A method for remediating the rear deviation of concealed lattice columns in tower crane foundation

Abstract

The present invention is a post-remediation method for the inward deviation of concealed lattice columns of tower crane foundations, and the specific steps are: prefabricate correctable lattice columns; cast foundations; excavate earthwork; observe the correctable lattice columns in the excavation section, and estimate the deflection rate of the correctable lattice columns at the buried depth position: if the inward deviation horizontal displacement exceeds the specification requirements, correction measures should be adopted; column bottom correction, two columns, one as a magnetized column coil is energized, magnetized, and a magnetic field is generated. The generated magnetic field covers the deviated column, and the deviated column is energized with a straight wire under the magnetic field to generate a correction force for correction; top correction. The present invention not only realizes the adjustment of the exposed part of the tower crane foundation, but also realizes the precise adjustment of the concealed part of the correctable lattice columns buried in the soil, adds a measure that can be used for post-remediation, and ensures the safety of tower crane construction.

Description

Technical Field

[0001] The invention relates to the technical field of deviation correction construction of a column-type foundation, and in particular to a method for remediating the inner deviation of a concealed lattice column of a tower crane foundation. Background Art

[0002] As an important component of vertical transportation in construction, tower cranes are heavy and installed at high locations. Once an accident occurs, the consequences are very serious. Among the accident types, collapse accidents account for the largest proportion of tower crane accidents, and the reliability of tower crane foundations is highly correlated with tower crane accidents. Therefore, the safety and effectiveness of tower crane foundations is an important prerequisite for ensuring the safety of tower crane applications.

[0003] In order to make full use of the tower crane to maximize the vertical transportation benefits, a combined foundation is generally used, which is composed of a cap and a steel column. Among the steel columns, lattice steel columns are the most commonly used. They are constructed simultaneously during the pile foundation construction stage and put into use before earth excavation. As the earth is excavated, the lattice columns are gradually exposed in the foundation pit. However, due to the deep driving depth, many errors are superimposed and the lattice columns often deflect. The deviation of the lattice foundation is divided into the outer deviation of the column bottom, that is, the column bottom is far away from the center relative to the column top, and the inner deviation of the column bottom, that is, the column bottom is close to the center relative to the column top. The outer deviation of the column bottom is more favorable to the force of the tower crane foundation, and no correction is required; the inner deviation of the column bottom is extremely unfavorable to the force of the tower crane foundation, and it is easy to overturn the tower crane, so correction is required. The deflection gradually appears with the excavation of the earth layer by layer, but the deviation adjustment of the lattice column can only be set from the top of the horizontal pull bar. How to adjust the deviation of the lattice column buried in the soil and further ensure the safety of the tower crane foundation is an urgent problem to be solved in this field. Summary of the invention

[0004] The present invention aims to solve the deficiencies of the prior art and provides a method for remediating the rearward deviation of a concealed lattice column of a tower crane foundation.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for remediating the rearward deviation of a concealed lattice column in a tower crane foundation, comprising the following specific steps:

[0007] S1. Prefabricated deviation-correcting lattice columns:

[0008] The deflection-correcting lattice column comprises an embedded cast iron block, and lattice column angle steels are welded at the four corners of the embedded cast iron block. Adjacent lattice column angle steels are fixedly connected by a plurality of tie strips arranged at equal intervals from top to bottom. Two U-shaped protective sleeves are cross-arranged in the deflection-correcting lattice column, and the side edges of the U-shaped protective sleeves are welded to the middle position of the inner wall of the tie strips. A power-carrying wire is passed through the U-shaped protective sleeve, and the power-carrying wire is connected to an external adjustable voltage power supply. The outer periphery of the four lattice column angle steels corresponding to the embedded cast iron block is wrapped with a power-carrying coil, and the power-carrying coil is wrapped with a bottom protective cover, and the power-carrying coil is connected to a remote control power supply.

[0009] S2. Casting the cap:

[0010] Four deviation-correcting lattice columns are installed into the hole along with the cast-in-place pile reinforcement cage, and the cap is cast;

[0011] S3. Excavation:

[0012] During the construction phase of pile foundation, earthwork is excavated and the lattice columns that can be corrected are gradually exposed in the foundation pit;

[0013] S4. Observe the correctable lattice columns in the excavation section and estimate the deflection rate of the correctable lattice columns at the buried depth:

[0014] It is known that the depth of the correctable lattice column is H. With the excavation of earthwork, the correctable lattice column is gradually exposed in the foundation pit. The exposed height of the four correctable lattice columns is h. Divide h into three equal parts to obtain four observation heights h1, h2, h3, and h4 with equal spacing from top to bottom; the horizontal displacement of the first correctable lattice column from the design center at the four observation heights is a1, a2, a3, and a4, the horizontal displacement of the second correctable lattice column from the design center at the four observation heights is b1, b2, b3, and b4, the horizontal displacement of the third correctable lattice column from the design center at the four observation heights is c1, c2, c3, and c4, and the horizontal displacement of the fourth correctable lattice column from the design center at the four observation heights is d1, d2, d3, and d4;

[0015] The deflection rates of the four deflection-correcting lattice columns are , , , ; The horizontal distance of the bottom inner deviation of the four correctable lattice columns is H. H. H. H;

[0016] If the inward horizontal displacement exceeds the specification requirements, corrective measures should be adopted;

[0017] S5, column bottom correction:

[0018] S51, selecting a lattice column to be corrected;

[0019] S52. Measure the magnetic permeability of the soil layer at the position to be corrected. ;

[0020] S53, bottom deviation correction operation:

[0021] Another correctable lattice column is selected as the magnetized column. The electromagnet principle is used to energize the coil at the bottom of the correctable lattice column, so that the embedded cast iron block at the bottom of the correctable lattice column produces magnetic poles. The magnetic field strength is , where N is the number of turns of the energized coil, I a is the current, r is the distance from the magnetic field; the induced magnetic field generated by the magnetic field covers the support leg of the correctable lattice column to be corrected, and the strength , so ;

[0022] A current is passed along the length of the column in the current-carrying wire of the correctable lattice column to be corrected. , calculated according to the Ampere force ,in is the current in a straight wire, The supply voltage can change the voltage direction, L represents the length of the straight wire in the magnetic field, and the corrective force is ; For the inwardly deflected correctable lattice column, the larger the inwardly deflected absolute horizontal spacing and the larger the spacing r with the magnetic field, the greater the corrective force, and the accurate correction of the inwardly deflected correctable lattice column can be achieved;

[0023] S6, top deviation correction:

[0024] A number of lifting rings are welded from top to bottom on the inner side of the lattice column angle steel of each correctable lattice column. L-shaped angle steel is selected as the tie rod. Steel wire ropes are fixed at the corners of the tie rods. The steel wire ropes pass through the lifting rings to pull back the top of the correctable lattice column that is deviated outward, and then the tie rods are cut and welded to fix them.

[0025] In step S4, if, as the observation height increases, the horizontal deviation of the observation height h4>the horizontal deviation of the observation height h3>the horizontal deviation of the observation height h2>the horizontal deviation of the observation height h1, then the deviation correction of the correctable lattice column is not performed.

[0026] In step S4, the allowable deviation of the installation verticality of the correctable lattice column is 0.5H / 100 and ≤35mm.

[0027] In step S51, if there is only one inwardly deviated correctable lattice column to be corrected, then another correctable lattice column that is closest to this correctable lattice column and is in the corrected position is selected as a magnetizing column for correction operation; if there are more than two inwardly deviated correctable lattice columns with inward inclination defects at the bottom of the column, two inwardly deviated correctable lattice columns that are close to each other are selected as magnetizing columns and correction columns respectively for correction together.

[0028] In step S52, the magnetic permeability of the soil layer The measurement process is as follows:

[0029] At the junction of the excavation area at the top of the column and the soil layer, excavate 0.3m around the correctable lattice column, and arrange a current-carrying wire with a resistance R around the correctable lattice column in the excavation area, and use a constant current source, a constant voltage source, an ammeter, a voltmeter, and a magnetic field meter. After covering the soil layer, change the adjustable voltage power supply to a voltage of V1, V2, adjust the distance between the insertion point of the magnetic field meter and the magnetic field r1, r2, r3, and obtain the magnetic induction intensity value b measured by the magnetic field meter 11 、b 12 、b 13 、b 21 、b 22 、b 23 ;

[0030] Magnetic field strength around a current-carrying conductor Calculation, where The physical quantity that characterizes the vacuum magnetic properties is 4×10 -7 Tm / A; is the current, measured by the ammeter, which is I1 and I2 respectively; r is the distance from the magnetic field, which is r1, r2, and r3 respectively, and then B is obtained 11 , B 12 , B 13 , B 21 , B 22 , B 23 ;

[0031] The obtained B 11 , B 12 , B 13 , B 21 , B 22 , B 23 Substitute into the formula ,get ,right Taking the average value, we can get the magnetic permeability of the soil layer. .

[0032] The beneficial effects of the present invention are as follows: the present invention not only realizes the adjustment of the exposed part of the tower crane foundation, but also can realize the precise adjustment of the concealed part of the correctable lattice column buried in the soil, adds a measure that can be used for post-remediation, and ensures the safety of the tower crane construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic structural diagram of the lattice column capable of correcting deviation in the present invention;

[0034] Figure 2 This is a schematic diagram of the deviation of the existing tower crane foundation;

[0035] Figure 3 This is a schematic diagram of the measurement after the excavated part is covered with soil;

[0036] Figure 4 This is a schematic diagram of deviation correction after the excavated part is covered with soil;

[0037] In the figure: 1-correctable lattice column; 2-cap; 3-lifting ring; 4-tension rod; 5-wire rope;

[0038] 101-embedded cast iron block; 102-lattice column angle steel; 103-stitched strip plate; 104-U-shaped protective sleeve; 105-powered wire; 106-adjustable voltage power supply; 107-powered coil; 108-bottom protective sleeve;

[0039] The following is a detailed description of the embodiments of the present invention with reference to the accompanying drawings. DETAILED DESCRIPTION

[0040] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The embodiments are only used to explain the present invention and are not used to limit the scope of the present invention. The present invention is described in more detail by way of example with reference to the accompanying drawings in the following paragraphs. The advantages and features of the present invention will become clearer according to the following description. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, and are only used to facilitate and clearly assist in explaining the purpose of the embodiments of the present invention.

[0041] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a component centered. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a component centered. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a component centered. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0043] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0044] A method for remediating the rearward deviation of a concealed lattice column in a tower crane foundation, comprising the following specific steps:

[0045] S1. Prefabricated deviation-correcting lattice column 1:

[0046] Lattice column 1 can be corrected Figure 1 As shown, it includes an embedded cast iron block 101, and lattice column angle steels 102 are welded at the four corners of the embedded cast iron block 101. Adjacent lattice column angle steels 102 are fixedly connected by a plurality of tie strips 103 arranged at equal intervals from top to bottom. Two U-shaped protective sleeves 104 are cross-arranged in the lattice column 1 that can correct deviation. The side of the U-shaped protective sleeve 104 is welded to the middle position of the inner wall of the tie strip 103. A power-carrying wire 105 is passed through the U-shaped protective sleeve 104, and the power-carrying wire 105 is connected to an external adjustable voltage power supply 106. The outer periphery of the four lattice column angle steels 102 corresponding to the embedded cast iron block 101 is wound with a power-carrying coil 107, and the power-carrying coil 107 is wrapped with a bottom protective cover 108, and the power-carrying coil 107 is connected to a remote control power supply.

[0047] The embedded cast iron block 101 is customized according to the hollow inner diameter of the correctable lattice column 1, and four lattice column angle steels 102 are respectively welded at the four corners of the embedded cast iron block 101. A number of tie plates 103 between two adjacent lattice column angle steels 102 are arranged at intervals along the longitudinal direction, and the tie plates 103 are welded and connected to the lattice column angle steels 102; the energized coil 107 has its own remote control power supply, which can power the coil at any time.

[0048] S2. Casting cap 2:

[0049] Four correctable lattice columns 1 are installed into the hole along with the cast-in-place pile reinforcement cage, and the cap 2 is cast. Figure 2 shown.

[0050] S3. Excavation:

[0051] During the pile foundation construction phase, the earthwork is excavated synchronously, and the deviation-correcting lattice column 1 is gradually exposed in the foundation pit.

[0052] S4. Observe the correctable lattice column 1 in the excavation section and estimate the deflection rate of the correctable lattice column 1 at the buried depth:

[0053] like Figure 3 As shown, it is known that the depth of the correctable lattice column 1 is H. With the excavation of earthwork, the correctable lattice column 1 is gradually exposed in the foundation pit. The exposed height of the four correctable lattice columns 1 is h. Dividing h into three equal parts, four observation heights h1, h2, h3, and h4 with equal spacing from top to bottom are obtained; the horizontal displacements of the first correctable lattice column 1 from the design center at the four observation heights are a1, a2, a3, and a4, the horizontal displacements of the second correctable lattice column 1 from the design center at the four observation heights are b1, b2, b3, and b4, the horizontal displacements of the third correctable lattice column 1 from the design center at the four observation heights are c1, c2, c3, and c4, and the horizontal displacements of the fourth correctable lattice column 1 from the design center at the four observation heights are d1, d2, d3, and d4;

[0054] The deflection rates of the four deflection-correcting lattice columns 1 are , , , ; If, as the observation height increases, the horizontal deviation of the observation height h4>the horizontal deviation of the observation height h3>the horizontal deviation of the observation height h2>the horizontal deviation of the observation height h1, then the deflection-correctable lattice column 1 will not be corrected;

[0055] The horizontal distance of the bottom inner deviation of the four correctable lattice columns 1 is H. H. H. H;

[0056] According to the current JGJ / T 187-2019 "Technical Code for Concrete Foundation Engineering of Tower Cranes" (hereinafter referred to as "Code"), Section 8.5.5 stipulates that the allowable deviation of the installation verticality of the steel columns of the combined tower crane foundation is 0.5H / 100 and ≤35 mm. If the inward horizontal displacement of the correctable lattice column 1 exceeds the requirements of the code, corrective measures should be adopted.

[0057] S5, column bottom correction:

[0058] S51, selecting a lattice column 1 to be corrected;

[0059] If there is only one inwardly deviated correctable lattice column 1 to be corrected, then another correctable lattice column 1 that is closest to this correctable lattice column 1 and is in the corrected position is selected as a magnetizing column for correction operation; if there are more than two inwardly deviated correctable lattice columns 1 with inward inclination defects at the bottom of the column, two inwardly deviated correctable lattice columns 1 that are close to each other are selected as magnetizing columns and correction columns respectively for correction together.

[0060] S52. Measure the magnetic permeability of the soil layer at the position to be corrected. ;

[0061] At the junction of the column top excavation area and the soil layer, 0.3m is excavated along the four sides of the correctable lattice column 1, and a current-carrying wire with a resistance R is arranged around the correctable lattice column 1 in the excavation area, and a constant current source, a constant voltage source, an ammeter, a voltmeter, and a magnetic field meter are applied. After covering the soil layer, the adjustable voltage power supply 106 is changed to a voltage of V1, V2, and the distance between the insertion point of the magnetic field meter and the magnetic field is adjusted to r1, r2, and r3, and the magnetic induction intensity value b measured by the magnetic field meter is obtained. 11 、b 12 、b 13 、b 21 、b 22 、b 23 ;

[0062] Magnetic field strength around the current-carrying conductor 105 Calculation, where The physical quantity that characterizes the vacuum magnetic properties is 4×10 -7 Tm / A; is the current, measured by the ammeter, which is I1 and I2 respectively; r is the distance from the magnetic field, which is r1, r2, and r3 respectively, and then B is obtained 11 , B 12 , B 13 , B 21 , B 22 , B 23 ;

[0063] The obtained B 11 , B 12 , B 13 , B 21 , B 22 , B 23 Substitute into the formula ,get ,right Taking the average value, we can get the magnetic permeability of the soil layer. ;

[0064] S53, bottom deviation correction operation:

[0065] Another correctable lattice column 1 is selected as a magnetized column. The electromagnet principle is used to energize the energized coil 107 at the bottom of the correctable lattice column 1, so that the embedded cast iron block 101 at the bottom of the correctable lattice column 1 generates magnetic poles. Then the magnetic field strength is , where N is the number of turns of the energized coil 107, I a is the current, r is the distance from the magnetic field; the induced magnetic field generated by the magnetic field covers the support leg of the correctable lattice column 1 to be corrected, and the strength , so ;

[0066] A current is passed along the length direction of the column in the current-carrying wire 105 of the deflection-correcting lattice column 1 to be corrected. , calculated according to the Ampere force ,in is the current in a straight wire, The supply voltage can change the voltage direction, L represents the length of the straight wire in the magnetic field, and the corrective force is For the inwardly deflected correctable lattice column 1, the larger the inwardly deflected absolute horizontal spacing and the larger the spacing r with the magnetic field, the greater the correcting force, and the accurate correction of the inwardly deflected correctable lattice column 1 can be achieved.

[0067] S6, top deviation correction:

[0068] A plurality of lifting rings 3 are welded from top to bottom on the inner side of the lattice column angle steel 102 of each deflection-correcting lattice column 1. Figure 4 As shown, L-shaped angle steel is selected as the tie rod 4, and a steel wire rope 5 is fixed at the corner of the tie rod 4. The steel wire rope 5 passes through the lifting ring 3 to pull back the top of the correctable lattice column 1 that is deviated outward from the top of the column, and then the tie rod 4 is cut and welded to fix it.

[0069] The present invention not only realizes the adjustment of the exposed part of the tower crane foundation, but also can realize the precise adjustment of the concealed part of the correctable lattice column 1 buried in the soil, adds a measure that can be used for post-remediation, and ensures the safety of the tower crane construction.

[0070] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for remediating the rear deviation of concealed lattice columns in tower crane foundation, characterized in that: The specific steps are: S1. Prefabricated correctable lattice column (1): The deflection-correcting lattice column (1) comprises an embedded cast iron block (101), lattice column angle steels (102) are welded at four corners of the embedded cast iron block (101), adjacent lattice column angle steels (102) are fixedly connected by a plurality of tie bars (103) arranged at equal intervals from top to bottom, two U-shaped protective sleeves (104) are cross-arranged in the deflection-correcting lattice column (1), the side edges of the U-shaped protective sleeves (104) are welded to the middle position of the inner wall of the tie bars (103), a power-carrying wire (105) is passed through the U-shaped protective sleeves (104), and the power-carrying wire (105) is connected to an external adjustable voltage power supply (106), and a power-carrying coil (107) is wound around the outer periphery of the four lattice column angle steels (102) corresponding to the embedded cast iron block (101), the power-carrying coil (107) is wrapped with a bottom protective sleeve (108), and the power-carrying coil (107) is connected to a remote control power supply; S2. Casting of the foundation (2): Four correctable lattice columns (1) are installed into the hole along with the cast-in-place pile reinforcement cage, and the cap (2) is cast; S3. Excavation: During the pile foundation construction phase, the excavation of earth is carried out simultaneously, and the deviation-correcting lattice column (1) is gradually exposed in the foundation pit; S4. Observe the correctable lattice column (1) in the excavation section and estimate the deflection rate of the correctable lattice column (1) at the buried depth: It is known that the depth of the correctable lattice column (1) is H. As the earthwork is excavated, the correctable lattice column (1) is gradually exposed in the foundation pit. The exposure height of the four correctable lattice columns (1) is h. H is divided into three equal parts to obtain four observation heights h1, h2, h3, and h4 with equal spacing from top to bottom; the horizontal displacement of the first correctable lattice column (1) from the design center at the four observation heights is a1, a2, a3, and a4; the horizontal displacement of the second correctable lattice column (1) from the design center at the four observation heights is b1, b2, b3, and b4; the horizontal displacement of the third correctable lattice column (1) from the design center at the four observation heights is c1, c2, c3, and c4; the horizontal displacement of the fourth correctable lattice column (1) from the design center at the four observation heights is d1, d2, d3, and d4; The deflection rates of the four deflection-correcting lattice columns (1) are , , , ; The horizontal distance of the bottom inner deviation of the four correctable lattice columns (1) is H. H. H. H; If the inward horizontal displacement exceeds the specification requirements, corrective measures should be adopted; S5, column bottom correction: S51, selecting a lattice column (1) to be corrected; S52. Measure the magnetic permeability of the soil layer at the position to be corrected. ; S53, bottom deviation correction operation: Another correctable lattice column (1) is selected as a magnetized column, and the electromagnet principle is applied to energize the energized coil (107) at the bottom of the correctable lattice column (1), so that the embedded cast iron block (101) at the bottom of the correctable lattice column (1) generates magnetic poles, and the magnetic field strength is , where N is the number of turns of the energized coil (107), I a is the current, r is the distance from the magnetic field; the induced magnetic field generated by the magnetic field covers the support leg of the correctable lattice column (1) to be corrected, and the strength , so ; A current is passed along the length of the column in the current-carrying wire (105) of the correctable lattice column (1) to be corrected. , calculated according to the Ampere force ,in is the current in a straight wire, The supply voltage can change the voltage direction, L represents the length of the straight wire in the magnetic field, and the corrective force is For the inwardly deflected correctable lattice column (1), the larger the inwardly deflected absolute horizontal spacing and the larger the spacing r with the magnetic field, the greater the corrective force, and the accurate correction of the inwardly deflected correctable lattice column (1) can be achieved; S6, top deviation correction: A plurality of lifting rings (3) are welded from top to bottom on the inner side of the lattice column angle steel (102) of each correctable lattice column (1), and an L-shaped angle steel is selected as a tie rod (4). A steel wire rope (5) is fixed at the corner of the tie rod (4). The steel wire rope (5) passes through the lifting ring (3) to pull back the top of the correctable lattice column (1) that is deviated outward from the top of the column, and then the tie rod (4) is cut and fixed by welding.

2. A method for remediating the rear deviation of a concealed lattice column in a tower crane foundation according to claim 1, characterized in that: In step S4, if, as the observation height increases, the horizontal deviation of the observation height h4>the horizontal deviation of the observation height h3>the horizontal deviation of the observation height h2>the horizontal deviation of the observation height h1, then the deflection-correctable lattice column (1) is not corrected.

3. A method for remediating the rear deviation of concealed lattice columns in tower crane foundation according to claim 2, characterized in that: In step S4, the allowable deviation of the installation verticality of the correctable lattice column (1) is 0.5H / 100 and is ≤35mm.

4. A method for remediating the rear deviation of concealed lattice columns in tower crane foundation according to claim 3, characterized in that: In step S51, if there is only one inwardly deviated correctable lattice column (1) to be corrected, then another inwardly deviated correctable lattice column (1) closest to the correctable lattice column (1) is selected as a magnetizing column to perform the correction operation; if there are more than two inwardly deviated correctable lattice columns (1) with an inwardly tilted column bottom defect, two inwardly deviated correctable lattice columns (1) that are close to each other are selected as magnetizing columns and correction columns respectively to perform correction together.

5. A method for remediating the rear deviation of concealed lattice columns in tower crane foundation according to claim 4, characterized in that: In step S52, the magnetic permeability of the soil layer The measurement process is as follows: At the junction of the column top excavation area and the soil layer, 0.3 m is excavated along the four sides of the correctable lattice column (1), and a current-carrying wire with a resistance R is arranged around the correctable lattice column (1) in the excavation area, and a constant current source, a constant voltage source, an ammeter, a voltmeter, and a magnetic field meter are applied. After covering the soil layer, the adjustable voltage power supply (106) is changed to a voltage of V1, V2, and the distance between the insertion point of the magnetic field meter and the magnetic field is adjusted to r1, r2, r3, and the magnetic induction intensity value b measured by the magnetic field meter is obtained. 11 , b 12 , b 13 , b 21 , b 22 , b 23 ; Magnetic field strength around the current-carrying conductor (105) Calculation, where The physical quantity that characterizes the vacuum magnetic properties is 4×10 -7 Tm / A; is the current, measured by the ammeter, which is I1 and I2 respectively; r is the distance from the magnetic field, which is r1, r2, and r3 respectively, and then B is obtained 11 , B 12 , B 13 , B 21 , B 22 , B 23 ; The obtained B 11 , B 12 , B 13 , B 21 , B 22 , B 23 Substitute into the formula ,get ,right Taking the average value, we can get the magnetic permeability of the soil layer. .

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