CN113756355B - Weak magnetic foundation replacement method and weak magnetic laboratory - Google Patents

Weak magnetic foundation replacement method and weak magnetic laboratory Download PDF

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Publication number
CN113756355B
CN113756355B CN202111043588.5A CN202111043588A CN113756355B CN 113756355 B CN113756355 B CN 113756355B CN 202111043588 A CN202111043588 A CN 202111043588A CN 113756355 B CN113756355 B CN 113756355B
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foundation
ferromagnetic
weak magnetic
magnetic
pile
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CN113756355A (en
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刘云峰
杨宏
郑彩霞
刘斌
孙洁
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Anfang Gaoke Electromagnetic Safety Technology Beijing Co ltd
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Anfang Gaoke Electromagnetic Safety Technology Beijing Co ltd
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    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D27/00—Foundations as substructures
    • E02D27/10—Deep foundations
    • E02D27/12—Pile foundations
    • E02D27/14—Pile framings, i.e. piles assembled to form the substructure
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D15/00—Handling building or like materials for hydraulic engineering or foundations
    • E02D15/02—Handling of bulk concrete specially for foundation or hydraulic engineering purposes
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
    • E02D5/22—Piles
    • E02D5/24—Prefabricated piles
    • E02D5/28—Prefabricated piles made of steel or other metals
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
    • E04H5/00—Buildings or groups of buildings for industrial or agricultural purposes
    • E04H5/02—Buildings or groups of buildings for industrial purposes, e.g. for power-plants or factories
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D2250/00—Production methods
    • E02D2250/0007—Production methods using a mold
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D2250/00—Production methods
    • E02D2250/003—Injection of material
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D2300/00—Materials
    • E02D2300/0026—Metals
    • E02D2300/0029—Steel; Iron

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  • Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Civil Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Mining & Mineral Resources (AREA)
  • Paleontology (AREA)
  • Architecture (AREA)
  • Piles And Underground Anchors (AREA)

Abstract

The invention provides a weak magnetic foundation replacement method and a weak magnetic laboratory, which greatly improve the shielding performance of a weak magnetic foundation under low frequency by adopting non-magnetic characteristic slurry to replace ferromagnetic materials; meanwhile, the shielding body prepared by adopting the permalloy plate can be effectively prevented from being uniform and free of sedimentation and stress variation, and the material performance of the original shielding body is greatly maintained; in addition, except that can reduce magnetism effectively, can also promote the antidetonation effect of shield by a wide margin, simultaneously, in whole work progress, not receive the restriction of upper magnetic shielding room size, the replacement column base that all accessible bottom slip casting mode realized evenly does not have subsidence.

Description

Weak magnetic foundation replacement method and weak magnetic laboratory
Technical Field
The invention relates to the technical field of nonmagnetic laboratories, in particular to a weak magnetic foundation replacement method and a weak magnetic laboratory.
Background
Modern science and technology have revealed that everything is magnetic, and that there is a magnetic field in any space. The field weakening phenomenon is various phenomena represented by a field weakening substance. In the field of constructional engineering, the weak magnetic foundation is a bearing foundation applied to a zero magnetic space, is used for bearing a non-magnetic laboratory for the purpose of restraining various magnetic field signals, and is an indispensable important means in many research fields such as geomagnetism, aerospace, biomedicine, physics and the like.
In the prior art, permalloy materials with high magnetic conductivity are selected during construction of a nonmagnetic laboratory, finished permalloy plates subjected to machining and heat treatment are arranged on 12 surfaces inside and outside the nonmagnetic laboratory according to a plurality of layers, and the influence of a high magnetic conduction shielding body shielding geomagnetic field on the inner space of the nonmagnetic laboratory is formed.
Similar to the traditional foundation structure, the weak magnetic foundation is used as a connecting key piece between a nonmagnetic laboratory and the ground, and the performance index directly influences the design requirement of the nonmagnetic laboratory. At present, a common weak magnetic foundation adopts 304 stainless steel square tubes, a single independent vibration reduction support bracket is manufactured through welding, and the single independent vibration reduction support bracket is used as the weak magnetic foundation after demagnetizing treatment. The steel material can be gradually magnetized by the geomagnetic field along with the time, and the magnetized foundation can influence the performance index of the nonmagnetic laboratory at the upper part. The magnetized 304 weak magnetic foundation is not suitable for non-magnetic laboratories, and particularly for zero magnetic shielding rooms with static magnetic field strength less than 50nT, the 304 weak magnetic foundation cannot be adopted, and the laboratory which is built needs to be replaced.
However, the permalloy plate has the greatest defects that the magnetic performance is extremely sensitive to stress and is not stress-resistant, and the installed finished product cannot be stressed secondarily, otherwise, the high magnetic permeability of the material is affected, and the performance index of a non-magnetic laboratory is reduced.
At present, the prior art does not have a process for replacing 304 stainless steel while ensuring the stability of the stress of the permalloy plate.
Disclosure of Invention
Therefore, the invention aims to overcome the defect that a nonmagnetic laboratory in the prior art adopts 304 stainless steel as a foundation, and once magnetization occurs, no related process is used for replacing the foundation.
Therefore, the invention provides a method for replacing a weak magnetic foundation, which comprises the following steps: obtaining the layout of a plurality of ferromagnetic pile foundations in a non-magnetic laboratory; carrying out stress analysis on each ferromagnetic pile foundation; protecting the outer surface of the ferromagnetic pile foundation; cleaning a foundation pit where the ferromagnetic pile foundation is located, and arranging a pouring die; the slurry mixing ratio is designed, non-magnetic slurry is prepared, and pouring operation is carried out in the pouring mould to form a strip foundation; performing maintenance operation on the strip-shaped foundation; and when the strength of the strip foundation reaches the design strength, removing the ferromagnetic pile foundation.
The weak magnetic foundation replacement method provided by the invention comprises the following steps of: and analyzing parameters such as the cross-sectional area of the foundation, the compressive strength and the like.
According to the weak magnetic foundation replacement method provided by the invention, in the protection step of the outer surface of the ferromagnetic pile foundation, the ferromagnetic pile foundation is fully wrapped by adopting the rubber and plastic insulation board.
The invention provides a weak magnetic foundation replacement method, which comprises the following steps of: and chiseling the parts of degradation phenomena such as slag inclusion, sand lifting, peeling and the like to expose the concrete structure layer.
The method for replacing the weak magnetic foundation, provided by the invention, prepares non-magnetic characteristic slurry according to the designed slurry mixing ratio, and performs pouring operation into the pouring mold, and the step of forming the strip-shaped foundation comprises the following steps: and (3) vibrating by adopting a miniature vibrating rod, and grouting from the center to the two ends.
The invention provides a weak magnetic foundation replacement method, which further comprises the following steps: after grouting of the single strip-shaped foundation is finished, the grouting observation port is blocked at first, the grouting valve is closed, pressure is relieved at last, the grouting port is blocked by adopting a wood plate after grouting is finished, and all strip-shaped foundations are guaranteed to be poured before initial setting.
The method for replacing the weak magnetic foundation provided by the invention comprises the following steps of: and gradually removing the ferromagnetic pile foundation from the center point of the foundation pit to the periphery one by one, and observing the change of sedimentation records in real time in the removal process, wherein the local sedimentation is required to be smaller than 0.5mm.
According to the method for replacing the weak magnetic foundation, the non-magnetic characteristic slurry is made of the cement-based composite material, and the 3d compressive strength of the non-magnetic characteristic slurry is larger than 30MPa.
According to the weak magnetic foundation replacement method provided by the invention, the ferromagnetic pile foundation is made of 304 stainless steel.
The invention also provides a weak magnetic laboratory which is obtained by modifying the weak magnetic foundation replacement method.
The technical scheme of the invention has the following advantages:
1. the invention provides a weak magnetic foundation replacement method, which comprises the following steps: obtaining the layout of a plurality of ferromagnetic pile foundations in a non-magnetic laboratory; carrying out stress analysis on each ferromagnetic pile foundation; protecting the outer surface of the ferromagnetic pile foundation; cleaning a foundation pit where the ferromagnetic pile foundation is located, and arranging a pouring die; the slurry mixing ratio is designed, non-magnetic slurry is prepared, and pouring operation is carried out in the pouring mould to form a strip foundation; performing maintenance operation on the strip-shaped foundation; and when the strength of the strip foundation reaches the design strength, removing the ferromagnetic pile foundation.
The non-magnetic slurry is adopted to replace a ferromagnetic pile foundation, so that the shielding performance of the pile foundation under low frequency is greatly improved; meanwhile, the shielding body prepared by adopting the permalloy plate can be effectively prevented from being uniform and free of sedimentation and stress variation, and the material performance of the original shielding body is greatly maintained;
in addition, except that can reduce magnetism effectively, can also promote the antidetonation effect of shield by a wide margin, simultaneously, in whole work progress, not receive the restriction of upper magnetic shielding room size, the replacement column base that all accessible bottom slip casting mode realized evenly does not have subsidence.
2. According to the method for replacing the weak magnetic foundation, the expanding agent such as the calcium alum expanding agent is added into the nonmagnetic characteristic material, cement reacts with the expanding agent in the hydration process to generate hydrated calcium sulfoaluminate (ettringite) or calcium hydroxide and the like with micro-expansion effect, so that the nonmagnetic characteristic material has micro-expansion performance to compensate the volume shrinkage of the cement in the hydration process, preferably, the expansion rate can be controlled to be between 0 and 0.05 percent, if the expansion rate is lower than 0, the structure shrinkage can occur, and a poured supporting structure cannot be tightly combined with a zero magnetic space to generate deformation stress; if the content is more than 0.05%, the internal structure of the nonmagnetic material is damaged, resulting in a significant decrease in strength.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic structural view of the weak magnetic foundation in the construction process;
reference numerals illustrate:
1-ferromagnetic pile foundation; 2-bar foundation.
Detailed Description
The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
In addition, the technical features of the different embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.
Example 1
A method for replacing weak magnetic foundation features that the permalloy with high magnetic conductivity is chosen at top of weak magnetic laboratory, the permalloy plates after machining and heat treatment are installed to 12 surfaces of non-magnetic laboratory, and multiple ferromagnetic pile foundations are arranged under weak magnetic laboratory to support the main body of laboratory. The replacement method comprises the following steps:
obtaining the layout of a plurality of ferromagnetic pile foundations 1 in a non-magnetic laboratory;
specifically, a drawing of a field weakening laboratory in the construction process can be adopted to analyze the setting position of the existing ferromagnetic pile foundation 1 and the foundation stress analysis of the field follow-up equipment arrangement condition.
Carrying out stress analysis on each ferromagnetic pile foundation;
specifically, in this embodiment, the step of performing stress analysis on each ferromagnetic pile foundation includes: and analyzing parameters such as the cross-sectional area of the foundation, the compressive strength and the like.
Protecting the outer surface of the ferromagnetic pile foundation;
specifically, after the stress analysis of each ferromagnetic pile foundation is completed, a rubber and plastic insulation board is adopted to fully wrap the ferromagnetic pile foundations. As a modification, a plastic plate, a wood plate and the like can be adopted to protect the ferromagnetic pile foundation, so that vibration and impact in the construction process are avoided, and the performance of the permalloy plate is influenced.
When the protection operation of the ferromagnetic pile foundation is finished, a construction drawing is drawn, the part of the strip foundation is definitely poured on the drawing, then the line is sprung on the component, the contour line of the strip foundation is popped up, and the periphery of the line is widened by 3 cm respectively on the basis, so that the polishing area is widened.
Further, the preparation step of the strip foundation is started, and specifically comprises the following steps:
cleaning a foundation pit where the ferromagnetic pile foundation is located, and arranging a pouring die;
specifically, the method comprises the following steps: and chiseling the parts of degradation phenomena such as slag inclusion, sand lifting, peeling and the like to expose the concrete structure layer. And meanwhile, watering and wetting the control line substrate to carry out local roughening, and carrying out vibration-free roughening treatment on the surface of the aluminum plate at the top of the control line.
In this embodiment, in the step of setting the pouring die, it includes:
the foundation is supported by a 15 mm thick multi-layer plywood formwork, the batten is 50 mm in size, the release agent is water-soluble, the opposite-pull bolt is coated with a phi 20PVC pipe by a phi 12 high-strength screw, and the butterfly buckle is arranged. h is less than or equal to 500 mm, a counter-pulling screw rod is not arranged; when the h is more than 500 mm and less than or equal to 800 mm, a phi 12 opposite-pulling screw rod is arranged along the middle part of the foundation, and the horizontal spacing is not more than 600 mm; h is more than 800 mm, a phi 12 opposite-pulling screw rod is arranged along the foundation with the height not more than 400 mm, and the horizontal spacing is not more than 500 mm; reserving 150 x 200 mm grouting holes on two sides of the template, wherein the holes are 100 mm higher than the top surface of the foundation; and a 20 mm slurry overflow observation port is reserved at the middle top position of the template, and the horizontal spacing is not more than 1000 mm.
The slurry mixing ratio is designed, non-magnetic slurry is prepared, and pouring operation is carried out in the pouring mould to form a strip foundation;
specifically, a miniature vibrating rod is adopted for vibrating in the grouting process, and grouting is carried out at two ends from the center to the outside. In the grouting process, the slurry overflow condition of a slurry overflow port is closely concerned, after a single strip-shaped foundation grouting is finished, the slurry overflow observation port is blocked at first, then the grouting valve is closed, and finally the pressure is relieved, so that the slurry in the pipe is prevented from flowing back. And after grouting is completed, the grouting openings are plugged by adopting a wood board, so that all strip foundations are guaranteed to be poured before initial setting.
In this embodiment, as shown in fig. 1, the strip foundation is also called a strip foundation, and is a structural form in which the length of the foundation is much longer than the width. Specifically, the strip foundation can be arranged at one side of the ferromagnetic pile foundation, and also can be arranged between two adjacent ferromagnetic pile foundations in a penetrating way. The arrangement of the strip foundation and the ferromagnetic pile foundation is approximately consistent so as to ensure the stability of the support after the ferromagnetic pile foundation is removed.
In the embodiment, the nonmagnetic characteristic slurry is prepared by adopting the nonmagnetic characteristic material, and the nonmagnetic characteristic material is a cement-based structural material and has the characteristics of weak magnetism, micro expansion, high strength and the like. The components of the magnetic flux meter have fewer magnetic components, mainly comprise Portland cement, sand, rubber powder, expanding agent and the like, so that the magnetic induction intensity after water is added and solidified is lower than 2000nT, and the magnetic flux meter can be used for measuring in a weak magnetic space with the magnetic induction intensity lower than 1000 nT.
Specifically, the cement-based material is a composite material which is formed by taking silicate cement as a matrix, taking alkali-resistant glass fibers, general synthetic fibers, various ceramic fibers, high-performance fibers such as carbon and aramid fibers, metal wires, natural plant fibers and mineral fibers as reinforcements, adding fillers, chemical additives and water and adopting a composite process.
Further, in this embodiment, an expanding agent, such as a calcium alum expanding agent, is added to the nonmagnetic material, and cement reacts with the expanding agent during hydration to generate hydrated calcium sulfoaluminate (ettringite) or calcium hydroxide with micro-expansion effect, so that the nonmagnetic material has micro-expansion performance to compensate the volume shrinkage of cement during hydration, preferably the expansion rate can be controlled between 0 and 0.05%, if the expansion rate is lower than 0, the structure shrinkage can occur, and the poured supporting structure cannot be tightly combined with the zero magnetic space, so as to generate deformation stress; if the content is more than 0.05%, the internal structure of the nonmagnetic material is damaged, resulting in a significant decrease in strength.
And finally, the 3d compressive strength of the nonmagnetic material is required to be more than 30MPa, so that sufficient supporting force can be provided in a short time, and the deformation of the supporting structure is prevented.
Next, maintenance operation is required for the strip foundation 2;
the curing time period is not limited, and in this embodiment, the curing time period is limited to 7 days.
And when the strength of the strip foundation 2 reaches the design strength, removing the ferromagnetic pile foundation.
Specifically, after the strength of the strip foundation reaches the design strength, the step of removing the ferromagnetic pile foundation comprises the following steps: and gradually removing the ferromagnetic pile foundation from the center point of the foundation pit to the periphery one by one, and observing the change of sedimentation records in real time in the removal process, wherein the local sedimentation is required to be less than 0.5mm.
In summary, the whole construction process flow comprises the following steps: column protection, measurement paying-off, foundation pit cleaning, interface treatment, template support, pouring construction, curing and maintenance, settlement monitoring, independent column dismantling, residual magnetism measurement and quality inspection and acceptance.
In this embodiment, the material of the ferromagnetic pile foundation itself is not limited as long as it has a certain ferromagnetism and can be magnetized by a magnetic field under the action of a geomagnetic field, and as an embodiment, the ferromagnetic pile foundation itself is made of 304 stainless steel, or may be made of nickel, cobalt, or other elements by high-temperature melting and mechanical processing heat treatment. In this embodiment, ferromagnetic pile foundation itself can set up to square pile to play the effect of stable support.
According to the replacement method provided by the embodiment, the non-magnetic slurry is adopted to replace the 304 stainless steel material, so that the shielding performance of the stainless steel material under low frequency is greatly improved; meanwhile, the shielding body prepared by adopting the permalloy plate can be effectively prevented from being uniform and free of sedimentation and stress variation, and the material performance of the original shielding body is greatly maintained; in addition, except that can reduce magnetism effectively, can also promote the antidetonation effect of shield by a wide margin, simultaneously, in whole work progress, not receive the restriction of upper magnetic shielding room size, the replacement column base that all accessible bottom slip casting mode realized evenly does not have subsidence.
In this example, to further characterize the magnetic distribution of the entire laboratory after replacement with nonmagnetic material, the residual magnetic state inside the nonmagnetic laboratory was measured, three locations of the laboratory were selected, and measurements were made at three different heights at each location. As shown in tables 1 and 2, the residual magnetic state in the nonmagnetic laboratory when the ferromagnetic pile foundation was used in the prior art is shown in table 1, and the residual magnetic state in the nonmagnetic laboratory after the replacement method provided in this example is shown in table 2.
TABLE 1
TABLE 2
The data above can clearly show that the residual magnetism in the nonmagnetic laboratory is greatly reduced after the pile foundation made of nonmagnetic characteristic materials is replaced, so that normal experimental operation can be effectively ensured.
Example 2
The embodiment provides a weak magnetic laboratory which is obtained by modifying the weak magnetic foundation replacement method provided in the embodiment 1.
In the weak magnetic laboratory obtained by modification of the embodiment, the shielding performance of the weak magnetic laboratory under low frequency is greatly improved by adopting non-magnetic characteristic slurry to replace 304 ferromagnetic materials such as stainless steel; meanwhile, the shielding body prepared by adopting the permalloy plate can be effectively prevented from being uniform and free of sedimentation and stress variation, and the material performance of the original shielding body is greatly maintained.
It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the invention.

Claims (10)

1. The weak magnetic foundation replacing method is characterized by comprising the following steps:
obtaining the layout of a plurality of ferromagnetic pile foundations in a non-magnetic laboratory;
carrying out stress analysis on each ferromagnetic pile foundation;
protecting the outer surface of the ferromagnetic pile foundation;
cleaning a foundation pit where the ferromagnetic pile foundation is located, and arranging a pouring die;
the slurry mixing ratio is designed, non-magnetic slurry is prepared, and pouring operation is carried out in the pouring mould to form a strip foundation;
performing maintenance operation on the strip-shaped foundation;
and when the strength of the strip foundation reaches the design strength, removing the ferromagnetic pile foundation.
2. The method of changing a weak magnetic foundation according to claim 1, wherein the step of performing stress analysis on each of the ferromagnetic pile foundations comprises: at least the cross-sectional area of the foundation and the compressive strength are analyzed.
3. The method according to claim 2, wherein the ferromagnetic pile foundation is entirely covered with a rubber-plastic insulation board in the step of protecting the outer surface of the ferromagnetic pile foundation.
4. The method for replacing a weak magnetic foundation according to claim 3, wherein the step of cleaning the foundation pit where the ferromagnetic pile foundation is located comprises: and chiseling the parts with slag inclusion, sand lifting and peeling degradation phenomena to expose the concrete structure layer.
5. The method of changing a weak magnetic foundation according to claim 4, wherein the step of preparing a non-magnetic slurry in the designed slurry mixture ratio and pouring the slurry into the pouring mold to form a bar-shaped foundation comprises:
and (3) vibrating by adopting a miniature vibrating rod, and grouting from the center to the two ends.
6. The method of changing a weak magnetic foundation according to claim 5, further comprising:
after grouting of the single strip-shaped foundation is finished, the grouting observation port is blocked at first, the grouting valve is closed, pressure is relieved at last, the grouting port is blocked by adopting a wood plate after grouting is finished, and all strip-shaped foundations are guaranteed to be poured before initial setting.
7. The method of changing a weak magnetic foundation according to claim 1, wherein the step of removing the ferromagnetic pile foundation after the strength of the strip foundation reaches the design strength comprises:
and gradually removing the ferromagnetic pile foundation from the center point of the foundation pit to the periphery one by one, and observing the change of sedimentation records in real time in the removal process, wherein the local sedimentation is required to be smaller than 0.5mm.
8. The method of changing a weak magnetic foundation according to claim 1, wherein the non-magnetic slurry is a cement-based composite material, and the 3d compressive strength of the cement-based composite material is greater than 30MPa.
9. The method of claim 1, wherein the ferromagnetic pile foundation is made of 304 stainless steel.
10. A field weakening laboratory, characterized in that it is manufactured by the field weakening foundation replacement method according to any one of claims 1-9.
CN202111043588.5A 2021-09-07 2021-09-07 Weak magnetic foundation replacement method and weak magnetic laboratory Active CN113756355B (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004190397A (en) * 2002-12-12 2004-07-08 Seko Komuten:Kk Tip cover mounting tool for pipe pile
JP2016201440A (en) * 2015-04-09 2016-12-01 共栄テクノ株式会社 Installation method for electromagnetic wave shield room, and shield plywood panel
CN110284491A (en) * 2019-07-31 2019-09-27 南京林业大学 A kind of magnetized solution microorganism soil-fixing device and solid indigenous method
CN112963495A (en) * 2021-03-03 2021-06-15 哈尔滨工业大学 Strain gauge and piezoelectric ceramic combined magnetic noise suppression active vibration isolation device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004190397A (en) * 2002-12-12 2004-07-08 Seko Komuten:Kk Tip cover mounting tool for pipe pile
JP2016201440A (en) * 2015-04-09 2016-12-01 共栄テクノ株式会社 Installation method for electromagnetic wave shield room, and shield plywood panel
CN110284491A (en) * 2019-07-31 2019-09-27 南京林业大学 A kind of magnetized solution microorganism soil-fixing device and solid indigenous method
CN112963495A (en) * 2021-03-03 2021-06-15 哈尔滨工业大学 Strain gauge and piezoelectric ceramic combined magnetic noise suppression active vibration isolation device

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