Precast stairs and their construction methods

Abstract

This application relates to a precast staircase and its construction method. The precast staircase includes a precast base slab, precast steps, and supporting ribs. The precast base slab includes an upper extension, a lower extension, and several slabs. A grouting cavity is formed by splicing the precast steps and the precast base slab. A grouting port is provided on the upper extension. The precast steps include several tread blocks. Both the precast base slab and precast steps are assembled separately, reducing the weight and volume of individual precast staircase components. They can be transported to the installation site manually or by trolley, facilitating handling and construction, improving construction efficiency, and eliminating the need for hoisting, thus reducing hoisting costs and overall construction costs.

Description

Technical Field

[0001] This application relates to the field of stairs, and more particularly to a prefabricated staircase and its construction method. Background Technology

[0002] Prefabricated modular buildings have become a development trend in modern building structures due to their simple construction, short construction period, low environmental pollution, and labor saving. Among them, prefabricated staircases have been widely used in the field of prefabricated buildings because of their high degree of standardization, low production difficulty, and convenient construction and installation.

[0003] Currently, the weight of a single prefabricated staircase component used in engineering practice is typically 800-2000 kg, requiring large lifting equipment such as tower cranes and truck cranes for installation. However, in narrow sites (such as old building renovation sites, urban core building complexes, and indoor staircase replacement scenarios), the lifting operation space is insufficient (no lifting holes or limited lifting radius), making it difficult for lifting equipment to enter the site or expand its operating radius, resulting in low lifting efficiency and high construction costs, which need to be improved. Summary of the Invention

[0004] To address the issues of insufficient hoisting space and difficulty in accessing or expanding the working radius of hoisting equipment when installing prefabricated stairs in narrow spaces, resulting in low hoisting efficiency and high construction costs, this application provides a prefabricated staircase and its construction method.

[0005] Firstly, this application provides a prefabricated staircase, which adopts the following technical solution:

[0006] A precast staircase includes a precast base slab, precast steps, and supporting ribs. The precast base slab includes an upper extension section, a lower extension section, and several slabs. The several slabs are located between the upper extension section and the lower extension section. Each slab has a dovetail block 1. A dovetail groove 1 is formed on the side of the slab away from the dovetail block 1 for the dovetail block 1 to be inserted. A dovetail groove 2 is formed on the upper extension section for the dovetail block 1 to be inserted. A dovetail block 2 is formed on the lower extension section. The dovetail groove 1 is for the dovetail block 2 to be inserted.

[0007] The precast step is located above the precast base plate. A grouting cavity is formed by splicing the precast step and the precast base plate. A grouting port is opened on the upper extension section. The grouting port is connected to the grouting cavity. The precast step includes a number of step blocks. A rectangular steel frame and an L-shaped steel bar are respectively provided on both sides of the step block. The rectangular steel frame and the L-shaped steel bar are both located in the grouting cavity. The rectangular steel frame and the step block are spliced ​​to form a through hole for the L-shaped steel bar to pass through. The L-shaped steel bar is used to hook the rectangular steel frame on the adjacent step block.

[0008] The upper extension section is provided with an L-shaped steel bar frame, and the L-shaped steel bar frame and the upper extension section are spliced ​​together to form a slot for the rectangular steel bar frame one to be inserted. The step block is provided with a rectangular steel bar frame two, and the plate is provided with a rectangular steel bar frame three. The rectangular steel bar frame three and the rectangular steel bar frame two are both located in the grouting cavity. The rectangular steel bar frame one, the rectangular steel bar frame two, and the rectangular steel bar frame three are spliced ​​together to form a through hole for the support reinforcement to pass through.

[0009] A sealing plate is provided on the step block located at the lower end. The injection cavity is into which the sealing plate is inserted. The sealing plate is used to block the outlet of the injection cavity. The lower extension section abuts against the lower end of the sealing plate.

[0010] By adopting the above technical solution, when assembling the prefabricated stairs, the upper extension section and each panel are spliced ​​by inserting the dovetail block one into the dovetail groove two and the dovetail block one into the dovetail groove one. Then the upper extension section is installed and fixed in the designated position.

[0011] Next, place the step blocks so that the rectangular steel frame one on the step block is inserted into the slot. The step block is limited by the L-shaped steel frame abutting against the rectangular steel frame one. Then, place each step block in sequence so that the L-shaped steel bar passes through the through hole on the adjacent step block. Then, use a tool to bend the part of the L-shaped steel bar that passes through the through hole so that the L-shaped steel bar hooks onto the rectangular steel frame one on the adjacent step block, realizing the connection between the adjacent step blocks. Then, insert the support bar through the through hole. The support bar abuts against the rectangular steel frame one, rectangular steel frame two, and rectangular steel frame three to realize the limitation between adjacent step blocks, between adjacent slabs, and between the slab and the step block, and connect the slab and the step block. After pouring concrete, the overall structural strength of the precast staircase can be strengthened.

[0012] Then, the sealing plate is inserted into the grouting cavity on the lower step block to seal the outlet of the grouting cavity. The sealing plate abuts against the lower end of the support rib to limit the support rib. Then, the second dovetail block is inserted into the first dovetail groove so that the lower extension section abuts against the lower end of the sealing plate to limit the sealing plate. Then, concrete is poured into the grouting port until the concrete fills the grouting cavity, thus completing the construction of the precast staircase. The precast base plate and precast steps are assembled separately, which reduces the weight and volume of each precast staircase component. They can be transported to the installation site by manpower or trolley, which is convenient for transportation and construction and helps to improve construction efficiency. Moreover, there is no need to use hoisting for installation, which reduces hoisting costs and thus reduces construction costs.

[0013] Optionally, the second rectangular steel reinforcement frame and the third rectangular steel reinforcement frame are in one-to-one correspondence, with the second rectangular steel reinforcement frame abutting against the side of the third rectangular steel reinforcement frame near the upper extension section.

[0014] By adopting the above technical solution, the prefabricated stairs are supported at multiple points by the three rectangular steel frame abutting against the two rectangular steel frame pairs of prefabricated steps, thereby improving the overall structural stability of the prefabricated stairs.

[0015] Optionally, the lower extension section is provided with a limiting surface, which is used to abut against the side of the sealing plate away from the step block.

[0016] By adopting the above technical solution and setting a limiting surface, after the concrete is poured, the limiting surface abuts against the sealing plate to limit the sealing plate, reducing the situation where the sealing plate is pushed away from the step block under the gravity of the concrete, making the surface of the precast staircase smoother.

[0017] Optionally, the plate body is provided with a limiting block, and the step block is provided with a limiting groove for the limiting block to be engaged.

[0018] By adopting the above technical solution, the limiting block and the inner wall of the limiting groove abut against each other to achieve the limiting between the step block and the plate. There is no need to manually adjust the relative position between the second and third rectangular steel reinforcement frames, which facilitates the subsequent installation of the supporting bars through the holes. It can also transfer horizontal loads (such as lateral impacts and seismic forces) and reduce stress concentration.

[0019] Optionally, the L-shaped steel bar is a Q235 steel bar with a diameter of 6-8mm.

[0020] By adopting the above technical solution, the L-shaped steel bar can be bent with conventional tools such as pliers, and after bending, it still has a certain strength to connect adjacent step blocks.

[0021] Secondly, this application provides a construction method for prefabricated stairs, employing the following technical solution:

[0022] A construction method for the aforementioned prefabricated staircase includes the following steps:

[0023] S1. Insert the dovetail block one into the dovetail groove two, and then insert the dovetail block one on each plate into the dovetail groove one on the adjacent plate to achieve the splicing of the upper extension section and each plate. Then fix the upper extension section in the designated position.

[0024] S2. Place the first step block on the plate and make the rectangular steel bar frame on the step block snap into the slot to limit the first step block. Continue to place the remaining step blocks on the plate in sequence, and make the L-shaped steel bar on the upper step block pass through the through hole on the lower adjacent step block. Use a tool to bend the part of the L-shaped steel bar that passes through the through hole upward so that the L-shaped steel bar hooks the rectangular steel bar frame on the adjacent step block to achieve the connection of the adjacent step blocks.

[0025] S3. Pass the support bars through the holes;

[0026] S4. Insert the sealing plate into the injection cavity on the lower step block to block the outlet of the injection cavity. Then insert the second dovetail block into the first dovetail groove so that the lower extension section abuts the lower end of the sealing plate. Then fix the lower extension section.

[0027] S5. Pour concrete into the grouting port until the grouting cavity is filled with concrete, and smooth the concrete at the grouting port.

[0028] By adopting the above technical solution, transportation is convenient, hoisting is not required, construction efficiency is improved, and construction costs are reduced.

[0029] In summary, this application includes at least one of the following beneficial technical effects:

[0030] 1. The precast base plate and precast steps are assembled separately, which reduces the weight and volume of each precast stair component. They can be transported to the installation site by hand or trolley, which is convenient for handling and construction, and helps to improve construction efficiency. Moreover, installation does not require hoisting, which reduces hoisting costs and thus reduces construction costs.

[0031] 2. By connecting three rectangular steel reinforcement frames to two rectangular steel reinforcement frames, multiple points of support are formed for the precast steps, thereby improving the overall structural stability of the precast staircase;

[0032] 3. By abutting against the inner wall of the limiting block and the limiting groove, the step block and the plate are limited, which facilitates the subsequent installation of the supporting ribs through the holes and can also transfer horizontal loads and reduce stress concentration. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of an embodiment of this application.

[0034] Figure 2 This is a cross-sectional view of an embodiment of this application.

[0035] Figure 3 for Figure 2 The enlarged view in section A mainly shows the positional relationship between rectangular steel reinforcement frame two and rectangular steel reinforcement frame three.

[0036] Figure 4 This is a partial structural diagram of an embodiment of this application, mainly showing the structure of the L-shaped steel bar frame and the slot.

[0037] Figure 5 for Figure 2 The enlarged view of section B mainly shows the structure of the dovetail block 2 and the limiting surface.

[0038] Figure 6 This is a partial exploded structural diagram of an embodiment of this application when the L-shaped steel bar is not bent, mainly showing the structure of the limiting block and the limiting groove.

[0039] Figure 7This is a partial cross-sectional view of an embodiment of this application, mainly showing the relationship between the rectangular steel reinforcement frame and the L-shaped steel bar.

[0040] Figure 8 This is a partial structural diagram of an embodiment of this application, mainly showing the perforated structure.

[0041] Explanation of reference numerals in the attached drawings: 1. Precast base plate; 11. Upper extension section; 111. Dovetail groove II; 112. Grouting port; 12. Lower extension section; 13. Plate body; 131. Dovetail groove I; 2. Precast step; 21. Step block; 211. Limiting groove; 212. Embedded groove; 3. Supporting rib; 4. Dovetail block I; 5. Dovetail block II; 6. Grouting cavity; 7. Limiting block; 8. Rectangular steel reinforcement frame I; 9. L-shaped steel bar; 10. Through hole; 14. L-shaped steel reinforcement frame; 15. Slot; 16. Rectangular steel reinforcement frame II; 17. Rectangular steel reinforcement frame III; 18. Perforation; 19. Sealing plate; 20. Limiting surface. Detailed Implementation

[0042] The following is in conjunction with the appendix Figures 1-8 This application will be described in further detail.

[0043] This application discloses a prefabricated staircase. See also... Figures 1-5 The precast staircase includes a precast base slab 1, precast steps 2, and supporting ribs 3. The precast base slab 1 includes an upper extension section 11, a lower extension section 12, and several slabs 13. The upper extension section 11 is located above the lower extension section 12. The several slabs 13 are located between the upper extension section 11 and the lower extension section 12 and are distributed along the line connecting the upper extension section 11 and the lower extension section 12. A dovetail block 4 is fixed to one end of each slab 13, and a dovetail groove 13 is formed on the side of the slab 13 away from the dovetail block 4. 1. A dovetail groove 131 extends horizontally through the plate 13 and is used to insert a dovetail block 4. A dovetail groove 111 is provided on the side of the upper extension section 11 near the plate 13 for inserting the dovetail block 4. The dovetail groove 111 extends horizontally through the upper extension section 11. An injection port 112 is provided on the upper end face of the upper extension section 11. A dovetail block 5 is fixed on the side of the lower extension section 12 near the plate 13 and is used to insert the dovetail block 5.

[0044] See Figures 1-6The precast step 2 is located above the precast base plate 1 and between the upper extension section 11 and the lower extension section 12. The precast step 2 and the precast base plate 1 are spliced ​​together to form a grouting cavity 6. The grouting cavity 6 is connected to the grouting port 112. The precast step 2 includes a number of step blocks 21. The number of step blocks 21 are distributed along the distribution direction of the plate 13, and the number and position of the step blocks 21 correspond one-to-one with the number and position of the plate 13. A limit block 7 is integrally fixed on the top of each plate 13. A limit groove 211 is provided on the step block 21 for the limit block 7 to be inserted. The limit groove 211 is connected to the grouting cavity 6.

[0045] See Figures 1-6 Each step block 21 has a groove 212 on the side away from the upper extension section 11 for inserting adjacent step blocks 21, so that the step blocks 21 are arranged in a stepped manner, and the groove 212 constitutes part of the injection cavity 6.

[0046] See Figures 1-6 Each step block 21 is fixed with two rectangular steel bar frames 8 and L-shaped steel bars 9. The rectangular steel bar frames 8 and L-shaped steel bars 9 are located inside the grouting cavity 6. The two rectangular steel bar frames 8 are located on the side of the step block 21 near the upper extension section 11 and on both sides of the grouting cavity 6 respectively. The two rectangular steel bar frames 8 are arranged opposite to each other. Each rectangular steel bar frame 8 is spliced ​​with the step block 21 to form a through hole 10. The through hole 10 allows the L-shaped steel bars 9 to pass through.

[0047] See Figures 1-7 Both L-shaped steel bars 9 are located on the side of the step block 21 away from the rectangular steel bar frame 8 and are located in the groove 212. The two L-shaped steel bars 9 are spaced apart. The positions of the two L-shaped steel bars 9 correspond one-to-one with the positions of the two rectangular steel bar frames 8. The L-shaped steel bars 9 face away from the rectangular steel bar frames 8 and are used to hook the rectangular steel bar frames 8 on the adjacent step block 21. The L-shaped steel bars 9 are Q235 steel bars with a diameter of 6-8mm.

[0048] See Figures 1-7 An L-shaped steel bar frame 14 is fixed on the upper extension section 11. The number and position of the L-shaped steel bar frame 14 correspond one-to-one with the number and position of the rectangular steel bar frame 8. The L-shaped steel bar frame 14 faces the upper extension section 11. Each L-shaped steel bar frame 14 is spliced ​​with the upper extension section 11 to form a slot 15. The opening of the slot 15 faces upward, and the slot 15 is used for the rectangular steel bar frame 8 to be inserted.

[0049] See Figures 1-8Each step block 21 is fixed with a rectangular steel reinforcement frame 2 16, and each plate 13 is fixed with a rectangular steel reinforcement frame 3 17. The rectangular steel reinforcement frame 3 17 extends out of the limiting block 7 on the plate 13. The rectangular steel reinforcement frame 3 17 and the rectangular steel reinforcement frame 2 16 are both located in the grouting cavity 6, and the number and position of the rectangular steel reinforcement frame 2 16 correspond one-to-one with the number and position of the rectangular steel reinforcement frame 3 17. Each rectangular steel reinforcement frame 2 16 abuts against the side of the corresponding rectangular steel reinforcement frame 3 17 near the upper extension section 11. The two rectangular steel reinforcement frames 1 8 and the rectangular steel reinforcement frame 2 16 on each step block 21 and the rectangular steel reinforcement frame 3 17 on the corresponding plate 13 are spliced ​​to form two through holes 18. The number of supporting ribs 3 corresponds one-to-one with the number of through holes 18. The through holes 18 are used for the supporting ribs 3 to pass through.

[0050] See Figures 1-8 A sealing plate 19 is placed on the step block 21 at the lower end. The injection cavity 6 on the step block 21 at the lower end is into which the sealing plate 19 is inserted. The sealing plate 19 is used to block the outlet of the injection cavity 6. The lower extension section 12 abuts against the lower end of the sealing plate 19. A limiting surface 20 is formed on the lower extension section 12. The limiting surface 20 is located on the side of the sealing plate 19 away from the upper extension section 11 and is vertically arranged. The limiting surface 20 is used to abut against the side of the sealing plate 19 away from the step block 21.

[0051] The implementation principle of a prefabricated staircase in this application embodiment is as follows:

[0052] When assembling the prefabricated staircase, dovetail block 14 is inserted into dovetail groove 211 and dovetail block 14 is inserted into dovetail groove 131 to achieve splicing of the upper extension section 11 and each panel 13. Then the upper extension section 11 is installed and fixed in the designated position.

[0053] Next, step blocks 21 are placed so that the rectangular steel reinforcement frame 8 on step blocks 21 is inserted into the slot 15 and the limiting block 7 is inserted into the limiting groove 211. The step blocks 21 are limited by the L-shaped steel reinforcement frame 14 abutting against the rectangular steel reinforcement frame 8. Then, each step block 21 is placed in sequence so that the L-shaped steel bar 9 passes through the through hole 10 on the adjacent step block 21. Then, the part of the L-shaped steel bar 9 that passes through the through hole 10 is bent with the tool so that the L-shaped steel bar 9 hooks onto the rectangular steel reinforcement frame 8 on the adjacent step block 21, thereby connecting the adjacent step blocks 21. Then, the support bar 3 is inserted through the through hole 18. The support bar 3 abuts against the rectangular steel reinforcement frame 8, the rectangular steel reinforcement frame 16, and the rectangular steel reinforcement frame 17, thereby limiting the movement between adjacent step blocks 21, between adjacent slabs 13, and between slabs 13 and step blocks 21, and connecting slabs 13 and step blocks 21. After subsequent concrete pouring, the overall structural strength of the precast staircase can be strengthened.

[0054] Then, the sealing plate 19 is inserted into the grouting cavity 6 on the lower step block 21 to block the outlet of the grouting cavity 6. The sealing plate 19 abuts against the lower end of the support rib 3 to limit the support rib 3. Then, the dovetail block 2 5 is inserted into the dovetail groove 131, so that the lower extension section 12 abuts against the lower end of the sealing plate 19 and the limiting surface 20 abuts against the sealing plate 19 to limit the sealing plate 19. Then, concrete is poured into the grouting port 112 until the concrete fills the grouting cavity 6, and the construction of the precast staircase is completed.

[0055] Both the precast base slab 1 and the precast steps 2 are assembled separately, which reduces the weight and volume of each precast stair component. They can be transported to the installation site manually or by trolley, which is convenient for handling and construction and helps to improve construction efficiency. Moreover, installation does not require hoisting, which reduces hoisting costs and thus lowers construction costs.

[0056] This application also discloses a construction method for a prefabricated staircase, including the following steps:

[0057] S1. Insert the dovetail block 14 into the dovetail groove 211, and then insert the dovetail block 14 on each plate 13 into the dovetail groove 131 on the adjacent plate 13 to achieve the splicing of the upper extension section 11 and each plate 13. Then fix the upper extension section 11 in the designated position by applying concrete to the surface of the upper extension section 11.

[0058] S2. Place the first step block 21 on the plate 13. The limiting block 7 on the plate 13 is inserted into the limiting groove 211 on the step block 21, and the rectangular steel bar frame 8 on the step block 21 is inserted into the slot 15 to limit the first step block 21. Continue to place the remaining step blocks 21 on the plate 13 in sequence. The limiting block 7 on the plate 13 is inserted into the limiting groove 211 on each step block 21 in sequence, and the L-shaped steel bar 9 on the upper step block 21 passes through the through hole 10 on the lower adjacent step block 21. Use pliers or other tools to bend the part of the L-shaped steel bar 9 that passes through the through hole 10 upwards, so that the L-shaped steel bar 9 hooks the rectangular steel bar frame 8 on the adjacent step block 21, thereby connecting the adjacent step blocks 21.

[0059] S3. Pass the support bar 3 through the through hole 18;

[0060] S4. Using tools such as pliers, bend the L-shaped steel strip 9 on the lower step block 21 upwards until the remaining area in the groove 212 is available for the subsequent insertion of the sealing plate 19. Then, insert the sealing plate 19 into the injection cavity 6 on the lower step block 21 to block the outlet of the injection cavity 6. Then, insert the second dovetail block 5 into the first dovetail groove 131 so that the lower extension section 12 abuts against the lower end of the sealing plate 19 and the limiting surface 20 abuts against the side of the sealing plate 19 away from the step block 21. Then, fix the lower extension section 12 by applying concrete to the surface of the lower extension section 12.

[0061] S5. Pour concrete into the grouting port 112 until the concrete fills the grouting cavity 6, and smooth the concrete at the grouting port 112.

[0062] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A prefabricated staircase, characterized in that: The precast base plate (1), precast steps (2), and supporting ribs (3) are included. The precast base plate (1) includes an upper extension section (11), a lower extension section (12), and several plates (13). Several plates (13) are located between the upper extension section (11) and the lower extension section (12). A dovetail block (4) is provided on the plate (13). A dovetail groove (131) is provided on the side of the plate (13) away from the dovetail block (4) for the dovetail block (4) to be inserted. A dovetail groove (111) is provided on the upper extension section (11) for the dovetail block (4) to be inserted. A dovetail block (5) is provided on the lower extension section (12). The dovetail groove (131) is provided for the dovetail block (5) to be inserted. The precast step (2) is located above the precast base plate (1). The precast step (2) and the precast base plate (1) are spliced ​​together to form a grouting cavity (6). A grouting port (112) is opened on the upper extension section (11). The grouting port (112) is connected to the grouting cavity (6). The precast step (2) includes several step blocks (21). A rectangular steel frame (8) and an L-shaped steel bar (9) are respectively provided on both sides of the step block (21). The rectangular steel frame (8) and the L-shaped steel bar (9) are both located in the grouting cavity (6). The rectangular steel frame (8) and the step block (21) are spliced ​​together to form a through hole (10) for the L-shaped steel bar (9) to pass through. The L-shaped steel bar (9) is used to hook the rectangular steel frame (8) on the adjacent step block (21). The upper extension section (11) is provided with an L-shaped steel bar frame (14), and the L-shaped steel bar frame (14) and the upper extension section (11) are spliced ​​together to form a slot (15) for the rectangular steel bar frame one (8) to be inserted. The step block (21) is provided with a rectangular steel bar frame two (16), and the plate (13) is provided with a rectangular steel bar frame three (17). The rectangular steel bar frame three (17) and the rectangular steel bar frame two (16) are both located in the grouting cavity (6). The rectangular steel bar frame one (8), the rectangular steel bar frame two (16), and the rectangular steel bar frame three (17) are spliced ​​together to form a through hole (18) for the support bar (3) to pass through. A sealing plate (19) is provided on the step block (21) located at the lower end. The injection cavity (6) is for the sealing plate (19) to be inserted into. The sealing plate (19) is used to block the outlet of the injection cavity (6). The lower extension section (12) abuts against the lower end of the sealing plate (19).

2. The prefabricated staircase according to claim 1, characterized in that: The second rectangular steel reinforcement frame (16) and the third rectangular steel reinforcement frame (17) correspond one-to-one, with the second rectangular steel reinforcement frame (16) abutting against the side of the third rectangular steel reinforcement frame (17) near the upper extension section (11).

3. The prefabricated staircase according to claim 1, characterized in that: The lower extension section (12) is provided with a limiting surface (20), which is used to abut against the side of the sealing plate (19) away from the step block (21).

4. The prefabricated staircase according to claim 1, characterized in that: The plate (13) is provided with a limiting block (7), and the step block (21) is provided with a limiting groove (211) for the limiting block (7) to be inserted.

5. The prefabricated staircase according to claim 1, characterized in that: The L-shaped steel bar (9) is a Q235 steel bar with a diameter of 6-8mm.

6. A construction method for a prefabricated staircase according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Insert the dovetail block 1 (4) into the dovetail groove 2 (111), and then insert the dovetail block 1 (4) on each plate (13) into the dovetail groove 1 (131) on the adjacent plate (13) to achieve splicing of the upper extension section (11) and each plate (13), and then fix the upper extension section (11) in the designated position. S2. Place the first step block (21) on the plate (13) and make the rectangular steel bar frame (8) on the step block (21) fit into the slot (15) to limit the first step block (21). Continue to place the remaining step blocks (21) on the plate (13) in sequence, and make the L-shaped steel bar (9) on the upper step block (21) pass through the through hole (10) on the lower adjacent step block (21). Use a tool to bend the part of the L-shaped steel bar (9) that passes through the through hole (10) upwards, so that the L-shaped steel bar (9) hooks the rectangular steel bar frame (8) on the adjacent step block (21) to achieve the connection of the adjacent step blocks (21). S3. Pass the support bar (3) through the through hole (18); S4. Insert the sealing plate (19) into the injection cavity (6) on the step block (21) at the lower end to block the outlet of the injection cavity (6), and then insert the second dovetail block (5) into the first dovetail groove (131) so that the lower extension section (12) abuts against the lower end of the sealing plate (19), and then fix the lower extension section (12). S5. Pour concrete into the grouting port (112) until the concrete fills the grouting cavity (6), and smooth the concrete at the grouting port (112).

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