A method for installing a deep-buried grounding elongated grounding electrode in a nuclear power plant

Abstract

The application discloses a kind of nuclear power plant deep burying ground connection slender ground electrode installation construction methods, comprising the following steps: temporarily fixed support is fixedly installed on the outer wall of nuclear power plant workshop;Reinforced anchor rod is installed in the backfill layer below the lower end of ground electrode;The body of ground electrode is tied and fixed on temporarily fixed support, and the lower end of ground electrode is tied and fixed on reinforced anchor rod;Ground electrode is accepted for concealed works;From the lower end of ground electrode, backfill is carried out layer by layer upwards, the connection of temporarily fixed support and ground electrode is released layer by layer, and temporarily fixed support at the place is removed;After the height of backfill layer rises to the top end of ground electrode, lightning protection grounding well is installed at the top of ground electrode;Continue backfill until the height of backfill layer and the well lid of lightning protection grounding well are flush.The application solves the problems of complex process, large workload of traditional ground electrode installation construction method, and the problem that ground resistance increases due to the fact that ground electrode and backfill layer are not in close contact, which affects the grounding effect.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, specifically to a method for installing a slender grounding electrode for deep burial in a nuclear power plant.

[0002] Background Method

[0003] In the construction of deep-buried grounding circuits in nuclear power plants, the grounding electrodes in the lightning protection grounding wells are typically bare copper rods up to 7 meters long with a cross-section of 185 square millimeters. This length far exceeds the general design requirement of 2.5 meters for vertical grounding electrodes in grounding specifications, making it an ultra-long and slender structure. Due to its small diameter and large length, it cannot be directly driven into the ground. Traditional construction methods require pre-burying pipes or drilling holes in the backfill layer of the foundation pit around the nuclear island plant. After the pipes are pulled out or the holes are drilled, the grounding electrode is installed, and then backfill material or resistance-reducing agent is poured into the hole to ensure close contact between the grounding electrode and the soil and reduce grounding resistance. This construction method is not only complicated and labor-intensive, but also has the potential quality hazard of insufficient compaction, which may prevent the grounding electrode from being completely wrapped by the backfill material or resistance-reducing agent, thus increasing the grounding resistance and affecting the grounding effect. Summary of the Invention

[0004] The purpose of this invention is to provide a method for installing a slender grounding electrode for deep burial in nuclear power plants, in order to solve the problems of complex procedures, large workload, and poor contact between the grounding electrode and the backfill layer, which leads to increased grounding resistance and affects the grounding effect.

[0005] To achieve the above objectives, the method provided by this invention is as follows:

[0006] A method for installing a slender, deeply buried grounding electrode in a nuclear power plant is provided, including the following steps:

[0007] Temporary fixing brackets are fixedly installed on the outer wall of the nuclear power plant building; steel anchor rods are installed in the backfill layer below the lower end of the grounding electrode on the outer side of the nuclear power plant building; the temporary fixing brackets are higher than the backfill layer below the lower end of the grounding electrode.

[0008] The grounding electrode body is tied and fixed to a temporary fixing bracket, and the lower end of the grounding electrode is tied and fixed to a steel anchor rod, and the grounding electrode remains vertical after tying; the temporary fixing bracket includes at least two temporary fixing brackets of different heights;

[0009] Conduct concealed works acceptance inspection of the grounding electrode;

[0010] Starting from the bottom of the grounding electrode, backfilling is carried out layer by layer upwards. As the height of the backfill layer increases, the connection between the temporary fixing support and the grounding electrode is disconnected layer by layer at the height reached, and the temporary fixing support at that point is removed, until all the temporary fixing supports are removed.

[0011] When the backfill layer rises to the top of the grounding electrode, install a lightning protection grounding well at the top of the grounding electrode;

[0012] Continue backfilling until the backfill layer is level with the cover of the lightning protection grounding well.

[0013] To optimize the above method, the specific limitations also include:

[0014] The temporary fixing bracket includes a first temporary fixing bracket that is tied to the middle of the grounding electrode body and a second temporary fixing bracket that is tied to the upper part of the grounding electrode body.

[0015] Furthermore, one end of the temporary fixed bracket is fixed to the waterproof layer protective brick wall of the outer wall of the nuclear power plant building, and the other end is fixed to the grounding electrode by steel bar binding wire.

[0016] The temporary fixed support includes a support base plate and a support body. The support body is an angle steel, and its rear end face is vertically welded and fixed to the support base plate. The support base plate has standard holes for fixing the support base plate to the waterproof layer protective brick wall of the outer wall of the nuclear power plant building with expansion bolts.

[0017] The steel anchor rod is installed vertically in the backfill layer below the lower end of the grounding electrode, and its top extends out of the backfill layer below the lower end of the grounding electrode.

[0018] Furthermore, two-thirds of the length of the steel anchor rod is installed in the backfill layer below the lower end of the grounding electrode, and each binding point of the grounding electrode and the temporary fixing bracket corresponds vertically to each binding point of the grounding electrode and the steel anchor rod in the vertical direction.

[0019] The acceptance of concealed works includes the acceptance of the plane position, elevation and installation and fixing of the grounding electrode.

[0020] Preferably, the vertical spacing between adjacent temporary fixed supports is 2.5~3.5m.

[0021] Furthermore, space is provided between the highest temporary fixed support and the outdoor ground surface to install a lightning protection grounding well and to ensure the distance between the grounding electrode and the outdoor ground surface.

[0022] The top of the grounding electrode is buried at a depth of 1m below the outdoor ground surface.

[0023] Compared with existing methods, the beneficial effects of the present invention are:

[0024] This invention provides a method for installing slender grounding electrodes for deep-buried grounding in nuclear power plants. By backfilling the foundation pit in layers, the slender grounding electrodes are brought into close contact with the backfill layer, ensuring a reduction in grounding resistance and improving the electrical reliability of the deep-buried grounding system. In addition, the slender grounding electrodes are rigidly fixed by both temporary fixing brackets and steel anchor rods, ensuring that they maintain verticality, design spacing, and design elevation during the backfilling process. Furthermore, the temporary fixing brackets are removed layer by layer as the backfill layer height increases, effectively preventing quality hazards such as bending and displacement of the slender grounding electrodes. Attached Figure Description

[0025] Figure 1 : Schematic diagram of the installation of the elongated grounding electrode for deep-buried grounding of the nuclear island according to the present invention.

[0026] Figure 2 View AA in the schematic diagram of the installation of the elongated grounding electrode for deep-buried grounding of the nuclear island of the present invention.

[0027] In the diagram: 1-Waterproof layer protecting the brick wall, 2-Temporary fixing bracket, 3-Grounding electrode, 4-Rebar binding wire, 5-Backfill layer, 6-Rebar anchor rod, 7-Expansion bolt, 8-Lightning protection grounding well. Detailed Implementation

[0028] This invention provides a method for installing a slender, deeply buried grounding electrode in a nuclear power plant, comprising the following steps:

[0029] Temporary fixing brackets 2 are fixedly installed on the waterproof layer protective brick wall 1 of the outer wall of the nuclear power plant building; steel anchor rods 6 are installed in the backfill layer 5 below the lower end of the grounding electrode on the outer side of the outer wall of the nuclear power plant building; the temporary fixing brackets 2 are higher than the backfill layer below the lower end of the grounding electrode 3.

[0030] The grounding electrode 3 is tied and fixed to the temporary fixing bracket 2, and the lower end of the grounding electrode 3 is tied and fixed to the steel anchor rod 6, and the grounding electrode 3 remains vertical after tying; the temporary fixing bracket 2 includes at least two temporary fixing brackets 2 with different heights;

[0031] Conduct concealed works acceptance inspection on grounding electrode 3;

[0032] Starting from the bottom of the grounding electrode 3, backfilling is carried out layer by layer upwards. As the height of the backfill layer 5 increases, the connection between the temporary fixing bracket 2 and the grounding electrode 3 is disconnected layer by layer at the height reached, and the temporary fixing bracket 2 at that point is removed until all the temporary fixing brackets 2 are removed.

[0033] When the height of the backfill layer 5 rises to the top of the grounding electrode 3, install the lightning protection grounding well 8 on the top of the grounding electrode 3;

[0034] Continue backfilling until the height of backfill layer 5 is level with the manhole cover of lightning protection grounding well 8.

[0035] like Figure 1 As shown, the temporary fixing bracket 2 includes a first temporary fixing bracket tied to the middle of the grounding electrode 3 and a second temporary fixing bracket tied to the upper part of the grounding electrode 3. The vertical distance between adjacent temporary fixing brackets 2 is 2.5~3.5m to ensure that the grounding electrode 3 does not bend after installation and fixing.

[0036] One end of the temporary fixed bracket 2 is fixed to the waterproof layer protective brick wall 1 of the outer wall of the nuclear power plant building, and the other end is fixed to the grounding electrode 3 by steel bar binding wire 4.

[0037] like Figure 2 As shown, the temporary fixed support 2 includes a support base plate 21 and a support body 22. The support body 22 is an angle steel, and its rear end face is vertically welded and fixed to the support base plate 21. The support base plate 21 has standard holes for fixing the support base plate 21 to the waterproof layer protective brick wall 1 of the outer wall of the nuclear power plant building through expansion bolts 7, so as to ensure that the grounding electrode 3 together with the temporary fixed support 2 is fixed and stable.

[0038] A space is provided between the highest temporary fixed support 2 and the outdoor ground surface to allow for the installation of a lightning protection grounding well 8 and to ensure the distance between the grounding electrode 3 and the outdoor ground surface.

[0039] The top of the grounding electrode 3 is buried at a depth of 1m below the outdoor ground surface. The grounding electrode 3 will not fluctuate due to changes in the shallow surface environment, ensuring the sustainability of the system. At the same time, it also provides sufficient operating space for the installation and foundation treatment of the lightning protection grounding well 8, ensuring the reliability of the connection point and facilitating future maintenance.

[0040] The steel anchor rod 6 is installed vertically in the backfill layer 5 below the lower end of the grounding electrode 3, with its top extending out of the backfill layer below the grounding electrode 3, and is used to tie and fix the lower end of the grounding electrode 3.

[0041] Two-thirds of the length of the steel anchor rod 6 is installed in the backfill layer 5 below the lower end of the grounding electrode 3 to provide a stable lateral support point, ensuring that the lower end of the grounding electrode 3 will not shift or swing in the horizontal direction after being tied and fixed, and together with the temporary fixing bracket 2 above, it forms a stable support.

[0042] Each binding point of the grounding electrode 3 and the temporary fixing bracket 2 corresponds vertically to each binding point of the grounding electrode 3 and the steel anchor rod 6 in the vertical direction, so that the grounding electrode 3 is in a vertical state after installation and fixing, so as to ensure that the grounding electrode 3 is subjected to uniform force when backfilling the backfill layer 5 and avoid bending deformation.

[0043] The acceptance of concealed works includes the acceptance of the plane position, elevation and installation and fixing of grounding electrode 3, to ensure that the installation of grounding electrode 3 complies with the design specifications and effectively identify possible installation defects.

[0044] The technical solution of the present invention will be further described below with reference to specific embodiments:

[0045] According to the design location and elevation requirements, a prefabricated temporary fixing bracket 2 is constructed. The main body 22 of the bracket is made of ∠40×4 angle steel with a length of 1.6m, and the base plate 21 is a steel plate with specifications of 200×60×4. Expansion bolts 7 are used to fix the temporary fixing bracket 2 to the waterproof layer protective brick wall 1 of the outer wall of the nuclear power plant building. The temporary fixing brackets 2 are located at different heights, with a vertical spacing of 3m between adjacent temporary fixing brackets 2. Reinforcing bar anchors 6 are installed in the backfill layer 5 below the lower end of the grounding electrode 3 on the outer side of the nuclear power plant building's outer wall. Two-thirds of the length of the reinforcing bar anchors 6 is installed in the backfill layer 5 below the lower end of the grounding electrode 3. The temporary fixing bracket 2 is higher than the backfill layer 5 below the lower end of the grounding electrode 3. The first temporary fixing bracket and the middle part of the grounding electrode 3, the second temporary fixing bracket and the upper part of the grounding electrode 3, and the bottom of the reinforcing bar anchors 6 are respectively tied and fixed using reinforcing bar binding wire 4. The grounding electrode 3... Three bare copper rods, each 7m long and 185mm² in cross-section, are used. The first temporary fixing bracket is located 3m above the lower end of the grounding electrode 3. The top of the grounding electrode 3 is buried at a depth of 1m below the outdoor ground surface. Then, the planar position, elevation, and installation and fixing of the grounding electrode 3 are inspected for concealed works. After the concealed works of the grounding electrode 3 area are inspected and approved, the area above the backfill layer 5 below the lower end of the grounding electrode 3 is manually backfilled according to the progress of the backfilling of the foundation pit around the factory. As the height of the backfill layer 5 rises, the connection between the temporary fixing bracket 2 and the grounding electrode 3 is disconnected layer by layer at the height reached, and the temporary fixing bracket 2 at that point is removed until all the temporary fixing brackets 2 are removed. When the height of the backfill layer 5 rises to the top of the grounding electrode 3, the lightning protection grounding well 8 is installed on the top of the grounding electrode 3. Backfilling continues until the height of the backfill layer 5 is level with the cover of the lightning protection grounding well 8.

[0046] The construction method of this invention achieves precise installation and efficient construction of the grounding electrode through the synergistic effect of temporary fixed supports and steel anchor rods. Compared with existing technologies, this invention can utilize scrap steel materials such as angle steel, steel plates, and steel bars to make supports and anchor rods, making the materials readily available and easy to process and install, significantly reducing construction costs. Simultaneously, this method avoids the cumbersome procedures of burying, pulling, or drilling pipes in traditional construction, as well as the potential for incomplete wrapping when injecting backfill or resistance-reducing agents, ensuring that the grounding electrode is tightly wrapped by the backfill material, thereby effectively reducing grounding resistance and improving construction quality. Furthermore, this method involves fewer installation steps, higher work efficiency, and simpler operation, falling under the category of green construction. While improving construction quality, it significantly reduces project costs and accelerates the progress of the main project.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent substitutions, and improvements made by those skilled in the art to the above embodiments without departing from the scope of the present invention and based on the essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method of installing a deep-buried grounding elongated grounding electrode for a nuclear power plant, characterized by, Includes the following steps: A temporary fixing bracket (2) is fixedly installed on the outer wall of the nuclear power plant building; a steel anchor rod (6) is installed in the backfill layer (5) below the lower end of the grounding electrode (3) on the outer side of the nuclear power plant building; the temporary fixing bracket (2) is higher than the backfill layer (5) below the lower end of the grounding electrode (3); The electrode body of the grounding electrode (3) is tied and fixed to the temporary fixing bracket (2), and the lower end of the grounding electrode (3) is tied and fixed to the steel anchor rod (6), and the grounding electrode (3) remains vertical after tying; the temporary fixing bracket (2) includes at least two temporary fixing brackets (2) of different heights. Conduct concealed works acceptance inspection on the grounding electrode (3); Starting from the bottom of the grounding electrode (3), backfilling is carried out layer by layer upwards. As the height of the backfill layer (5) increases, the connection between the temporary fixed support (2) and the grounding electrode (3) at the height reached is gradually disconnected, and the temporary fixed support (2) at that point is removed until all the temporary fixed supports (2) are removed. When the height of the backfill layer (5) rises to the top of the grounding electrode (3), a lightning protection grounding well (8) is installed on the top of the grounding electrode (3). Continue backfilling until the height of the backfill layer (5) is level with the cover of the lightning protection grounding well (8).

2. The method of installing a deep ground bed elongated grounding electrode for a nuclear power plant according to claim 1, characterized in that: The temporary fixing bracket (2) includes a first temporary fixing bracket tied to the middle of the grounding electrode (3) and a second temporary fixing bracket tied to the upper part of the grounding electrode (3).

3. The method for installing a slender, deeply buried grounding electrode in a nuclear power plant according to claim 1, characterized in that: One end of the temporary fixed bracket (2) is fixed to the waterproof layer protective brick wall (1) of the outer wall of the nuclear power plant building, and the other end is tied to the grounding electrode (3) by steel bar binding wire (4).

4. The method for installing a slender, deeply buried grounding electrode in a nuclear power plant according to claim 3, characterized in that: The temporary fixed support (2) includes a support base plate (21) and a support body (22). The support body (22) is an angle steel, and its rear end face is vertically welded and fixed on the support base plate (21). The support base plate (21) has standard holes for fixing the support base plate (21) to the waterproof layer protective brick wall (1) of the outer wall of the nuclear power plant building by means of expansion bolts (7).

5. The method for installing a slender, deeply buried grounding electrode in a nuclear power plant according to claim 1, characterized in that: The steel anchor rod (6) is vertically installed in the backfill layer (5) below the lower end of the grounding electrode (3), and its top extends out of the backfill layer (5) below the lower end of the grounding electrode (3).

6. The method for installing a slender, deeply buried grounding electrode in a nuclear power plant according to claim 1, characterized in that: Two-thirds of the length of the steel anchor rod (6) is installed in the backfill layer (5) below the lower end of the grounding electrode (3). The binding points of the grounding electrode (3) and the temporary fixing bracket (2) are vertically aligned with the binding points of the grounding electrode (3) and the steel anchor rod (6) in the vertical direction.

7. The method for installing a slender, deeply buried grounding electrode in a nuclear power plant according to claim 1, characterized in that: The acceptance of the concealed works includes the acceptance of the plane position, elevation and installation and fixing of the grounding electrode (3).

8. The method for installing a slender, deeply buried grounding electrode in a nuclear power plant according to claim 1, characterized in that: The vertical distance between adjacent temporary fixed supports (2) is 2.5~3.5m.

9. The method for installing a slender, deeply buried grounding electrode in a nuclear power plant according to claim 1, characterized in that: The highest temporary fixed support (2) and the outdoor ground surface shall be provided with space for the installation of lightning protection grounding well (8) and to ensure the distance between the grounding electrode (3) and the outdoor ground surface.

10. The method for installing a slender, deeply buried grounding electrode in a nuclear power plant according to claim 9, characterized in that: The top of the grounding electrode (3) is buried at a depth of 1m below the outdoor ground surface.

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