Peripheral stiffening rib and grouting integrated reinforced concrete filled steel tube column and method

Abstract

This invention discloses an integrated reinforcement method for steel-concrete composite columns with external stiffening ribs and grouting. The method includes a steel-concrete composite column and a reinforcement device disposed on the outer ring of the steel-concrete composite column. The reinforcement device includes an upper circumferential stiffening rib and a lower circumferential stiffening rib. The upper circumferential stiffening rib and the lower circumferential stiffening rib are connected by multiple pairs of first longitudinal steel plate stiffening ribs and pairs of second longitudinal steel plate stiffening ribs to form a whole. One or more of the pairs of first longitudinal steel plate stiffening ribs are equipped with a grout outlet and an air inlet pipe, and the grout outlet and grout inlet pipe is located above the air inlet pipe.

Description

Technical Field

[0001] This invention belongs to the field of steel-concrete composite column reinforcement, specifically relating to a device and method for reinforcing steel-concrete composite columns by integrating external stiffening ribs and grouting. Background Technology

[0002] In actual engineering projects, due to the combined effects of concrete construction techniques, sunlight and seasonal temperature differences during operation, and the later shrinkage of concrete, large-diameter concrete-tube steel columns commonly exhibit varying degrees of void defects as their service life increases. Although the "Technical Standard for Concrete-Tube Steel Structures" (GB / T51446) provides a shrinkage limit of 0.025% that does not significantly reduce the strength of the concrete-tube steel structure, this void limit only applies to localized voids along the circumferential direction between the concrete and the steel tube wall. However, the problems encountered in actual engineering projects are not so simple. Most voids easily exceed the 0.025% limit and are penetrating voids along the circumferential or longitudinal direction. This causes the concrete and steel tube to completely lose their bond, preventing the transfer of force and reducing the stiffness and load-bearing capacity of the concrete-tube steel structure.

[0003] CN220504625U discloses a steel-concrete composite column reinforcement device, including a main structure and a reinforcement structure. The main structure includes an outer steel pipe and concrete, with the outer steel pipe filled with grout. The reinforcement structure includes several reinforcing members and additional members. The reinforcing members are installed at equal intervals inside the outer steel pipe, and their outer walls are welded to the inner walls of the additional members at equal intervals and then filled with concrete. The additional members are positioned between the outer steel pipe and the reinforcing members. However, this patent does not solve the problem of internal voids.

[0004] Patent CN201820191279.X discloses a reinforced structure for a hollowed-out steel pipe reinforced with concrete, comprising a steel pipe and concrete. Multiple bolt sections are spaced apart along the axis of the steel pipe at locations within the hollowed-out area, each bolt section perpendicular to the steel pipe axis. Along the axial direction, the coverage length of the bolt sections is greater than the length of the hollowed-out area. Each bolt section consists of multiple expansion bolts spaced circumferentially, each expansion bolt inserted into the concrete from the outer wall of the steel pipe and expanding to fix itself within the concrete. Each expansion bolt rivets the steel pipe wall to the concrete. On the same bolt section, the axes of all expansion bolts intersect the steel pipe axis at a single point. However, the reinforcement effect of this patent is not good, and the hollowed-out area still exists.

[0005] In other fields, some technical means of solving voids by grouting have been disclosed, but simply solving voids by grouting is still insufficient to meet reinforcement requirements. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide an integrated reinforcement method for steel-concrete composite columns with external stiffening ribs and grouting. This method can not only reinforce the void area inside the steel-concrete composite column, but also reinforce the external steel-concrete column. The ingenious combination of internal and external components achieves integrated reinforcement of the steel-concrete composite column.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0008] In a first aspect, embodiments of the present invention provide an integrated reinforcement of steel-concrete composite columns with external stiffening ribs and grouting, including a steel-concrete composite column and a reinforcement device disposed on the outer ring of the steel-concrete composite column. The reinforcement device includes an upper circumferential stiffening rib and a lower circumferential stiffening rib. The upper circumferential stiffening rib and the lower circumferential stiffening rib are connected by multiple pairs of first longitudinal steel plate stiffening ribs and pairs of second longitudinal steel plate stiffening ribs to form an integral whole. One or more of the pairs of first longitudinal steel plate stiffening ribs are equipped with a grout outlet and an air inlet pipe, and the grout outlet and grout inlet pipe is located above the air inlet pipe.

[0009] As a further technical solution, the shapes of the upper and lower circumferential stiffening ribs are determined according to the shape of the steel-concrete composite column to be reinforced.

[0010] As a further technical solution, the paired first longitudinal steel plate stiffening ribs and the paired second longitudinal steel plate stiffening ribs are spaced apart.

[0011] As a further technical solution, the reinforcement device is mainly installed on the outer ring of the void area of ​​the steel-concrete composite column.

[0012] As a further technical solution, the upper circumferential stiffening rib and the lower circumferential stiffening rib are welded to the outer steel pipe of the concrete-filled steel tube column.

[0013] As a further technical solution, the top and bottom of the first longitudinal steel plate stiffening rib and the second longitudinal steel plate stiffening rib are welded to the upper circumferential stiffening rib and the lower circumferential stiffening rib, and the sides are welded to the outer ring steel pipe of the steel-concrete composite column.

[0014] As a further technical solution, the upper circumferential stiffening rib includes multiple upper stiffening ribs; the lower circumferential stiffening rib includes multiple lower stiffening ribs, the upper stiffening rib and the lower stiffening rib are arranged vertically, and the middle position of the upper stiffening rib and the lower stiffening rib is connected by a pair of first longitudinal steel plate stiffening ribs, and the two ends are connected by a single second longitudinal steel plate stiffening rib.

[0015] Secondly, the present invention also provides a method for reinforcing steel-concrete composite columns by integrating external stiffening ribs and grouting, as follows:

[0016] Step (1) Determine the void area of ​​the concrete-filled steel tube column and mark the range of the void area;

[0017] Step (2) Weld the fixing device to the hollow steel pipe wall of the steel-concrete composite column, position it through the grout outlet and vent pipe and the grouting air inlet pipe, and drill holes in the steel pipe wall of the steel-concrete composite column through the grout outlet and vent pipe and the grouting air inlet pipe.

[0018] Step (3) Connect one or more grouting air inlet pipes to the air compressor to start air testing. The air compressor starts working, and the air pressure should be low at first and then high. Ventilate to remove internal debris and water. Other grouting air inlet pipes and grout outlet exhaust pipes are used to exhaust and remove debris. After cleaning, connect valves and grouting devices to the ends of one or more grouting air inlet pipes as grouting holes. Seal the grouting air inlet pipes that are not connected to the grouting device, and also connect valves to the grout outlet exhaust pipes.

[0019] Step (5) Start grouting. During pressure grouting, follow the principle of grouting from bottom to top to ensure the compactness of the grouting.

[0020] Step (6) During the grouting process, keep tapping and observing the grout outlet and exhaust pipe. When grout comes out of the grout outlet and exhaust pipe, close the valve of the grout outlet and exhaust pipe. After pausing the grouting machine for the set time, reopen the grout outlet valve and observe whether there is any grout backflow. If there is backflow, restart the grouting machine until the grout outlet and exhaust pipe is full of grout. Repeat this process until there is no grout backflow.

[0021] Step (7) When the grout in the slurry exhaust pipe no longer falls back, close all valves, pause the grouting machine for the set time, and then restart the grouting machine. At this time, observe that the pressure gauge value of the grouting machine rises significantly or the grout level drops significantly. Then stop grouting, close the grouting pipe valve, wait for the set time, and then remove the grouting machine to complete the pressure grouting work in the voided area.

[0022] Step (8) After the grout has solidified, seal all grout outlet and vent pipes and grout inlet pipes.

[0023] As a further technical solution, in step (2), only the assembly with the slurry outlet and slurry inlet pipes is welded, and the remaining assemblies are welded after step (8) is completed.

[0024] As a further technical solution, in step (1), the knocking method and CT method are used to determine the void area of ​​the steel tube concrete column.

[0025] The beneficial effects of the above embodiments of the present invention are as follows:

[0026] The invention proposes an integrated device and method for reinforcing steel-concrete composite columns with external stiffening ribs and grouting. Through the ingenious combination of a grout outlet and vent pipe, a grouting inlet pipe, and external stiffening ribs, it solves the problem of density in the void areas inside the steel-concrete composite column, avoids local buckling of the steel pipe wall, improves the axial compression, bending, and shear stiffness of the steel-concrete composite column, and enhances the restraint effect of the steel pipe on the concrete, significantly improving the ultimate axial compression bearing capacity of the steel-concrete composite column. Specifically, the invention directly sets the grout outlet and vent pipe and the grouting inlet pipe on the reinforcement device. While the reinforcement device is fixed to the steel-concrete composite column, the grout outlet and vent pipe and the grouting inlet pipe are also fixed. After grouting, the grout remaining in the grout outlet and vent pipe solidifies and forms an integral part with the grout inside the steel-concrete composite column, equivalent to radial reinforcement on the steel-concrete composite column; simultaneously, the annular stiffening ribs provide circumferential and axial reinforcement. Attached Figure Description

[0027] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0028] Figure 1 This is a schematic diagram of a single piece disclosed in some embodiments of the present invention;

[0029] Figure 2 This is a schematic diagram of the overall structure disclosed in the embodiments of the present invention;

[0030] In the figure: 1 Upper circumferential stiffening rib, 2 Lower circumferential stiffening rib, 3 First longitudinal steel plate stiffening rib, 4 Second longitudinal steel plate stiffening rib, 5 Grout outlet and exhaust pipe, 6 Grouting air inlet pipe, 7 Steel pipe concrete column. Detailed Implementation

[0031] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0032] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0033] For ease of description, the use of the words "upper" and "lower" in this invention only indicates that they correspond to the upper and lower directions of the accompanying drawings and do not limit the structure. They are merely for the purpose of describing the invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0034] As described in the background section, the existing technology has shortcomings. To address the aforementioned technical problems, this invention proposes a device and method for reinforcing a steel-concrete composite column 7 with integrated external stiffening ribs and grouting. Due to the voids in the concrete inside the steel-concrete composite column, the outer steel pipe directly bears the pressure, which may cause buckling. Therefore, stiffening ribs are added. Grouting solves the problem of density in the voided area inside the steel-concrete composite column 7. At the same time, the external stiffening ribs prevent local buckling of the steel pipe wall, improve the axial compression, bending, and shear stiffness of the steel-concrete composite column 7, and enhance the restraint effect of the steel pipe on the concrete, significantly improving the axial compression ultimate bearing capacity of the steel-concrete composite column 7.

[0035] In a typical embodiment of the present invention, such as Figure 1 , Figure 2 As shown in this embodiment, an integrated reinforcement system for steel-concrete composite columns 7, comprising an external stiffening rib and grouting, includes a steel-concrete composite column 7 and a reinforcement device disposed on the outer ring of the steel-concrete composite column 7. The reinforcement device includes an upper circumferential stiffening rib 1 and a lower circumferential stiffening rib 2. The upper circumferential stiffening rib 1 and the lower circumferential stiffening rib 2 are connected by multiple pairs of first longitudinal steel plate stiffening ribs 3 and pairs of second longitudinal steel plate stiffening ribs 4 to form a whole. One or more sets of the first longitudinal steel plate stiffening ribs 3 are equipped with a grout outlet and exhaust pipe 5 and a grouting air inlet pipe 6. The grout outlet and exhaust pipe 5 is located above the grouting air inlet pipe 6. The grout outlet and exhaust pipe 5 is mainly used for grouting and air removal during grouting and impurity removal. After grouting is completed, the pipe needs to be sealed. The grouting air inlet pipe 6 has two functions: one is for grouting, and the other is to allow air to enter through the pipe, and then discharge the debris in the voided area inside the steel-concrete column 7 through the grout outlet vent pipe 5. After grouting is completed, the pipe also needs to be sealed. It should be noted that the present invention directly sets the grout outlet vent pipe 5 and the grouting air inlet pipe 6 on the reinforcement device. While the reinforcement device is fixed to the steel-concrete column 7, the grout outlet vent pipe 5 and the grouting air inlet pipe 6 are fixed. After grouting is completed, the grout remaining in the grout outlet vent pipe 5 and the grouting air inlet pipe 6 solidifies and forms an integral part with the grout inside the steel-concrete column 7, which is equivalent to forming radial reinforcement on the steel-concrete column 7.

[0036] This embodiment cleverly combines the grout outlet and exhaust pipe 5, the grouting inlet pipe 6, and the external stiffening ribs to solve the problem of density in the void area inside the steel-concrete composite column 7, avoid the occurrence of local buckling of the steel pipe wall, improve the axial compression, bending and shear stiffness of the steel-concrete composite column 7, and enhance the restraint effect of the steel pipe on the concrete, thus significantly improving the axial compression ultimate bearing capacity of the steel-concrete composite column 7.

[0037] It should be noted that the shape of the upper circumferential stiffening rib 1 and the lower circumferential stiffening rib 2 can be circular, rectangular, or other shapes. The specific shape is determined according to the shape of the steel-concrete composite column 7 to be reinforced.

[0038] It should be noted that the paired first longitudinal steel plate stiffening ribs 3 and the paired second longitudinal steel plate stiffening ribs 4 are distributed at intervals.

[0039] It should be noted that the above-mentioned reinforcement devices are mainly set on the outer ring of the void area of ​​the steel-concrete composite column 7. Therefore, when there are multiple void areas in a steel-concrete composite column 7, reinforcement devices need to be set at multiple locations in the steel-concrete composite column 7.

[0040] It should be noted that the aforementioned upper circumferential stiffening rib 1 and lower circumferential stiffening rib 2 are welded to the outer ring steel pipe of the steel-concrete composite column 7, and the top and bottom of the first longitudinal steel plate stiffening rib 3 and the second longitudinal steel plate stiffening rib 4 are welded to the upper circumferential stiffening rib 1 and lower circumferential stiffening rib 2, and the sides are welded to the outer ring steel pipe of the steel-concrete composite column 7.

[0041] It should be noted that the aforementioned upper circumferential stiffening rib 1 includes multiple upper stiffening ribs; the lower circumferential stiffening rib 2 includes multiple lower stiffening ribs; one upper stiffening rib and one lower stiffening rib are arranged vertically, and the upper stiffening rib and the lower stiffening rib are connected in the middle by a pair of first longitudinal steel plate stiffening ribs 3, and the two ends are connected by a single second longitudinal steel plate stiffening rib 4. The upper stiffening rib, the lower stiffening rib, the first longitudinal steel plate stiffening rib 3 and the second longitudinal steel plate stiffening rib 4 together form a group; a grout outlet and exhaust pipe 5 and a grouting air inlet pipe 6 are provided on one or more of the components.

[0042] Based on the aforementioned external stiffening ribs and grouting integrated reinforcement of the steel tube concrete column 7, this embodiment discloses a method for external stiffening ribs and grouting integrated reinforcement of the steel tube concrete column 7 as follows:

[0043] When the aforementioned fixing device consists of multiple pairs of first longitudinal steel plate reinforcing ribs 3, each equipped with a grout outlet and vent pipe 5 and a grouting air inlet pipe 6, the following construction method can be used:

[0044] (1) The void area of ​​the steel-concrete composite column 7 was determined by the percussion method and CT method, and the range of the void area was marked.

[0045] (2) Weld the above-mentioned fixing device (all parts) to the hollow steel pipe wall of the steel pipe concrete column 7, and position it through the above-mentioned grout outlet and exhaust pipe 5 and grouting air inlet pipe 6, and drill holes in the steel pipe wall of the steel pipe concrete column 7 through the grout outlet and exhaust pipe 5 and grouting air inlet pipe 6.

[0046] (3) Connect one or more grouting air inlet pipes 6 to the air compressor to start air testing. The air compressor should start working, and the air pressure should be small at first and then large. Ventilate to remove internal debris and water, etc. The other grouting air inlet pipes 6 and grout outlet exhaust pipes 5 should be used to exhaust and remove debris. After cleaning, connect valves and grouting devices to the ends of one or more grouting air inlet pipes 6 as grouting holes. Seal the grouting air inlet pipes 6 that are not connected to the grouting device, and also connect valves to the grout outlet exhaust pipes 5.

[0047] (5) Start grouting. During pressure grouting, follow the principle of grouting from bottom to top to ensure the compactness of the grouting.

[0048] (6) During the grouting process, keep tapping and observing the grout outlet pipe 5. When grout comes out of the grout outlet pipe 5, close the valve of the grout outlet pipe 5. After pausing the grouting machine for 10 minutes, reopen the grout outlet valve and observe whether there is any grout drop. If there is a drop, restart the grouting machine until the grout outlet pipe 5 is full of grout. Repeat this process until there is no grout drop.

[0049] (7) When the grout in the grout outlet pipe 5 no longer falls back, close all valves, pause the grouting machine for 10 minutes and then restart the grouting machine. At this time, observe that the pressure gauge value of the grouting machine rises significantly or the rate of grout level drop slows down significantly. Then stop grouting, close the grouting pipe valve, wait for 5 minutes and then remove the grouting machine to complete the pressure grouting work in the voided area.

[0050] (8) After the grout has solidified, the above-mentioned grout outlet and vent pipe 5 and grout inlet pipe 6 are sealed by plug welding.

[0051] (9) Reinforce other voided areas of the steel-concrete composite column 7 using the same method described above.

[0052] When the aforementioned fixing device consists of only one pair of first longitudinal steel plate reinforcing ribs 3 with grout outlet and vent pipe 5 and grout inlet pipe 6 installed between them, the following construction method can be used:

[0053] The above methods can also be implemented as follows:

[0054] (1) The void area of ​​the steel-concrete composite column 7 was determined by the percussion method and CT method, and the range of the void area was marked.

[0055] (2) Weld the assembly with the slurry exhaust pipe 5 and the grouting air inlet pipe 6 to the hollow steel pipe wall of the steel-concrete composite column 7, and position it through the slurry exhaust pipe 5 and the grouting air inlet pipe 6, and drill holes in the steel pipe wall of the steel-concrete composite column 7 through the slurry exhaust pipe 5 and the grouting air inlet pipe.

[0056] (3) Connect the grouting air inlet pipe 6 to the air compressor to start the air test. The air compressor starts to work. The air pressure should be small first and then large. Ventilate to remove internal debris and water, etc. The grout outlet exhaust pipe 5 is used to exhaust and remove debris. After cleaning, the end of the grouting air inlet pipe 6 is connected to a valve and a grouting device as a grouting hole. The grout outlet exhaust pipe 5 is also connected to a valve.

[0057] (5) Start grouting. During pressure grouting, follow the principle of grouting from bottom to top to ensure the compactness of the grouting.

[0058] (6) During the grouting process, keep tapping and observing the grout outlet pipe 5. When grout comes out of the grout outlet pipe 5, close the valve of the grout outlet pipe 5. After pausing the grouting machine for 10 minutes, reopen the grout outlet valve and observe whether there is any grout drop. If there is a drop, restart the grouting machine until the grout outlet pipe 5 is full of grout. Repeat this process until there is no grout drop.

[0059] (7) When the grout in the grout outlet pipe 5 no longer falls back, close all valves, pause the grouting machine for 10 minutes and then restart the grouting machine. At this time, observe that the pressure gauge value of the grouting machine rises significantly or the rate of grout level drop slows down significantly. Then stop grouting, close the grouting pipe valve, wait for 5 minutes and then remove the grouting machine to complete the pressure grouting work in the voided area.

[0060] (8) After the grout has solidified, the above-mentioned grout outlet and vent pipe 5 and grout inlet pipe 6 are sealed by plug welding.

[0061] (9) Other components are welded onto the steel-concrete composite column 7 to form a ring that encloses the steel-concrete composite column 7.

[0062] It should be noted that, in step 2, after all components have been soldered, the following steps can be performed directly, thus omitting step (9).

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for reinforcing steel-concrete composite columns using integrated external stiffening ribs and grouting, characterized in that, The system includes a steel-concrete composite column and a reinforcement device installed around the outer ring of the column. The reinforcement device includes upper and lower circumferential stiffening ribs, which are connected by multiple pairs of first and second longitudinal steel plate stiffening ribs to form a single unit. One or more of these pairs of first longitudinal steel plate stiffening ribs are equipped with grout outlet and grout inlet pipes, with the grout outlet and grout inlet pipes positioned above the grout inlet pipes. Specific steps include: Step (1) Determine the void area of ​​the concrete-filled steel tube column and mark the range of the void area; Step (2) Weld the reinforcement device to the hollow steel pipe wall of the steel-concrete composite column, position it through the grout outlet and vent pipe and the grouting air inlet pipe, and drill holes in the steel pipe wall of the steel-concrete composite column through the grout outlet and vent pipe and the grouting air inlet pipe. Step (3) Connect one or more grouting air inlet pipes to the air compressor to start air testing. The air compressor starts working, and the air pressure should be low at first and then high. Ventilate to remove internal debris and water. Other grouting air inlet pipes and grout outlet exhaust pipes are used to exhaust and remove debris. After cleaning, connect valves and grouting devices to the ends of one or more grouting air inlet pipes as grouting holes. Seal the grouting air inlet pipes that are not connected to the grouting device, and also connect valves to the grout outlet exhaust pipes. Step (5) Start grouting. During pressure grouting, follow the principle of grouting from bottom to top to ensure the compactness of the grouting. Step (6) During the grouting process, keep tapping and checking the grout outlet and exhaust pipe. When grout comes out of the grout outlet and exhaust pipe, close the valve of the grout outlet and exhaust pipe. After pausing the grouting machine for the set time, reopen the grout outlet valve and observe whether there is any grout backflow. If there is backflow, restart the grouting machine until the grout outlet and exhaust pipe is full of grout. Repeat this process until there is no grout backflow. Step (7) When the grout in the slurry outlet pipe no longer falls back, close all valves, pause the grouting machine for the set time, and then restart the grouting machine. At this time, observe that the pressure gauge value of the grouting machine rises significantly or the grout level drops significantly. Then stop grouting, close the grouting pipe valve, wait for the set time, and then remove the grouting machine to complete the pressure grouting work in the voided area. Step (8) After the grout has solidified, seal all grout outlet and grout inlet pipes.

2. The method of claim 1, wherein the method is characterized by: The shapes of the upper and lower circumferential stiffening ribs are determined according to the shape of the steel-concrete composite column to be reinforced.

3. The reinforcement method for steel-concrete composite columns with integrated external stiffening ribs and grouting as described in claim 1, characterized in that, The paired first longitudinal steel plate stiffeners and the paired second longitudinal steel plate stiffeners are spaced apart.

4. The method of claim 1, wherein the method is characterized by: The reinforcement device is installed around the outer ring of the void area of ​​the steel-concrete composite column.

5. The method of claim 1, wherein the method is characterized by: The upper and lower circumferential stiffening ribs are welded to the outer steel pipe of the concrete-filled steel tube column.

6. The method of claim 1, wherein the method is characterized by: The top and bottom of the first longitudinal steel plate stiffening rib and the second longitudinal steel plate stiffening rib are welded to the upper circumferential stiffening rib and the lower circumferential stiffening rib, and the sides are welded to the outer ring steel pipe of the steel-concrete composite column.

7. The method of claim 1, wherein the method is characterized by: The upper circumferential stiffening rib includes multiple upper stiffening ribs; the lower circumferential stiffening rib includes multiple lower stiffening ribs. The upper and lower stiffening ribs are arranged vertically, and the upper and lower stiffening ribs are connected in the middle by a pair of first longitudinal steel plate stiffening ribs, and the two ends are connected by a single second longitudinal steel plate stiffening rib.

8. The reinforcement method for steel-concrete composite columns with integrated external stiffening ribs and grouting as described in claim 1, characterized in that: In step (2), only the assembly with the slurry outlet and grouting inlet pipe is welded. After step (8) is completed, the remaining assemblies are welded.

9. The reinforcement method for steel-concrete composite columns with integrated external stiffening ribs and grouting as described in claim 1, characterized in that: In step (1), the knocking method and CT method are used to determine the void area of ​​the steel tube concrete column.

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