Rapid construction method for upstream and downstream concrete blocks of rock-fill concrete arch dam

Abstract

The invention provides a rapid and safe construction method for upstream and downstream concrete blocks of a rock-fill concrete arch dam, and relates to the technical field of rapid construction of rock-fill concrete arch dams. S2, a formwork system is installed; s3, pouring and initial setting; s4, partial mold removal; s5, rock-fill concrete construction; and S6, circulating construction is conducted. Due to the fact that the construction technology is simplified, the production and masonry links of precast blocks are omitted, and the related material cost, the transportation cost and a large amount of labor cost are effectively saved. According to measurement and calculation, by adopting the technical scheme provided by the invention, the project investment can be saved by about 8% compared with the traditional means, and the economic benefit is remarkable.

Description

Technical Field

[0001] This invention relates to the technical field of rapid and safe construction of rockfill concrete arch dams in water conservancy and hydropower projects, and in particular to a rapid and safe construction method for upstream and downstream concrete blocks of rockfill concrete arch dams. Background Technology

[0002] Rockfill concrete arch dams, as an important dam type, are widely used in water conservancy and hydropower projects. Formwork engineering is a crucial aspect of their construction, directly impacting the dam's quality, progress, and safety. In the construction of rockfill concrete arch dams both domestically and internationally, the formwork methods typically employed include sliding formwork, climbing formwork, internal tension formwork, or cantilever formwork. However, existing construction techniques have revealed numerous technical problems in practice.

[0003] First, riprap concrete exhibits high self-compactness and strong fluidity, resulting in significant lateral pressure on the formwork during pouring. Traditional formwork systems, with numerous joints and the need for extensive internal reinforcement, are highly susceptible to grout leakage at these joints under this high lateral pressure. More seriously, during the riprap placement process, construction equipment or riprap materials can easily collide with the formwork or its internal reinforcement, causing deformation. This deformation and grout leakage not only severely impact the dam's appearance but also negatively affect the construction schedule.

[0004] Secondly, the traditional process of constructing concrete blocks for the upstream and downstream faces of arch dams is cumbersome and inefficient. This process typically requires prefabrication of concrete blocks in a prefabrication plant, followed by transportation to the construction site where bricklayers perform the construction work. This not only increases the complexity of material transportation and management but also makes on-site operations inconvenient, prolongs the construction period, and introduces additional construction safety hazards.

[0005] Therefore, how to solve the problems of grout leakage and deformation caused by high lateral pressure of formwork in the construction of existing rockfill concrete arch dams, and simplify the construction process to avoid the use of precast blocks and on-site masonry, so as to effectively improve construction efficiency and shorten the construction period while ensuring construction quality and safety, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] This invention provides a rapid and safe construction method for upstream and downstream concrete blocks of a rockfill concrete arch dam, aiming to solve at least one of the technical problems existing in the prior art mentioned in the background section.

[0007] The present invention provides the following technical solution to achieve the above objectives: A rapid and safe construction method for upstream and downstream concrete blocks of a rockfill concrete arch dam includes the following steps: S1: Foundation Confirmation: Confirm that the strength of the poured lower layer of concrete meets the preset requirements for a lateral support and restraint structure; S2: Formwork System Installation: Installing a formwork system on the already poured lower layer of concrete to form the plenum to be poured, the installation steps include: A. Fix the left-side formwork to the lower layer of concrete using ground anchors; B. Install the right-side formwork, which is connected to the lower formwork via connecting rods and supported by trusses; C. Use a formwork tie rod to connect the left template and the right template laterally to form the pouring chamber; S3: Pouring and initial setting: Pouring normal concrete into the pouring chamber and waiting for it to reach the initial setting state; S4: Partial demolding: After the normal concrete reaches the initial setting state, remove the formwork rod and the left side formwork to expose one side of the normal concrete. S5: Construction of riprap concrete: After the strength of the normal concrete meets the lateral pressure requirements, the riprap concrete is constructed adjacent to the exposed side. S6: Cyclic construction: Using the completed normal concrete and the embedded stone concrete as the new lower foundation, repeat steps S2 to S5 to carry out the pouring construction of the upper layer.

[0008] Furthermore, in step S2C, the pull rod is detachably connected to the left template and the right template via sleeve bolts.

[0009] A formwork system for constructing a rockfill concrete arch dam includes: The left formwork is configured to be fixed to the poured concrete by ground anchors, and its surface facing the right formwork has a concave structure. The right-side formwork includes connecting rods for connecting to the lower formwork and trusses for providing support; A formwork rod is configured to detachably connect the left template and the right template to enclose and form a pouring chamber between the recessed structural surface of the left template and the right template.

[0010] Furthermore, it also includes sleeve bolts for fixing the pull rod to the left and right side templates.

[0011] Furthermore, the truss of the right-side template is a wooden truss.

[0012] Furthermore, the recessed structure is arranged in a quincunx pattern on the left template.

[0013] Furthermore, the recessed structure of the left template is arc-shaped.

[0014] Furthermore, the radius of the arc-shaped concave structure is 15cm.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The formwork system employed in this invention forms a stable whole through methods such as tie rods and ground anchors. This effectively resists the enormous lateral pressure brought about by the high fluidity of riprap concrete, fundamentally solving the technical problems of easy deformation of formwork and easy leakage of grout at joints in traditional construction, and significantly improving the appearance quality of the project. At the same time, since the formwork is removed during riprap operations, the risk of collision between construction equipment and the formwork is avoided, improving construction safety.

[0016] 2. This invention completely replaces the cumbersome process of "precast block production, transportation, and on-site construction" in traditional methods by directly bonding conventional concrete with its concave structural surface through on-site casting of normal concrete. This method eliminates the need for precast plants and bricklayers, and also eliminates the need for diagonal bracing within the dam body. The entire construction process is smoother and more efficient.

[0017] 3. This invention simplifies the construction process, eliminating the production and laying of precast blocks, effectively saving related material costs, transportation costs, and significant labor costs. Calculations show that using this invention can reduce project investment by approximately 8% compared to traditional methods, demonstrating significant economic benefits.

[0018] 4. This invention, by setting a recessed structure on the left-side template, increases the contact surface and strengthens the interlocking between the normal concrete and the embedded stone concrete, thereby enhancing the frictional resistance between them. Compared to the simple contact surface of traditional blocks, this structural optimization enhances the bonding force between concretes of different materials, which has a positive effect on improving the long-term structural integrity and stability of the dam. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention; Attached reference numerals: 1-Tie rod; 2-Sleeve bolt; 3-Draping plate; 4-Truss; 5-Buried stone concrete; 6-Ground anchor; 7-Left side formwork; 8-Pouring chamber; 9-Connecting rod; 10-Connecting plate; 11-Pouring concrete. Detailed Implementation

[0020] To facilitate understanding of the present invention, a more complete description of this application will be given below with reference to the accompanying drawings, which illustrate preferred embodiments of the invention. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to enable a more thorough and complete understanding of the disclosure of the present invention.

[0021] It should be noted that the terms "vertical," "horizontal," "up," "down," "left," "right," and similar expressions used in this article are for illustrative purposes only and do not represent the only possible implementation.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to limit the invention; the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0023] Example 1. A rapid and safe construction method for upstream and downstream concrete blocks of a rockfill concrete arch dam, comprising the following steps: S1: Foundation Confirmation: Confirm that the strength of the poured lower layer of concrete 11 meets the preset requirements for a lateral support and restraint structure; S2: Formwork System Installation: Installing a formwork system on the already poured lower layer of concrete 11 to form the pouring chamber 8, the installation steps include: A. Fix the left formwork 7 onto the lower concrete layer 11 using ground anchors 6; B. Install the right-side template, which is connected to the lower template via connecting rod 9 and supported by truss 4; C. Use the formwork tie rod 1 to connect the left template 7 and the right template laterally to form the pouring chamber 8; S3: Pouring and initial setting: Pouring normal concrete into the pouring chamber 8 and waiting for it to reach the initial setting state; S4: Partial demolding: After the normal concrete reaches the initial setting state, remove the formwork rod 1 and the left formwork 7 to expose one side of the normal concrete. S5: Construction of riprap concrete: After the strength of the normal concrete meets the lateral pressure requirements, the riprap concrete 5 is constructed adjacent to the exposed side.

[0024] S6: Cyclic construction: Using the completed normal concrete and the embedded stone concrete 5 as the new lower foundation, repeat steps S2 to S5 to carry out the pouring construction of the upper layer.

[0025] In step S2C, the pull rod 1 is detachably connected to the left template 7 and the right template through the sleeve bolt 2.

[0026] Example 2. A formwork system for constructing a rockfill concrete arch dam, characterized in that it comprises: The left template 7 is configured to be fixed to the poured concrete 11 by ground anchors 6, and its surface facing the right template has a concave structure. The right-side template includes connecting rods 9 for connecting to the lower template and trusses 4 for providing support; A formwork rod 1 is configured to detachably connect the left template 7 and the right template to enclose and form a pouring chamber 8 between the recessed structural surface of the left template 7 and the right template.

[0027] It also includes sleeve bolts 2 for fixing the pull rod 1 to the left and right templates.

[0028] The truss 4 of the right-side template is a wooden truss.

[0029] The recessed structure is arranged in a quincunx pattern on the left template 7.

[0030] The recessed structure of the left template 7 is arc-shaped.

[0031] The radius of the arc-shaped concave structure is 15cm.

[0032] Combined with appendix Figure 1 The specific implementation steps of the method of the present invention are described in detail below: 1. Foundation Confirmation: Before pouring the next layer of concrete, the strength of the already poured lower layer of concrete 11, which serves as the foundation for construction, is first tested. By using a rebound hammer or core sampling test, it is confirmed that its compressive strength has reached no less than 2.5 MPa, meeting the preset requirements for the upper formwork system, especially the lateral support and constraint structure of the ground anchor 6.

[0033] This step ensures the stability and safety of the construction foundation. Only when the lower layer of concrete has sufficient strength can it provide reliable anchoring points and support surfaces for the upper formwork system, preventing safety accidents such as formwork displacement, deformation, or even collapse due to an unstable foundation. This is a prerequisite for the safe conduct of all subsequent procedures.

[0034] 2. Formwork system installation: On the lower layer of concrete 11 that has reached the required strength, the formwork system is installed. The height of the formwork is determined according to the construction site to form the pouring chamber 8. Hoist the left formwork 7 into place, drill holes at the pre-drilled holes at its bottom and insert M24 chemical anchors 6 to firmly anchor the left formwork 7 to the lower concrete 11. The right-side formwork is hoisted into place and connected to the lower-level right-side formwork via connecting rod 9 and connecting plate 10. Meanwhile, truss 4 provides it with the main vertical stiffness and support. The formwork rod 1 is passed horizontally through the reserved holes of the two side templates and tightened at both ends by the sleeve bolt 2 to firmly connect the left and right side templates into a whole, forming a pouring chamber 8 with a defined width; The formwork system constructed in this step possesses extremely high stability and rigidity. Ground anchors 6 provide strong anti-overturning capabilities; connecting rods 9 and trusses 4 ensure the verticality and stability of the right-side formwork; while the core tie rod 1 provides enormous lateral restraint, directly resisting the lateral pressure of the concrete. This combined system effectively solves the problems of easy deformation and grout leakage in existing technologies, ensuring the appearance quality of the poured concrete. Simultaneously, since all reinforcement is completed on the outside of the formwork or through tie rods, no diagonal bracing is required inside the dam body, greatly simplifying internal operations and avoiding collisions between the reinforcing steel and the formwork.

[0035] 3. Pour normal concrete into the 8th hopper. After pouring, wait about 4-6 hours, depending on the on-site temperature and concrete mix ratio, until the concrete reaches the initial setting state.

[0036] 4. After confirming the initial setting of the normal concrete, immediately begin partial formwork removal. Workers first loosen and remove the sleeve bolts 2, pull out the formwork rods 1, and then dismantle the entire left-side formwork 7 and hoist it to the next work area. At this point, the sides of the newly poured normal concrete are fully exposed, while the right-side formwork remains in place to support the concrete that has not yet fully hardened.

[0037] This "single-sided quick-release" design is key to the rapid construction achieved by this invention. It breaks away from the traditional model of waiting for the concrete to reach sufficient strength before overall formwork removal, significantly reducing the time spent on formwork. While ensuring the stability of the newly poured concrete, it quickly creates a working surface for subsequent embedded stone concrete construction, achieving seamless connection between processes and effectively shortening the overall construction period.

[0038] 5. Continue to cure the newly poured normal concrete for about 12-24 hours until its strength reaches more than 1.5MPa. After confirming that it is strong enough to withstand the lateral compression during the construction of the embedded stone concrete, start the construction of embedded stone concrete 5 next to the exposed concave side of the structure.

[0039] The exposed concave structural surface forms a regular, rough bonding surface with a large contact area between the conventional concrete and the embedded stone concrete 5. This significantly enhances the frictional resistance and mechanical interlocking force between the two types of concrete, ensuring the integrity of the dam structure and the quality of interlayer bonding. More importantly, this method of forming the bonding surface through on-site casting completely replaces the cumbersome process of precast concrete blocks, on-site transportation, and masonry in traditional processes, saving precast space and significant labor costs, and eliminating safety hazards associated with related transportation and masonry operations.

[0040] Obviously, the above description is only a part of the embodiments of the present invention, and not all of the embodiments. The above embodiments are not intended to limit the present invention, and various modifications and variations can be made to the present invention by those skilled in the art. Any combination, modification, equivalent substitution, improvement, and all other embodiments that can be made by those skilled in the art within the spirit and principles of the present invention should be within the protection scope of the present invention.

Claims

1. A rapid and safe construction method for upstream and downstream concrete blocks of a rockfill concrete arch dam, characterized in that... This includes the following steps: S1: Foundation confirmation: Confirm that the strength of the poured lower layer concrete (11) meets the preset requirements for a lateral support constraint structure; S2: Formwork system installation: Installing a formwork system on the already poured lower layer of concrete (11) to form the plenum to be poured (8), the installation steps include: A. Fix the left formwork (7) to the lower concrete layer (11) using ground anchors (6); B. Install the right-side template, which is connected to the lower template via connecting rod (9) and supported by truss (4); C. Use a pull rod (1) to connect the left template (7) and the right template laterally to form the pouring chamber (8); S3: Pouring and initial setting: Pouring normal concrete into the pouring chamber (8) and waiting for it to reach the initial setting state; S4: Partial demolding: After the normal concrete reaches the initial setting state, remove the formwork rod (1) and the left formwork (7) to expose one side of the normal concrete. S5: Construction of riprap concrete: After the strength of the normal concrete meets the lateral pressure requirements, the riprap concrete (5) is constructed adjacent to the exposed side. S6: Cyclic construction: Using the completed normal concrete and the embedded stone concrete (5) as the new lower foundation, repeat steps S2 to S5 to carry out the pouring construction of the upper layer.

2. The rapid and safe construction method for upstream and downstream concrete blocks of a rockfill concrete arch dam according to claim 1, characterized in that, In step S2C, the pull rod (1) is detachably connected to the left template (7) and the right template through the sleeve bolt (2).

3. A formwork system for constructing a rockfill concrete arch dam using the method of claim 1, characterized in that, include: The left template (7) is configured to be fixed to the poured concrete (11) by ground anchors (6), and its surface facing the right template is a concave structure. The right-side template includes connecting rods (9) for connecting the lower template and trusses (4) for providing support; A formwork rod (1) is configured to detachably connect the left template (7) and the right template to enclose and form a pouring chamber (8) between the recessed structural surface of the left template (7) and the right template.

4. The system according to claim 3, characterized in that, It also includes sleeve bolts (2) for fixing the pull rod (1) to the left and right templates.

5. The system according to claim 3 or 4, characterized in that: The truss (4) of the right-side template is a wooden truss.

6. The system according to claim 4, characterized in that, The recessed structure is arranged in a plum blossom shape on the left template (7).

7. The system according to claim 4, characterized in that, The recessed structure of the left template (7) is arc-shaped.

8. The system according to claim 7, characterized in that, The radius of the arc-shaped concave structure is 15cm.

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