Construction method of nuclear island plant wall body with through-wall bushing

Abstract

The application discloses a kind of nuclear island plant wall construction methods of being provided with through-wall sleeve, it is related to nuclear island plant construction technical field, when using, heat shrinkable rubber sleeve is sleeved on the outer wall of the opposite end of two sleeve pipe sections, ensure that the outer wall of corresponding sleeve pipe section is tightly combined with the two ends of rubber sleeve respectively.Subsequently, using special heating tool to uniformly heat heat shrinkable rubber sleeve, make it shrink in radial direction and form reliable sealing connection with the outer wall of sleeve pipe section.After the heat shrinkable rubber sleeve is heated and shrunk, not only can it withstand the pressure difference that may occur on both sides of the wall, but also can maintain excellent sealing performance for a long time, effectively prevent radioactive medium or cooling water from leaking along the outer wall of sleeve pipe, solve the technical problems of poor sealing connection between sleeve pipes in the prior art, and prone to water leakage hazards.

Description

Technical Field

[0001] This invention relates to the field of nuclear island plant construction technology, and in particular to a method for constructing nuclear island plant walls using through-wall sleeves. Background Technology

[0002] As one of the core buildings of a nuclear power plant, the construction technology of the nuclear island building's walls is crucial to the plant's safety, airtightness, and structural stability. With the continuous advancement of nuclear energy technology and increasingly stringent nuclear safety standards, the construction of nuclear island building walls is gradually developing towards higher precision, higher quality, and higher efficiency. Especially in the construction methods for various pipes and sleeves running through the walls, the construction process must meet the dual requirements of structural strength and sealing performance to ensure the safe and reliable operation of the nuclear island building.

[0003] Currently, the construction of nuclear island plant walls typically employs a layered concrete pouring method, combined with the erection of a steel reinforcement framework and formwork system, to achieve overall wall forming and reinforcement. For the installation of through-wall sleeves, single-layer formwork is often erected and sleeve sections are pre-embedded. After the concrete side pouring is completed, the sleeve is then sealed to the wall. While this construction method is widely used, it often faces challenges in coordinating the expansion and contraction of formwork layers and ensuring proper sealing between sleeves, particularly in multi-layered wall structures and complex pipeline layouts. Furthermore, the concrete pouring speed and synchronization are difficult to control, affecting construction quality and schedule.

[0004] The existing construction method for through-wall sleeves in nuclear island plant walls suffers from several drawbacks. Firstly, the lack of effective expansion joints between formwork layers leads to stress concentration during wall pouring, affecting structural integrity and the stability of the sleeves. Secondly, the single sealing connection method between sleeve sections results in poor sealing performance and potential leakage. Furthermore, the traditional layered pouring process struggles to ensure simultaneous pouring of each layer of concrete, leading to low construction efficiency and difficulty in quality control. Summary of the Invention

[0005] The main objective of this invention is to propose a construction method for nuclear island plant walls using through-wall sleeves. This method aims to address the technical problems of existing wall construction techniques, such as stress concentration during pouring due to the lack of effective expansion joints between formwork layers, which affects the overall structural integrity and the stable fixing of the sleeves; the limited sealing connection methods between sleeve sections resulting in poor sealing performance and potential leakage; and the difficulty in ensuring synchronous pouring of concrete layers using traditional layered pouring processes, leading to low construction efficiency and difficulty in quality control.

[0006] To achieve the above objectives, in a first aspect, the present invention proposes a construction method for the wall of a nuclear island plant with through-wall sleeves, comprising the following steps: Two radially distributed template layers are erected in the pre-designed construction area; each template layer contains a concrete pouring space, and an expansion joint is formed between the two template layers. A sleeve section is installed in each of the two template layers; wherein, both sleeve sections penetrate the corresponding concrete pouring space and extend out of the corresponding template layer; A heat-shrinkable sleeve is installed inside the expansion joint; wherein, both ends of the heat-shrinkable sleeve are respectively sealed and connected to one of the sleeve sections; Concrete is poured into the two concrete pouring spaces simultaneously to complete the construction of the nuclear island plant wall.

[0007] In one embodiment, the step of installing a sleeve section within each of the two template layers includes: A steel cage is installed in each of the two template layers; A sleeve section is installed inside the reinforcing cage; wherein each sleeve section is welded to the corresponding reinforcing cage, and each sleeve section extends out of the template layer and into the expansion joint.

[0008] In one embodiment, prior to the step of installing one of the sleeve sections within the reinforcing cage, the method further includes: An installation groove is formed on the steel cage; The step of installing one of the sleeve sections inside the reinforcing cage includes: Install one of the sleeve sections on the mounting slot.

[0009] In one embodiment, the length of the sleeve section extending beyond the corresponding template layer and into the expansion joint is A, wherein A ≥ 50 mm.

[0010] In one embodiment, the step of installing a heat-shrinkable sleeve inside the expansion joint includes: A heat-shrinkable sleeve is installed inside the expansion joint, with both ends of the heat-shrinkable sleeve extending through the corresponding template layer and into the corresponding concrete pouring space.

[0011] In one embodiment, the step of installing a heat-shrinkable sleeve within the expansion joint, and ensuring that both ends of the heat-shrinkable sleeve extend through the corresponding template layer and into the corresponding concrete pouring space, includes: Install a heat-shrinkable rubber sleeve inside the expansion joint; The heat-shrinkable sleeve is heat-shrinked so that both ends of the heat-shrinkable sleeve extend through the corresponding template layer and into the corresponding concrete pouring space.

[0012] In one embodiment, the step of simultaneously pouring concrete into the two concrete pouring spaces to complete the construction of the nuclear island building walls includes: Concrete is poured into the two concrete pouring spaces simultaneously, and both ends of the heat-shrinkable sleeve are embedded in the corresponding concrete pouring spaces to complete the construction of the nuclear island plant wall.

[0013] In one embodiment, the step of erecting two radially distributed template layers in a predetermined construction area includes: Install a sheet metal unit in the pre-designated construction area; The template is attached to the sheet metal; wherein the sheet metal extends into the concrete pouring space; The I-beams are supported on the side of the template away from the concrete pouring space to form the template layer.

[0014] In one embodiment, before the step of supporting the I-beam on the side of the formwork away from the concrete pouring space and forming the formwork layer, the method further includes: Wooden blocks are placed in the pre-designated construction area; wherein the wooden blocks are spaced apart from the template, and the wooden blocks are placed on the side of the sheet metal away from the concrete pouring space; The step of supporting the I-beams on the side of the formwork away from the concrete pouring space to form the formwork layer includes: The I-beams are placed on top of the pads and secured with high-strength bolts to form the template layer.

[0015] In one embodiment, the step of attaching the template to the galvanized iron sheet includes: The template is snapped onto the sheet metal, and the sheet metal is anchored to the template using rivets.

[0016] The technical solution of this invention involves fitting heat-shrinkable sleeves onto the outer walls of opposite ends of two sleeve sections, ensuring that both ends of the sleeves are tightly fitted to the outer walls of their respective sleeve sections. A specialized heating tool is then used to uniformly heat the heat-shrinkable sleeves, causing them to shrink radially and form a reliable seal with the outer walls of the sleeve sections. After heating and shrinking, the heat-shrinkable sleeves can not only withstand pressure differences that may occur on both sides of the wall but also maintain excellent sealing performance over a long period, effectively preventing leakage of radioactive media or cooling water along the outer walls of the sleeves. This solves the technical problem of poor sealing connections between sleeves and the potential for water leakage in existing technologies. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 A flowchart of the construction method for the wall of a nuclear island plant with through-wall sleeves provided by the present invention.

[0019] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0022] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] This invention proposes a construction method for the walls of a nuclear island plant with through-wall sleeves.

[0024] Please see Figure 1To facilitate understanding, this construction method for a nuclear island plant wall with through-wall sleeves includes the following steps: S100. Two radially distributed template layers are erected in the pre-designed construction area; wherein, a concrete pouring space is formed in each template layer, and an expansion joint is formed between the two template layers. S200. Install a sleeve section in each of the two template layers; wherein, both sleeve sections penetrate the corresponding concrete pouring space and extend out of the corresponding template layer; S300. Install a heat-shrinkable sleeve inside the expansion joint; wherein, both ends of the heat-shrinkable sleeve are respectively sealed and connected to one of the sleeve sections; S400, Simultaneously pour concrete into the two concrete pouring spaces to complete the construction of the nuclear island plant wall.

[0025] Specifically, before constructing the walls of the nuclear island plant, two radially distributed template layers are erected in the pre-designed construction area, based on the elevation, axial position, and wall thickness of the through-wall sleeves in the design drawings. During erection, the spacing between the two template layers is strictly controlled to form a uniformly wide expansion joint. Each template layer consists of a template panel, back ribs, through-wall bolts, and a tie rod system to ensure that the template system does not shift or deform under the pressure of concrete pouring. The inner side of each template layer, together with the corresponding steel reinforcement skeleton, encloses the concrete pouring space, the dimensions of which are adapted to the designed wall thickness.

[0026] It should be noted that, in this embodiment, the width of the expansion joint is preferably controlled within the range of 20mm-50mm, and can be adjusted according to the wall thickness and ambient temperature. The expansion joint effectively absorbs the shrinkage stress of the wall during concrete solidification and the thermal expansion and contraction deformation caused by temperature and radiation during subsequent operation, thereby preventing stress concentration at the root of the sleeve and significantly improving the overall integrity of the wall structure and the stability of the sleeve installation.

[0027] Furthermore, after the two template layers are installed, a sleeve section is installed in each template layer. During installation, the sleeve sections are first precisely positioned according to the design elevation and angle, and then fixed in the corresponding concrete pouring space using a special fixing bracket. Each sleeve section is ensured to penetrate the entire concrete pouring space vertically or at the design angle, extending at least 300mm beyond each of the two template layers to meet the subsequent connection requirements with the internal and external piping systems of the plant. A certain gap is reserved at the ends of the two sleeve sections at the corresponding positions of the expansion joint. This gap is consistent with the width of the expansion joint, providing operating space for the subsequent installation of the heat-shrinkable sleeve.

[0028] Next, a heat-shrinkable sleeve is installed inside the expansion joint. During installation, the heat-shrinkable sleeve is placed on the outer walls of the opposite ends of the two sleeve sections, ensuring that both ends of the sleeve are tightly fitted to the outer walls of the corresponding sleeve sections. Then, a special heating tool is used to uniformly heat the heat-shrinkable sleeve, causing it to shrink radially and form a reliable seal with the outer walls of the sleeve sections. After heating and shrinking, this heat-shrinkable sleeve can not only withstand the pressure difference that may occur on both sides of the wall, but also maintain excellent sealing performance over a long period, effectively preventing leakage of radioactive media or cooling water along the outer walls of the sleeves. This solves the technical problem of poor sealing connections between sleeves and the potential for leakage in existing technologies.

[0029] In this embodiment, the heat-shrinkable sleeve is preferably made of a cross-linked polyolefin material that is radiation-resistant, high-temperature resistant, and has a high elastic recovery rate, with a shrinkage ratio of not less than 3:1 and a heating shrinkage temperature controlled between 120℃ and 150℃. Of course, in other embodiments, depending on the operating parameters of different nuclear island plants, fluoropolymer heat-shrinkable materials with higher radiation resistance or multi-layer composite heat-shrinkable sleeves can be selected to further improve sealing reliability.

[0030] Concrete is poured simultaneously into both of the aforementioned concrete pouring spaces. During the pouring process, two or more concrete pumps simultaneously pump concrete with the same mix proportion and slump into both concrete pouring spaces, strictly controlling the difference in the rising speed of the concrete on both sides to not exceed 0.5 m / h, so that the concrete levels on both sides rise synchronously. This synchronous pouring method ensures that the lateral pressure acting on the two sleeve sections is basically balanced, preventing the sleeve from shifting or tilting due to excessive pressure on one side, thereby ensuring that the axial position accuracy of the through-wall sleeve meets the stringent requirements for nuclear-grade equipment installation.

[0031] After the concrete is poured, an immersion vibrator is used for layered compaction. During compaction, direct contact between the vibrator and the casing section and heat-shrink sleeve should be avoided to prevent damage to the sealing interface due to excessive local vibration. After the concrete has initially set, the exposed part of the expansion joint is surface-treated, and protective covers are installed as needed.

[0032] In one embodiment, step S200 includes: S210. Install a steel cage in each of the two template layers; S220. Install one of the sleeve sections inside the reinforcing cage; wherein each sleeve section is welded to the corresponding reinforcing cage, and each sleeve section extends out of the template layer and into the expansion joint.

[0033] Specifically, after the two radially distributed formwork layers are erected and the concrete pouring space and expansion joints are formed, the reinforcing cage must first be installed in the concrete pouring space corresponding to each formwork layer. During installation, according to the reinforcing bar diameter, spacing, and protective layer thickness specified in the nuclear island plant wall design drawings, an integral reinforcing cage is fabricated using a combination of binding and spot welding. It is then fixed to the inside of the formwork layer using tie bolts and special positioning clamps, ensuring that the reinforcing cage maintains the designed required concrete protective layer thickness with the inner wall of the formwork. The installation of this reinforcing cage provides a rigid framework for the precise positioning of subsequent casing sections.

[0034] It should be specifically and clearly stated that, in this embodiment, the reinforcing cage preferably adopts a cage structure composed of HRB400 grade main bars with a diameter of 16mm-25mm and stirrups with a diameter of 8mm-12mm. Its axial length should be greater than 1.2 times the corresponding wall thickness to ensure that the sleeve section is reliably constrained in both the axial and radial directions. More specifically, during installation, the reinforcing cage needs to be reliably lapped and tied with other structural reinforcing bars in the wall to form a continuous force-bearing system. This allows the invention to effectively resist the impact of lateral pressure on the sleeve section during concrete pouring and prevent the sleeve from shifting.

[0035] Currently, after the reinforcing cage is installed in place, the casing sections are installed immediately. When installing one casing section inside the reinforcing cage, the casing section is first inserted into the center of the reinforcing cage according to the design elevation, axial position, and tilt angle. A special adjusting screw is then used to fine-tune its spatial position, ensuring that the centerline deviation of the casing section does not exceed 2mm. After the position adjustment is completed, the casing section is welded to the corresponding reinforcing cage.

[0036] Each sleeve section is welded to its corresponding reinforcing cage, and each sleeve section extends beyond the template layer and into the expansion joint. Specifically, manual arc welding or argon arc welding is used for welding. Multiple symmetrical welds are performed at the intersection of the outer wall of the sleeve section and the main reinforcement of the reinforcing cage. Each weld is at least 50mm long, at least 6mm high, and of grade III or higher. After welding, one end of each sleeve section extends at least 300mm beyond the template layer to meet subsequent connection requirements with internal and external pipelines in the plant, while the other end extends at least 15mm into the expansion joint to provide sufficient overlap for the heat-shrinkable sleeve.

[0037] By using the above-mentioned welding and fixing method, the sleeve section and the reinforcing cage form a rigid whole. During the subsequent synchronous concrete pouring process, the lateral pressure of the concrete can be evenly transmitted to the entire reinforcing steel system, effectively suppressing the rotation or translation of the sleeve section caused by the unilateral pressure difference. This significantly improves the positioning accuracy and anti-disturbance ability of the through-wall sleeve, and fundamentally solves the problems of axial displacement and wall stress concentration caused by the insecure fixing of the sleeve in the existing technology.

[0038] Of course, it can be further clarified that in another embodiment, the steel cage can also be a prefabricated modular steel cage unit in the factory, which can be quickly assembled with the template system on site through mechanical connectors. In this case, the connection between the sleeve section and the steel cage can be made by submerged arc welding or multi-layer multi-pass welding process to further improve the fatigue performance and radiation aging resistance of the welded joint, so as to meet the construction needs under different wall thicknesses and radiation dose environments.

[0039] By first installing the reinforcing cage inside the formwork layer, and then welding the sleeve section to the reinforcing cage and extending it into the expansion joint, a stable sleeve positioning and stress system is formed. This significantly improves the installation accuracy and structural integrity of the through-wall sleeves in the nuclear island plant wall, effectively solving the technical problems of difficult coordination of expansion and contraction between formwork layers, poor sleeve fixing stability, and easy displacement during the pouring process in the existing technology, thereby ensuring the sealing performance and long-term operational safety of the wall.

[0040] In one embodiment, prior to step S220, the method further includes: S220. An installation groove is formed on the steel cage; Step S220 includes: Install one of the sleeve sections on the mounting slot.

[0041] Specifically, after the installation of the reinforcing cage within the two layers of formwork is completed, an installation groove needs to be formed on the reinforcing cage before installing the sleeve section. Based on the design elevation and axial position of the sleeve section, construction personnel select the intersection of multiple main reinforcing bars in the central area of ​​the reinforcing cage and fix prefabricated positioning components by welding, thus forming the installation groove. The inner diameter of this installation groove is slightly larger than the outer diameter of the sleeve section, and its axial length is not less than 1.5 times the diameter of the sleeve section to ensure stable support during subsequent installation.

[0042] It should be specifically and clearly stated that, in this embodiment, the installation groove is preferably made of Q235 steel plate with a thickness of not less than 8mm, bent into a U-shaped groove and then fully welded to the main reinforcement of the reinforcing cage. Multiple grout drain holes with a diameter of 20mm are provided at the bottom of the groove to allow the grout to flow fully and encapsulate the sleeve section during concrete pouring. It can be further clarified that the opening of the installation groove faces the center of the concrete pouring space, and its positioning accuracy is controlled within ±1mm. This allows the invention to precisely align the installation position of the sleeve section with the expansion joint, avoiding subsequent sealing failure due to positioning deviations.

[0043] Currently, after the installation groove is formed, the operation of installing one of the sleeve sections on the installation groove is immediately carried out. Specifically, the sleeve section is pushed axially into the installation groove, with one end extending at least 300mm beyond the formwork layer and the other end extending at least 15mm into the expansion joint. Then, symmetrical fillet welds are made on both sides of the contact surface between the sleeve section and the installation groove, with a weld height of at least 6mm and a weld length continuously arranged along the axial direction of the section. Through this installation method, the sleeve section can form a rigid connection with the reinforcing cage. During the subsequent synchronous pouring of concrete, the installation groove can evenly transfer the lateral pressure of the concrete to the entire reinforcing system.

[0044] The installation groove design allows for more precise positioning of the sleeve section and significantly improves its constraint stiffness. This enables the invention to effectively resist dynamic disturbances during the pouring process, preventing radial offset or axial rotation of the sleeve section. It fundamentally solves the problems of stress concentration in the wall and poor sleeve stability caused by the single fixing method in existing technologies. Simultaneously, the reliable welding of the installation groove to the reinforcing cage increases the contact area between the sleeve section and the wall reinforcement system, enhancing the overall structure's seismic and radiation deformation resistance, and ensuring the sealing performance of the nuclear island plant wall under long-term operating conditions.

[0045] In one embodiment, the length of the sleeve section extending beyond the corresponding template layer and into the expansion joint is A, wherein A ≥ 50 mm.

[0046] Specifically, after the installation groove on the reinforcing cage is fabricated and the sleeve sections are installed in the groove, the extension length of each sleeve section towards the expansion joint must be strictly controlled. During construction, a laser rangefinder or steel ruler is used to measure and adjust the actual length of each sleeve section extending into the expansion joint to ensure that its extension length A meets the condition A≥50mm. In this embodiment, it is preferable to control the extension length A within the range of 60mm-80mm.

[0047] It should be specifically and clearly stated that, in this embodiment, the parameter A≥50mm, which refers to the length of the sleeve section extending into the expansion joint, is a minimum safe value determined after comprehensively considering factors such as the width of the expansion joint, the effective shrinkage length of the heat-shrinkable sleeve, interface disturbance during concrete pouring, and temperature stress during long-term operation. It can be further clarified that when A is less than 50mm, the overlap area between the heat-shrinkable sleeve and the sleeve section is insufficient, making it difficult to form a reliable sealing ring. However, A≥50mm ensures that after heating and shrinking, the heat-shrinkable sleeve forms an effective sealing section of not less than 40mm with the outer wall of the sleeve section.

[0048] More specifically, after the casing section is installed in place, construction personnel need to symmetrically arrange temporary fixing supports on both sides of the expansion joint to axially limit the casing section and prevent it from slipping or retracting into the expansion joint due to the pressure of the grout flow during concrete pouring. By strictly controlling the extension length within the range of A≥50mm, the heat-shrinkable sleeve installed subsequently can obtain sufficient overlap allowance, thereby enabling the present invention to form a continuous and reliable sealing structure at the expansion joint, effectively blocking the channel for leakage of radioactive media or cooling water along the outer wall of the casing.

[0049] Currently, during synchronous concrete pouring, the sufficient overlap length between the sleeve section and the inner wall of the expansion joint prevents concrete slurry from directly penetrating to the sealing interface of the heat-shrinkable sleeve, thus significantly reducing the risk of seal failure. Simultaneously, this extended length also provides necessary space for the expansion and contraction of the wall during operation due to temperature changes, concrete creep, and radiation-induced deformation, preventing tearing or detachment of the sealing interface due to insufficient overlap length.

[0050] In one embodiment, step S300 includes: S310. Install a heat-shrinkable sleeve inside the expansion joint, and make both ends of the heat-shrinkable sleeve extend through the corresponding template layer and into the corresponding concrete pouring space.

[0051] Specifically, after completing the erection of two layers of formwork, installation of the reinforcing cage, positioning and welding of the sleeve sections, and cleaning of the expansion joint, the next step is to install a heat-shrinkable sleeve inside the expansion joint. First, the heat-shrinkable sleeve is placed on the outer walls of the opposite ends of the two precisely positioned sleeve sections. Then, by adjusting the axial position of the sleeve sections, the two ends of the heat-shrinkable sleeve are extended towards the concrete pouring space on both sides, passing through the corresponding formwork layer and entering the concrete pouring space by at least 30mm.

[0052] It should be specifically and clearly stated that, in this embodiment, the feature that both ends of the heat-shrinkable sleeve extend through the corresponding template layer and into the corresponding concrete pouring space is a key measure to ensure reliable anchoring between the sealing structure and the concrete. It can be further clarified that the length of the middle section of the heat-shrinkable sleeve within the expansion joint is adapted to the width of the expansion joint, while the length of both ends extending into the concrete pouring space is preferably controlled within the range of 40mm-60mm. This extension length allows the heat-shrinkable sleeve to form an effective mechanical interlocking and bonding interface with the concrete within the concrete pouring space after heating and shrinking.

[0053] More specifically, when installing the heat-shrinkable sleeve, a special heating tool is first used to preheat and shrink the middle of the sleeve, ensuring a tight fit against the outer wall of the sleeve section. Then, both ends are uniformly heated and shrunk to ensure that the sleeve opens in a funnel shape within the concrete pouring space. This installation method not only covers the expansion joint area but also extends its ends into the concrete pouring space on both sides, thus enabling the invention to form a continuous sealing structure that extends through the entire thickness of the wall between the sleeve section and the concrete wall.

[0054] Currently, during synchronous concrete pouring, because the ends of the heat-shrinkable sleeve extend into the concrete pouring space, the poured concrete can directly wrap around and encase both ends of the sleeve, forming an integrated anchor body with the heat-shrinkable sleeve after solidification. This structure allows the heat-shrinkable sleeve to no longer rely solely on bonding and sealing with the sleeve section, but simultaneously obtains strong constraint and protection for its ends from the concrete. This significantly improves the tensile strength and shear resistance of the sealing structure, effectively solving the technical problems of single sealing connection methods between sleeves, poor sealing performance, and easy leakage risks in existing technologies.

[0055] In one embodiment, step S310 includes: S311. Install a heat-shrinkable rubber sleeve inside the expansion joint; S312. Perform heat shrinking operation on the heat shrink sleeve, and make both ends of the heat shrink sleeve extend through the corresponding template layer and into the corresponding concrete pouring space.

[0056] Specifically, after the precise positioning of the casing sections and the cleaning of the expansion joint are completed, the first step is to install a heat-shrinkable sleeve inside the expansion joint. The construction personnel place the pre-selected heat-shrinkable sleeve at the connection between two opposing casing sections, ensuring that the center of the sleeve completely covers the expansion joint area. Then, a special clamp is used to temporarily fix the sleeve to prevent axial slippage during subsequent heating.

[0057] It should be specifically and clearly stated that, in this embodiment, the heat-shrinkable sleeve must be selected to match the outer diameter of the sleeve section and the width of the expansion joint, with a shrinkage ratio of not less than 3:1 and a wall thickness of not less than 2.5mm. It can be further clarified that, when installing the heat-shrinkable sleeve, sufficient length must be reserved at both ends of the sleeve so that, after heat shrinkage, it can naturally extend through the corresponding template layer and enter the concrete pouring space by at least 35mm.

[0058] More specifically, after the initial installation of the heat-shrinkable sleeve, a heat-shrinking operation is immediately performed. A medium-temperature hot air gun or a dedicated electric heating element is used to heat the sleeve evenly and in sections along its circumference, controlling the heating temperature between 120℃ and 160℃. First, the middle section of the sleeve is shrunk and fixed, then gradually pushed towards both ends. During the heat-shrinking process, the axial position of the sleeve section is continuously adjusted so that both ends of the shrunk sleeve can simultaneously extend through the formwork layer and enter the corresponding concrete pouring space. Through this heat-shrinking operation, the heat-shrinkable sleeve can form a tight radial clamping force with the outer wall of the sleeve section, while its ends are subsequently wrapped and anchored by concrete as they enter the concrete pouring space.

[0059] Currently, during concrete pouring, because the two ends of the heat-shrinkable sleeve extend into the concrete pouring space, the poured concrete can directly form a mechanical and chemical bonding interface with the sleeve ends. This structure allows the heat-shrinkable sleeve to no longer rely solely on radial shrinkage sealing with the sleeve section, but simultaneously obtains axial constraint and radial protection of its ends by the concrete. Consequently, this invention can significantly improve the overall stability and pull-out resistance of the sealing structure, effectively solving the technical problems of heat-shrinkable sleeves easily shifting due to concrete pouring disturbances, easy detachment of the sealing interface, and insufficient sealing reliability in the prior art.

[0060] In one embodiment, the step of simultaneously pouring concrete into the two concrete pouring spaces to complete the construction of the nuclear island building walls includes: Concrete is poured into the two concrete pouring spaces simultaneously, and both ends of the heat-shrinkable sleeve are embedded in the corresponding concrete pouring spaces to complete the construction of the nuclear island plant wall.

[0061] Specifically, after the installation and heat shrinking of the heat shrink sleeves are completed, the next step is to simultaneously pour concrete into the two concrete pouring spaces. Construction workers simultaneously deploy multiple concrete pump trucks in both concrete pouring spaces, employing a symmetrical, layered pouring method, advancing from the bottom of the wall upwards. Each layer is controlled to a thickness of 300mm-400mm, ensuring that the pouring surfaces on both sides remain at the same elevation within ±20mm. During the pouring process, a vibrator is used to focus on compacting the concrete around both ends of the heat shrink sleeves, ensuring that both ends of the heat shrink sleeves are completely embedded in the corresponding concrete pouring spaces to a depth of not less than 45mm.

[0062] It should be specifically and clearly stated that, in this embodiment, the feature of simultaneously pouring concrete into the two concrete pouring spaces and embedding both ends of the heat-shrinkable sleeve within the corresponding concrete pouring spaces is a key parameter to ensure that the sealing structure and the wall concrete form an integral whole. It can be further clarified that the embedment depth of the heat-shrinkable sleeve end in the concrete is preferably 50mm-70mm. This range is the minimum effective value determined after considering the concrete flow characteristics, the stiffness of the sleeve material after shrinkage, and the seismic requirements of the nuclear island plant.

[0063] More specifically, during synchronous pouring, the concrete temperature, slump, and pouring rate on both sides must be strictly controlled to ensure that the lateral pressure on both sides of the formwork is basically balanced. Before the concrete initially sets, the end area of ​​the heat-shrinkable sleeve is continuously vibrated a second time to ensure that the concrete slurry fully fills all gaps between the sleeve end and the reinforcing steel. Through this pouring method, both ends of the heat-shrinkable sleeve can be completely wrapped by concrete to form a dense interface transition layer, thereby enabling the present invention to establish a continuous concrete anchor body on both sides of the expansion joint.

[0064] Currently, during concrete curing, because the ends of the heat-shrinkable sleeve are reliably embedded in the concrete pouring space, the shrinkage stress generated by the concrete during solidification can be evenly transmitted to the ends of the sleeve, avoiding sleeve displacement or interface debonding caused by pressure difference during unilateral pouring. This synchronous pouring and embedding method significantly improves the integrity of the sealing structure, enabling the heat-shrinkable sleeve to not only form a radial seal with the sleeve section, but also to form a double anchoring with the concrete on both sides in the axial and radial directions. Consequently, this invention can effectively resist the combined stress generated by temperature gradient, concrete creep, and radiation-induced deformation of the wall during operation, solving the technical problems of stress concentration at the sealing interface, easy formation of micro-cracks, and leakage channels caused by asynchronous pouring in the prior art.

[0065] In one embodiment, step S100 includes: S110. Install a sheet metal tin in the pre-designed construction area; S120. The template is fastened onto the sheet metal; wherein the sheet metal extends into the concrete pouring space; S130. The I-beams are supported on the side of the template away from the concrete pouring space to form the template layer.

[0066] Specifically, when setting up the formwork layer in the pre-designed construction area, the first step is to install a sheet metal sheet in the pre-designed construction area. Based on the design elevation of the nuclear island plant wall and the reserved location of the expansion joints, the sheet metal sheet is vertically hoisted into the center plane of the pre-designed construction area. Expansion bolts are used to reliably fix its bottom to the base plate, and a laser plumb line is used to calibrate its verticality deviation to within 1 / 1000, ensuring that symmetrical concrete pouring spaces are formed on both sides of the sheet metal sheet.

[0067] It should be specifically and clearly stated that, in this embodiment, the length of the galvanized iron sheet extending into the concrete pouring space is preferably 40mm-60mm. This parameter is the minimum effective value determined after comprehensively considering the requirements for embedding the heat-shrinkable sleeve end, the concrete flow path, and the lateral pressure of the formwork. It can be further clarified that the thickness of the galvanized iron sheet is 0.8mm, and the surface is treated with rust prevention to ensure that it does not deform or corrode and contaminate the concrete interface during the pouring process.

[0068] More specifically, after the galvanized iron sheet is installed, the template is clamped onto it, and special clamps are used to ensure a tight fit between the template edges and the galvanized iron sheet, preventing gaps during pouring. Then, the I-beams are erected on the side of the template away from the concrete pouring space, arranged vertically at intervals no greater than 600mm. Tie rods and diagonal braces are used to connect the I-beams to the template and external scaffolding, forming a template layer with sufficient rigidity. Through this sequential construction, the galvanized iron sheet not only serves as the installation reference for the template layer but also extends a portion of its length into the concrete pouring space, providing a smooth interface for the accurate positioning of the heat-shrinkable sleeve ends and the subsequent concrete wrapping.

[0069] Currently, during synchronous concrete pouring, because the galvanized iron sheet extends into the concrete pouring space, the concrete can flow naturally along the ends of the galvanized iron sheet and fully wrap around both ends of the heat-shrinkable sleeve, forming a dense interlocking zone after solidification. This structure effectively avoids the problem of unclear boundaries caused by direct contact between the formwork and the expansion joint, allowing the ends of the heat-shrinkable sleeve to receive uniform concrete covering pressure. Consequently, this invention can significantly improve the overall continuity and impermeability of the sealing structure, effectively solving the technical problems of low formwork layer erection accuracy, easy misalignment of the expansion joint interface, and hollowing and leakage of the sealing interface caused by concrete pouring disturbance in the prior art.

[0070] In one embodiment, before the step of supporting the I-beam on the side of the formwork away from the concrete pouring space and forming the formwork layer, the method further includes: Wooden blocks are placed in the pre-designated construction area; wherein the wooden blocks are spaced apart from the template, and the wooden blocks are placed on the side of the sheet metal away from the concrete pouring space; The step of supporting the I-beams on the side of the formwork away from the concrete pouring space to form the formwork layer includes: The I-beams are placed on top of the pads and secured with high-strength bolts to form the template layer.

[0071] Specifically, when erecting the formwork layer, wooden blocks are first placed in the pre-designated construction area. Based on the wall design elevation and expansion joint width requirements, wooden blocks of 100mm×100mm×200mm are evenly placed at 800mm-1000mm intervals on the side of the galvanized iron sheet away from the concrete pouring space. This ensures that each wooden block is spaced apart from the subsequent formwork position, and that the bottom surface of the wooden block is in close contact with the top surface of the galvanized iron sheet without any obvious gaps.

[0072] It should be specifically and clearly stated that, in this embodiment, the wooden blocks are spaced apart from the formwork, and the wooden blocks are placed on the side of the sheet metal away from the concrete pouring space. This feature provides a stable reference plane for the subsequent precise erection of the I-beams. It can be further clarified that, in this embodiment, the top surface elevation of the wooden blocks must be strictly controlled using a laser level, with a height deviation not exceeding 2mm, to ensure that the overall flatness of the formwork layer meets the construction specifications for the nuclear island plant.

[0073] More specifically, after the pads are placed, the I-beams are supported on top of the pads and secured with high-strength bolts to form the template layer. In practice, the I-beams are first placed vertically in the center of the top surface of the pads. Then, high-strength bolts with a diameter of at least 16mm are used to pass through the template, sheet metal, pads, and flanges of the I-beams, and are tightened symmetrically in stages with nuts to form a rigid whole. Through this construction sequence, the pads not only adjust the elevation and transfer loads, but also, together with the I-beams, form a stable back support system, ensuring that the template does not shift during concrete pouring.

[0074] Currently, during synchronous concrete pouring, because the wooden blocks are spaced apart from the formwork and placed on the back of the galvanized iron sheet, the I-beams can evenly transfer lateral pressure to the galvanized iron sheet and external scaffolding through the wooden blocks, avoiding bulging or misalignment of the formwork due to uneven local stress. This structure significantly improves the overall rigidity of the formwork layer, and the relative position between the ends of the galvanized iron sheet and the heat-shrinkable sleeve remains stable throughout the pouring process. This allows the invention to ensure that both ends of the heat-shrinkable sleeve are evenly wrapped and embedded in concrete, effectively solving the technical problems of easy deformation of the formwork support system, low interface control accuracy in the expansion joint area, and sealing failure caused by easy displacement of sealing components during concrete pouring in existing technologies.

[0075] In one embodiment, the step of attaching the template to the galvanized iron sheet includes: The template is snapped onto the sheet metal, and the sheet metal is anchored to the template using rivets.

[0076] Specifically, after the installation of the sheet metal in the pre-designed construction area is completed, the template is immediately attached to the sheet metal. Construction workers precisely attach the corrosion-resistant steel or wooden template along both sides of the sheet metal, ensuring a tight fit between the template edges and the sheet metal. Then, using a specialized rivet gun, aluminum or stainless steel rivets are arranged in a double-row, staggered pattern along the length of the template, reliably anchoring the sheet metal and the template together.

[0077] It should be specifically and clearly stated that, in this embodiment, the method of anchoring the galvanized iron sheet to the template using rivets can effectively resist the lateral pressure and vibration load generated during the concrete pouring process.

[0078] More specifically, when engaging the template and the sheet metal and anchoring it with rivets, a laser plumb line and a straightedge must be used to calibrate the verticality and flatness of the template in real time, ensuring that the deviations are controlled within 1 / 1000 and 2mm respectively. Through this construction method, the sheet metal and the template form a rigid connection, providing a stable installation benchmark for the subsequent erection of wooden supports and I-beams, and keeping their ends fixed within the concrete pouring space. This, in turn, allows the ends of the heat-shrinkable sleeve to obtain precise positioning space during subsequent pouring.

[0079] Currently, during synchronous concrete pouring, the galvanized iron sheet and formwork are reliably anchored by rivets, preventing local bulging or misalignment of the formwork layer under lateral pressure. This ensures the flatness of the concrete pouring surfaces on both sides of the expansion joint and precise control of the expansion joint width. This structure allows the ends of the heat-shrinkable sleeve to be evenly wrapped by concrete, avoiding sleeve eccentricity or insufficient embedment depth caused by formwork displacement. Consequently, this invention significantly improves the density and bonding strength of the sealing interface, effectively solving the technical problems of weak connection between the formwork and the isolation layer, easy displacement, resulting in concrete interface misalignment and deviation in the embedment position of the sealing components in the prior art.

[0080] The above description is merely an exemplary embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent structural transformations made based on the technical concept of the present invention and the contents of the specification and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the protection scope of the present invention.

Claims

1. A construction method for the wall of a nuclear island plant with through-wall sleeves, characterized in that, Includes the following steps: Two radially distributed template layers are erected in the pre-designed construction area; each template layer contains a concrete pouring space, and an expansion joint is formed between the two template layers. A sleeve section is installed in each of the two template layers; wherein, both sleeve sections penetrate the corresponding concrete pouring space and extend out of the corresponding template layer; A heat-shrinkable sleeve is installed inside the expansion joint; wherein, both ends of the heat-shrinkable sleeve are respectively sealed and connected to one of the sleeve sections; Concrete is poured into the two concrete pouring spaces simultaneously to complete the construction of the nuclear island plant wall.

2. The construction method for the nuclear island plant wall with through-wall sleeves as described in claim 1, characterized in that, The step of installing a sleeve section in each of the two template layers includes: A steel cage is installed in each of the two template layers; A sleeve section is installed inside the reinforcing cage; wherein each sleeve section is welded to the corresponding reinforcing cage, and each sleeve section extends out of the template layer and into the expansion joint.

3. The construction method for the nuclear island plant wall with through-wall sleeves as described in claim 2, characterized in that, Before the step of installing one of the sleeve sections inside the reinforcing cage, the method further includes: An installation groove is formed on the steel cage; The step of installing one of the sleeve sections inside the reinforcing cage includes: Install one of the sleeve sections on the mounting slot.

4. The construction method for the nuclear island plant wall with through-wall sleeves as described in claim 3, characterized in that, The length of the sleeve section extending from the corresponding template layer into the expansion joint is A, where A ≥ 50 mm.

5. The construction method for the nuclear island plant wall with through-wall sleeves as described in claim 4, characterized in that, The step of installing a heat-shrinkable rubber sleeve inside the expansion joint includes: A heat-shrinkable sleeve is installed inside the expansion joint, with both ends of the heat-shrinkable sleeve extending through the corresponding template layer and into the corresponding concrete pouring space.

6. The construction method for the wall of a nuclear island plant with through-wall sleeves as described in claim 5, characterized in that, The step of installing a heat-shrinkable sleeve within the expansion joint, ensuring that both ends of the heat-shrinkable sleeve extend through the corresponding template layer and into the corresponding concrete pouring space, includes: Install a heat-shrinkable rubber sleeve inside the expansion joint; The heat-shrinkable sleeve is heat-shrinked so that both ends of the heat-shrinkable sleeve extend through the corresponding template layer and into the corresponding concrete pouring space.

7. The construction method for the nuclear island plant wall with through-wall sleeves as described in claim 6, characterized in that, The step of simultaneously pouring concrete into the two concrete pouring spaces to complete the construction of the nuclear island plant wall includes: Concrete is poured into the two concrete pouring spaces simultaneously, and both ends of the heat shrink sleeve are embedded in the corresponding concrete pouring spaces to complete the construction of the nuclear island plant wall.

8. The construction method for the nuclear island plant wall with through-wall sleeves as described in claim 7, characterized in that, The step of erecting two radially distributed template layers in the pre-designated construction area includes: Install a sheet metal unit in the pre-designated construction area; The template is attached to the sheet metal; wherein the sheet metal extends into the concrete pouring space; The I-beams are supported on the side of the template away from the concrete pouring space to form the template layer.

9. The construction method for the wall of a nuclear island plant with through-wall sleeves as described in claim 8, characterized in that, Before the step of supporting the I-beam on the side of the formwork away from the concrete pouring space to form the formwork layer, the method further includes: Wooden blocks are placed in the pre-designated construction area; wherein the wooden blocks are spaced apart from the template, and the wooden blocks are placed on the side of the sheet metal away from the concrete pouring space; The step of supporting the I-beams on the side of the formwork away from the concrete pouring space to form the formwork layer includes: The I-beams are placed on top of the pads and secured with high-strength bolts to form the template layer.

10. The construction method for the wall of a nuclear island plant with through-wall sleeves as described in claim 8, characterized in that, The step of attaching the template to the sheet metal includes: The template is snapped onto the galvanized iron sheet, and the galvanized iron sheet is anchored to the template using rivets.

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