A method for reinforcing pre-tensioned lattice steel using assembled full bolt connection

Abstract

The present invention discloses an assembled full-bolt connection pre-tensioned lattice steel reinforcement method, S1, grinding: grinding the concrete column body to be reinforced with a grinding wheel machine, and grinding the four corners of the concrete column to be smooth; S2, installing the lattice steel: calculating the number of lattice steels to be installed according to the length of the concrete column body, and marking the corresponding positions of the column body, and installing the lattice steels at the four corners of the concrete column from top to bottom in sequence according to the column body marks. The present invention adopts the above-mentioned assembled full-bolt connection pre-tensioned lattice steel reinforcement method, combines the pre-tensioning technology with the full-bolt connection technology, so that the lattice steel and the concrete column are fitted together, and the two form a whole to bear force together, reducing concrete cracking, and can effectively improve the rigidity and bearing capacity of the component; no on-site welding is required, avoiding the problem that welding affects the quality of the adhesive, and the full-bolt connection is quick and convenient to install, and the connection is reliable, which effectively improves the construction efficiency and construction quality.

Description

Technical Field

[0001] The invention relates to the technical field of building engineering, and in particular to an assembled full-bolt connection pre-tensioned lattice steel reinforcement method. Background Art

[0002] As buildings age, they are affected by earthquakes, fires, rainwater erosion and other natural phenomena, which greatly affects the stability of buildings and creates safety hazards. Therefore, it is of great engineering significance to reinforce and renovate old buildings. When the use of a building structure changes, the actual bearing capacity of the structure differs from the designed bearing capacity. In order to ensure the stability of the building structure, the corresponding building structure must be reinforced and renovated.

[0003] Existing building reinforcement technologies mainly include: increasing the cross-section method, external steel reinforcement method, steel plate bonding reinforcement method, concrete replacement reinforcement method, fiber bonding method, and external pre-tension reinforcement method. The increasing cross-section method increases the cross-sectional area of ​​the original component to increase its bearing capacity and rigidity, but the construction period is long, wet work is required on site, and the use space of the house will be compressed, causing certain inconveniences; the external steel reinforcement method refers to the external steel outside the original reinforced concrete component, which is reinforced by welding or injecting structural adhesive. The steel and concrete form a whole, but the external steel reinforcement method does not improve the structural rigidity much, and requires on-site welding, which may affect the quality of the adhesive.

[0004] The stress-bonded steel plate reinforcement method refers to the use of structural adhesive to bond thin steel plates on the surface of concrete components to form a composite cross-section to improve the bearing capacity, but the stiffness of the components is slightly improved; the replacement concrete reinforcement method uses higher strength grade concrete to replace the severely defective concrete, but the new and old concretes have poor synergy, the original structure may be damaged by chiseling, and the wet operation cycle is long; the fiber bonding method refers to the use of structural adhesives to bond fiber cloth or fiber sheets on the surface of reinforced concrete structural components, but the structural bearing capacity and stiffness are not greatly improved; the external pre-tension reinforcement method refers to the arrangement of high-strength steel bars or steel strands outside the component body, and the application of external pre-tension to improve or adjust the original structure and component stress. A reinforcement method, but when the pre-tension is small, the reinforcement effect is not obvious, and when the pre-tension is too large, the structural bearing capacity will decrease, the optimal pre-tension is difficult to grasp, and the construction process is relatively complicated. It can be seen that the existing reinforcement methods all have certain shortcomings. Summary of the invention

[0005] The purpose of the present invention is to provide an assembled full-bolt connection pre-tensioned lattice steel reinforcement method, which solves the problems in the prior art of the external steel reinforcement method that the structural rigidity is not greatly improved, the steel section volume is large, the transportation and assembly are inconvenient, the welding affects the quality of the adhesive, and causes certain damage to the structural components.

[0006] To achieve the above object, the present invention provides an assembled full-bolt connection pre-tensioned lattice steel reinforcement method, comprising the following steps:

[0007] S1. Grinding: Grinding the concrete column to be reinforced with a grinding machine to make the four corners of the concrete column smooth;

[0008] S2. Installing lattice steel: Calculate the number of lattice steels to be installed according to the length of the concrete column, and mark the corresponding positions of the column. According to the column marks, install the lattice steels at the four corners of the concrete column from top to bottom in sequence;

[0009] S3, installing the tie plate and the pre-tensioned steel member: fixing the tie plate to the ear plate of the lattice steel by high-strength bolts, the nuts of the high-strength bolts are kept loose and can slide freely, after the lattice steel is installed, the angle steel is installed at the reserved position of the angle steel on the lattice steel, and the angle steel and the lattice steel are tightly connected by high-strength bolts;

[0010] Pre-tension is applied at the upper and lower parts of the lattice steel respectively, and no tie plates are installed at the places where the pre-tension is applied. The pre-tension steel member is installed at the places where the pre-tension is applied on the lattice steel using high-strength bolts. The pre-tension steel member is connected to the lattice steel via ear plates, and the high-strength bolts are tightened to the design value of the high-strength bolts. During the application of the pre-tension, the high-strength bolts cannot slide;

[0011] S4, applying pre-tension: one end of the high-strength bolt on the pre-tension steel member is fixed by a wrench, and a torque is applied to one end of the nut by a torque wrench, and the torque is converted into a pre-tension on the lattice steel. The torque is applied symmetrically from top to bottom and from small to large, and the application process is divided into three stages; the first application is to 30% of the pre-tension design value, the second application is to 60% of the pre-tension design value, and the third application is to the specified pre-tension design value, and the pre-tension application is completed;

[0012] S5. Reinforcement is completed: a certain period of time after the pre-tension is applied, the high-strength bolts on the remaining fascia plates are tightened to the design value of the high-strength bolts, the pre-tension steel members are removed, and the fascia plates are installed at the removed positions. After all the high-strength bolts are tightened to the design value of the high-strength bolts, the reinforcement of the concrete column is completed.

[0013] Preferably, in step S3, the lattice steel and the ear plate are firmly welded in the factory and then transported to the construction site. Before reinforcing the concrete column, the lattice steel, the tie plate and the angle steel are ensured to be intact in appearance and free of surface rust.

[0014] Preferably, in step S4, the optimal pre-tension design value is 1 / 20 of the ultimate load of the concrete column 1, and the side length of the pre-tension application should be no less than 1 / 8 of the side length of the concrete column.

[0015] Preferably, in step S4, during the torque application process, after the lattice steel on one side reaches the specified torque, the torque is applied to the lattice steel on its symmetrical side, and after the upper areas of the lattice steels on the four sides reach the specified torque, the torque is applied to the lower area of ​​the lattice steel. After the upper and lower areas of the lattice steel each reach the specified torque on all four sides, one stage is completed, and the above steps are repeated.

[0016] Therefore, the present invention adopts the above-mentioned assembled full-bolt connection pre-tensioned lattice steel reinforcement method. According to the external steel reinforcement method, the pre-tensioning technology is combined with the full-bolt connection technology, so that the lattice steel and the concrete column are fitted together, and the two form a whole to bear the force together, reducing concrete cracking, and can effectively improve the stiffness and bearing capacity of the component; no on-site welding is required, avoiding the problem of welding affecting the quality of the adhesive, and the full-bolt connection is quick and convenient to install, the connection is reliable, and the construction efficiency and construction quality are effectively improved.

[0017] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of a lattice steel structure in an embodiment of an assembled full-bolt connection pre-tensioned lattice steel reinforcement method of the present invention;

[0019] Figure 2 It is a plan view of the appearance of the lattice steel in an embodiment of an assembled full-bolt connection pre-tensioned lattice steel reinforcement method of the present invention;

[0020] Figure 3 It is a schematic diagram of a cross section of lattice steel in an embodiment of an assembled full-bolt connection pre-tensioned lattice steel reinforcement method of the present invention;

[0021] Figure 4 It is a pre-tension reinforcement diagram in an embodiment of an assembled full-bolt connection pre-tension lattice steel reinforcement method of the present invention;

[0022] Figure 5 It is a schematic diagram of a pre-tension reinforcement cross section in an embodiment of an assembled full-bolt connection pre-tension lattice steel reinforcement method of the present invention;

[0023] Figure 6 The present invention is a schematic diagram of the structure of a pre-tensioned component in an embodiment of an assembled full-bolt connection pre-tensioned lattice steel reinforcement method.

[0024] Reference numerals

[0025] 1. Lattice steel; 2. Ear plate; 3. Angle steel; 4. Tie plate; 5. Concrete column; 6. Pre-tensioned member; 7. Nut; 8. High-strength bolt. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0027] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0028] Example

[0029] An assembled full-bolt connection pre-tensioned lattice steel reinforcement method comprises the following steps:

[0030] S1. Grinding: Use a grinding machine to carefully grind the concrete column 5 to be reinforced, and grind the four corners of the concrete column 5 to be smooth. Grinding does not affect the bearing capacity of the concrete column 5, and at the same time facilitates the subsequent installation of the lattice steel 1, so that it fits the concrete column 5.

[0031] S2. Install lattice steel: Calculate the number of lattice steels 1 that need to be installed according to the length of the concrete column 5, and mark the corresponding positions on the column to facilitate subsequent installation. The lattice steel 1 and the ear plate 2 are firmly welded in the factory and then transported to the construction site. Before reinforcing the concrete column 5, ensure that the lattice steel 1, the gusset plate 4, and the angle steel 2 are in good appearance and free of rust on the surface. According to the markings on the column, the lattice steel 1 is installed from top to bottom. Place a pair of lattice steels 1 on the upper part of the column and at the four corners of the column. When the distance between the lattice steels 1 allows the gusset plate 4 to be installed, use high-strength bolts 8 to fix the gusset plate 4 to the lattice steel 1.

[0032] S3. Install the gusset plate 4 and the pre-tensioned steel member 6: Fix the gusset plate 4 to the ear plate 2 of the lattice steel 1 with high-strength bolts 8. Keep the nuts 7 of the gusset plate 4 loose and free to slide to ensure that the lattice steel 1 is fixed without displacement. Avoid deformation of the lattice steel 1 caused by tightening the nuts 7, which will affect the accurate application of subsequent pre-tension. After the upper lattice steel 1 is installed, continue to install downwards. After all lattice steels 1 are installed, install the angle steel 3 at the reserved position of the angle steel 3. By installing the angle steel 3, the lattice steel 1 is formed into a whole. The nuts 7 connecting the angle steel 1 need to be tightened.

[0033] Pre-tension is applied to the upper and lower parts of the lattice steel 1 respectively, and the tie plate 4 is not installed at the place where the pre-tension is applied. The pre-tension steel member 6 is installed at the corresponding position of the ear plate 2 using high-strength bolts 8, and the high-strength bolts 8 are tightened to the design value of the high-strength bolts. During the application of the pre-tension, the high-strength bolts 8 cannot slide.

[0034] S4, applying pre-tension: one end of the high-strength bolt 8 on the pre-tension steel member 6 is fixed by a wrench, and one end of the nut 7 is converted into pre-tension on the lattice steel 1 by applying torque through a torque wrench. The optimal pre-tension design value is 1 / 20 of the ultimate load of the concrete column 5, and the side length of the pre-tension application should be no less than 1 / 8 of the side length of the concrete column 5. The torque is applied symmetrically. After the lattice steel 1 on one side reaches the specified torque, the torque is applied to the lattice steel 1 on its symmetrical surface. After the upper areas of the four sides of the lattice steel 1 have reached the specified torque, the torque is applied to the lower area of ​​the lattice steel 1. After the upper and lower areas of the lattice steel 1 have reached the specified torque on all four sides, one stage is completed. The above steps are repeated in the next stage. After the third application, the specified maximum torque is reached, and then the target pre-tension is reached, and the pre-tension application is completed.

[0035] The first application is to 30% of the pre-tension design value, the second application is to 60% of the pre-tension design value, and the third application is to the specified pre-tension design value. Through multiple applications in three stages, the lattice steel 1 gradually hugs the concrete column 5 to prevent the lattice steel from deforming due to excessive single torque.

[0036] S5, reinforcement completed: After a certain period of time after the pre-tensioning force is applied, the high-strength bolts 8 on the remaining gusset plates 4 are tightened to the design value of the high-strength bolts, the pre-tensioning steel member 6 is removed, and the gusset plates 4 are reinstalled at the removed position. After all the high-strength bolts 8 are tightened to the design value of the high-strength bolts, the application of the pre-tensioning force is completed. At this point, the entire reinforcement process is completed, and the structure forms an extrusion force on the core concrete column 5.

[0037] Therefore, the present invention adopts the above-mentioned assembled full-bolt connection pre-tensioned lattice steel reinforcement method. According to the external steel reinforcement method, the pre-tensioning technology is combined with the full-bolt connection technology, so that the lattice steel and the concrete column are fitted together, and the two form a whole to bear the force together, reducing concrete cracking, and can effectively improve the stiffness and bearing capacity of the component; no on-site welding is required, avoiding the problem of welding affecting the quality of the adhesive, and the full-bolt connection is quick and convenient to install, the connection is reliable, and the construction efficiency and construction quality are effectively improved.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. An assembled full bolt connection pre-tensioned lattice steel reinforcement method, characterized in that: The steps include: S1. Grinding: Grinding the concrete column to be reinforced with a grinding machine to make the four corners of the concrete column smooth; S2. Installing lattice steel: Calculate the number of lattice steels to be installed according to the length of the concrete column, and mark the corresponding positions of the column. According to the column marks, install the lattice steels at the four corners of the concrete column from top to bottom in sequence; S3, installing the tie plate and the pre-tensioned steel member: fixing the tie plate to the ear plate of the lattice steel by high-strength bolts, the nuts of the high-strength bolts are kept loose and can slide freely, after the lattice steel is installed, the angle steel is installed at the reserved position of the angle steel on the lattice steel, and the angle steel and the lattice steel are tightly connected by high-strength bolts; Pre-tension is applied at the upper and lower parts of the lattice steel respectively, and no tie plates are installed at the places where the pre-tension is applied. The pre-tension steel member is installed at the places where the pre-tension is applied on the lattice steel using high-strength bolts. The pre-tension steel member is connected to the lattice steel via ear plates, and the high-strength bolts are tightened to the design value of the high-strength bolts. During the application of the pre-tension, the high-strength bolts cannot slide; S4, applying pre-tension: one end of the high-strength bolt on the pre-tension steel member is fixed by a wrench, and a torque is applied to one end of the nut by a torque wrench, and the torque is converted into a pre-tension on the lattice steel. The torque is applied symmetrically from top to bottom and from small to large, and the application process is divided into three stages; the first application is to 30% of the pre-tension design value, the second application is to 60% of the pre-tension design value, and the third application is to the specified pre-tension design value, and the pre-tension application is completed; S5. Reinforcement is completed: a certain period of time after the pre-tension is applied, the high-strength bolts on the remaining fascia plates are tightened to the design value of the high-strength bolts, the pre-tension steel members are removed, and the fascia plates are installed at the removed positions. After all the high-strength bolts are tightened to the design value of the high-strength bolts, the reinforcement of the concrete column is completed.

2. The method for reinforcing pre-tensioned lattice steel with fully bolted assembly according to claim 1, characterized in that: In the step S3, the lattice steel and the ear plate are firmly welded in the factory and then transported to the construction site. Before reinforcing the concrete column, the appearance of the lattice steel, the tie plate and the angle steel is ensured to be intact and free of surface corrosion.

3. The method for reinforcing pre-tensioned lattice steel with fully assembled bolt connection according to claim 1, characterized in that: In step S4, the optimal pre-tension design value is 1 / 20 of the ultimate load of the concrete column, and the side length of the pre-tension application should be no less than 1 / 8 of the side length of the concrete column.

4. The method for reinforcing pre-tensioned lattice steel with fully assembled bolt connection according to claim 1, characterized in that: In step S4, during the torque application process, after the lattice steel on one side reaches the specified torque, the torque is applied to the lattice steel on its symmetrical side. After the upper areas of the four-sided lattice steels reach the specified torque, the torque is applied to the lower area of ​​the lattice steel. After the upper and lower areas of the lattice steel reach the specified torque on all four sides, the stage is completed, and the above steps are repeated.

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