A method for grouting a narrow cavity of a stainless steel pool wall in a nuclear power plant

Abstract

The present invention discloses a method for grouting a narrow and long cavity of a nuclear power plant stainless steel pool wall. Inclined stainless steel pipes for grouting the cavity of the nuclear power plant pool wall are buried in the pool wall concrete at intervals along the height of the nuclear power plant pool wall to form a plurality of grouting cavity sections; groove structures on both sides of the nuclear power plant pool wall cavity, stainless steel pool steel covering panels and anchors are installed to form a narrow and long cavity of the nuclear power plant pool wall with an irregular inner cross-section; grouting is performed from bottom to top from each stainless steel pipe into the cavity of the nuclear power plant pool wall; the last grouting cavity section is left at the top of the nuclear power plant pool wall cavity, and grouting is performed in small amounts and multiple times from the top. The scheme of the present invention solves the problems in the existing grouting construction of the narrow and long cavity of the nuclear power plant stainless steel pool wall with high height and strict requirements, especially for the stainless steel pool wall with high height that does not conform to the theoretical vertical structure, reducing the construction difficulty and improving the construction quality, safety and construction efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear power plant construction, and in particular to a method for grouting a narrow and long cavity of a stainless steel pool wall of a nuclear power plant. Background Art

[0002] The stainless steel water pool of a nuclear power plant needs to be filled with enough water and prevent the leakage of radioactive liquid. A water pool steel covering as a stainless steel lining structure is laid on the concrete surface of the water pool of the nuclear power plant. The water pool steel covering ensures the sealing of the water pool. Therefore, for the installation of the steel covering of the water pool of the nuclear power plant, a matching installation structure with better sealing and stability is required, as well as dense concrete grouting in the inner cavity of the steel covering of the water pool of the nuclear power plant to achieve the anchoring of the stainless steel covering and the concrete structure.

[0003] The height of the cavity in the stainless steel pool of a nuclear power plant is relatively high, usually more than 10m. The cavity is located in the plaster layer of the pool wall, and the thickness of the plaster layer is 50~60mm. After the construction of the stainless steel pool covering the pool wall is completed, the narrow cavity needs to be grouted to achieve the function of anchoring the stainless steel covering and the concrete structure. At present, the common grouting method for the narrow cavity is to use a hose to penetrate the bottom of the cavity, and then flow the grouting material and water mixed slurry into the top. However, due to the large height of the narrow cavity, there will be slurry segregation, inability to grout densely, and hose clogging. Problems, which bring great progress and quality risks to the construction; and due to the high height of the cavity in the stainless steel pool, it is impossible to fully guarantee verticality during construction, and the overall displacement deviation is large. After construction, the inner wall of the cavity is irregular in shape. It is difficult to achieve uniform density in all parts using the existing grouting method, which affects the sealing and stability of the stainless steel pool of the nuclear power plant. Summary of the invention

[0004] The purpose of the present invention is to provide a method for grouting a narrow and long cavity of a stainless steel water pool wall in a nuclear power plant, which can effectively solve the problems of grouting segregation, inability to grout densely and blockage in the narrow and long cavity, and ensure the safety of the stainless steel water pool in the nuclear power plant.

[0005] The present invention is achieved through the following technical solutions:

[0006] A method for grouting a narrow cavity of a stainless steel pool wall in a nuclear power plant comprises the following steps:

[0007] During the construction of the nuclear power plant pool wall concrete, stainless steel pipes for grouting the nuclear power plant pool wall cavity are buried in the pool wall concrete at intervals along the height direction of the nuclear power plant pool wall to form a number of grouting cavity sections;

[0008] The stainless steel pipe buried in the pool wall concrete is set obliquely, with its outer end extending out of the pool wall concrete and its inner end penetrating into the pool wall cavity of the nuclear power plant pool; the distance that the inner end of the obliquely set stainless steel pipe penetrates into the pool wall cavity of the nuclear power plant pool is controlled to be within a set range;

[0009] Install the stainless steel pool steel covering matching structure, including the groove structure on both sides of the nuclear power plant pool wall cavity, the stainless steel pool steel covering panels and anchors, install the stainless steel pool steel covering panels on the outside of the groove structure on both sides of the nuclear power plant pool wall cavity, and install anchors on the inside of the stainless steel pool steel covering panels and between the groove structures on both sides to form a narrow and long cavity of the nuclear power plant pool wall with an irregular inner cross-section;

[0010] Grouting is performed from bottom to top through the inclined stainless steel pipes into the cavity of the water pool wall of the nuclear power plant. After the slurry in each grouting cavity section is initially solidified, the upper stainless steel pipe continues to grout into the cavity of the water pool wall of the nuclear power plant;

[0011] The topmost inclined stainless steel pipe is spaced apart from the top of the nuclear power plant pool wall cavity to form the last grouting cavity section. The grouting of the last grouting cavity section is performed by vertically inserting a stainless steel pipe into the bottom of the last grouting cavity section, and grouting is performed in small amounts and multiple times from the top of the stainless steel pipe to complete the grouting of the narrow and long cavity.

[0012] To optimize the above technical solutions, the specific measures taken also include:

[0013] The stainless steel pipes are buried in the middle of the pool wall cavity of the nuclear power plant, and the stainless steel pipes buried in the pool wall concrete are evenly spaced and inclined and parallel.

[0014] The groove structures on both sides of the pool wall cavity of the nuclear power plant water pool are respectively composed of a first angle steel and a second angle steel in opposite directions. The first angle steel is arranged outward, one side of the first angle steel is attached to the pool wall concrete, and the other side is attached to one side of the second angle steel. The second angle steel is arranged inward, and the other side of the second angle steel is attached to the stainless steel pool steel covering panel. The groove structures on both sides are arranged symmetrically.

[0015] The stainless steel pool steel covering panel consists of a left steel covering and a right steel covering; the anchor comprises a channel steel and a steel plate, the channel steel is arranged toward the stainless steel pool steel covering panel, the left wing end of the channel steel is fixed to the left steel covering, and the right wing end is fixed to the right steel covering; the steel plate is fixed to the web of the channel steel.

[0016] The distance that the inner end of the stainless steel pipe that is controlled to be inclined penetrates into the cavity of the nuclear power plant pool wall is within a set range. The embedding is first completed by controlling the inner end of the stainless steel pipe to penetrate into the cavity to a distance slightly greater than the set range, and the distance that the inner end of the stainless steel pipe penetrates into the cavity is checked. The inner end of the stainless steel pipe is polished to control the final distance that the inner end of the buried stainless steel pipe penetrates into the cavity to be within the set range.

[0017] During grouting, a grouting bucket is provided at the outer end of the stainless steel pipe, and a mechanical stirring device is used to evenly stir water and grouting material to form a slurry, and grouting is performed from the grouting bucket; preferably, the crushed stone particle size in the grouting material is ≤2.5mm.

[0018] As a preferred embodiment, the stainless steel pipes buried in the pool wall concrete are spaced 1.5 to 2.5 m apart, the stainless steel pipes are inclined at 30° to 45°, and the inner ends of the stainless steel pipes penetrate 0 to 10 mm into the pool wall cavity of the nuclear power plant pool.

[0019] When grouting stainless steel pipes, a micro vibration motor is used to vibrate the stainless steel pipes at the bottom of the grouting bucket; an endoscope is placed on the top of the pool wall cavity of the nuclear power plant to observe the slurry liquid level and solidification state.

[0020] Preferably, the stainless steel pipe embedded in the pool wall concrete and the stainless steel pipe vertically inserted into the final grouting cavity section are both square steel pipes or round steel pipes with a side length or diameter greater than 10 mm.

[0021] Specifically, the initial solidification of the slurry is that the slurry solidifies for 6 to 10 hours after grouting; the small amount and multiple times grouting method is to calculate the required slurry volume according to each grouting height ≤ 0.5m for grouting.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] Aiming at the requirements of sealing and stability of stainless steel water pools in nuclear power plants, the present invention adopts a matching structure of installing a stainless steel water pool steel covering to form a narrow and long cavity of the nuclear power plant water pool wall with an irregular inner cross-section, and combines it with the stainless steel pipe at the bottom of the vibration grouting bucket buried in sections to perform observable sectioned grouting, effectively solving the problems of grouting segregation and inability to be dense, avoiding slurry blockage in a small space, optimizing the anchoring between the stainless steel covering and the concrete structure, ensuring the sealing and stability of the stainless steel water pool in the nuclear power plant, and the scheme of the present invention can also improve the progress and quality of engineering construction.

[0024] The solution of the present invention solves the problem of grouting construction of narrow and long cavities of stainless steel pool walls of nuclear power plants with high height and strict requirements, especially for stainless steel pool walls with high height and not conforming to the theoretical vertical structure, thereby reducing the construction difficulty and improving the construction quality, safety and construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the construction of the grouting method for the narrow and long cavity of the wall of the stainless steel pool of a nuclear power plant in Example 1 of the present invention.

[0026] Figure 2 for Figure 1 Schematic side view of .

[0027] Figure 3 for Figure 1 Schematic top view of .

[0028] Figure 4 It is a structural schematic diagram of the grouting bucket.

[0029] Figure 5 This is a schematic diagram of the steel cladding coordination structure of a stainless steel pool.

[0030] Figure 6 It is a schematic diagram of the construction of the grouting method for the narrow and long cavity of the wall of the stainless steel pool of a nuclear power plant in Example 2 of the present invention.

[0031] The symbols in the accompanying drawings are:

[0032] 1. Cavity of the nuclear power plant pool wall; 2. The first stainless steel pipe; 3. Grouting bucket; 4. Top of the narrow cavity; 5. Bottom of the grouting bucket; 6. Pool wall concrete; 7. Stainless steel pool steel covering panel; 8. Anchors; 9. Groove structure; 10. Inner wall of the narrow cavity with excessive displacement; 11. The first angle steel; 12. The second angle steel. DETAILED DESCRIPTION

[0033] The above contents of the present invention are further described in detail below in the form of embodiments, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the above contents of the present invention belong to the scope of the present invention.

[0034] In the description of the present invention, it is also necessary to explain:

[0035] The orientation or position relationship is based on the relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, terms such as "first, second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0036] The present invention provides a method for grouting a narrow and long cavity of a stainless steel pool wall of a nuclear power plant, comprising the following steps:

[0037] During the construction of the nuclear power plant pool wall concrete, a first stainless steel pipe 2 for grouting the nuclear power plant pool wall cavity 1 is buried in the pool wall concrete 6 along the height of the nuclear power plant pool wall at intervals to form a plurality of grouting cavity sections;

[0038] The outer end of the first stainless steel pipe 2 buried in the pool wall concrete 6 extends out of the pool wall concrete 6, and the inner end goes deep into the pool wall cavity 1 of the nuclear power plant pool. The first stainless steel pipe 2 is arranged obliquely;

[0039] Install the stainless steel pool steel cladding matching structure, stainless steel pool steel cladding matching structure such as Figure 5As shown, it includes groove structures 9 on the left and right sides of the nuclear power plant water pool wall cavity 1, stainless steel water pool steel covering panels 7 and anchors 8, stainless steel water pool steel covering panels 7 are installed on the outside of the groove structures 9 on the left and right sides of the nuclear power plant water pool wall cavity 1, and anchors 8 are installed between the groove structures 9 on the inner side and on both sides of the stainless steel water pool steel covering panels 7, so as to form a narrow and long cavity of the nuclear power plant water pool wall with an irregular inner cross section;

[0040] Grouting is performed from the first stainless steel pipes 2 into the pool wall cavity 1 of the nuclear power plant water pool from bottom to top. After the slurry in each grouting cavity section is initially solidified, grouting is performed from the previous first stainless steel pipe 2 into the pool wall cavity 1 of the nuclear power plant water pool;

[0041] The top inclined first stainless steel pipe 2 is spaced apart from the top of the nuclear power plant pool wall cavity 1 to form the last grouting cavity section. The grouting of the last grouting cavity section is to vertically insert a second stainless steel pipe from the top 4 of the narrow cavity into the bottom of the last grouting cavity section, and grout is poured into it from the top of the stainless steel pipe in small amounts and multiple times.

[0042] As a preferred solution, the first stainless steel pipe 2 is arranged in the middle of the pool wall cavity 1 of the nuclear power plant; the first stainless steel pipes 2 buried in the pool wall concrete 6 are arranged in parallel and inclined at uniform intervals.

[0043] In the embodiment, the first stainless steel tube 2 is about 1 m long, and the outer end of the first stainless steel tube 2 extends out of the pool wall concrete 6 by no more than 0.2 m. The bottom end of the first stainless steel tube 2 cannot penetrate too far into the narrow cavity to avoid affecting the installation of the matching structure of the stainless steel water pool, and cannot fail to penetrate into the cavity to avoid slurry clogging the wall.

[0044] The groove structures 9 on the left and right sides of the nuclear power plant water pool wall cavity 1 are respectively composed of a first angle steel 11 and a second angle steel 12 in opposite directions. The first angle steel 11 is arranged outward, one side of the first angle steel 11 is in contact with the pool wall concrete 6, and the other side is in contact with one side of the second angle steel 12. The second angle steel 12 is arranged inward, and the other side of the second angle steel 12 is in contact with the stainless steel water pool steel covering panel 7; the groove structures 9 on the left and right sides are symmetrical.

[0045] The stainless steel pool steel covering panel 7 is composed of a left steel covering and a right steel covering; the anchor 8 includes a channel steel and a steel plate, the channel steel is arranged toward the stainless steel pool steel covering panel 7, the left wing end of the channel steel is fixed to the left steel covering, and the right wing end of the channel steel is fixed to the right steel covering; the steel plate is fixed to the web of the channel steel.

[0046] During grouting, a grouting bucket 3 is set at the outer ends of the first stainless steel pipe 2 and the second stainless steel pipe, and a mechanical stirring device is used to evenly stir the water and the grouting material to form a slurry. Grouting is carried out from the grouting bucket 3, and a personnel operating platform is set up on one side of the grouting bucket 3 to fix the grouting bucket 3. Before grouting, a vacuum cleaner is used to clean the floating dust and accumulated water in the cavity.

[0047] Starting from the bottom, grouting is gradually carried out upwards. After the lower slurry is initially solidified, the upper slurry is grouting. The grouting method is:

[0048] (a) When grouting from the first stainless steel pipe 2 buried in the pool wall concrete 6, the grouting bucket 3 is placed at the outer end of the first stainless steel pipe 2, and grouting begins until it overflows from the first stainless steel pipe 2;

[0049] (b) However, when grouting the second vertical stainless steel pipe from the last grouting cavity section, adopt a small amount and multiple times grouting method. The height of the last grouting cavity section is ≤2m. Strictly avoid slurry overflow, which will flow into the stainless steel pool, causing pollution to the stainless steel plate of the pool or blocking other functional pipes.

[0050] The initial solidification of the slurry is 6 to 10 hours of solidification of the slurry after grouting to prevent the residual slurry from bonding to the stainless steel pipe.

[0051] The method of grouting in small amounts and multiple times is to calculate the volume of the required slurry according to the grouting height ≤ 0.5m each time, pour it into the grouting bucket 3 and grout it successively to avoid slurry overflow.

[0052] Grouting bucket Figure 4 As shown, in the preferred embodiment, when grouting through the stainless steel pipe, the micro vibration motor vibrates the stainless steel pipe at position 5 at the bottom of the grouting bucket to prevent slurry segregation and blockage; the stainless steel pipe is small in size, and a rechargeable handheld micro vibration motor can be selected with a vibration frequency of 9~20Hz and an amplitude of 6mm.

[0053] In a preferred embodiment, the stirring time is not less than 5 minutes, so that the slurry is fully stirred and has good fluidity; to avoid the slurry clogging the pipeline, the particle size of the crushed stone in the grouting material is ≤2.5mm.

[0054] In a preferred embodiment, the ratio of water to grouting material is 0.13-0.16:1, the final compressive strength of the slurry is not less than 50 MPa, and the time from stirring to the end of grouting is less than 1 hour.

[0055] The first stainless steel pipe 2 buried in the pool wall concrete 6 is spaced 1.5-2.5m apart and tilted 30-45 degrees. The buried height and tilt angle of the first stainless steel pipe 2 must be within a suitable range. When the slurry flows into the cavity along the first stainless steel pipe 2, it is accelerated downward by its own weight. It is necessary to avoid excessive travel and too fast speed, which may cause the slurry to splash in the cavity and hang on the wall, making it difficult for the slurry to be dense.

[0056] The inner end of the first stainless steel pipe 2 buried in the pool wall concrete 6 penetrates into the pool wall cavity 1 of the nuclear power plant pool by 0 to 10 mm. The distance from the bottom end of the first stainless steel pipe 2 to the narrow cavity needs to be controlled within an appropriate range. It cannot be too long to avoid affecting the installation of the stainless steel pool steel cladding matching structure, and it cannot extend into the cavity to avoid slurry clogging the wall.

[0057] In a preferred embodiment, the stainless steel pipe can be made of 304 or 316 series, which has strong corrosion resistance and can be buried in concrete for a long time to avoid later pollution.

[0058] The first stainless steel tube 2 embedded in the pool wall concrete 6 and the second stainless steel tube vertically inserted into the final grouting cavity section are square steel tubes or round steel tubes with a side length or diameter greater than 10 mm. In a preferred embodiment, the cross-sectional width of the square steel tube is 10-15 mm and the cross-sectional length is 25-30 mm.

[0059] An endoscope is placed on the top of the wall cavity 1 of the nuclear power plant water pool to observe the slurry liquid level and solidification state.

[0060] The present invention is further described in detail below in conjunction with specific embodiments: Example 1

[0061] like Figure 1-3 As shown, a method for grouting a narrow cavity of a stainless steel pool wall in a nuclear power plant is provided. The height of the narrow cavity of the stainless steel pool wall is about 10m. The grouting method comprises the following steps:

[0062] The first step is to evenly bury inclined stainless steel square pipes in the pool wall concrete 6 structure construction;

[0063] The second step is to install the trough structure 9 and the stainless steel pool steel covering panel 7 and the anchor 8 on the back to form a narrow and long cavity;

[0064] The third step is to use a machine to stir the water and grouting material to form a slurry;

[0065] The fourth step is to pour the stirred slurry into the grouting bucket 3, start grouting from the bottom of the inclined first stainless steel pipe 2, use a micro vibration motor to vibrate the 5 square pipes at the bottom of the grouting bucket, and use an endoscope to observe the slurry liquid level and solidification state;

[0066] Step 5: clean the residual slurry in the grouting bucket 3, and repeat the grouting operation of the upper section after the bottom slurry is initially solidified until the highest inclined first stainless steel pipe 2 is reached;

[0067] Step 6, during the last section of grouting, move the grouting bucket 3 to the top of the narrow and long cavity, insert the stainless steel square pipe directly into the narrow and long cavity from the top 4 of the narrow and long cavity, and grout from the second stainless steel pipe in a small amount and multiple times.

[0068] The first stainless steel tube 2 and the second stainless steel tube are square steel tubes with a cross-sectional width of 15 mm and a cross-sectional length of 25 mm.

[0069] In the first step, following the progress of the pool wall concrete 6 construction, the first stainless steel pipe 2 is buried every 2m along the height direction; the first stainless steel pipe 2 is inclined at an angle of 40°, the inner end of the first stainless steel pipe 2 penetrates 0~10mm into the pool wall cavity 1 of the nuclear power plant pool, and the top extends out of the wall by no more than 0.2m; the total length of the first stainless steel pipe 2 is about 1m, and the end of the pipe extending out of the wall is first screwed with a pipe cap to prevent foreign matter from entering the pipe during construction.

[0070] In the third step, water and grouting material are stirred mechanically for 10 minutes, and the formed slurry is fully stirred and has good fluidity; the ratio of water to grouting material is 0.15:1, and the final compressive strength of the slurry is 60MPa.

[0071] In the fourth step, the grouting bucket 3 is placed at the bottom of the first stainless steel pipe 2, and grouting begins until the buried first stainless steel pipe 2 overflows; a personnel operating platform is set up on one side of the grouting bucket 3 to fix the grouting bucket 3; a vacuum cleaner is used to clean the floating dust and accumulated water in the cavity before grouting; the grouting sequence is from the bottom and gradually upwards; after the slurry is poured into the grouting bucket 3, a micro vibration motor is used to vibrate the 5 square tubes at the bottom of the grouting bucket to prevent the slurry from segregating and clogging. The first stainless steel pipe 2 is small in size, and a rechargeable handheld micro vibration motor is selected with a vibration frequency of 12Hz and an amplitude of 6mm.

[0072] An endoscope is placed on the top of the cavity, and the lens penetrates into the bottom of the narrow cavity to observe the slurry liquid level and solidification state.

[0073] In the fifth step, the residual slurry in the grouting bucket 3 is cleaned to prevent the residual slurry from adhering to the first stainless steel pipe 2. The grouting is stopped for 8 hours. After the bottom slurry is initially solidified, the grouting operation at the upper first stainless steel pipe 2 can be carried out. The method is the same as the third step.

[0074] In the sixth step, during the last section of grouting, the ungrouted height in the cavity is 1.5m. The required slurry volume is calculated based on the grouting height of each time ≤0.5m, and poured into the grouting bucket 3 and grouted successively from the second stainless steel pipe to avoid slurry overflow. Example 2

[0075] like Figure 6 As shown, the height of the narrow cavity of the stainless steel pool wall is greater than 10m. During construction, the concrete structure and the trough structure cannot be completely vertical due to their high height, and the overall displacement deviation cannot be guaranteed to be less than 10mm. After construction, the inner wall 10 of the narrow cavity with excessive displacement presents an irregular shape similar to an "S" shape.

[0076] The difference from Example 1 is that when the first stainless steel tube 2 is buried in the pool wall concrete 6 structure in the first step, the distance that the inner end of the first stainless steel tube 2 penetrates into the cavity is controlled to be slightly greater than 10 mm. After all the burials are completed, the steps of checking the distance that the inner end of the first stainless steel tube 2 penetrates into the cavity and polishing the inner end of the first stainless steel tube 2 are added. Finally, the distance that the inner end of each buried first stainless steel tube 2 penetrates into the cavity is controlled to be 0~10 mm, which does not affect the installation of the matching structure in the second step.

[0077] Comparative Example 1

[0078] A method for grouting a narrow cavity of a stainless steel pool wall in a nuclear power plant by sections, comprising the following steps:

[0079] In the first step, a stainless steel square tube with a cross-section width of 15 mm and a length of 30 mm is taken and inserted from the top 4 of the narrow cavity to a height of 2 m from the bottom.

[0080] The second step is to install the trough structure and the stainless steel pool steel covering panel 7 and the anchoring pieces 8 on the back to form a long and narrow cavity.

[0081] The third step is to use a machine to stir the water and grouting material to form a slurry;

[0082] The fourth step is to pour the stirred slurry into the grouting bucket 3 and start grouting from the bottom stainless steel pipe. After grouting for 2m, pull out the stainless steel square pipe. Use a micro vibration motor to vibrate the 5 square pipes at the bottom of the grouting bucket, and use an endoscope to observe the slurry liquid level and solidification state.

[0083] The fifth step is to clean the residual slurry in the grouting bucket 3, shorten the stainless steel square tube after the bottom slurry is initially solidified, and then go deep into the top 4 of the narrow cavity to a height of 4m from the bottom.

[0084] Step 6. Repeat the grouting operations in steps 4 and 5 until the top.

[0085] There is a situation where the stainless steel pipe cannot be inserted into the cavity. When the height of the narrow cavity is greater than 10m, the overall displacement deviation of the cavity is greater than 10mm. The inner wall of the cavity is not a vertical theoretical structure. The stainless steel pipe cannot be inserted vertically into the deep cavity and the grouting cannot be completed smoothly. Therefore, it is necessary to repeatedly shorten the inserted steel pipe and require multiple insertions and extractions. At the beginning, a steel pipe greater than 10m is inserted. Each grouting needs to be pulled up and shortened, which greatly increases the risk of high-altitude construction and electrical fire prevention.

[0086] Compared with Comparative Example 1, the solution of the present invention solves the problem of grouting construction of narrow and long cavities of stainless steel water pool walls in nuclear power plants with high height and strict requirements, especially for stainless steel water pool walls with high height that do not conform to the theoretical vertical structure, reducing the construction difficulty and improving the construction quality, safety and construction efficiency.

[0087] Comparative Example 2

[0088] This comparative example adopts the same construction method as that of Example 1, and the difference from Example 1 is that the stainless steel square tubes in Example 1 are replaced by PE plastic hoses.

[0089] Test results: slurry blockage occurred, the PE plastic pipe was not rigid enough, the pipe was not straight, and was easy to bend and deform.

[0090] Comparative Example 3

[0091] This comparative example adopts the same construction method as that of Example 1, and the difference from Example 1 is that the stainless steel square tubes in Example 1 are replaced by stainless steel round tubes with a diameter of 8 mm.

[0092] Test results: In case of slurry blockage, the cross-sectional size of the stainless steel pipe needs to be larger than 10mm.

[0093] Comparative Example 4

[0094] This comparative example adopts the same construction method as that of Example 1, except that the first stainless steel pipe 2 is buried every 4 m instead of every 1.5 to 2.5 m in the height direction.

[0095] Test results: When the mold expands, the lateral pressure generated by the grouting is proportional to the height. When the height exceeds 2.5m, the lateral pressure is too large.

[0096] Compared with comparative examples 2-4, the solution of the present invention has been rigorously tested and can meet the construction requirements of grouting the narrow and long cavity of the stainless steel pool wall of a nuclear power plant with high height and strict requirements.

[0097] The first stainless steel pipe embedded in the pool wall concrete of the present invention does not need to be taken out after construction, and does not affect the construction progress, quality and safety of other structures.

[0098] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any technician familiar with the profession, without departing from the scope of the technical solution of the present invention, according to the technical essence of the present invention, any simple modification, equivalent replacement and improvement made to the above embodiment still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for grouting a narrow cavity of a stainless steel pool wall in a nuclear power plant, characterized in that: The following steps are involved: During the construction of the nuclear power plant pool wall concrete, stainless steel pipes for grouting the nuclear power plant pool wall cavity are buried in the pool wall concrete at intervals along the height direction of the nuclear power plant pool wall to form a number of grouting cavity sections; The stainless steel pipe buried in the pool wall concrete is set obliquely, with its outer end extending out of the pool wall concrete and its inner end penetrating into the pool wall cavity of the nuclear power plant pool; the distance that the inner end of the obliquely set stainless steel pipe penetrates into the pool wall cavity of the nuclear power plant pool is controlled to be within a set range; Install the stainless steel pool steel covering matching structure, including the groove structure on both sides of the nuclear power plant pool wall cavity, the stainless steel pool steel covering panels and anchors, install the stainless steel pool steel covering panels on the outside of the groove structure on both sides of the nuclear power plant pool wall cavity, and install anchors on the inside of the stainless steel pool steel covering panels and between the groove structures on both sides to form a narrow and long cavity of the nuclear power plant pool wall with an irregular inner cross-section; Grouting is performed from bottom to top through the inclined stainless steel pipes into the cavity of the water pool wall of the nuclear power plant. After the slurry in each grouting cavity section is initially solidified, the upper stainless steel pipe continues to grout into the cavity of the water pool wall of the nuclear power plant; The topmost inclined stainless steel pipe is spaced apart from the top of the nuclear power plant pool wall cavity to form the last grouting cavity section. The grouting of the last grouting cavity section is performed by vertically inserting a stainless steel pipe into the bottom of the last grouting cavity section, and grouting is performed in small amounts and multiple times from the top of the stainless steel pipe to complete the grouting of the narrow and long cavity.

2. The method for grouting a narrow and long cavity of a stainless steel pool wall in a nuclear power plant according to claim 1, characterized in that: The stainless steel pipes are buried in the middle of the pool wall cavity of the nuclear power plant, and the stainless steel pipes buried in the pool wall concrete are evenly spaced and inclined and parallel.

3. The method for grouting a narrow and long cavity of a stainless steel pool wall in a nuclear power plant according to claim 1, characterized in that: The groove structures on both sides of the pool wall cavity of the nuclear power plant water pool are respectively composed of a first angle steel and a second angle steel in opposite directions. The first angle steel is arranged outward, one side of the first angle steel is attached to the pool wall concrete, and the other side is attached to one side of the second angle steel. The second angle steel is arranged inward, and the other side of the second angle steel is attached to the stainless steel pool steel covering panel. The groove structures on both sides are arranged symmetrically.

4. The method for grouting a narrow and long cavity of a stainless steel pool wall in a nuclear power plant according to claim 1, characterized in that: The stainless steel pool steel covering panel is composed of a left steel covering and a right steel covering; the anchoring piece includes a channel steel and a steel plate, the channel steel is arranged toward the stainless steel pool steel covering panel, the left wing end of the channel steel is fixed to the left steel covering, and the right wing end is fixed to the right steel covering; The steel plate is fixed to the web of the channel steel.

5. The method for grouting the narrow and long cavity of the stainless steel pool wall of a nuclear power plant according to claim 1, characterized in that: The distance that the inner end of the stainless steel pipe that is controlled to be inclined penetrates into the cavity of the nuclear power plant pool wall is within a set range. The embedding is first completed by controlling the inner end of the stainless steel pipe to penetrate into the cavity to a distance slightly greater than the set range, and the distance that the inner end of the stainless steel pipe penetrates into the cavity is checked. The inner end of the stainless steel pipe is polished to control the final distance that the inner end of the buried stainless steel pipe penetrates into the cavity to be within the set range.

6. The method for grouting a narrow and long cavity of a stainless steel pool wall in a nuclear power plant according to claim 1, characterized in that: During grouting, a grouting bucket is set at the outer end of the stainless steel pipe, and a mechanical stirring device is used to evenly stir the water and grouting material to form a slurry, and grouting is carried out from the grouting bucket; the particle size of the crushed stone in the grouting material is ≤2.5mm.

7. The method for grouting a narrow and long cavity of a stainless steel pool wall in a nuclear power plant according to claim 1, characterized in that: When grouting stainless steel pipes, a micro vibration motor is used to vibrate the stainless steel pipes at the bottom of the grouting bucket; an endoscope is placed on the top of the pool wall cavity of the nuclear power plant to observe the slurry liquid level and solidification state.

8. The method for grouting a narrow and long cavity of a stainless steel pool wall in a nuclear power plant according to claim 1, characterized in that: The stainless steel pipes buried in the pool wall concrete and the stainless steel pipes vertically inserted into the final grouting cavity section are all square steel pipes or round steel pipes with a side length or diameter greater than 10mm.

9. The method for grouting a narrow and long cavity of a stainless steel pool wall in a nuclear power plant according to claim 1, characterized in that: The initial solidification of the slurry is that the slurry solidifies for 6 to 10 hours after grouting; the small amount and multiple times grouting method is to calculate the required slurry volume according to each grouting height ≤ 0.5m for grouting.

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