Device for reinforcing steel column through reverse supporting type external prestressing technology and construction method of device

Abstract

The invention discloses a device for reinforcing a steel column through a back-supporting external prestressing technology and a construction method of the device, belongs to the technical field of steel column reinforcement, and aims to achieve the technical purposes that on the premise that the original bearing capacity of the steel column is not affected, construction is convenient, the pressure borne by the steel column can be effectively reduced, and the bearing capacity of the steel column is improved. According to the technical scheme, the device comprises a reinforcing steel column, a column foot bottom plate is arranged at one end of the reinforcing steel column, a column top transverse partition plate is arranged at the other end of the reinforcing steel column, a column top force transmission mechanism is arranged above the column foot bottom plate, a column foot force transmission mechanism is arranged above the column top force transmission mechanism, and a plurality of sliding mechanisms arranged at intervals are arranged above the column foot force transmission mechanism; the total length of the column top force transmission mechanism is equal to the height of the reinforced steel column, a steel strand is arranged at the steel strand anchoring end of the column top force transmission mechanism, one end of the steel strand is connected with the steel strand anchoring end of the column top force transmission mechanism, and the steel strand anchoring end of the column top force transmission mechanism is used for anchoring the steel strand.

Description

Technical Field

[0001] The invention relates to the technical field of steel column reinforcement, in particular to a device for reinforcing steel columns using a reverse-bracing external prestressing technology and a construction method thereof. Background Art

[0002] Steel structures have many advantages such as light weight, high strength, fast construction speed, flexible design, and high environmental protection. They have been widely used in the fields of construction and engineering. In steel structures, steel columns, as the most important vertical force transmission components, play a vital role in the safety and stability of the main structure. During the construction and use of steel structures, due to various reasons such as insufficient design, material aging, corrosion problems, cross-sectional damage, and changes in use conditions, steel columns may need to be reinforced to meet new functional requirements or safety standards. A detailed analysis of existing steel column reinforcement methods and their shortcomings is as follows:

[0003] ① Increasing the cross-section reinforcement method: By increasing the cross-sectional area of ​​the steel column, such as adding a steel plate to the original steel column component through welding or bolting, its bearing capacity and rigidity can be improved. The reinforcement construction process is carried out under load, and the reinforced part is easily affected by the weakening of the cross section caused by welding heating, opening bolt holes, etc., and the construction process requires high requirements.

[0004] ② Steel bonding reinforcement method: Use structural adhesive to stick the steel plate on the surface of the component to improve its bending and shear resistance. It has high requirements for the cleanliness and roughness of the bonding surface and strict construction environment requirements. The original structure is under load, and the newly added steel plate cannot immediately deform with the original structure, resulting in stress lag. In addition, the aging problem of the structural adhesive seriously affects the reinforcement effect, and the bearing capacity after reinforcement cannot be accurately judged.

[0005] ③ New component reinforcement method: By adding new steel columns near the steel columns, they will share the vertical force with the original steel columns, which will affect the building's use space and aesthetics. The new steel columns also require an additional foundation for force transmission, which increases the construction difficulty and cost.

[0006] Therefore, how to facilitate construction and effectively reduce the pressure on the steel column itself without affecting the original bearing capacity of the steel column and improve the bearing capacity of the steel column is a technical problem that needs to be solved urgently. Summary of the invention

[0007] The technical task of the present invention is to provide a device for reinforcing steel columns using reverse-bracing external prestressing technology and a construction method thereof, and to effectively solve the problem of how to facilitate construction and effectively reduce the pressure on the steel columns themselves and improve the bearing capacity of the steel columns without affecting the original bearing capacity of the steel columns through rapid construction using an assembled method.

[0008] The technical task of the present invention is achieved in the following manner: a device for reinforcing a steel column by using an inverse bracing external prestressing technology, the device comprising a reinforced steel column, a column foot bottom plate being arranged at one end of the reinforced steel column, a column top diaphragm being arranged at the other end of the reinforced steel column, a column top force transmission mechanism being arranged above the column foot bottom plate, a column foot force transmission mechanism being arranged above the column top force transmission mechanism, and a plurality of sliding mechanisms arranged at intervals being arranged above the column foot force transmission mechanism;

[0009] The total length of the column top force transmission mechanism is equal to the height of the reinforced steel column, and the steel strand anchoring end of the column top force transmission mechanism is provided with a steel strand, one end of the steel strand is connected to the steel strand anchoring end of the column top force transmission mechanism, the steel strand anchoring end of the column top force transmission mechanism is used to anchor the steel strand, and the column top connection end of the column top force transmission mechanism is connected to the column top transverse diaphragm, which is used to transmit the vertical force to the top of the reinforced steel column;

[0010] The steel strand anchoring end of the column foot force transmission mechanism is connected to the other end of the steel strand, and the steel strand anchoring end of the column foot force transmission mechanism is used to anchor the steel strand. The bottom plate connecting end of the column foot force transmission mechanism is connected to the column foot bottom plate, and is used to transmit the vertical force to the bottom of the reinforced steel column.

[0011] Preferably, the reinforced steel columns are I-shaped reinforced steel columns and box-shaped reinforced steel columns.

[0012] Preferably, the column foot force transmission mechanism comprises a column foot force transmission assembly, a column foot anchor fastener is arranged on the top of the column foot force transmission assembly, and the bottom of the column foot force transmission assembly is fixedly connected to the column foot bottom plate.

[0013] More preferably, the column foot force transmission assembly includes two U-shaped column foot force transmission plates;

[0014] When the reinforced steel column is an I-shaped reinforced steel column, the two U-shaped column foot force transfer plates are arranged back to back and the two U-shaped column foot force transfer plates are assembled into an I-shape;

[0015] When the reinforced steel column is a box-type reinforced steel column, the two U-shaped column foot force transfer plates are arranged opposite to each other and the two U-shaped column foot force transfer plates are assembled into a box shape.

[0016] More preferably, the column foot anchor fastener comprises two column foot anchor plates and two column foot anchor gusset plates;

[0017] When the reinforced steel column is an I-shaped reinforced steel column, the two column foot anchoring gussets are arranged back to back and the two column foot anchoring gussets are assembled into an I-shape through the column foot connecting ear bolts; two column foot bent reinforcement plates arranged at intervals are respectively arranged on the two column foot anchoring gussets, and a column foot sealing plate is arranged between the two column foot bent reinforcement plates, and a plurality of column foot support plates arranged at intervals are arranged in the cavity formed by the column foot sealing plate and the two column foot bent reinforcement plates, and the two column foot anchor plates are respectively installed between the column foot anchoring gussets and the column foot sealing plates and are located on the top of the column foot anchoring gussets and the column foot sealing plates, and two column foot steel strand holes arranged at intervals are arranged on the column foot anchor plate, and the steel strands pass through the column foot steel strand holes through the column foot force transmission channel composed of the column foot force transmission plate, the column foot sealing plate, the column foot anchor plate and the column foot support plate to extend to the column top force transmission mechanism, and the column foot sealing plate and the column foot support plate are used to support the column foot anchor plate to bear force;

[0018] When the reinforced steel column is a box-type reinforced steel column, the two column foot anchoring gussets are arranged opposite to each other and the two column foot anchoring gussets are assembled into a box shape; the two column foot anchoring gussets are U-shaped, the two U-shaped column foot anchoring gussets are fixedly connected by column foot connecting ear bolts, and the outer sides of the two U-shaped column foot anchoring gussets are provided with a column foot sealing plate, and a plurality of column foot support plates are arranged between the outer sides of the column foot anchoring gussets and the column foot sealing plate, and a column foot anchor plate is arranged on the top of the column foot sealing plate, and two column foot steel strand holes are arranged on the column foot anchor plate. The steel strand passes through the column foot steel strand hole and passes through the column foot force transmission channel composed of the column foot anchor plate, the column foot sealing plate, the column foot support plate and the outer side of the column foot anchoring gusset to extend to the column top force transmission mechanism;

[0019] Among them, the steel strand is fixedly connected to the column foot anchor plate through an anchor.

[0020] More preferably, the column top force transmission mechanism includes a column top force transmission assembly, the top of the column top force transmission assembly is fixedly connected to the column top cross partition, and the bottom of the column top force transmission assembly is provided with a column top anchor fastener.

[0021] More preferably, the column top force transmission assembly includes four L-shaped column top force transmission rods;

[0022] When the reinforced steel column is an I-shaped reinforced steel column, four L-shaped column top force transmission rods are arranged back to back and the four L-shaped column top force transmission rods are assembled into an I-shape;

[0023] When the reinforced steel column is a box-type reinforced steel column, four L-shaped column top force transmission rods are arranged relatively and the four L-shaped column top force transmission rods are assembled into a box shape.

[0024] More preferably, the column top anchor fastener comprises two column top anchor plates and two column top anchor fastening plates;

[0025] When the reinforced steel column is an I-shaped reinforced steel column, two column top anchoring buckles are provided with two column top bent reinforcement plates arranged at intervals, and the two column top anchoring buckles with column top bent reinforcement plates are assembled into an I-shape through column top connecting ear bolts; a column top sealing plate is provided between the two column top bent reinforcement plates, and a plurality of column top support plates arranged at intervals are provided in the cavity formed by the column top sealing plate and the two column top bent reinforcement plates. The two column top anchor plates are respectively installed between the column top anchoring buckle plate and the column top sealing plate and are located at the bottom of the column top anchoring buckle plate and the column top sealing plate, and two column top steel strand holes arranged at intervals are provided on the column top anchor plate. The steel strand passes through the column top steel strand hole and passes through the column top force transmission channel composed of the column top force transmission rod, the column top sealing plate, the column top anchor plate and the column top support plate to extend to the column foot force transmission mechanism, and the column top sealing plate and the column top support plate are used to support the column top anchor plate to bear force;

[0026] When the reinforced steel column is a box-type reinforced steel column, the two column top anchoring gussets are arranged opposite to each other and the two column top anchoring gussets are assembled into a box shape; the two column top anchoring gussets are U-shaped, the two U-shaped column top anchoring gussets are fixedly connected by column top connecting ear bolts, and the outer sides of the two U-shaped column top anchoring gussets are provided with a column top sealing plate, and a plurality of column top support plates distributed at intervals are provided between the outer sides of the column top anchoring gussets and the column top sealing plate, and a column top anchor plate is provided on the top of the column top sealing plate, and two column top steel strand holes distributed at intervals are provided on the column top anchor plate, and the steel strand passes through the column top steel strand hole through the column top force transmission channel composed of the column top anchor plate, the column top sealing plate, the column top support plate and the outer side of the column top anchoring gusset to extend to the column foot force transmission mechanism;

[0027] The steel strand is fixedly connected to the anchor plate at the top of the column through an anchor;

[0028] The diameters of the steel strand holes at the column base and the column top are larger than the diameter of the steel strands. The diameter of the steel strands is 12.7 to 21.8 mm, the tensile strength of the steel strands is 1570 to 1960 MPa, and the load-bearing range of the steel strands is 3 to 46 tons.

[0029] Preferably, the sliding mechanism comprises two sliding buckle plates;

[0030] When the reinforced steel column is an I-shaped reinforced steel column, two sliding buckle plates are respectively provided with two sliding bending reinforcement plates arranged at intervals, and the two sliding buckle plates are fixedly connected by sliding connection ear bolts, and the two sliding buckle plates after fixed connection are in an I-shape;

[0031] When the reinforced steel column is a box-type reinforced steel column, the two sliding gussets are U-shaped, the two U-shaped sliding gussets are relatively arranged and assembled into a box shape, and the two U-shaped sliding gussets are fixedly connected by sliding connecting ear bolts.

[0032] A construction method of a device for reinforcing a steel column using an inverse bracing external prestressing technique, the method is specifically as follows:

[0033] S1. According to the actual use requirements of the building structure, determine the load conditions of the floor and roof, conduct a stress analysis on the main structure, and determine the number and location of the steel columns to be reinforced;

[0034] S2. According to the cross-sectional dimensions of the steel column to be reinforced, the cross-sectional dimensions of the column foot anchoring plate, the column top anchoring plate and the sliding plate are designed by lofting, so that the shapes of the inner surfaces of the column foot anchoring plate, the column top anchoring plate and the sliding plate can completely fit the cross-sectional dimensions of the steel column to be reinforced;

[0035] S3. Calculate the compressive bearing capacity of the steel column to be reinforced before reinforcement according to the cross-sectional size and height of the steel column to be reinforced, and combine the actual vertical force of the steel column to be reinforced obtained in step S1 to determine the size of the prestress to be applied by calculating the vertical force, the compressive bearing capacity of the reinforced steel column and the friction force. The formula is as follows:

[0036] N 预应力 =(N 实际 -N d ) / 4;

[0037] The tension control stress of each steel strand is determined according to the prestressing force. The formula is as follows:

[0038] N 张拉 =N 预应力 / 0.75;

[0039] S4. According to the size of prestress, the cross-sectional thickness of the column foot force transfer plate and the column top force transfer rod is calculated by the calculation formula of the axially compressed member; the calculated length of the column foot force transfer plate is twice the actual length of the plate; the calculated length of the column top force transfer rod is based on the spacing of the sliding buckle plate; the calculation formula of the axially compressed member is as follows:

[0040] ① The strength calculation formula of axially compressed components is: N≤N u ;

[0041] Where N is the design value of the axial pressure; N u is the design value of the section compressive bearing capacity when the axis is compressed, and the calculation formula is N u =f×A s ; Where f is the design value of the compressive strength of steel and concrete; A s is the cross-sectional area of ​​the steel column; when designing for earthquake resistance, it needs to be divided by the earthquake resistance adjustment factor γ RE ;

[0042] ②The stability calculation formula of axially compressed components is:

[0043] in, It is the stability coefficient of axially compressed members, which is determined based on factors such as the slenderness ratio of the member, the cross-section classification, and the yield strength of the steel material. The specific value can be obtained by referring to the current specification "Steel Structure Design Code" or related tables; Stability coefficient The smaller of the two main axis stability coefficients of the section should be taken; N u is the design value of the section compressive bearing capacity when subjected to axial compression, which is the same as N in the strength calculation formula. u same;

[0044] S5. Cutting of external steel strands and processing and manufacturing of components of column top force transmission mechanism and column foot force transmission mechanism;

[0045] S6. Grind the surface of the steel column to be reinforced and the anchoring gussets at the column base, the anchoring gussets at the column top, and the sliding gussets cleanly, and control the sliding friction coefficient of the steel column to be reinforced and the anchoring gussets at the column base, the anchoring gussets at the column top, and the sliding gussets to be between 0.05 and 0.15, so as to ensure that the device for reinforcing the steel column with the reverse-bracing external prestressing technology can slide relative to the reinforced steel column;

[0046] S7, assemble the column foot force transmission mechanism, assemble the two column foot force transmission plates to the bottom of the reinforced steel column through the column foot anchoring buckle plate, and fix the two column foot anchoring fasteners through the column foot connecting ear bolts, and then weld the bottom of the column foot force transmission plate to the column foot bottom plate;

[0047] S8. Assemble the column top force transmission mechanism and the sliding mechanism, assemble the sliding mechanism to the predetermined position according to the designed spacing, and connect them through the sliding connection ear bolts, so that the sliding mechanism and the reinforced steel column can slide relative to each other; then assemble the column top force transmission mechanism to the surface of the column foot force transmission mechanism and the sliding mechanism, so that the column top force transmission mechanism assembly and the column foot force transmission mechanism can slide relative to each other, and then weld the top of the column top force transmission rod to the column top cross partition, and weld the middle part of the column top force transmission rod to the sliding buckle plate;

[0048] S9, after the operation of step S7 and step S8, only the top of the column top force transmission rod of the column top force transmission mechanism is welded to the column top cross partition, and the rest of the parts are not connected to the reinforced steel column; only the bottom of the column foot force transmission plate of the column foot force transmission mechanism is welded to the column foot bottom plate, and the rest of the parts are not connected to the reinforced steel column; the column top force transmission mechanism and the column foot force transmission mechanism are not connected, and the two can slide relative to each other;

[0049] S10, threading and installing external steel strands;

[0050] S11. Tension the external steel strands on both sides of the reinforced steel column at the same time. The tensioning is mainly controlled by tensioning force and the elongation value is checked. The deviation between the measured elongation value and the calculated elongation value should not exceed ±6%. When the tensioning force reaches the design value, anchor the tensioning end and the tensioning is finished.

[0051] S12. After the external steel strands are tensioned, the steel strands, the force transmission mechanism at the top of the column and the force transmission mechanism at the base of the column shall be protected.

[0052] The device for reinforcing steel columns by using the reverse-bracing external prestressing technology and the construction method thereof have the following advantages:

[0053] (i) The present invention converts the tension of the external steel strands into a force applied to both ends of the reinforced steel column by staggered arrangement of the column foot force transmission mechanism and the column top force transmission mechanism, thereby reducing the pressure on the steel column itself and improving the bearing capacity of the steel column;

[0054] (ii) The present invention adopts an assembled installation method, and does not require welding or bolt holes on the original steel column, which will not weaken the cross-sectional bearing capacity of the original steel column; due to the existence of prestress, the newly added present invention can immediately cooperate with the original structure to bear force, and there is no problem of stress lag; there is no need to occupy the use space around the steel column, and the normal use of the building function is not affected; when the prestress is relaxed, it can also be supplemented by tensioning or replacing the external prestressed tendons, etc., and the reinforcement effect is good;

[0055] (iii) The reinforcement construction of the steel column of the present invention can be carried out under load, and the reinforcement process adopts prefabricated assembly operation, which avoids the cross-sectional weakening caused by welding and opening holes on the reinforced steel column, and the construction process is simple;

[0056] (iv) After the steel column is reinforced by the external prestressing method of the present invention, the steel strand can immediately cooperate with the original steel column to deform and bear stress, and there is no stress lag problem. At the same time, the steel strand has a long service life and there is no aging problem;

[0057] (V) The present invention adds prestress and its components to the original steel column, which does not need to occupy the space around the steel column and will not affect the use of the space around the steel column.

[0058] Therefore, the invention has the characteristics of reasonable design, simple structure, easy processing, small size, convenient use, multi-purpose, etc., and thus has good promotion and use value. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The present invention is further described below in conjunction with the accompanying drawings.

[0060] Attached Figure 1 It is a schematic diagram of the three-dimensional structure of the device for reinforcing steel columns using the reverse-bracing external prestressing technology of Example 1;

[0061] Attached Figure 2 It is a schematic diagram of the explosion mechanism after the reinforcement steel column, the column foot force transmission mechanism, the column top force transmission mechanism and the sliding mechanism are assembled in Example 1;

[0062] Attached Figure 3 It is a three-dimensional structural schematic diagram of the column foot force transmission mechanism of Example 1;

[0063] Attached Figure 4 It is a schematic diagram of the exploded structure of the column foot force transmission mechanism of Example 1;

[0064] Attached Figure 5 It is a schematic diagram of the three-dimensional structure of the column top force transmission mechanism in Example 1;

[0065] Attached Figure 6 It is a schematic diagram of the exploded structure of the column top force transmission mechanism in Example 1;

[0066] Attached Figure 7 is a schematic diagram of the three-dimensional structure of the sliding mechanism in Example 1;

[0067] Attached Figure 8 It is a schematic diagram of the exploded structure of the sliding mechanism in Example 1;

[0068] Attached Fig. 9 It is a schematic diagram of the three-dimensional structure of the device for reinforcing steel columns using the reverse-bracing external prestressing technology of Example 2;

[0069] Attached Fig.10 It is a schematic diagram of the explosion mechanism after the reinforcement steel column, the column foot force transmission mechanism, the column top force transmission mechanism and the sliding mechanism are assembled in Example 2;

[0070] Attached Fig.11 It is a three-dimensional structural schematic diagram of the column foot force transmission mechanism of Example 2;

[0071] Attached Fig.12 It is a schematic diagram of the exploded structure of the column foot force transmission mechanism of Example 2;

[0072] Attached Fig.13 is a schematic diagram of the three-dimensional structure of the column top force transmission mechanism in Example 2;

[0073] Attached Fig.14 It is a schematic diagram of the exploded structure of the column top force transmission mechanism in Example 2;

[0074] Attached Fig.15 is a schematic diagram of the three-dimensional structure of the sliding mechanism in Example 2;

[0075] Attached Fig.16 This is a schematic diagram of the exploded structure of the sliding mechanism in Example 2.

[0076] In the figure: 1. Reinforced steel column, 2. Column foot bottom plate, 3. Column top transverse partition, 4. Column top force transmission mechanism, 5. Column foot force transmission mechanism, 6. Sliding mechanism, 7. Steel strand, 8. Column foot force transmission assembly, 9. Column foot anchor fastener, 10. Column foot force transmission plate, 11. Column foot anchor plate, 12. Column foot anchor buckle plate, 13. Column foot bending reinforcement plate, 14. Column foot sealing plate, 15. Column foot support plate, 16. Column foot steel strand hole, 17 , column base connecting ear bolts, 18, column top force transmission assembly, 19, column top anchor fasteners, 20, column top force transmission rod, 21, column top anchor plate, 22, column top anchor buckle plate, 23, column top bent reinforcement plate, 24, column top sealing plate, 25, column top support plate, 26, column top steel strand hole, 27, column top connecting ear bolts, 28, sliding buckle plate, 29, sliding connecting ear bolts, 30, sliding bent reinforcement plate, 31, anchor. DETAILED DESCRIPTION

[0077] The device for reinforcing steel columns using the reverse-bracing external prestressing technology and the construction method thereof are described in detail below with reference to the accompanying drawings and specific embodiments of the specification.

[0078] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0079] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0080] Embodiment 1:

[0081] As attached Figure 1As shown, this embodiment provides a device for reinforcing steel columns using a reverse-bracing external prestressing technology, and its structure includes an I-shaped reinforcing steel column 1, a column foot bottom plate 2 is installed at one end of the I-shaped reinforcing steel column 1, a column top cross partition 3 is installed at the other end of the reinforcing steel column 1, a column top force transmission mechanism 4 is installed above the column foot bottom plate 2, a column foot force transmission mechanism 5 is installed above the column top force transmission mechanism 4, and a plurality of sliding mechanisms 6 are installed above the column foot force transmission mechanism 5 at intervals.

[0082] As attached Figure 2 As shown, the total length of the column top force transmission mechanism 4 in this embodiment is equal to the height of the reinforced steel column 1, and the steel strand anchoring end of the column top force transmission mechanism 4 is installed with a steel strand 7, one end of the steel strand 7 is connected to the steel strand anchoring end of the column top force transmission mechanism 4, the steel strand anchoring end of the column top force transmission mechanism 4 is used to anchor the steel strand 7, and the column top connecting end of the column top force transmission mechanism 4 is connected to the column top cross diaphragm 3, which is used to transmit vertical force to the top of the reinforced steel column 1.

[0083] The steel strand anchoring end of the column base force transmission mechanism 5 in this embodiment is connected to the other end of the steel strand 7, the steel strand anchoring end of the column base force transmission mechanism 5 is used to anchor the steel strand 7, and the bottom plate connecting end of the column base force transmission mechanism 5 is connected to the column base bottom plate 2, which is used to transmit the vertical force to the bottom of the reinforced steel column 1.

[0084] As attached Figure 3 and 4 As shown, the column foot force transmission mechanism 5 in this embodiment includes a column foot force transmission component 8, a column foot anchor fastener 9 is installed on the top of the column foot force transmission component 8, and the bottom of the column foot force transmission component 8 is fixedly connected to the column foot bottom plate 2.

[0085] The column foot force transmission assembly 8 in this embodiment includes two U-shaped column foot force transmission plates 10, which are arranged back to back and assembled into an I-shape.

[0086] The column foot anchor fastener 9 in this embodiment includes two column foot anchor plates 11 and two column foot anchor gussets 12, the two column foot anchor gussets 12 are arranged back to back and the two column foot anchor gussets 12 are assembled into an I-shape through the column foot connecting ear bolts 17; two column foot bent reinforcement plates 13 arranged at intervals are respectively installed on the two column foot anchor gussets 12, a column foot sealing plate 14 is installed between the two column foot bent reinforcement plates 13, a plurality of column foot support plates 15 arranged at intervals are installed in the cavity formed by the column foot sealing plate 14 and the two column foot bent reinforcement plates 13, and the two column foot anchor plates 11 are respectively installed Between the column base anchoring plate 12 and the column base sealing plate 14 and located on the top of the column base anchoring plate 12 and the column base sealing plate 14, two column base steel strand holes 16 arranged at intervals are opened on the column base anchor plate 11, and the steel strand 7 passes through the column base steel strand holes 16 and extends through the column base force transmission channel composed of the column base force transmission plate 10, the column base sealing plate 14, the column base anchor plate 11 and the column base support plate 15 to the column top force transmission mechanism 4, the column base sealing plate 14 and the column base support plate 15 are used to support the column base anchor plate 11 to bear force; wherein, the steel strand 7 is fixedly connected to the column base anchor plate 11 through the anchor 31.

[0087] As attached Figure 5 and 6 As shown, the column top force transmission mechanism 4 in this embodiment includes a column top force transmission component 18, the top of the column top force transmission component 18 is fixedly connected to the column top cross partition 3, and the bottom of the column top force transmission component 18 is installed with a column top anchor fastener 19.

[0088] The column top force transmission assembly 19 in this embodiment includes four L-shaped column top force transmission rods 20, and the four L-shaped column top force transmission rods 20 are arranged back to back and assembled into an I-shape.

[0089] The column top anchor fastener 19 in this embodiment includes two column top anchor plates 21 and two column top anchor gussets 22. Two column top anchor gussets 22 are provided with two column top bent reinforcement plates 23 arranged at intervals. The two column top anchor gussets 22 with column top bent reinforcement plates 23 are assembled into an I-shape through column top connecting ear bolts 27; a column top sealing plate 24 is installed between the two column top bent reinforcement plates 23, and a plurality of column top support plates 25 arranged at intervals are installed in the cavity between the column top sealing plate 24 and the two column top bent reinforcement plates 23. The two column top anchor plates 21 are respectively installed on the column top and the column top. Between the top anchoring buckle plate 22 and the column top sealing plate 24 and located at the bottom of the column top anchoring buckle plate 22 and the column top sealing plate 24, two column top steel strand holes 26 arranged at intervals are opened on the column top anchor plate 21, and the steel strand 7 passes through the column top steel strand holes 26 and passes through the column top force transmission channel composed of the column top force transmission rod 20, the column top sealing plate 24, the column top anchor plate 21 and the column top support plate 25 to extend to the column foot force transmission mechanism 5, the column top sealing plate 24 and the column top support plate 25 are used to support the column top anchor plate 21 to bear force; the steel strand 7 is fixedly connected to the column top anchor plate 21 through the anchor 31.

[0090] The diameters of the steel strand holes 16 at the column base and the steel strand holes 26 at the column top in this embodiment are larger than the diameter of the steel strand 7. The diameter of the steel strand 7 is 12.7 to 21.8 mm, the tensile strength of the steel strand 7 is 1570 to 1960 MPa, and the load-bearing range of the steel strand 7 is 3 to 46 tons.

[0091] As attached Figure 7 and 8 As shown, the sliding mechanism 6 in this embodiment includes two sliding buckle plates 28, on which two sliding buckle plates 28 are respectively provided with two sliding bending reinforcement plates 30 arranged at intervals, and the two sliding buckle plates 28 are fixedly connected by sliding connecting ear bolts 29. After being fixedly connected, the two sliding buckle plates 28 are in an I-shape.

[0092] Embodiment 2:

[0093] As attached Fig. 9 As shown, this embodiment provides a device for reinforcing steel columns using a reverse-bracing extracorporeal prestressed technology, and its structure includes a box-type reinforcing steel column 1, a column foot bottom plate 2 is installed at one end of the box-type reinforced steel column 1, a column top cross partition 3 is installed at the other end of the box-type reinforced steel column 1, a column top force transmission mechanism 4 is installed above the column foot bottom plate 2, a column foot force transmission mechanism 5 is installed above the column top force transmission mechanism 4, and a plurality of sliding mechanisms 6 are installed above the column foot force transmission mechanism 5 at intervals.

[0094] As attached Fig.10 As shown, the total length of the column top force transmission mechanism 4 in this embodiment is equal to the height of the reinforced steel column 1 and the steel strand anchoring end of the column top force transmission mechanism 4 is installed with a steel strand 7, one end of the steel strand 7 is connected to the steel strand anchoring end of the column top force transmission mechanism 4, the steel strand anchoring end of the column top force transmission mechanism 4 is used to anchor the steel strand 7, and the column top connecting end of the column top force transmission mechanism 4 is connected to the column top cross partition 3, which is used to transmit vertical force to the top of the reinforced steel column 1.

[0095] The steel strand anchoring end of the column base force transmission mechanism 5 in this embodiment is connected to the other end of the steel strand 7, the steel strand anchoring end of the column base force transmission mechanism 5 is used to anchor the steel strand 7, and the bottom plate connecting end of the column base force transmission mechanism 5 is connected to the column base bottom plate 2, which is used to transmit the vertical force to the bottom of the reinforced steel column 1.

[0096] As attached Fig.11 and 12 As shown, the column foot force transmission mechanism 5 in this embodiment includes a column foot force transmission component 8, a column foot anchor fastener 9 is installed on the top of the column foot force transmission component 8, and the bottom of the column foot force transmission component 8 is fixedly connected to the column foot bottom plate 2.

[0097] The column base force transmission assembly 8 in this embodiment includes two U-shaped column base force transmission plates 10. The two U-shaped column base force transmission plates 10 are arranged opposite to each other and are assembled into a box shape.

[0098] The column foot anchor fastener 9 in this embodiment includes two column foot anchor plates 11 and two column foot anchor gussets 12, the two column foot anchor gussets 12 are arranged opposite to each other and the two column foot anchor gussets 12 are assembled into a box shape; the two column foot anchor gussets are U-shaped, the two U-shaped column foot anchor gussets 12 are fixedly connected by column foot connecting ear bolts 17, and the outer side surfaces of the two U-shaped column foot anchor gussets 12 are installed with column foot sealing plates 14, and some The column base support plates 15 are arranged at intervals, and a column base anchor plate 11 is installed on the top of the column base sealing plate 14. Two column base steel strand holes 16 are arranged at intervals on the column base anchor plate 11. The steel strand 7 passes through the column base steel strand holes 16 and passes through the column base force transmission channel composed of the column base anchor plate 11, the column base sealing plate 14, the column base support plate 15 and the outer side surface of the column base anchoring buckle plate 12 to extend to the column top force transmission mechanism 4; wherein, the steel strand 7 is fixedly connected to the column base anchor plate 11 through the anchor 31.

[0099] As attached Fig.13 and 14 As shown, the column top force transmission mechanism 4 in this embodiment includes a column top force transmission component 18, the top of the column top force transmission component 18 is fixedly connected to the column top cross partition 3, and the bottom of the column top force transmission component 18 is installed with a column top anchor fastener 19.

[0100] The column top force transmission assembly 18 in this embodiment includes four L-shaped column top force transmission rods 20. The four L-shaped column top force transmission rods 20 are arranged opposite to each other and are assembled into a box shape.

[0101] The column top anchor fastener 19 in this embodiment includes two column top anchor plates 21 and two column top anchor gussets 22, the two column top anchor gussets 22 are arranged opposite to each other and the two column top anchor gussets 22 are assembled into a box shape; the two column top anchor gussets 22 are U-shaped, the two U-shaped column top anchor gussets 22 are fixedly connected by column top connecting ear bolts 27, and the outer side surfaces of the two U-shaped column top anchor gussets 22 are installed with column top sealing plates 24, and the outer side surfaces of the column top anchor gussets 22 and the column top sealing plates 24 are fixedly connected. A plurality of spaced-apart column top support plates 25 are installed, a column top anchor plate 21 is installed on the top of the column top sealing plate 24, two spaced-apart column top steel strand holes 26 are opened on the column top anchor plate 21, and the steel strand 7 passes through the column top steel strand holes 26 and passes through the column top force transmission channel composed of the column top anchor plate 21, the column top sealing plate 24, the column top support plate 25 and the outer side surface of the column top anchoring buckle plate 22 to extend to the column foot force transmission mechanism 5; the steel strand 7 is fixedly connected to the column top anchor plate 21 through an anchor.

[0102] The diameters of the steel strand holes 16 at the column base and the steel strand holes 26 at the column top in this embodiment are larger than the diameter of the steel strands. The diameter of the steel strands 7 is 12.7 to 21.8 mm, the tensile strength of the steel strands 7 is 1570 to 1960 MPa, and the load-bearing range of the steel strands 7 is 3 to 46 tons.

[0103] As attached Fig.15 and16 As shown, the sliding mechanism 6 in this embodiment includes two sliding buckle plates 28, the two sliding buckle plates 28 are U-shaped, the two U-shaped sliding buckle plates 28 are relatively arranged and assembled into a box shape, and the two U-shaped sliding buckle plates 28 are fixedly connected by sliding connecting ear bolts 29.

[0104] Embodiment 3:

[0105] This embodiment provides a construction method for a device for reinforcing a steel column using an inverse bracing external prestressing technique, the method being specifically as follows:

[0106] S1. According to the actual use requirements of the building structure, determine the load conditions of the floor and roof, conduct a stress analysis on the main structure, and determine the number and location of the steel columns to be reinforced;

[0107] S2. According to the cross-sectional dimensions of the steel column 1 to be reinforced, the cross-sectional dimensions of the column foot anchoring plate 12, the column top anchoring plate 19 and the sliding plate 28 are designed by lofting, so that the shapes of the inner surfaces of the column foot anchoring plate 12, the column top anchoring plate 19 and the sliding plate 28 can completely fit the cross-sectional dimensions of the steel column 1 to be reinforced;

[0108] S3. Calculate the compressive bearing capacity of the steel column 1 to be reinforced before reinforcement according to the cross-sectional size and height of the steel column 1 to be reinforced, and combine the actual vertical force of the steel column 1 to be reinforced obtained in step S1 to determine the size of the prestress to be applied by calculating the vertical force, the compressive bearing capacity of the reinforced steel column 1 and the friction force. The formula is as follows:

[0109] N 预应力 =(N 实际 -N d ) / 4;

[0110] The tension control stress of each steel strand 7 is determined according to the prestressing force, and the formula is as follows:

[0111] N 张拉 =N 预应力 / 0.75;

[0112] S4. According to the size of the prestress, the cross-sectional thickness of the column foot force transfer plate 10 and the column top force transfer rod 20 is calculated by the calculation formula of the axially compressed member; wherein the calculated length of the column foot force transfer plate 10 is twice the actual length of the plate; the calculated length of the column top force transfer rod 20 is the spacing of the sliding buckle plate 28; wherein the calculation formula of the axially compressed member is as follows:

[0113] ① The strength calculation formula of axially compressed components is: N≤N u ;

[0114] Where N is the design value of the axial pressure; N u is the design value of the section compressive bearing capacity when the axis is compressed, and the calculation formula is Nu =f×A s ; Where f is the design value of the compressive strength of steel and concrete; A s is the cross-sectional area of ​​the steel column; when designing for earthquake resistance, it needs to be divided by the earthquake resistance adjustment factor γ RE ;

[0115] ②The stability calculation formula of axially compressed components is:

[0116] in, It is the stability coefficient of axially compressed members, which is determined based on factors such as the slenderness ratio of the member, the cross-section classification, and the yield strength of the steel material. The specific value can be obtained by referring to the current specification "Steel Structure Design Code" or related tables; Stability coefficient The smaller of the two main axis stability coefficients of the section should be taken; N u is the design value of the section compressive bearing capacity when subjected to axial compression, which is the same as N in the strength calculation formula. u same;

[0117] S5, cutting of the external steel strand 7 and processing and manufacturing of the components of the column top force transmission mechanism 4 and the column foot force transmission mechanism 5;

[0118] S6. Grind the surface of the steel column 1 to be reinforced and the column foot anchoring plate 12, the column top anchoring plate 22 and the sliding plate 28 to make them clean, and control the sliding friction coefficient between the surface of the steel column 1 to be reinforced and the column foot anchoring plate 12, the column top anchoring plate 22 and the sliding plate 28 to be between 0.05 and 0.15, so as to ensure that the device for reinforcing the steel column with the reverse-bracing external prestressing technology can slide relative to the reinforced steel column 1;

[0119] S7, assemble the column foot force transmission mechanism 5, assemble the two column foot force transmission plates 10 to the bottom of the reinforced steel column 1 through the column foot anchoring buckle plate 12, and fix the two column foot anchoring fasteners 9 through the column foot connecting ear bolts 17, and then weld the bottom of the column foot force transmission plate 10 to the column foot bottom plate 2;

[0120] S8, assemble the column top force transmission mechanism 4 and the sliding mechanism 6, assemble the sliding mechanism 6 to the predetermined position according to the designed spacing, and connect them through the sliding connection ear bolts 29, so that the sliding mechanism 6 and the reinforced steel column 1 can slide relative to each other; then assemble the column top force transmission mechanism 4 to the surface of the column foot force transmission mechanism 5 and the sliding mechanism 6, so that the column top force transmission mechanism 4 assembly and the column foot force transmission mechanism 5 can slide relative to each other, and then weld the top of the column top force transmission rod 20 to the column top cross partition 3, and weld the middle part of the column top force transmission rod 20 to the sliding buckle plate 28;

[0121] S9, after the operation of step S7 and step S8, only the top of the column top force transmission rod 20 of the column top force transmission mechanism 4 is welded to the column top cross partition 3, and the rest of the parts are not connected to the reinforced steel column 1; only the bottom of the column foot force transmission plate 10 of the column foot force transmission mechanism 5 is welded to the column foot bottom plate 2, and the rest of the parts are not connected to the reinforced steel column 1; the column top force transmission mechanism 4 and the column foot force transmission mechanism 5 are not connected, and the two can slide relative to each other;

[0122] S10, threading and installing the external steel strand 7;

[0123] S11, tensioning the external steel strands 7 on both sides of the reinforced steel column 1 at the same time, the tensioning adopts the method of tensioning force control as the main method and elongation value verification, the deviation between the measured elongation value and the calculated elongation value should not exceed ±6%, when the tensioning force reaches the design value, the tensioning end is anchored, and the tensioning ends;

[0124] S12. After the external steel strands 7 are tensioned, the steel strands 7, the column top force transmission mechanism 4 and the column foot force transmission mechanism 5 are protected.

[0125] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for reinforcing steel columns using reverse bracing external prestressing technology, characterized in that: The device comprises a reinforced steel column, one end of which is provided with a column foot bottom plate, the other end of which is provided with a column top cross partition plate, a column top force transmission mechanism is provided above the column foot bottom plate, a column foot force transmission mechanism is provided above the column top force transmission mechanism, and a plurality of sliding mechanisms arranged at intervals are provided above the column foot force transmission mechanism; The total length of the column top force transmission mechanism is equal to the height of the reinforced steel column, and the steel strand anchoring end of the column top force transmission mechanism is provided with a steel strand, one end of the steel strand is connected to the steel strand anchoring end of the column top force transmission mechanism, the steel strand anchoring end of the column top force transmission mechanism is used to anchor the steel strand, and the column top connection end of the column top force transmission mechanism is connected to the column top transverse diaphragm, which is used to transmit the vertical force to the top of the reinforced steel column; The steel strand anchoring end of the column foot force transmission mechanism is connected to the other end of the steel strand, and the steel strand anchoring end of the column foot force transmission mechanism is used to anchor the steel strand. The bottom plate connecting end of the column foot force transmission mechanism is connected to the column foot bottom plate, and is used to transmit the vertical force to the bottom of the reinforced steel column.

2. The device for reinforcing steel columns by using reverse bracing external prestressing technology according to claim 1 is characterized in that: The reinforced steel columns are I-shaped reinforced steel columns and box-shaped reinforced steel columns.

3. The device for reinforcing steel columns by using reverse bracing external prestressing technology according to claim 1 is characterized in that: The column foot force transmission mechanism comprises a column foot force transmission component, a column foot anchor fastener is arranged on the top of the column foot force transmission component, and the bottom of the column foot force transmission component is fixedly connected to the column foot bottom plate.

4. The device for reinforcing steel columns by using reverse bracing external prestressing technology according to claim 3 is characterized in that: The column foot force transmission assembly includes two U-shaped column foot force transmission plates; When the reinforced steel column is an I-shaped reinforced steel column, the two U-shaped column foot force transfer plates are arranged back to back and the two U-shaped column foot force transfer plates are assembled into an I-shape; When the reinforced steel column is a box-type reinforced steel column, the two U-shaped column foot force transfer plates are arranged opposite to each other and the two U-shaped column foot force transfer plates are assembled into a box shape.

5. The device for reinforcing steel columns by using reverse bracing external prestressing technology according to claim 3 is characterized in that: The column foot anchor fastener comprises two column foot anchor plates and two column foot anchor gusset plates; When the reinforced steel column is an I-shaped reinforced steel column, the two column foot anchoring gussets are arranged back to back and the two column foot anchoring gussets are assembled into an I-shape through the column foot connecting ear bolts; two column foot bent reinforcement plates arranged at intervals are respectively arranged on the two column foot anchoring gussets, and a column foot sealing plate is arranged between the two column foot bent reinforcement plates, and a plurality of column foot support plates arranged at intervals are arranged in the cavity formed by the column foot sealing plate and the two column foot bent reinforcement plates, and the two column foot anchor plates are respectively installed between the column foot anchoring gussets and the column foot sealing plates and are located on the top of the column foot anchoring gussets and the column foot sealing plates, and two column foot steel strand holes arranged at intervals are arranged on the column foot anchor plate, and the steel strands pass through the column foot steel strand holes through the column foot force transmission channel composed of the column foot force transmission plate, the column foot sealing plate, the column foot anchor plate and the column foot support plate to extend to the column top force transmission mechanism, and the column foot sealing plate and the column foot support plate are used to support the column foot anchor plate to bear force; When the reinforced steel column is a box-type reinforced steel column, the two column foot anchoring gussets are arranged opposite to each other and the two column foot anchoring gussets are assembled into a box shape; the two column foot anchoring gussets are U-shaped, the two U-shaped column foot anchoring gussets are fixedly connected by column foot connecting ear bolts and the outer sides of the two U-shaped column foot anchoring gussets are provided with a column foot sealing plate, a plurality of column foot support plates are arranged between the outer sides of the column foot anchoring gussets and the column foot sealing plates, a column foot anchor plate is arranged on the top of the column foot sealing plate, and two column foot steel strand holes are arranged on the column foot anchor plate, and the steel strand passes through the column foot steel strand hole through the column foot force transmission channel composed of the column foot anchor plate, the column foot sealing plate, the column foot support plate and the outer side of the column foot anchoring gusset to extend to the column top force transmission mechanism; wherein, the steel strand is fixedly connected to the column foot anchor plate through an anchor.

6. The device for reinforcing steel columns by using reverse bracing external prestressing technology according to claim 3 is characterized in that: The column top force transmission mechanism comprises a column top force transmission component, the top of the column top force transmission component is fixedly connected to the column top cross partition, and the bottom of the column top force transmission component is provided with a column top anchor fastener.

7. The device for reinforcing steel columns by using reverse bracing external prestressing technology according to claim 6 is characterized in that: The column top force transmission assembly includes four L-shaped column top force transmission rods; When the reinforced steel column is an I-shaped reinforced steel column, four L-shaped column top force transmission rods are arranged back to back and the four L-shaped column top force transmission rods are assembled into an I-shape; When the reinforced steel column is a box-type reinforced steel column, four L-shaped column top force transmission rods are arranged relatively and the four L-shaped column top force transmission rods are assembled into a box shape.

8. The device for reinforcing steel columns by using reverse bracing external prestressing technology according to claim 6 is characterized in that: The column top anchor fastener comprises two column top anchor plates and two column top anchor buckle plates; When the reinforced steel column is an I-shaped reinforced steel column, two column top anchoring buckles are provided with two column top bent reinforcement plates arranged at intervals, and the two column top anchoring buckles with column top bent reinforcement plates are assembled into an I-shape through column top connecting ear bolts; a column top sealing plate is provided between the column top bent reinforcement plates, and a plurality of column top support plates arranged at intervals are provided in the cavity formed by the column top sealing plate and the two column top bent reinforcement plates. The two column top anchor plates are respectively installed between the column top anchoring buckle plate and the column top sealing plate and are located at the bottom of the column top anchoring buckle plate and the column top sealing plate, and two column top steel strand holes arranged at intervals are provided on the column top anchor plate. The steel strand passes through the column top steel strand hole through the column top force transmission channel composed of the column top force transmission rod, the column top sealing plate, the column top anchor plate and the column top support plate to extend to the column foot force transmission mechanism, and the column top sealing plate and the column top support plate are used to support the column top anchor plate to bear force; When the reinforced steel column is a box-type reinforced steel column, the two column top anchoring gussets are arranged opposite to each other and the two column top anchoring gussets are assembled into a box shape; the two column top anchoring gussets are U-shaped, the two U-shaped column top anchoring gussets are fixedly connected by column top connecting ear bolts, and the outer sides of the two U-shaped column top anchoring gussets are provided with a column top sealing plate, and a plurality of column top support plates distributed at intervals are provided between the outer sides of the column top anchoring gussets and the column top sealing plate, and a column top anchor plate is provided on the top of the column top sealing plate, and two column top steel strand holes distributed at intervals are provided on the column top anchor plate, and the steel strand passes through the column top steel strand hole through the column top force transmission channel composed of the column top anchor plate, the column top sealing plate, the column top support plate and the outer side of the column top anchoring gusset to extend to the column foot force transmission mechanism; The steel strand is fixedly connected to the anchor plate at the top of the column through an anchor; The diameters of the steel strand holes at the column base and the column top are larger than the diameter of the steel strands. The diameter of the steel strands is 12.7 to 21.8 mm, the tensile strength of the steel strands is 1570 to 1960 MPa, and the load-bearing range of the steel strands is 3 to 46 tons.

9. The device for reinforcing steel columns by using reverse bracing external prestressing technology according to claim 1 is characterized in that: The sliding mechanism includes two sliding buckle plates; When the reinforced steel column is an I-shaped reinforced steel column, two sliding buckle plates are respectively provided with two sliding bending reinforcement plates arranged at intervals, and the two sliding buckle plates are fixedly connected by sliding connection ear bolts, and the two sliding buckle plates after fixed connection are in an I-shape; When the reinforced steel column is a box-type reinforced steel column, the two sliding gussets are U-shaped, the two U-shaped sliding gussets are relatively arranged and assembled into a box shape, and the two U-shaped sliding gussets are fixedly connected by sliding connecting ear bolts.

10. A construction method for a device for reinforcing a steel column using an inverse bracing external prestressing technique, characterized in that: The method is as follows: S1. According to the actual use requirements of the building structure, determine the load conditions of the floor and roof, conduct a stress analysis on the main structure, and determine the number and location of the steel columns to be reinforced; S2. According to the cross-sectional dimensions of the steel column to be reinforced, the cross-sectional dimensions of the column foot anchoring plate, the column top anchoring plate and the sliding plate are designed by lofting, so that the shapes of the inner surfaces of the column foot anchoring plate, the column top anchoring plate and the sliding plate can completely fit the cross-sectional dimensions of the steel column to be reinforced; S3. Calculate the compressive bearing capacity of the steel column to be reinforced before reinforcement according to the cross-sectional size and height of the steel column to be reinforced, and combine the actual vertical force of the steel column to be reinforced obtained in step S1 to determine the size of the prestress to be applied by calculating the vertical force, the compressive bearing capacity of the reinforced steel column and the friction force. The formula is as follows: N 预应力 =(N 实际 -N d ) / 4; The tension control stress of each steel strand is determined according to the prestressing force. The formula is as follows: N 张拉 =N 预应力 / 0.75; S4. According to the size of prestress, the cross-sectional thickness of the column foot force transfer plate and the column top force transfer rod is calculated by the calculation formula of the axially compressed member; the calculated length of the column foot force transfer plate is twice the actual length of the plate; the calculated length of the column top force transfer rod is based on the spacing of the sliding buckle plate; the calculation formula of the axially compressed member is as follows: ① The strength calculation formula of axially compressed components is: N≤N u ; Where N is the design value of the axial pressure; N u is the design value of the section compressive bearing capacity when the axis is compressed, and the calculation formula is N u =f×A s ; Where f is the design value of the compressive strength of steel and concrete; A s is the cross-sectional area of ​​the steel column; when designing for earthquake resistance, it needs to be divided by the earthquake resistance adjustment factor γ RE ; ②The stability calculation formula of axially compressed components is: in, It is the stability coefficient of axially compressed members, which is determined based on factors such as the slenderness ratio of the member, the cross-section classification, and the yield strength of the steel material. The specific value can be obtained by referring to the current specification "Steel Structure Design Code" or related tables; Stability coefficient The smaller of the two main axis stability coefficients of the section should be taken; N u is the design value of the section compressive bearing capacity when subjected to axial compression, which is the same as N in the strength calculation formula. u same; S5. Cutting of external steel strands and processing and manufacturing of components of column top force transmission mechanism and column foot force transmission mechanism; S6. Grind the surface of the steel column to be reinforced and the anchoring gussets at the column base, the anchoring gussets at the column top, and the sliding gussets cleanly, and control the sliding friction coefficient of the steel column to be reinforced and the anchoring gussets at the column base, the anchoring gussets at the column top, and the sliding gussets to be between 0.05 and 0.15, so as to ensure that the device for reinforcing the steel column with the reverse-bracing external prestressing technology can slide relative to the reinforced steel column; S7, assemble the column foot force transmission mechanism, assemble the two column foot force transmission plates to the bottom of the reinforced steel column through the column foot anchoring buckle plate, and fix the two column foot anchoring fasteners through the column foot connecting ear bolts, and then weld the bottom of the column foot force transmission plate to the column foot bottom plate; S8. Assemble the column top force transmission mechanism and the sliding mechanism, assemble the sliding mechanism to the predetermined position according to the designed spacing, and connect them through the sliding connection ear bolts, so that the sliding mechanism and the reinforced steel column can slide relative to each other; then assemble the column top force transmission mechanism to the surface of the column foot force transmission mechanism and the sliding mechanism, so that the column top force transmission mechanism assembly and the column foot force transmission mechanism can slide relative to each other, and then weld the top of the column top force transmission rod to the column top cross partition, and weld the middle part of the column top force transmission rod to the sliding buckle plate; S9, after the operation of step S7 and step S8, only the top of the column top force transmission rod of the column top force transmission mechanism is welded to the column top cross partition, and the rest of the parts are not connected to the reinforced steel column; only the bottom of the column foot force transmission plate of the column foot force transmission mechanism is welded to the column foot bottom plate, and the rest of the parts are not connected to the reinforced steel column; the column top force transmission mechanism and the column foot force transmission mechanism are not connected, and the two can slide relative to each other; S10, threading and installing external steel strands; S11. Tension the external steel strands on both sides of the reinforced steel column at the same time. The tensioning is mainly controlled by tensioning force and the elongation value is checked. The deviation between the measured elongation value and the calculated elongation value should not exceed ±6%. When the tensioning force reaches the design value, anchor the tensioning end and the tensioning is finished. S12. After the external steel strands are tensioned, the steel strands, the force transmission mechanism at the top of the column and the force transmission mechanism at the base of the column shall be protected.

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