A movable assembly type magnetic force adsorption back-jacking steel pipe centering positioning marking device and construction method

Abstract

The application discloses a movable assembly type magnetic adsorption back-up steel pipe centering and positioning marking device and a construction method.The device composition comprises an upper positioning steel pipe, a movable and rotatable and detachable moving arm, a detachable sliding arm fixing support, an adjustable spring group, an upper semicircular magnet device, a lower back-up steel pipe, an ear banded hoop, a lower semicircular magnet device and a hard rubber support gasket.The application utilizes the height-adjustable spring group screw sleeve, spring group magnetic force measurement, magnetic ring magnetic force penetration floor adsorption and other accurate positioning technologies in the construction process, and solves the problem of invisible steel pipe centering and positioning in the floors.

Description

Technical Field

[0001] This invention relates to the field of building structure engineering construction technology, specifically to a movable prefabricated magnetic adsorption return steel pipe centering and positioning marking device and construction method. Background Technology

[0002] In building construction, after the concrete floor slab of a multi-story basement is poured, construction operations such as overload loading, heavy steel structure assembly, and heavy vehicle operation need to be carried out on the top slab of the basement. Since the design load of the floor slab is lower than the actual construction load, vertically aligned backfill steel pipes need to be added from the basement foundation to the top slab in the loading area of ​​the floor slab to increase the floor slab support force transmission points and effectively distribute the overload load and vertically transmit the force to the bottom of the foundation.

[0003] During construction, the separation of basement floors by floor slabs made vertical construction work less visible. Furthermore, the lack of GPS signals and the presence of darkness made traditional surveying and positioning techniques difficult, leading to significant horizontal deviations in the alignment of the roof support pipes between floors. Under heavy vertical loads, when these deviations exceeded a certain value, substantial shear forces were generated in the floor slabs, causing shear failure and instability of the support system, resulting in serious quality and safety incidents.

[0004] Traditional solutions for reducing the centering deviation of the backfill steel pipes often employ a full-span support system with densely packed uprights. This approach reduces the load transmitted by each upright and decreases the spacing between them, thereby reducing the deviation distance between upper and lower floors. However, this results in significant resource waste. In recent years, with advancements in construction technology, several auxiliary tools for steel pipe centering have emerged, such as GPS positioning and laser positioning devices. However, these devices are often complex in structure, expensive, and lack adaptability in environments without GPS signals or in dark, obstructed basements, leading to substantial measurement errors.

[0005] Therefore, there is still a lack of a device in the existing technology that is simple in structure, easy to operate, low in cost, and can effectively improve centering accuracy and efficiency. Summary of the Invention

[0006] Therefore, this invention aims to solve the problems of low centering accuracy, poor efficiency, and complex operation in the steel pipe back-top centering method under non-visual, low-light, and signal-free environments between basement floors. Here, a movable prefabricated magnetic adsorption back-top steel pipe centering and positioning marking device and construction method are provided to improve construction efficiency and quality and reduce construction costs.

[0007] The present invention is implemented as follows: a movable assembled magnetic adsorption return steel pipe centering and positioning marking device is constructed. The device consists of an upper positioning steel pipe (1), a movable, rotatable and detachable moving arm (2), a detachable sliding arm fixed support (3), an adjustable spring group (4), an upper semi-circular magnet device (5), a lower return steel pipe (6), a clamp with ear pieces (9), a lower semi-circular magnet device (10), and a hard rubber support pad (11).

[0008] The top of the upper positioning steel pipe (1) is fitted with a leveling bubble, the upper part of the steel pipe is opened to connect a handle, the middle part of the steel pipe is connected to a disassembly moving arm (2), and the lower part of the steel pipe is connected to an adjustable spring assembly (4).

[0009] The movable, rotatable, and detachable movable arm (2) consists of three arms, each 120 degrees in the shape of a triangular support, bolted to the upper positioning steel pipe (1), which can rotate along the bolt and is detachable.

[0010] There are three detachable sliding arm fixed supports (3), each 120 degrees, used to position the movable, rotatable and detachable movable arm (2).

[0011] The adjustable spring assembly (4) consists of 4 groups, each at 90 degrees, and is attached to the lug of the upper steel pipe column 1.

[0012] The upper semi-circular magnet device (5) consists of two semi-circular U-shaped steel channels connected to form a ring, and two semi-circular magnets connected to form a ring, which are fixed inside the U-shaped steel channels. The lower inner ring of the U-shaped steel is covered with an ink-absorbing adhesive strip, which is used to adhere to the floor marking tube for positioning after being pressed.

[0013] Lower jacking steel pipe (6): The jacking steel pipe that has been supported;

[0014] Clamp with ear pieces (9): It is fixed to the top of the lower top steel pipe (6) by the rear installation method, and supports the lower semi-circular magnet device (10).

[0015] The lower semi-circular magnet device (10) consists of two semi-circular U-shaped steel channels connected to form a ring, and two semi-circular magnets connected to form a ring, which are fixed inside the U-shaped steel channels.

[0016] The rigid rubber bearing pad (11) is used to connect the top of the lower jacking steel pipe (6) with the floor slab (7) for uniform force transmission.

[0017] According to the present invention, a movable assembled magnetic adsorption return steel pipe centering and positioning marking device is provided, wherein the upper positioning steel pipe (1) has a round pipe upright (101), a handle (102), a bubble level (103), a steel pipe top sealing level plate (104), a hanging spring group ear plate (105), a double ear clip (106) and a middle single ear clip (107).

[0018] The top of the cylindrical upright (101) has an opening for connecting the upper spring assembly, the movable arm and the handle (102).

[0019] The handle (102) is used for both the moving device and the lifting device;

[0020] The bubble level (103) is used to indicate whether the upright is perpendicular to the horizontal direction and is fixed on the top sealing level plate (104) of the steel pipe;

[0021] The top sealing horizontal plate (104) of the steel pipe is welded to the top of the round pipe upright (101);

[0022] The hanging spring assembly lugs (105) are welded to the riser, and the lugs have horizontal elongated holes to adjust the spring position;

[0023] The double-ear clip (106) has a hole for bolting the upper side of the movable arm;

[0024] The central single-ear clip (107) has a hole for bolt fixing of the support.

[0025] According to the present invention, a movable assembled magnetic adsorption return steel pipe centering and positioning marking device is provided, wherein the movable, rotatable and detachable movable arm (2) has a movable arm bending steel pipe (201), a universal wheel (202), a movable arm upper end ear plate (203), a universal wheel upper screw (204) and a movable arm upper fixing bolt (205).

[0026] The upper part of the bending steel pipe (201) of the movable arm is welded with a single lug, and the lower part of the steel pipe is threaded inside to fix the lower universal wheel (202).

[0027] The upper end lug (203) of the movable arm is fixed to the riser lug with bolts;

[0028] The lower end of the upper screw (204) of the universal wheel is welded to the universal wheel (202), and the upper end is rotated into the bolt hole of the lower part of the moving arm;

[0029] The upper fixing bolt (205) of the mobile arm is used to fix the upper end of the mobile arm.

[0030] According to the present invention, a movable assembled magnetic adsorption return steel pipe centering and positioning marking device is provided, wherein the detachable sliding arm fixed support (3) has a support lug (301), a support steel pipe (302), a support U-shaped groove (303), a fixing bolt A (304) and a fixing bolt B (305).

[0031] The support lug (301) has a hole, one end is bolted to the column lug, and the other end is welded to the support steel pipe (302);

[0032] The support U-shaped groove (303) has an opening for bolting the movable arm;

[0033] The fixing bolt A (304) is used to fix the support and the steel pipe;

[0034] The fixing bolt B (305) is used to fix the U-shaped groove and the sliding arm.

[0035] According to the present invention, a movable assembled magnetic adsorption return steel pipe centering and positioning marking device is characterized in that: the adjustable spring group (4) has a long screw bolt (401), a fixing nut (402), an adjusting sleeve (403), and a readable spring (404).

[0036] The long screw bolt (401) is installed on the elongated hole lug. Since the lug is an elongated screw hole, its position can be adjusted.

[0037] The fixing nut (402) is tightened to clamp the ear piece;

[0038] The adjusting sleeve (403) is used to rotate and adjust the height of the lower spring, and the lower part has an opening for hanging lugs;

[0039] The readable spring (404) is hung on the upper sleeve.

[0040] According to the present invention, a movable assembled magnetic adsorption return steel pipe centering and positioning marking device is provided, wherein the upper semi-circular magnet device (5) has a semi-circular U-shaped groove A (501), a semi-circular U-shaped groove B (502), a semi-circular magnet A (503), a semi-circular magnet B (504), an ear piece A (505), an ear piece B (506), an ear piece C (507), an ear piece D (508), an ear piece E (509), an ear piece F (510), a connecting bolt A (511), a connecting bolt B (512), an ink-absorbing adhesive strip A (513), an ink-absorbing adhesive strip B (514), and lubricating oil (515); the ear piece A (505) has one hanging hole and one bolt hole, and is welded to the end of the lower semi-circular U-shaped top surface;

[0041] The ear piece B (506) has a small hanging hole and is welded to the end of the lower semi-circular U-shaped top surface;

[0042] The ear piece C (507) has one hanging hole and one bolt hole, and is welded to the end of the top surface of the lower semi-circular U-shaped groove;

[0043] The ear piece D (508) has one hanging hole and one bolt hole, and is welded to the end of the lower semi-circular U-shaped top surface;

[0044] The ear piece E (509) has a small hanging hole and is welded to the end of the lower semi-circular U-shaped top surface;

[0045] The ear piece F (510) has one hanging hole and one bolt hole, and is welded to the end of the top surface of the lower semi-circular U-shaped groove;

[0046] The connecting bolt A (511) is used to fix the two lower semi-circular U-shaped grooves;

[0047] The connecting bolt B (512) is used to fix the two lower semi-circular U-shaped grooves;

[0048] The ink-absorbing adhesive strip A (513) is attached to the inner arc of the bottom surface of the semi-circular U-shaped groove, and is used at the top to be adsorbed onto the floor marking tube for positioning after being pressed.

[0049] The ink-absorbing strip B (514) is attached to the inner arc of the bottom surface of the semi-circular U-shaped groove, and is used to be positioned on the floor slab marking tube after being pressed.

[0050] Lubricating oil (515) is used to reduce the friction of steel pipe caused by magnetic force.

[0051] According to the present invention, a movable assembled magnetic adsorption return steel pipe centering and positioning marking device is provided, wherein the clamp (9) with ear pieces has a U-shaped clamp A (901), a U-shaped clamp B (902), a connecting bolt C (903), a connecting bolt D (904), a horizontal support arc plate A (905), and a horizontal support arc plate B (906).

[0052] The U-shaped clamp A (901) has screw holes at both ends;

[0053] The U-shaped clamp B (902) has screw holes at both ends;

[0054] Tighten the connecting bolt C (903) to the clamp;

[0055] The connecting bolt D (904) is tightened to secure the clamp;

[0056] The horizontal support arc-shaped plate A (905) consists of two pieces, which are welded to the top of the clamp;

[0057] The horizontal support arc-shaped plate B (906) consists of two pieces, which are welded to the top of the clamp.

[0058] According to the present invention, a movable assembled magnetic adsorption return steel pipe centering and positioning marking device is provided, wherein the lower semi-circular magnet device (10) has a semi-circular U-shaped groove A (1001), a semi-circular U-shaped groove B (1002), a semi-circular magnet C (1003), a semi-circular magnet D (1004), an ear piece G (1005), an ear piece H (1006), an ear piece I (1007), an ear piece J (1008), a connecting bolt E (1009), and a connecting bolt F (1010).

[0059] The ear piece G (1005) has one bolt hole and is welded to the bottom end of the upper semi-circular U-shaped groove;

[0060] The ear piece H (1006) has one bolt hole and is welded to the bottom end of the upper semi-circular U-shaped groove;

[0061] The ear piece I (1007) has one bolt hole and is welded to the end of the bottom surface of the upper semi-circular U-shaped groove;

[0062] The ear piece J (1008) has one bolt hole and is welded to the end of the bottom surface of the upper semi-circular U-shaped groove;

[0063] The connecting bolt E (1009) is used to fix the two upper semi-circular U-shaped grooves;

[0064] The connecting bolt F (1010) is used to fix the two semi-circular U-shaped grooves above.

[0065] A marking construction method based on the above-mentioned movable prefabricated magnetic adsorption return steel pipe centering and positioning marking device is as follows:

[0066] Step 1: Installation of the magnetic ring device at the bottom of the jacking steel pipe:

[0067] (1) The underground third basement level back jacking steel pipes are installed in separate areas;

[0068] (2) Install clamps on the top of the return steel pipe and level the top plate of the clamps to ensure sufficient space for the upper magnetic ring;

[0069] (3) Install the lower magnetic ring device;

[0070] Step 2: Initial leveling of the upper riser assembly:

[0071] (1) Assemble the upper moving device riser, handle, support and moving arm and place it on the second basement floor slab;

[0072] (2) The fixing bolt group, height adjustable sleeve group, readable spring group, and magnetic ring device are installed in the air;

[0073] (3) Adjust the three universal wheel screws to ensure that the bubble of the horizontal bubble instrument is centered on the upper part of the riser. It is assumed that the moving device has been leveled and the riser is perpendicular to the plate.

[0074] Step 3: Initial leveling of the upper magnetic ring device off the ground:

[0075] Because of the steel reinforcement in the floor slab, the magnetic ring will have a weak attraction to the slab surface.

[0076] (1) Make preliminary adjustments to the adjustable sleeve at the top of the magnetic ring to ensure that the annular magnetic ring device is 5cm~8cm away from the floor slab;

[0077] (2) Finely adjust the adjustable sleeve and record the readings of the four sets of readable springs: a1, a2, a3, and a4.

[0078] (3) When the readings of the readable spring group are a1=a2=a3=a4, the precise horizontal leveling of the magnetic ring device is completed;

[0079] Step 4: Upper magnetic ring device for adsorption and positioning:

[0080] (1) In this area, the upper centering device is moved by the upper riser handle and the moving arm. When the device moves to the position of the lower top steel pipe with magnetic ring, the magnetic force increases and the upper magnetic ring is attracted to the floor surface.

[0081] (2) Record the readings of the four sets of readable springs b1, b2, b3, b4. When the readings of the same spring are equal, i.e. b1-a1=b2-a2=b3-a3=b4-a4, the centering of the magnetic ring adsorption point is completed by default.

[0082] (3) After the ink-absorbing adhesive strip attached to the lower part of the magnetic ring is adsorbed onto the floor slab, the circular mark on the floor slab is the positioning mark for the upper centering steel pipe; Step 5: Install the underground second basement level return steel pipe according to the positioning mark:

[0083] The above process is repeated continuously to achieve the precise alignment and positioning of the upper and lower jacking steel pipes. The jacking steel pipe construction proceeds from the 3rd basement level to the 2nd basement level and then to the 1st basement level.

[0084] The present invention has the following advantages: This invention patent addresses the problem of centering and positioning of non-visual steel pipes between floors by using precise positioning technologies such as adjustable height of spring group screw sleeve, magnetic force measurement of spring group, and magnetic force penetration and adsorption of magnetic rings during construction.

[0085] (a) Performance improvement

[0086] (1) Improved Centering Accuracy: Due to the separation of floor slabs between basement floors, construction operations between floors are not visible. Furthermore, traditional measurement and positioning techniques (measuring tape, laser measurement, GPS measurement) are difficult to operate in environments without GPS positioning signals and in dim lighting. In many engineering applications, construction teams often neglect centering or rely on manual measurement methods on the same floor for centering the backfill steel pipes. Accuracy is limited by the operator's skill level and experience, and deviations are usually large, making it difficult to meet the demands of high-precision construction. This invention achieves precise centering and marking through precise positioning technologies such as adjustable spring group height, spring group magnetic measurement technology, and magnetic ring magnetic penetration and adsorption through floor slabs. The centering deviation is controlled within 2mm, far superior to traditional methods. This high precision is due to the accurate reading of the spring magnetic force and the automatic attraction and locking of the centering position by magnetic penetration, eliminating human error in non-visual environments.

[0087] (2) Improved centering efficiency: Traditional manual centering methods involve measuring the position of the lower floor's back-top steel pipes using a measuring tape or GPS instrument, followed by measuring and locating the steel pipes on the current floor. Furthermore, in the dark environment of the basement and under the cover of columns and walls, traditional visual manual centering methods are time-consuming, especially in large floor slabs or densely supported areas, where manual centering measurement is inefficient. This invention utilizes a movable, prefabricated, magnetically adsorbed automatic centering technology for the back-top steel pipes, which is simple to operate, eliminates the need to measure the lower floor's back-top steel pipes, and significantly reduces the time required for moving, centering, and marking the upper steel pipes. This efficiency improvement significantly shortens the construction cycle and improves the overall project progress.

[0088] (3) Strong adaptability: Some existing centering auxiliary strategies and tools, such as laser positioning technology and GPS positioning technology, have high requirements for the construction environment, especially in the environment of multi-story basements, and their adaptability is limited. The device of the present invention has a simple structure, is suitable for steel pipes of various specifications, and can maintain stable performance in environments where there is no visibility between floors and no GPS signal, showing stronger adaptability.

[0089] This invention is lightweight, compact, and easy to assemble and disassemble, making it suitable for various building construction environments.

[0090] (ii) Cost reduction

[0091] (1) Simple structure and low manufacturing cost: The device of the present invention consists of a few parts, such as a short steel pipe, perforated steel lugs, a readable spring assembly, a semi-circular U-shaped groove, a semi-circular magnet, a U-shaped clamp, small connecting bolts, and ink-absorbing adhesive strips. The materials are readily available, the processing technology is simple, and the assembly cost is low. Compared with the complex mechanical or electronic alignment equipment on the market, the manufacturing cost of the present invention is significantly reduced, which facilitates large-scale production and promotion.

[0092] (2) Low maintenance cost: The modular design of this device makes component replacement and maintenance more convenient, further reducing long-term maintenance costs. At the same time, the components are conventional, with high durability and low probability of damage.

[0093] (III) How key technical solutions produce good technical effects

[0094] (1) Magnetic adsorption technology: This invention uses a ring-shaped neodymium iron boron strong magnet to achieve automatic attraction and centering of the upper and lower ring-shaped devices through strong magnetic force. This technology avoids the tedious process of traditional manual centering adjustment in environments where the interlayer is not visible, reduces errors, and improves centering accuracy and efficiency. The semi-circular design of the magnet and the C-shaped clamp ensures that the device fits tightly against the steel pipe, enhancing the stability and reliability of the adsorption.

[0095] (2) Adjustable height technology of spring group screw sleeve: The device can make fine adjustments to the height of the spring group and the lower magnet through the height-adjustable screw sleeve, which avoids the influence of the existing steel bars in the floor slab on the magnetic ring device when the alignment of the upper and lower steel pipes of the floor has not yet started, thus reducing the risk of mispositioning. At the same time, the adjustable height of the spring group can be used to level the magnetic ring device, ensuring the accuracy of magnetic ring adsorption and alignment in the later stage.

[0096] (3) Magnetic force measurement of spring group: The device is connected to the magnetic ring device through the spring group for measuring readings, and records the initial suspended leveling gravity and magnetic force readings, and the gravity and magnetic force readings after adsorption. The quantitative measurement data is used to analyze the magnetic adsorption state of the annular magnetic ring and the magnetic ring at the top of the steel pipe at the bottom of the floor, so as to ensure the accuracy of the centering value after the magnetic ring is adsorbed.

[0097] (4) Adsorption marking technology: The bottom of the U-shaped groove of the upper magnetic ring of the device is glued with ink-absorbing adhesive strips. Under the action of magnetic force, the ink in the adhesive strip will form a ring mark circle on the floor. This mark circle will improve the centering accuracy and precision of the upper return steel pipe during the later installation work. Attached Figure Description

[0098] Figure 1 A top-view schematic diagram of the movable, prefabricated magnetic adsorption return steel pipe centering and positioning device.

[0099] Figure 2 A top-back view of the movable, modular magnetic adsorption return steel pipe centering and positioning device.

[0100] Figure 3 Overall schematic diagram of the upper centering device;

[0101] Figure 4 Schematic diagram of the sliding arm of the upper centering device;

[0102] Figure 5 Schematic diagram of the upper centering device sliding arm connection;

[0103] Figure 6 Schematic diagram showing the connection between the upper centering device and the lower magnetic adsorption device;

[0104] Figure 7 A schematic diagram showing the disassembled parts of the upper centering device and the lower magnetic adsorption device.

[0105] Figure 8 Cross-sectional schematic diagram of the upper centering device and the lower magnetic adsorption device;

[0106] Figure 9 Schematic diagram of the connection between the lower return steel pipe and the upper magnetic adsorption device;

[0107] Figure 10 A schematic diagram showing the disassembled parts of the upper magnetic adsorption device for the lower return steel pipe;

[0108] Figure 11 A schematic diagram showing the disassembly of the lower jacking steel pipe clamp device.

[0109] Among them: 1. Upper positioning steel pipe, 2. Movable, rotatable and detachable moving arm, 3. Detachable sliding arm fixed support, 4. Adjustable spring assembly, 5. Upper semi-circular magnet device, 6. Lower top steel pipe, 7. Floor slab, 8. Floor slab reinforcement, 9. Clamp with ear plate, 10. Lower semi-circular magnet device, 11. Hard rubber support pad.

[0110] 101. Round tube upright, 102. Handle, 103. Bubble level, 104. Top sealing level plate of steel pipe, 105. Hanging spring lug, 106. Double lug clip, and 107. Middle single lug clip.

[0111] 201. Bending steel pipe of the movable arm; 202. Universal wheel; 203. Upper lug of the movable arm; 204. Upper screw of the universal wheel; 205. Upper fixing bolt of the movable arm.

[0112] Support lugs 301, support steel pipes 302, support U-shaped channels 303, fixing bolts A304 and B305;

[0113] Long screw bolt 401, fixing nut 402, adjusting sleeve 403, and readable spring 404;

[0114] Semicircular U-shaped groove A501, semicircular U-shaped groove B502, semicircular magnet A503, semicircular magnet B504, ear piece A505, ear piece B506, ear piece C507, ear piece D508, ear piece E509, ear piece F510, connecting bolt A511, connecting bolt B512, ink-absorbing adhesive strip A513, ink-absorbing adhesive strip B514, lubricating oil 515;

[0115] U-shaped clamp A901, U-shaped clamp B902, connecting bolt C903, connecting bolt D904, horizontal support arc plate A905, horizontal support arc plate B906;

[0116] Semicircular U-shaped groove A1001, semicircular U-shaped groove B1002, semicircular magnet C1003, semicircular magnet D1004, ear piece G1005, ear piece H1006, ear piece I1007, ear piece J1008, connecting bolt E1009, connecting bolt F1010. Detailed Implementation

[0117] The following will be combined with the appendix Figures 1-11This invention will be described in detail, and the technical solutions in the embodiments of this invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0118] This invention provides a movable, modular magnetic adsorption retraction steel pipe centering and positioning marking device, which is described in detail below with reference to the accompanying drawings;

[0119] like Figures 1-3 As shown; the device comprises an upper positioning steel pipe 1, a movable, rotatable, and detachable moving arm 2, a detachable sliding arm fixed support 3, an adjustable spring assembly 4, an upper semi-circular magnet device 5, a lower return steel pipe 6, a clamp with lugs 9, a lower semi-circular magnet device 10, and a hard rubber support pad 11.

[0120] A leveling bubble is installed on the top of the upper positioning steel pipe 1, a handle is connected to the upper part of the steel pipe, a disassembly moving arm 2 is connected to the middle of the steel pipe, and an adjustable height and readable spring is connected to the lower part of the steel pipe.

[0121] The movable, rotatable and detachable movable arm 2 consists of three 120-degree movable arms, each in the shape of a triangular support, and is bolted to the upper positioning steel pipe 1. It can rotate along the bolt and is detachable.

[0122] There are three detachable sliding arm fixed supports 3, each with a 120-degree angle, used to position the movable, rotatable, and detachable movable arm 2;

[0123] The adjustable spring assembly consists of four groups, each at 90 degrees, which are attached to the lug of the upper steel pipe column.

[0124] The upper semi-circular magnet device 5 consists of two semi-circular U-shaped steel channels connected to form a ring, and two semi-circular magnets connected to form a ring, which are fixed inside the U-shaped steel channels. Ink-absorbing adhesive strips are attached to the lower inner ring of the U-shaped steel channel for adsorption onto the floor marking tube for positioning under pressure.

[0125] Lower jacking steel pipe 6: The jacking steel pipe that has been supported;

[0126] Clamp 9 with ear pieces: It is fixed to the top of the lower return steel pipe 6 by the rear installation method, and supports the lower semi-circular magnet device 10;

[0127] The lower semi-circular magnet device 10 consists of two semi-circular U-shaped steel channels connected to form a ring, and two semi-circular magnets connected to form a ring, which are fixed inside the U-shaped steel channels.

[0128] Rigid rubber bearing pad 11: The top of the lower jacking steel pipe 6 is evenly connected to the floor slab 7 for force transmission.

[0129] like Figures 4-5 As shown, the upper positioning steel pipe 1 has a round pipe upright 101, a handle 102, a bubble level 103, a steel pipe top sealing level plate 104, a hanging spring group ear piece 105, a double ear clip 106, and a middle single ear clip 107.

[0130] The top of the cylindrical upright 101 has an opening for connecting the upper spring assembly, the movable arm and the handle 102;

[0131] The handle 102 is used for both the moving device and the lifting device;

[0132] The bubble level 103 is used to indicate whether the upright is perpendicular to the horizontal direction and is fixed on the top sealing level plate 104 of the steel pipe.

[0133] The horizontal sealing plate 104 at the top of the steel pipe is welded to the top of the round pipe upright 101;

[0134] The hanging spring assembly lug 105 is welded to the riser, and the lug has a horizontal elongated hole to adjust the spring position.

[0135] The double-ear clip 106 has a hole for bolting the upper side of the moving arm;

[0136] The central single-ear clip 107 has a hole for bolt fixing of the support.

[0137] The movable, rotatable and detachable movable arm 2 has a movable arm bending steel pipe 201, a universal wheel 202, a movable arm upper end lug 203, a universal wheel upper screw 204 and a movable arm upper fixing bolt 205.

[0138] The upper part of the bending steel pipe 201 of the movable arm is welded with a single lug, and the lower steel pipe is threaded inside to fix the lower universal wheel 202.

[0139] The upper end lug 203 of the movable arm is fixed to the riser lug with bolts;

[0140] The lower end of the upper screw 204 of the universal wheel is welded to the universal wheel 202, and the upper end is rotated into the bolt hole of the lower part of the moving arm.

[0141] The upper fixing bolt 205 of the mobile arm is used to fix the upper end of the mobile arm.

[0142] The detachable sliding arm fixed support 3 has a support lug 301, a support steel pipe 302, a support U-shaped groove 303, a fixing bolt A304, and a fixing bolt B305.

[0143] The support lug 301 has a hole, one end is bolted to the column lug, and the other end is welded to the support steel pipe 302;

[0144] The support U-shaped groove 303 has an opening for bolting the movable arm;

[0145] The fixing bolt A304 is used to fix the support and the steel pipe;

[0146] The fixing bolt B305 is used to fix the U-shaped groove and the sliding arm.

[0147] like Figures 6-8 As shown; the adjustable spring assembly 4 includes a long screw bolt 401, a fixing nut 402, an adjusting sleeve 403, and a readable spring 404;

[0148] The long screw bolt 401 is installed on the elongated hole lug. Since the lug is an elongated screw hole, its position can be adjusted.

[0149] The fixing nut 402 is tightened to clamp the ear piece;

[0150] The adjusting sleeve 403 is used to rotate and adjust the height of the lower spring, and the lower part has an opening for hanging lugs;

[0151] The readable spring 404 is hung on the upper sleeve;

[0152] The upper semi-circular magnet device 5 includes a semi-circular U-shaped groove A501, a semi-circular U-shaped groove B502, a semi-circular magnet A503, a semi-circular magnet B504, an ear piece A505, an ear piece B506, an ear piece C507, an ear piece D508, an ear piece E509, an ear piece F510, a connecting bolt A511, a connecting bolt B512, an ink-absorbing adhesive strip A513, an ink-absorbing adhesive strip B514, and lubricating oil 515; the ear piece A505 has one hanging hole and one bolt hole, and is welded to the end of the top surface of the lower semi-circular U-shaped part;

[0153] The ear piece B506 has one hanging hole and is welded to the end of the lower semi-circular U-shaped top surface;

[0154] The ear piece C507 has one hanging hole and one bolt hole, and is welded to the end of the top surface of the lower semi-circular U-shaped groove;

[0155] The ear piece D508 has one hanging hole and one bolt hole, and is welded to the end of the lower semi-circular U-shaped top surface;

[0156] The ear piece E509 has one hanging hole and is welded to the end of the lower semi-circular U-shaped top surface;

[0157] The ear piece F510 has one hanging hole and one bolt hole, and is welded to the end of the top surface of the lower semi-circular U-shaped groove;

[0158] The connecting bolt A511 is used to fix the two semi-circular U-shaped grooves below;

[0159] The connecting bolt B512 is used to fix the two semi-circular U-shaped grooves below;

[0160] The ink-absorbing adhesive strip A513 is attached to the inner arc of the bottom surface of the semi-circular U-shaped groove, and is used at the top to be adsorbed onto the floor marking tube for positioning after being pressed.

[0161] The ink-absorbing strip B514 is attached to the inner arc of the bottom surface of the semi-circular U-shaped groove, and is used at the top to be adsorbed onto the floor marking tube for positioning after being pressed.

[0162] Lubricating oil 515 is used to reduce the friction of steel pipes caused by magnetic force.

[0163] like Figures 9-11 As shown; the clamp 9 with ear pieces has a U-shaped clamp A901, a U-shaped clamp B902, a connecting bolt C903, a connecting bolt D904, a horizontal support arc plate A905, and a horizontal support arc plate B906;

[0164] The U-shaped clamp A901 has screw holes at both ends;

[0165] The U-shaped clamp B902 has screw holes at both ends;

[0166] Tighten the C903 connecting bolts to the clamp;

[0167] Tighten the D904 connecting bolts to the clamp;

[0168] The horizontal support arc-shaped plate A905 consists of two pieces, which are welded to the top of the clamp.

[0169] The horizontal support arc-shaped plate B906 consists of two pieces, which are welded to the top of the clamp.

[0170] The lower semi-circular magnet device 10 has a semi-circular U-shaped groove A1001, a semi-circular U-shaped groove B1002, a semi-circular magnet C1003, a semi-circular magnet D1004, an ear piece G1005, an ear piece H1006, an ear piece I1007, an ear piece J1008, a connecting bolt E1009, and a connecting bolt F1010;

[0171] The ear piece G1005 has one bolt hole and is welded to the bottom end of the upper semi-circular U-shaped groove;

[0172] The ear piece H1006 has one bolt hole and is welded to the bottom end of the upper semi-circular U-shaped groove;

[0173] The ear piece I1007 has one bolt hole and is welded to the bottom end of the upper semi-circular U-shaped groove;

[0174] The ear piece J1008 has one bolt hole and is welded to the bottom end of the upper semi-circular U-shaped groove;

[0175] The connecting bolt E1009 is used to fix the two semi-circular U-shaped grooves at the top;

[0176] The connecting bolt F1010 is used to fix the two semi-circular U-shaped grooves above.

[0177] This invention provides a construction method for a movable, prefabricated magnetic adsorption backfill steel pipe centering and positioning mark. The construction method and principle of the device are as follows: Assume that the basement has three negative floors.

[0178] Step 1: Installation of the magnetic ring device at the bottom of the jacking steel pipe:

[0179] (1) The underground third basement level back jacking steel pipes are installed in separate areas;

[0180] (2) Install clamps on the top of the return steel pipe and level the top plate of the clamps to ensure sufficient space for the upper magnetic ring;

[0181] (3) Install the lower magnetic ring device;

[0182] Step 2: Initial leveling of the upper riser assembly:

[0183] (1) Assemble the upper moving device riser, handle, support and moving arm and place it on the second basement floor slab;

[0184] (2) The fixing bolt group, height adjustable sleeve group, readable spring group, and magnetic ring device are installed in the air;

[0185] (3) Adjust the three universal wheel screws to ensure that the bubble of the horizontal bubble instrument is centered on the upper part of the riser. It is assumed that the moving device has been leveled and the riser is perpendicular to the plate.

[0186] Step 3: Initial leveling of the upper magnetic ring device off the ground:

[0187] Because of the steel reinforcement in the floor slab, the magnetic ring will have a weak attraction to the slab surface.

[0188] (1) Make preliminary adjustments to the adjustable sleeve at the top of the magnetic ring to ensure that the annular magnetic ring device is about 5cm to 8cm away from the floor slab;

[0189] (2) Finely adjust the adjustable sleeve and record the readings of the four sets of readable springs: a1, a2, a3, and a4.

[0190] (3) When the readings of the readable spring group are a1=a2=a3=a4, the precise horizontal leveling of the magnetic ring device is completed;

[0191] Step 4: Upper magnetic ring device for adsorption and positioning:

[0192] (1) In this area, the upper centering device is moved by the upper riser handle and the moving arm. When the device moves to the position of the lower top steel pipe with magnetic ring, the magnetic force increases and the upper magnetic ring is attracted to the floor surface.

[0193] (2) Record the readings of the four sets of readable springs b1, b2, b3, b4. When the readings of the same spring are equal, i.e. b1-a1=b2-a2=b3-a3=b4-a4, the centering of the magnetic ring adsorption point is completed by default.

[0194] (3) After the ink-absorbing adhesive strip attached to the lower part of the magnetic ring is adsorbed onto the floor slab, the circular mark on the floor slab is the positioning mark for the upper centering steel pipe; Step 5: Install the underground second basement level return steel pipe according to the positioning mark:

[0195] The above process is repeated continuously to achieve the precise alignment and positioning of the upper and lower jacking steel pipes. The jacking steel pipe construction proceeds from the 3rd basement level to the 2nd basement level and then to the 1st basement level.

[0196] Compared with existing technologies, this invention has significant advantages in terms of performance improvement and cost reduction. These advantages are achieved through innovative design and key technical solutions, which will be described in detail below with reference to specific technical features.

[0197] This invention patent addresses the problem of centering and positioning steel pipes between floors by utilizing precise positioning technologies such as adjustable height of spring group screw sleeve, magnetic force measurement of spring group, and magnetic force penetration and adsorption of magnetic rings during construction.

[0198] (a) Performance improvement

[0199] (1) Improved Centering Accuracy: Due to the separation of floor slabs between basement floors, construction operations between floors are not visible. Furthermore, traditional measurement and positioning techniques (measuring tape, laser measurement, GPS measurement) are difficult to operate in environments without GPS positioning signals and in dim lighting. In many engineering applications, construction teams often neglect centering or rely on manual measurement methods on the same floor for centering the backfill steel pipes. Accuracy is limited by the operator's skill level and experience, and deviations are usually large, making it difficult to meet the demands of high-precision construction. This invention achieves precise centering and marking through precise positioning technologies such as adjustable spring group height, spring group magnetic measurement technology, and magnetic ring magnetic penetration and adsorption through floor slabs. The centering deviation is controlled within 2mm, far superior to traditional methods. This high precision is due to the accurate reading of the spring magnetic force and the automatic attraction and locking of the centering position by magnetic penetration, eliminating human error in non-visual environments.

[0200] (4) Improved centering efficiency: Traditional manual centering methods involve measuring the position of the lower floor's back-top steel pipes using a measuring tape or GPS instrument, followed by measuring and locating the steel pipes on the current floor. Furthermore, in the dark environment of the basement and under the cover of columns and walls, traditional visual manual centering methods are time-consuming, especially in large floor slabs or densely supported areas, where manual centering measurement is inefficient. This invention utilizes a movable, prefabricated, magnetically adsorbed automatic centering technology for the back-top steel pipes. This technology is simple to operate, eliminates the need to measure the lower floor's back-top steel pipes, and significantly reduces the time required for moving, centering, and marking the upper steel pipes. This efficiency improvement significantly shortens the construction cycle and improves the overall project progress.

[0201] (5) Strong adaptability: Some existing centering auxiliary strategies and tools, such as laser positioning technology and GPS positioning technology, have high requirements for the construction environment, especially in the environment of multi-story basements, and their adaptability is limited. The device of the present invention has a simple structure, is suitable for steel pipes of various specifications, and can maintain stable performance in environments where there is no visibility between floors and no GPS signal, showing stronger adaptability.

[0202] This invention is lightweight, compact, and easy to assemble and disassemble, making it suitable for various building construction environments.

[0203] (ii) Cost reduction

[0204] (1) Simple structure and low manufacturing cost: The device of the present invention consists of a few parts, such as a short steel pipe, perforated steel lugs, a readable spring assembly, a semi-circular U-shaped groove, a semi-circular magnet, a U-shaped clamp, small connecting bolts, and ink-absorbing adhesive strips. The materials are readily available, the processing technology is simple, and the assembly cost is low. Compared with the complex mechanical or electronic alignment equipment on the market, the manufacturing cost of the present invention is significantly reduced, which facilitates large-scale production and promotion.

[0205] (2) Low maintenance cost: The modular design of this device makes component replacement and maintenance more convenient, further reducing long-term maintenance costs. At the same time, the components are conventional, with high durability and low probability of damage.

[0206] (III) How key technical solutions produce good technical effects

[0207] (1) Magnetic adsorption technology: This invention uses a ring-shaped neodymium iron boron strong magnet to achieve automatic attraction and centering of the upper and lower ring-shaped devices through strong magnetic force. This technology avoids the tedious process of traditional manual centering adjustment in environments where the interlayer is not visible, reduces errors, and improves centering accuracy and efficiency. The semi-circular design of the magnet and the C-shaped clamp ensures that the device fits tightly against the steel pipe, enhancing the stability and reliability of the adsorption.

[0208] (2) Adjustable height technology of spring group screw sleeve: The device can make fine adjustments to the height of the spring group and the lower magnet through the height-adjustable screw sleeve, which avoids the influence of the existing steel bars in the floor slab on the magnetic ring device when the alignment of the upper and lower steel pipes of the floor has not yet started, thus reducing the risk of mispositioning. At the same time, the adjustable height of the spring group can be used to level the magnetic ring device, ensuring the accuracy of magnetic ring adsorption and alignment in the later stage.

[0209] (3) Magnetic force measurement of spring group: The device is connected to the magnetic ring device through the spring group for measuring readings, and records the initial suspended leveling gravity and magnetic force readings, and the gravity and magnetic force readings after adsorption. The quantitative measurement data is used to analyze the magnetic adsorption state of the annular magnetic ring and the magnetic ring at the top of the steel pipe at the bottom of the floor, so as to ensure the accuracy of the centering value after the magnetic ring is adsorbed.

[0210] (4) Adsorption marking technology: The bottom of the U-shaped groove of the upper magnetic ring of the device is glued with ink-absorbing adhesive strips. Under the action of magnetic force, the ink in the adhesive strip will form a ring mark circle on the floor. This mark circle will improve the centering accuracy and precision of the upper return steel pipe during the later installation work.

[0211] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A mobile assembly type magnetic force adsorption back-up steel pipe centering positioning marking device, characterized in that ； The device consists of an upper positioning steel pipe (1), a movable, rotatable and detachable moving arm (2), a detachable sliding arm fixed support (3), an adjustable spring assembly (4), an upper semi-circular magnet device (5), a lower return steel pipe (6), a clamp with ear pieces (9), a lower semi-circular magnet device (10), and a hard rubber support pad (11). The top of the upper positioning steel pipe (1) is fitted with a leveling bubble, the upper part of the steel pipe is opened to connect a handle, the middle part of the steel pipe is connected to a disassembly moving arm (2), and the lower part of the steel pipe is connected to an adjustable spring assembly (4). The movable, rotatable and detachable movable arm (2) consists of three arms, each 120 degrees in the shape of a triangular support, bolted to the upper positioning steel pipe (1), which can rotate along the bolt and is detachable. There are three detachable sliding arm fixed supports (3), each 120 degrees, used to position the movable, rotatable and detachable movable arm (2). The adjustable spring assembly (4) consists of four groups, each at 90 degrees, which are attached to the lugs of the upper positioning steel pipe (1). The upper semi-circular magnet device (5) consists of two semi-circular U-shaped steel channels connected to form a ring, and two semi-circular magnets connected to form a ring, which are fixed inside the U-shaped steel channels. The lower inner ring of the U-shaped steel is covered with an ink-absorbing adhesive strip, which is used to adhere to the floor marking tube for positioning after being pressed. Lower jacking steel pipe (6): The jacking steel pipe that has been supported; Clamp with ear pieces (9): It is fixed to the top of the lower top steel pipe (6) by the rear installation method, and supports the lower semi-circular magnet device (10). The lower semi-circular magnet device (10) consists of two semi-circular U-shaped steel channels connected to form a ring, and two semi-circular magnets connected to form a ring, which are fixed inside the U-shaped steel channels. The rigid rubber bearing pad (11) is used to connect the top of the lower jacking steel pipe (6) with the floor slab (7) for uniform force transmission. The upper positioning steel pipe (1) has a round pipe upright (101), a handle (102), a bubble level (103), a steel pipe top sealing level plate (104), a hanging spring group ear plate (105), a double ear clip (106) and a middle single ear clip (107). The top of the cylindrical upright (101) has an opening for connecting the upper spring assembly, the movable arm and the handle (102). The handle (102) is used for both the moving device and the lifting device; The bubble level (103) is used to indicate whether the upright is perpendicular to the horizontal direction and is fixed on the top sealing level plate (104) of the steel pipe; The top sealing horizontal plate (104) of the steel pipe is welded to the top of the round pipe upright (101); The hanging spring assembly lugs (105) are welded to the riser, and the lugs have horizontal elongated holes to adjust the spring position; The double-ear clip (106) has a hole for bolting the upper side of the movable arm; The central single-ear clip (107) has a hole for bolt fixing of the support.

2. The mobile assembled magnetic force adsorption back-steel pipe centering positioning marking device according to claim 1, characterized in that ； The movable, rotatable and detachable mobile arm (2) has a mobile arm bending steel pipe (201), a universal wheel (202), a mobile arm upper end lug (203), a universal wheel upper screw (204) and a mobile arm upper fixing bolt (205). The upper part of the bending steel pipe (201) of the movable arm is welded with a single lug, and the lower part of the steel pipe is threaded inside to fix the lower universal wheel (202). The upper end lug (203) of the movable arm is fixed to the riser lug with bolts; The lower end of the upper screw (204) of the universal wheel is welded to the universal wheel (202), and the upper end is rotated into the bolt hole of the lower part of the moving arm; The upper fixing bolt (205) of the mobile arm is used to fix the upper end of the mobile arm.

3. The movable, assembled magnetic adsorption return steel pipe centering and positioning marking device according to claim 1, Its characteristics are: The detachable sliding arm fixed support (3) has a support lug (301), a support steel pipe (302), a support U-shaped groove (303), a fixing bolt A (304) and a fixing bolt B (305). The support lug (301) has a hole, one end is bolted to the column lug, and the other end is welded to the support steel pipe (302); The support U-shaped groove (303) has an opening for bolting the movable arm; The fixing bolt A (304) is used to fix the support and the steel pipe; The fixing bolt B (305) is used to fix the U-shaped groove and the sliding arm.

4. The movable prefabricated magnetic adsorption return steel pipe centering and positioning marking device according to claim 1, characterized in that; The adjustable spring assembly (4) has a long screw bolt (401), a fixing nut (402), an adjusting sleeve (403), and a readable spring (404). The long screw bolt (401) is installed on the elongated hole lug. Since the lug is an elongated screw hole, its position can be adjusted. The fixing nut (402) is tightened to clamp the ear piece; The adjusting sleeve (403) is used to rotate and adjust the height of the lower spring, and the lower part has an opening for hanging lugs; The readable spring (404) is hung on the upper sleeve.

5. The movable prefabricated magnetic adsorption return steel pipe centering and positioning marking device according to claim 1, characterized in that; The upper semi-circular magnet device (5) has a semi-circular U-shaped groove A (501), a semi-circular U-shaped groove B (502), a semi-circular magnet A (503), a semi-circular magnet B (504), an ear piece A (505), an ear piece B (506), an ear piece C (507), an ear piece D (508), an ear piece E (509), an ear piece F (510), a connecting bolt A (511), a connecting bolt B (512), an ink-absorbing adhesive strip A (513), an ink-absorbing adhesive strip B (514), and lubricating oil (515); the ear piece A (505) has one hanging hole and one bolt hole, and is welded to the end of the top surface of the lower semi-circular U-shaped part; The ear piece B (506) has a small hanging hole and is welded to the end of the lower semi-circular U-shaped top surface; The ear piece C (507) has one hanging hole and one bolt hole, and is welded to the end of the top surface of the lower semi-circular U-shaped groove; The ear piece D (508) has one hanging hole and one bolt hole, and is welded to the end of the lower semi-circular U-shaped top surface; The ear piece E (509) has a small hanging hole and is welded to the end of the lower semi-circular U-shaped top surface; The ear piece F (510) has one hanging hole and one bolt hole, and is welded to the end of the top surface of the lower semi-circular U-shaped groove; The connecting bolt A (511) is used to fix the two lower semi-circular U-shaped grooves; The connecting bolt B (512) is used to fix the two lower semi-circular U-shaped grooves; The ink-absorbing adhesive strip A (513) is attached to the inner arc of the bottom surface of the semi-circular U-shaped groove, and is used at the top to be adsorbed onto the floor marking tube for positioning after being pressed. The ink-absorbing strip B (514) is attached to the inner arc of the bottom surface of the semi-circular U-shaped groove, and is used to be positioned on the floor slab marking tube after being pressed. Lubricating oil (515) is used to reduce the friction of steel pipe caused by magnetic force.

6. The movable prefabricated magnetic adsorption return steel pipe centering and positioning marking device according to claim 1, characterized in that; The clamp (9) with ear pieces has a U-shaped clamp A (901), a U-shaped clamp B (902), a connecting bolt C (903), a connecting bolt D (904), a horizontal support arc plate A (905), and a horizontal support arc plate B (906). The U-shaped clamp A (901) has screw holes at both ends; The U-shaped clamp B (902) has screw holes at both ends; Tighten the connecting bolt C (903) to the clamp; The connecting bolt D (904) is tightened to secure the clamp; The horizontal support arc-shaped plate A (905) consists of two pieces, which are welded to the top of the clamp; The horizontal support arc-shaped plate B (906) consists of two pieces, which are welded to the top of the clamp.

7. The movable prefabricated magnetic adsorption return steel pipe centering and positioning marking device according to claim 1, characterized in that; The lower semi-circular magnet device (10) has a semi-circular U-shaped groove A (1001), a semi-circular U-shaped groove B (1002), a semi-circular magnet C (1003), a semi-circular magnet D (1004), an ear piece G (1005), an ear piece H (1006), an ear piece I (1007), an ear piece J (1008), a connecting bolt E (1009), and a connecting bolt F (1010). The ear piece G (1005) has one bolt hole and is welded to the bottom end of the upper semi-circular U-shaped groove; The ear piece H (1006) has one bolt hole and is welded to the bottom end of the upper semi-circular U-shaped groove; The ear piece I (1007) has one bolt hole and is welded to the end of the bottom surface of the upper semi-circular U-shaped groove; The ear piece J (1008) has one bolt hole and is welded to the end of the bottom surface of the upper semi-circular U-shaped groove; The connecting bolt E (1009) is used to fix the two upper semi-circular U-shaped grooves; The connecting bolt F (1010) is used to fix the two semi-circular U-shaped grooves above.

8. A marking construction method for a movable prefabricated magnetic adsorption return steel pipe centering and positioning marking device according to any one of claims 1 to 7, characterized in that... ； Step 1: Installation of the magnetic ring device at the bottom of the jacking steel pipe: (1) The underground third basement level back jacking steel pipes are installed in separate areas; (2) Install clamps on the top of the return steel pipe and level the top plate of the clamps to ensure sufficient space for the upper magnetic ring; (3) Install the lower magnetic ring device; Step 2: Initial leveling of the upper riser assembly: (1) Assemble the upper moving device riser, handle, support and moving arm and place it on the second basement floor slab; (2) The fixing bolt group, height adjustable sleeve group, readable spring group, and magnetic ring device are installed in the air; (3) Adjust the three universal wheel screws to ensure that the bubble of the horizontal bubble instrument is centered on the upper part of the riser. It is assumed that the moving device has been leveled and the riser is perpendicular to the plate. Step 3: Initial leveling of the upper magnetic ring device off the ground: Because of the steel reinforcement in the floor slab, the magnetic ring will have a weak attraction to the slab surface. (1) Make preliminary adjustments to the adjustable sleeve at the top of the magnetic ring to ensure that the annular magnetic ring device is 5cm~8cm away from the floor slab; (2) Finely adjust the adjustable sleeve and record the readings of the four sets of readable springs: a1, a2, a3, and a4. (3) When the readings of the readable spring group are a1=a2=a3=a4, the precise horizontal leveling of the magnetic ring device is completed; Step 4: Upper magnetic ring device for adsorption and positioning: (1) In this area, the upper centering device is moved by the upper riser handle and the moving arm. When the device moves to the position of the lower top steel pipe with magnetic ring, the magnetic force increases and the upper magnetic ring is attracted to the floor surface. (2) Record the readings of the four sets of readable springs b1, b2, b3, b4. When the readings of the same spring are equal, i.e. b1-a1=b2-a2=b3-a3=b4-a4, the centering of the magnetic ring adsorption point is completed by default. (3) After the ink-absorbing strip attached to the lower part of the magnetic ring is adsorbed onto the floor, the circular mark on the floor is the positioning of the upper centering steel pipe. Step 5: Install the underground second basement level jacking steel pipe according to the positioning marks: The above process is repeated continuously to achieve the precise alignment and positioning of the upper and lower jacking steel pipes. The jacking steel pipe construction proceeds from the 3rd basement level to the 2nd basement level and then to the 1st basement level.

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