Construction Method of High-Strength Tensile Anchor Rod in Clearance-Limited Area under Complex Geological Conditions

Abstract

The present invention provides a construction method for high-strength anti-pulling anchor rods in a clearance-restricted area under complex geological conditions, which relates to the technical field of anchor rod construction and includes threaded steel bar anchor rods, foundation blocks, foundation core columns, foundation grouting parts, at least one layer of intermediate systems, support columns, and anchor rod sleeves, second cushion blocks, and second nuts for installing base plates. In the present invention, by adopting a construction process of segmented drilling and segmented pouring, and cooperating with an alternating construction method of central pouring and outer soil grouting curing, a structure with a smaller upper part and a larger lower part is formed for each part of the pouring structure. Moreover, the soil curing layer formed by the grouting part can ensure good bonding between it and the original easily collapsible soil layer. The formed anchor rod structure has good anti-pulling performance and supporting performance, thus meeting the installation requirements of ultra-large-span vertical poles and providing a reference direction for subsequent construction of ultra-large-span structures in the clearance-restricted area.

Description

Technical Field

[0001] The invention relates to the technical field of anchor rod construction, in particular to a high-strength pull-out resistant anchor rod construction method in a clearance-restricted area under complex geological conditions. Background Art

[0002] A support system needs to be built in a certain clearance-restricted area. Considering the influence of the density of the vertical poles on the actual use, it needs to be adjusted to an ultra-large span, widening the spacing from 900mm to 1200-1500mm. This change makes the construction site space more spacious, which also puts forward higher requirements on the pull-out resistance of the anchor rod. For this reason, the present invention provides a high-strength pull-out resistant anchor rod construction method in a clearance-restricted area under complex geological conditions. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides a method for constructing high-strength pull-out anchor rods in clearance-restricted areas under complex geological conditions, thereby solving the problem of insufficient pull-out resistance of traditional anchor rods under ultra-large spans.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0005] A high-strength pull-out anchor construction structure for a clearance-restricted area under complex geological conditions, comprising a threaded steel bar anchor 2, a foundation block 1, a foundation core column 5, a foundation grouting portion 6, at least one layer of an intermediate system T, a support column 9, and an anchor sleeve 11 for installing a base plate 10, a second pad 12, and a second nut 13. The intermediate system T comprises an intermediate core column 8 and an intermediate grouting portion 7 located above the intermediate core column 8. The foundation grouting portion 6, the intermediate grouting portion 7, the intermediate core column 8, and the support column 9 all have an expanded structure.

[0006] The foundation block 1 is fixedly installed on the bottom end of the threaded steel bar anchor rod 2, and the bottom end of the threaded steel bar anchor rod 2 is installed with a first cushion block 4 and a first nut 3.

[0007] The foundation core column 5 is cast on the outer side of the foundation block 1 , and the outer side of the foundation core column 5 is solidified to form a foundation grouting portion 6 , and the foundation grouting portion 6 is expanded.

[0008] The construction method of high-strength anti-pullout anchor in clearance-restricted areas under complex geological conditions includes the following construction steps:

[0009] S1. Segmented drilling:

[0010] The spiral drill rods with different diameters are used to drill holes in sections, so as to form a pile hole composed of several sections of foundation holes with gradually decreasing diameters;

[0011] S2. Planting anchor rods:

[0012] The foundation block is fixedly installed at the bottom end of the threaded steel bar anchor rod, and then the foundation block at the bottom end of the threaded steel bar anchor rod is implanted into the bottom of the foundation pile hole;

[0013] S3. Segmented pouring:

[0014] Carry out segmented pouring alternately by central pouring and outer soil grouting and solidification;

[0015] S4. Installation operation:

[0016] When pouring the top layer, sleeve an anchor rod sleeve outside the threaded steel bar anchor rod, sleeving the substrate to be fixed on the ground outside the anchor rod sleeve, and installing a second cushion block and a second nut at the top end of the threaded steel bar anchor rod.

[0017] Preferably, the segmented drilling in step S1 specifically includes:

[0018] S101. Use the first drill pipe to drill the top layer at a predetermined position, and arrange a steel casing inside the top layer drill hole;

[0019] S102. Use the second drill pipe to drill the middle layer at the bottom of the top layer drill hole, and arrange a steel casing inside the middle layer drill hole;

[0020] S103. Use the third drill pipe to drill the sub-bottom layer at the bottom of the middle layer drill hole, and arrange a steel casing inside the sub-bottom layer drill hole;

[0021] S104. Use the fourth drill pipe to drill the bottom layer at the bottom of the sub-bottom layer drill hole.

[0022] Preferably, the first drill pipe is a Φ63.5mm drill pipe, the second drill pipe is a Φ60mm drill pipe, the third drill pipe is a 50mm drill pipe, and the fourth drill pipe is a Φ42mm drill pipe.

[0023] Preferably, in step S102, the second drill pipe with different diameters is used repeatedly to form multiple middle layer drill holes.

[0024] Preferably, a first cushion block and a first nut are installed at the bottom end of the threaded steel bar anchor rod, and an inverted buckle / side support embedded inside the foundation block is fixedly arranged on the side of the threaded steel bar anchor rod.

[0025] Preferably, the segmented pouring in step S3 specifically includes:

[0026] S301. Use a cylindrical mold to sleeve outside the foundation block and the threaded steel bar anchor rod, and pour the foundation core column. The outer diameter of the foundation core column is smaller than the inner diameter of the bottom layer drill hole, and the top end of the foundation core column is located inside the middle layer drill hole;

[0027] After the basic core column is cured, the cylindrical mold is removed, and then the steel casing arranged inside the sub-bottom layer drilling is removed. The soil collapse inside the bottom layer drilling and the sub-bottom layer drilling wraps around the outside of the basic core column, and the soil curing agent slurry is pumped into the soil outside the basic core column to form the basic grouting part;

[0028] After the basic grouting part is cured, a casting cylinder is sleeved outside the basic core column. The top end of the casting cylinder is located inside the top layer drilling. The bottom end of the casting cylinder is provided with a tapered enlarging part, and the outside of the tapered enlarging part forms a seal with the steel casing arranged inside the middle layer drilling. Then, the middle core column is cast. The bottom of the middle core column has a bulging part;

[0029] After the middle core column is cured, the casting cylinder is removed, and then the steel casing arranged inside the middle layer drilling is removed. The soil collapse inside the middle layer drilling wraps around the outside of the middle core column. Then, the soil curing agent slurry is pumped into the soil outside the middle core column to form the middle grouting part;

[0030] After the middle grouting part is cured, the steel casing arranged inside the top layer drilling is removed, and the collapsed soil is manually cleaned, and then the support column is cast. The bottom of the support column has a bulging part.

[0031] Preferably, multiple groups of threaded steel bar anchors are provided, and the multiple groups of threaded steel bar anchors are distributed in a circular array.

[0032] Preferably, the casting cylinder includes:

[0033] Two groups of symmetrically arranged semi-circular sleeves. Each group of semi-circular sleeves includes a semi-circular sleeve and a tapered guiding part fixedly connected to the bottom end of the semi-circular sleeve. The side of the semi-circular sleeve is fixedly connected with a side plate;

[0034] A U-shaped fastener. One end of the U-shaped fastener is rotatably connected to the side plate. A bayonet is provided on the side of the side plate. The other end of the U-shaped fastener is lengthened and fixedly connected with a limiting ring on the side;

[0035] A center plate. An installation hole is provided at the end of the center plate. A connecting ear is fixedly connected to the outer side of the top end of the semi-circular sleeve. The center plate is fixedly installed with the connecting ear by screws.

[0036] Preferably, the positions of multiple groups of anchor rods are located in the construction area, and the multiple groups of anchor rod positions are constructed in a pipeline according to steps S1-S4.

[0037] Preferably, the soil curing agent slurry is a silicate cement slurry.

[0038] The present invention provides a construction method for high-strength anti-pulling anchor rods in a restricted headroom area under complex geological conditions. It has the following beneficial effects:

[0039] 1. In the present invention, by adopting the construction process of segmented drilling and segmented pouring, and cooperating with the alternating construction of central pouring and outer soil grouting and solidifying, a structure with a smaller upper part and a larger lower part is formed for each part of the pouring structure. Moreover, the soil solidification layer formed by the grouting part can ensure good bonding between it and the original easily collapsible soil layer. The formed anchor structure has good anti-pulling performance and supporting performance, thus meeting the installation requirements of ultra-large-span vertical poles and providing a reference direction for the construction of ultra-large-span structures in the subsequent clearance-limited area.

[0040] 2. In the present invention, the designed segmented drilling forms a pile foundation hole with at least four-layer structure including a top layer drilling, an intermediate layer drilling (multiple layers can be designed), a sub-bottom layer drilling, and a bottom layer drilling. Steel casing is designed for all except the bottom layer drilling, thus avoiding the risk of soil collapse during the drilling process. The drill pipe diameters used for the top layer drilling, intermediate layer drilling (multiple layers can be designed), sub-bottom layer drilling, and bottom layer drilling decrease in sequence, forming a stepped hole structure with a larger upper part and a smaller lower part for the pile foundation hole, which can ensure that the steel casing installed in the upper layer does not affect the construction of the lower layer drilling. Specifically, a pipeline construction operation is also adopted, thus ensuring the construction progress and improving the construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of the anchor structure constructed by the high-strength anti-pulling anchor construction method in the clearance-limited area under complex geological conditions proposed based on the present invention;

[0042] Figure 2 For Figure 1 the partial enlarged view at A in

[0043] Figure 3 It is a schematic diagram of each link of the high-strength anti-pulling anchor construction method in the clearance-limited area under complex geological conditions proposed by the present invention;

[0044] Figure 4 It is a distribution schematic diagram of one kind of threaded steel bar anchor;

[0045] Figure 5 It is a three-dimensional schematic diagram of the pouring cylinder;

[0046] Figure 6 For Figure 5 the partial enlarged view at B in

[0047] Among them, 1. Foundation block; 2. Threaded steel bar anchor; 3. First nut; 4. First spacer; 5. Foundation core column; 6. Foundation grouting part; 7. Intermediate grouting part; 8. Intermediate core column; T. Intermediate system; 9. Support column; 10. Base plate; 11. Anchor sleeve; 12. Second spacer; 13. Second nut; 14. Foundation pile hole; 15. Steel casing; 16. Pouring cylinder; 1601. Semi-circular sleeve; 1602. Central disc; 1603. Conical guiding part; 1604. Connecting ear; 1605. Side plate; 1606. U-shaped fastener; 1607. Limiting ring; 1608. Bayonet. Specific implementation mode

[0048] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0049] Embodiment 1:

[0050] The embodiment of the present invention provides a high-strength anti-pulling anchor construction structure in a clearance-limited area under complex geological conditions, which is used for the construction of super-large-span structures under complex geological conditions with easy hole collapse to ensure the high-strength anti-pulling performance of the anchor structure. It includes a threaded steel bar anchor 2, a foundation block 1, a foundation core column 5, a foundation grouting part 6, at least one intermediate system T, a support column 9, and an anchor sleeve 11, a second spacer 12, and a second nut 13 for installing the base plate 10. The intermediate system T includes an intermediate core column 8 and an intermediate grouting part 7 located above the intermediate core column 8. The foundation grouting part 6, the intermediate grouting part 7, the intermediate core column 8, and the support column 9 all have enlarged structures to improve the anti-pulling performance.

[0051] As Figure 1 - Figure 2 shown in, the foundation block 1 is fixedly installed at the bottom end of the threaded steel bar anchor 2. The foundation block 1 can be formed by pouring. Reverse buckles / side branches can be designed on the side of the threaded steel bar anchor 2 to increase the tightness of the connection between the foundation block 1 and the threaded steel bar anchor 2. And a first spacer 4 and a first nut 3 can be installed at the bottom end of the threaded steel bar anchor 2.

[0052] The foundation core column 5 is poured on the outside of the foundation block 1 and increases in height upward. The outside of the foundation core column 5 is solidified to form the foundation grouting part 6. The foundation grouting part 6 is enlarged, which is in close contact with the soil part. Moreover, a relatively tight structure is also formed between the foundation grouting part 6 and the outside of the foundation core column 5 to prevent the foundation core column 5 from being non-anti-pulling due to loose soil.

[0053] Embodiment 2:

[0054] As Figure 1 - Figure 6 shown in , an embodiment of the present invention provides a construction method for high-strength anti-pulling anchor rods in a clearance-limited area under complex geological conditions, which is used for the construction of super-large-span structures under complex geological conditions where hole collapse is likely to occur, and ensures the high-strength anti-pulling performance of the anchor rod structure. The specific construction steps are as follows:

[0055] S1. Segment drilling:

[0056] Use spiral drill pipes with different diameters for segment drilling to form a pile hole 14 composed of several base holes with gradually decreasing diameters. The pile hole 14 is stepped from top to bottom; each time, drill pipes of different sizes are used for drilling, and the total depth of multiple segment drillings is the depth of the pile hole 14.

[0057] S2. Inserting the anchor rod:

[0058] First, fixedly install a base block 1 at the bottom end of the threaded steel bar anchor rod 2. A special integrated anchor rod (referring to an integrated structure including the threaded steel bar anchor rod 2 and the cast base block 1) can be manufactured by prefabrication in a factory and transported to the construction area for direct use. Alternatively, a design and installation structure of the threaded steel bar anchor rod 2 and the pre-cast base block 1 can be adopted and assembled together in the construction area. When inserting the anchor rod, implant the base block 1 at the bottom end of the threaded steel bar anchor rod 2 into the bottom of the pile hole 14.

[0059] The first method is: use one threaded steel bar anchor rod 2, which is located at the center of the base block 1. When inserting the anchor rod, the base block 1 is located at the center of the pile hole 14.

[0060] The second method is: use multiple threaded steel bar anchor rods 2, and the multiple threaded steel bar anchor rods 2 are circumferentially distributed on the base block 1. When inserting the anchor rod, the base block 1 is located at the center of the pile hole 14.

[0061] S3. Segment pouring:

[0062] Adopt alternating segment pouring of central pouring and outer soil grouting and solidification. The concrete structure formed by central pouring is tight with the solidified layer structure formed by outer soil grouting and solidification, and the solidified layer formed by outer soil grouting and solidification is also relatively tightly connected to the soil layer.

[0063] S4. Installation operation:

[0064] When pouring the uppermost layer, sleeved an anchor rod sleeve 11 outside the threaded steel bar anchor rod 2. The function of the anchor rod sleeve 11 is to protect the threaded steel bar anchor rod 2. The base plate 10 to be fixed on the ground is sleeved outside the anchor rod sleeve 11. Install a second cushion block 12 and a second nut 13 at the top end of the threaded steel bar anchor rod 2. The second cushion block 12 and the second nut 13 are used to compress the base plate 10.

[0065] During actual construction, multiple groups of anchor rod positions are located in the construction area, and the multiple groups of the anchor rod positions are constructed in a production line manner according to steps S1-S4, thereby improving the construction efficiency of the anchor rods and ensuring the construction progress.

[0066] In this embodiment, by adopting a construction process of segmented drilling and segmented pouring, and cooperating with an alternating construction method of central pouring and outer soil grouting solidification, a structure with a smaller upper part and a larger lower part is formed for each part of the pouring structure, and the soil solidification layer formed by the grouting part can ensure good bonding between it and the original easily collapsible soil layer. The formed anchor rod structure has better uplift resistance and support performance, thereby meeting the installation requirements of ultra-large-span vertical poles and providing a reference direction for the construction of ultra-large-span structures in the subsequent construction area with limited clearance.

[0067] In one embodiment, the segmented drilling in step S1 specifically includes:

[0068] S101. Use the line laying method to measure and then mark the predetermined position of the anchor rod structure, use the first drill rod to drill the top layer at the predetermined position, and arrange a steel casing inside the top layer drilling. The steel casing is formed by rolling a steel plate with a thickness of 10-25 mm, and its outer diameter is the same as the outer diameter of the top layer drilling.

[0069] S102. Use the second drill rod to drill the middle layer at the bottom of the top layer drilling, and arrange a steel casing inside the middle layer drilling. Step S102 can be repeated multiple times to form multiple layers of middle layer drillings.

[0070] S103. Use the third drill rod to drill the sub-bottom layer at the bottom of the middle layer drilling, and arrange a steel casing inside the sub-bottom layer drilling.

[0071] S104. Use the fourth drill rod to drill the bottom layer at the bottom of the sub-bottom layer drilling. After the bottom layer drilling, the anchor rod can be inserted, and it is not necessary to install a steel casing.

[0072] Specifically during construction, use the line laying method to measure and then mark the predetermined positions of the anchor rod structure, mark to form multiple predetermined positions of the anchor rod structure, and steps S101-S104 are constructed using a production line process. Generally, the depths of the top layer drilling, middle layer drilling (referring to the depth of each layer), sub-bottom layer drilling, and bottom layer drilling are all designed to be 300-500 mm; for example, according to the design requirements, if the depth of the foundation pile hole 14 is 2000 mm, choose one layer of middle layer drilling, and the depth of each layer of the top layer drilling, middle layer drilling, sub-bottom layer drilling, and bottom layer drilling is 500 mm; for example, according to the design requirements, if the depth of the foundation pile hole 14 is 2600 mm, three layers of middle layer drilling can be chosen, and the depth of each layer of the top layer drilling, middle layer drilling, sub-bottom layer drilling (three layers), and bottom layer drilling is 434 mm.

[0073] In one embodiment, the first drill pipe is a drill pipe with a diameter of Φ63.5mm, the second drill pipe is a drill pipe with a diameter of Φ60mm, the third drill pipe is a drill pipe with a diameter of 50mm, and the fourth drill pipe is a drill pipe with a diameter of Φ42mm.

[0074] In one embodiment, a first cushion block 4 and a first nut 3 are installed at the bottom end of the threaded steel bar anchor 2. An inverted buckle / side support embedded inside the foundation block 1 is fixedly arranged on the side of the threaded steel bar anchor 2, thereby increasing the connection strength between the threaded steel bar anchor 2 and the foundation block 1. The foundation block 1 is a cylindrical concrete casting block.

[0075] In one embodiment, the segmented pouring in step S3 specifically includes:

[0076] S301: Use a cylindrical mold to sleeve outside the foundation block 1 and the threaded steel bar anchor 2, and pour the foundation core column 5. The outer diameter of the foundation core column 5 is smaller than the inner diameter of the bottom layer drilling hole, and the top end of the foundation core column 5 is located inside the middle layer drilling hole. The formed foundation core column 5 covers the foundation block 1, making the foundation core column 5 have better integrity with the foundation block 1.

[0077] S302: After the foundation core column 5 is cured, remove the cylindrical mold, and then remove the steel casing arranged inside the sub-bottom layer drilling hole. Wait for a period of time / inject high-pressure water to cause the soil inside the bottom layer drilling hole and the sub-bottom layer drilling hole to collapse and cover the outside of the foundation core column 5. Pump the soil curing agent slurry into the soil outside the foundation core column 5 to form a foundation grouting part 6. The foundation grouting part 6 covers the outside of the foundation core column 5, and the foundation grouting part 6 bulges around and has a tight combination with the soil.

[0078] S303: After the foundation grouting part 6 is cured, use a pouring cylinder 16 to sleeve outside the foundation core column 5. The top end of the pouring cylinder 16 is located inside the top layer drilling hole. The bottom end of the pouring cylinder 16 is provided with a tapered enlarging part, and the outside of the tapered enlarging part forms a seal with the steel casing arranged inside the middle layer drilling hole, so that concrete can be poured inside the pouring cylinder 16 and the concrete will not overflow outside the pouring cylinder 16. Then pour the middle core column 8 to make the middle core column 8 tightly fitted with the foundation core column 5, and the bottom of the middle core column 8 has a bulging part to ensure its sufficient anti-pulling performance.

[0079] S304: After the middle core column 8 is cured, remove the pouring cylinder 16, and then remove the steel casing arranged inside the middle layer drilling hole. The soil inside the middle layer drilling hole collapses and covers the outside of the middle core column 8. Then pump the soil curing agent slurry into the soil outside the middle core column 8 to form a middle grouting part 7. The middle grouting part 7 also bulges outwards, has a tight combination with the remaining soil, and is tightly combined with the middle core column 8 to improve the anti-pulling performance of the middle core column 8.

[0080] The middle core column 8 and the middle grouting part 7 form the middle system T. During actual construction, multiple layers of the middle system T can be formed according to requirements.

[0081] S305. After the middle grouting part 7 solidifies, the steel casing arranged inside the top drilling is removed, and the collapsed soil is manually cleaned. Then, the support column 9 is poured. The bottom of the support column 9 has a bulging part. The support column 9 is a concrete structure with the largest diameter, which provides a relatively large support surface, so as to support the substrate 10. After the installation operation is completed, the substrate 10 is fixed to the threaded steel bar anchor 2, and a tensile force is applied to the substrate 10.

[0082] In one embodiment, the pouring cylinder 16 includes: two groups of symmetrically arranged semi-circular sleeves, U-shaped fasteners 1606, and a central disk 1602. Each group of semi-circular sleeves includes a semi-circular sleeve 1601 and a conical guiding part 1603 fixedly connected to the bottom end of the semi-circular sleeve 1601. The two semi-circular sleeves 1601 form a cylindrical shape. A side plate 1605 is fixedly connected to the side of the semi-circular sleeve 1601. One end of the U-shaped fastener 1606 is rotatably connected to the side plate 1605. A bayonet 1608 is formed on the side of the side plate 1605. The other end of the U-shaped fastener 1606 is lengthened and a limiting ring 1607 is fixedly connected to the side. An installation hole is formed at the end of the central disk 1602. A connecting ear 1604 is fixedly connected to the outer side of the top end of the semi-circular sleeve 1601. The central disk 1602 is fixedly installed with the connecting ear 1604 by screws.

[0083] As Figure 6 shown in the figure, multiple groups of U-shaped fasteners 1606 are used to fasten the two semi-circular sleeves 1601, and then the central disk 1602 is installed at the top of the pouring cylinder 16. The outer side of the central disk 1602 is located inside the steel casing 15. Relying on the central disk 1602, the pouring cylinder 16 can be positioned so that the pouring cylinder 16 is located at the center of the pile foundation hole 14.

[0084] In one embodiment, the soil curing agent slurry is a silicate cement slurry, which can have better integrality with the later-poured concrete structure.

[0085] The designed sectional drilling forms a pile foundation hole with at least four layers of structures including a top drilling, a middle layer drilling, a sub-bottom drilling, and a bottom drilling. Steel casings are designed for all except the bottom drilling, thus avoiding the risk of soil collapse during the drilling process. The drill pipe diameters used for the top drilling, the middle layer drilling (multiple layers can be designed), the sub-bottom drilling, and the bottom drilling decrease in sequence, forming a stepped hole structure of the pile foundation hole that is larger at the top and smaller at the bottom, which can ensure that the steel casing installed in the upper layer does not affect the construction of the lower layer drilling. Specifically, a pipeline construction operation is also adopted, thus ensuring the construction progress and improving the construction efficiency.

[0086] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art will appreciate that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Construction method of high-strength anti-pulling anchor rod in a restricted clearance area under complex geological conditions, characterized in that, It includes the following construction steps: S1. Segment drilling: Use spiral drill pipes with different diameters for segment drilling to form a pile foundation hole (14) composed of several segmental basic holes with gradually decreasing diameters; S2. Insert anchor rods: Fix and install a base block (1) at the bottom end of the threaded steel bar anchor rod (2), and then implant the base block (1) at the bottom end of the threaded steel bar anchor rod (2) into the bottom of the pile foundation hole (14); S3. Segment pouring: Adopt alternating central pouring and outer soil grouting curing for segment pouring; S4. Installation operation: During the pouring of the topmost layer, sleeve an anchor rod sleeve (11) outside the threaded steel bar anchor rod (2), sleevethe base plate (10) to be fixed on the ground outside the anchor rod sleeve (11), and install a second cushion block (12) and a second nut (13) at the top end of the threaded steel bar anchor rod (2).

2. The construction method of high-strength anti-pulling anchor rods in a clearance-limited area under complex geological conditions according to claim 1, characterized in that The segment drilling in step S1 specifically includes: S101. Use the first drill pipe to conduct top-layer drilling at a predetermined position, and arrange a steel casing inside the top-layer drilling; S102. Use the second drill pipe to conduct middle-layer drilling at the bottom of the top-layer drilling, and arrange a steel casing inside the middle-layer drilling; S103. Use the third drill pipe to conduct sub-bottom-layer drilling at the bottom of the middle-layer drilling, and arrange a steel casing inside the sub-bottom-layer drilling; S104. Use the fourth drill pipe to conduct bottom-layer drilling at the bottom of the sub-bottom-layer drilling.

3. The construction method of high-strength anti-pulling anchor rods in a clearance-restricted area under complex geological conditions according to claim 2, characterized in that: The first drill pipe is a Φ63.5mm drill pipe, the second drill pipe is a Φ60mm drill pipe, the third drill pipe is a Φ50mm drill pipe, and the fourth drill pipe is a Φ42mm drill pipe.

4. The construction method of high-strength anti-pulling anchor rods in a clearance-limited area under complex geological conditions according to claim 2, characterized in that: In step S102, the second drill pipe with different diameters is used repeatedly to form multiple middle-layer drillings.

5. The construction method of high-strength anti-pulling anchor rods in a clearance-restricted area under complex geological conditions according to claim 1, characterized in that: A first cushion block (4) and a first nut (3) are installed at the bottom end of the threaded steel bar anchor rod (2), and an inverted buckle / side branch embedded inside the base block (1) is fixedly arranged on the side of the threaded steel bar anchor rod (2).

6. The construction method of high-strength anti-pulling anchor rods in a clearance-restricted area under complex geological conditions according to claim 2, characterized in that The segment pouring in step S3 specifically includes: S301. Use a cylindrical mold to sleeve outside the base block (1) and the threaded steel bar anchor rod (2), and pour a base core column (5). The outer diameter of the base core column (5) is smaller than the inner diameter of the bottom-layer drilling, and the top end of the base core column (5) is located inside the middle-layer drilling; S302. After the base core column (5) is cured, remove the cylindrical mold, and then remove the steel casing arranged inside the sub-bottom-layer drilling. The soil inside the bottom-layer drilling and sub-bottom-layer drilling collapses and wraps around the outside of the base core column (5), and pump a soil curing agent slurry into the soil outside the base core column (5) to form a base grouting part (6); S303. After the base grouting part (6) is cured, use a pouring cylinder (16) to sleeve outside the base core column (5). The top end of the pouring cylinder (16) is located inside the top-layer drilling. A conical enlarging part is arranged at the bottom end of the pouring cylinder (16), and a seal is formed between the outside of the conical enlarging part and the steel casing arranged inside the middle-layer drilling. Then pour a middle core column (8), and the bottom of the middle core column (8) has a swelling part; After the middle core column (8) is cured, the casting cylinder (16) is removed, and then the steel casing arranged inside the middle layer drilling is removed. The soil that collapses inside the middle layer drilling is wrapped around the outside of the middle core column (8), and then the soil curing agent slurry is pumped into the soil outside the middle core column (8) to form the middle grouting part (7). After the middle grouting part (7) is cured, the steel casing arranged inside the top layer drilling is removed, and the collapsed soil is manually cleaned, and then the support column (9) is cast. The bottom of the support column (9) has a bulging part.

7. The construction method of high-strength anti-pulling anchor rods in a clearance-restricted area under complex geological conditions according to claim 1, characterized in that: A plurality of groups of the threaded steel bar anchors (2) are provided, and the plurality of groups of the threaded steel bar anchors (2) are distributed in a circular array.

8. The construction method of high-strength anti-pulling anchor rods in a clearance-restricted area under complex geological conditions according to claim 6, characterized in that, The casting cylinder (16) includes:[[]]END Two groups of symmetrically arranged semi-circular sleeves. Each group of the semi-circular sleeves includes a semi-circular sleeve (1601) and a conical guiding part (1603) fixedly connected to the bottom end of the semi-circular sleeve (1601). A side plate (1605) is fixedly connected to the side surface of the semi-circular sleeve (1601). A U-shaped clamping member (1606). One end of the U-shaped clamping member (1606) is rotatably connected to the side plate (1605). A clamping opening (1608) is formed in the side surface of the side plate (1605). The other end of the U-shaped clamping member (1606) is lengthened and a limiting ring (1607) is fixedly connected to the side surface. A central disc (1602). An installation hole is formed at the end of the central disc (1602). A connecting ear (1604) is fixedly connected to the outer side of the top end of the semi-circular sleeve (1601). The central disc (1602) is fixedly installed on the connecting ear (1604) by screws.

9. The construction method of high-strength anti-pulling anchor rods in a clearance-restricted area under complex geological conditions according to claim 1, characterized in that: Locate the positions of multiple groups of anchors in the construction area, and the multiple groups of anchor positions are constructed in a pipeline according to steps S1-S4.

10. The construction method of high-strength anti-pulling anchor rods in a clearance-restricted area under complex geological conditions according to claim 6, characterized in that: The soil curing agent slurry is a silicate cement slurry.

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