section. The reinforcement ratio in each direction is between 0.3% and 0.35%, with a horizontal reinforcement ratio of 0.3% and a vertical reinforcement ratio of 0.35%. In the tensile stress area or the bank peripheral seam and nearby, steel bars with one diameter higher are appropriately arranged to improve the crack resistance of the panel. On both sides of the vertical seam adjacent to the peripheral seam of the high dam, structural steel bars with bent steel bars to resist extrusion are appropriately arranged. However, it should be noted that these steel bars should not affect the installation of water stop and the vibration quality of the concrete nearby. The calculation of the steel bar area is based on the design thickness of the panel concrete;

[0105] S83 panel concrete pouring: Slipform pouring is adopted. The pouring method of the starting plate is sliding form translation, which is completed by the winch on the dam top and the lateral manual hoist. This is an efficient and continuous pouring method. The number of chutes is selected for distribution according to the width of the slipform. Two chutes are used for a 12m wide slipform. The tail section of the chute is manually moved for uniform distribution. The slump is controlled at 6cm. The vibrator is vibrated 50cm in front of the slipform to ensure the compactness of the concrete.

[0106] S84 panel maintenance: Maintenance is an important measure to avoid cracks in the panel. The maintenance of the panel includes two aspects: insulation and moisture retention. Generally, the panel is covered with insulation materials such as straw bags to reduce cracks caused by temperature gradients. The panel surface is kept moist by spraying water to prevent the concrete from cracking due to drying. The maintenance is carried out until water is stored.

[0107] Example 5

[0108] The construction method of the self-compacting rockfill concrete gravity dam includes the following steps:

[0109] S10 pouring normal concrete dam foundation cushion: the dam foundation pit is excavated and acceptance is carried out after completion. The normal concrete dam foundation cushion is poured on the dam foundation pit that has passed the acceptance. It ensures that the quality of the foundation pit meets the construction standards and requirements, laying a solid foundation for subsequent projects. This step aims to transition the dam foundation and the dam body, providing stable support for the structure of the entire dam;

[0110] S20 Casting of drainage corridors and surrounding transition layers: On the basis of the dam foundation cushion layer, further cast the drainage corridors and surrounding transition layers, and carry out curtain grouting and drainage hole drilling at the same time to ensure the effective operation of the dam's drainage system and prevent leakage;

[0111] S30 installation of upstream and downstream prefabricated blocks: on the dam foundation cushion layer, a layer of upstream and downstream prefabricated blocks is installed according to the "one Ding and one Shun" masonry method. The prefabricated blocks can not only improve the construction efficiency, but also enhance the overall stability of the dam;

[0112] Construction of the S40 dam belly self-compacting rockfill: The main processes are mining and material selection, rockfill storage and paving, self-compacting rock concrete pouring, construction layer treatment, and finally forming the dam belly rockfill;

[0113] S41 Mining and material selection: Choose rough stone, block stone or boulders as stone, with apparent density ≥2550kg / m 3 , block thickness ≥ 180mm, choose hard block stones, and choose complete, hard, non-weathering, non-disintegration stones for rockfill;

[0114] S42 Stone pile into warehouse for paving: The stone pile is directly transported into the warehouse by dump trucks. If road transportation is not available, the stone pile can be hoisted into the warehouse. After unloading, it is piled with the help of small excavators and manual labor. During the paving process, a small excavator is used to assist in the paving to avoid direct contact between the flat surfaces of the stone pile or with the foundation surface and construction joint surface, so that the concrete can flow into the cavity by gravity;

[0115] S43 self-compacting stone concrete pouring: Use concrete delivery pumps or concrete mixer trucks to transport self-compacting concrete to avoid segregation during transportation;

[0116] S44 Construction surface treatment: After the compressive strength of the cementing material on the rockfill surface reaches 2.5MPa, wash away the scum on the stone masonry surface, remove the accumulated water, and roughen the smooth surface of the cementing material;

[0117] S50 repeats steps S30 and S40: according to the design requirements, repeatedly installs the prefabricated blocks and performs the cementing material construction until the dam top height is reached. This process needs to be continuously repeated until the dam reaches the predetermined height and stability requirements;

[0118] S60 Dam top protection layer construction: laying a normal concrete or asphalt concrete protective layer on the dam top to protect the dam top from weathering and erosion. This step is crucial to extending the service life of the dam;

[0119] S70 drainage system is perfect: the whole drainage network is composed of multiple components such as drainage pipes, drainage channels and drainage holes. The excess water is directly guided out and connected to the existing drainage facilities by drilling. Before the construction of the dam top protection layer, a drilling rig is used to drill holes from the top to the drainage corridor with a hole diameter of 110mm. The drainage system is improved and debugged to ensure unobstructed drainage. This is one of the important measures to ensure the safe operation of the dam;

[0120] S80 upstream panel construction: including concrete panel segmentation, steel bar erection, panel concrete pouring, and panel maintenance;

[0121] S81 concrete panel block design: The panel block design needs to consider the deformation characteristics of the dam body and construction conditions. The vertical joint spacing is 12m, which is convenient for construction and quality control;

[0122] S82 Steel bar erection: The panel adopts single-layer bidirectional steel bars, and the steel bars are placed in the middle of the panel section. The reinforcement ratio in each direction is between 0.35% and 0.4%, with a horizontal reinforcement ratio of 0.35% and a vertical reinforcement ratio of 0.4%. In the tensile stress area or the bank peripheral seam and nearby, steel bars with one diameter higher are appropriately arranged to improve the crack resistance of the panel. On both sides of the vertical seam adjacent to the peripheral seam of the high dam, structural steel bars with bent steel bars to resist extrusion are appropriately arranged. However, it should be noted that these steel bars should not affect the installation of water stop and the vibration quality of the concrete nearby. The calculation of the steel bar area is based on the design thickness of the panel concrete;

[0123] S83 panel concrete pouring: Slipform pouring is adopted. The pouring method of the starting plate is that the slipform rotates first and then moves horizontally. It is completed by the winch on the dam top and the lateral manual hoist. This is an efficient and continuous pouring method. The number of chutes is selected according to the width of the slipform for material distribution. The 16m wide slipform uses three chutes. The tail section of the chute is manually moved to evenly distribute the material. The slump is controlled at 3cm. The vibrator is vibrated 50cm in front of the slipform to ensure the compactness of the concrete.

[0124] S84 panel maintenance: Maintenance is an important measure to avoid cracks in the panel. The maintenance of the panel includes two aspects: insulation and moisture retention. Generally, insulation materials such as straw bags are used to cover the panel to reduce cracks caused by temperature gradients. Water is used to keep the surface of the panel moist to prevent the concrete from cracking due to drying. The maintenance period is 90 days.

[0125] Although the present invention has been described in detail above by general explanation and specific implementation methods, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, these modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A self-compacting rockfill concrete gravity dam, characterized in that: It includes upstream panels, foundation concrete layer, upstream and downstream prefabricated blocks, dam belly self-compacting pile, dam top protection layer, and drainage system; The upstream panel is made of normal concrete with anti-seepage performance or normal concrete coated with anti-seepage coating. When normal concrete is used as the anti-seepage layer, the specific thickness is determined comprehensively according to the height of the dam body and the change of water level. The thickness is 1 / 30 to 1 / 60 of the corresponding water head, and the thickness gradually increases from the top to the bottom, and the top thickness is ≥0.3m; The foundation concrete layer is located at the bottom of the dam body, is made of normal concrete, has a thickness of 1 to 3 meters, and serves as a platform and weight for consolidation grouting and curtain grouting; The upstream and downstream assembled prefabricated blocks include a first prefabricated block and a second prefabricated block, which are laid in a "one-in-one-in-one" pattern and connected by cement mortar. When the upstream assembled prefabricated blocks are laid, each layer retreats 4 to 6 cm toward the belly of the dam to form a small offset. The self-compacting pile in the dam belly is transported into the warehouse by tower crane or dump truck, and after manual placement, it is poured and formed by pumped self-compacting concrete, which serves as the main supporting structure for transmitting water load; The dam top protective layer is located at the top of the dam body and is made of normal concrete or asphalt concrete; The drainage system includes a drainage pipe network, a drainage gallery and drainage holes.

2. The self-compacting rockfill concrete gravity dam according to claim 1, characterized in that: When the dam height exceeds 50m, anti-cracking steel bars need to be configured.

3. The self-compacting rockfill concrete gravity dam according to claim 1, characterized in that: The upstream and downstream assembled prefabricated blocks have a first prefabricated block size of 400mm×300mm×300mm, and a second prefabricated block size of 600mm×300mm×300mm.

4. The self-compacting rockfill concrete gravity dam according to claim 3, characterized in that: Drainage holes are reserved inside the assembled prefabricated blocks.

5. The self-compacting rockfill concrete gravity dam according to claim 1, characterized in that: The drainage system also includes a water level monitoring device.

6. The self-compacting rockfill concrete gravity dam according to claim 1, characterized in that: The drainage system is directly connected to the drainage network, drainage corridors and drainage holes by drilling.

7. The construction method of the self-compacting rockfill concrete gravity dam as claimed in claim 1, characterized in that: The steps include: S10 Casting of normal concrete dam foundation cushion layer: excavation of dam foundation pit, acceptance after completion, casting of normal concrete dam foundation cushion layer on the dam foundation pit that has passed the acceptance; S20 Casting of drainage corridor and surrounding transition layer: On the basis of the dam foundation cushion layer, further cast the drainage corridor and surrounding transition layer, and carry out curtain grouting and drainage hole drilling at the same time; S30 Install upstream and downstream prefabricated blocks: On the dam foundation cushion, install a layer of upstream and downstream prefabricated blocks according to the "one-by-one" masonry method; Construction of the S40 dam belly self-compacting rockfill: The main processes are mining and material selection, rockfill storage and paving, self-compacting rock concrete pouring, construction layer treatment, and finally forming the dam belly rockfill; S50 repeats steps S30 and S40: according to the design requirements, repeatedly installs the prefabricated blocks and performs the construction of the dam belly self-compacting rockfill body until the dam crest height is reached; S60 Dam top protective layer construction: lay normal concrete or asphalt concrete protective layer on the dam top; During the construction of the S70 drainage system, a drilling rig was used to drill holes from the top toward the drainage gallery before the construction of the dam top protective layer, with a hole diameter of 75 to 110 mm; S80 upstream panel construction: including concrete panel segmentation, steel bar erection, panel concrete pouring, and panel maintenance.

8. The construction method of the self-compacting rockfill concrete gravity dam according to claim 7, characterized in that: The construction of the self-compacting rockfill body at the dam belly in step S40 specifically includes the following steps: S41 Mining and material selection: Select block stone or boulders as stone, with apparent density ≥2550kg / m 3 , block thickness ≥150mm; S42 Rock piles are transported directly into the warehouse by dump trucks. If road transportation is not possible, the rocks can be hoisted into the warehouse. After unloading, they are piled with the help of small excavators and manual labor. During the piling process, manual labor or small excavators are used to assist in piling to avoid direct contact between the flat surfaces of the rocks or with the foundation surface or construction joint surface, so that concrete can flow into the cavity of the rock pile by gravity. S43 self-compacting stone concrete pouring: Use concrete delivery pumps or concrete mixer trucks to transport self-compacting concrete to avoid segregation during transportation; S44 Construction surface treatment: After the compressive strength of the cementing material on the stonefill surface reaches 2.5MPa, wash away the scum on the stonefill surface, remove the accumulated water, and roughen the smooth surface of the cementing material.

9. The construction method of the self-compacting rockfill concrete gravity dam according to claim 7, characterized in that: The step S80 of upstream panel construction specifically includes the following steps: S81 concrete panel block: the vertical joint spacing of the panel block is 12 to 18m; S82 reinforcement erection: The panel adopts single-layer bidirectional reinforcement, and the reinforcement is placed in the middle of the panel section. The reinforcement ratio in each direction is between 0.3% and 0.4%, the horizontal reinforcement ratio is 0.3% to 0.35%, and the vertical reinforcement ratio is 0.35% to 0.4%. The structural reinforcement of bent steel bars to resist extrusion is arranged in the seams around the shore; S83 panel concrete pouring: The panel is poured by slipform pouring, and the starting plate is poured by one of the following methods: rotation, translation, or rotation followed by translation of the slipform. It is completed by the winch on the dam top and the lateral manual hoist. The number of chutes is selected according to the width of the slipform for material distribution. If the slipform is 12m wide, two chutes are used; if the slipform is 16m wide, three chutes are used. The tail section of the chute is moved manually for uniform material distribution, and the slump is controlled between 3 and 6cm. The vibrator is vibrated 50cm in front of the slipform. S84 panel maintenance: including heat preservation and moisture retention. The panel is covered with heat preservation materials for heat preservation, and the panel surface is kept moist by spraying water. The maintenance period is 90 days, or the maintenance continues until water is stored.

Images