A reinforcing construction method for a net rack rod and a net rack reinforcing structure

Abstract

This invention provides a method and structure for reinforcing space frame members, relating to the field of space frame reinforcement. Addressing the current problem that space frame reinforcement relies on open-flame welding, which is impossible in fire-restricted spaces, and that complete replacement can easily lead to structural instability, this invention uses segmented reinforcing segments fastened to the outside of the original pipes. External fasteners provide initial clamping and positioning force, and adhesive is filled into the resulting gaps and joints. This transforms traditional high-temperature metallurgical bonding into a composite force transmission path of room-temperature high-strength bonding and mechanical clamping. The shear strength of the cured adhesive, combined with radial constraint, allows the old and new pipes to form a combined cross-section that shares the load. This improves the tensile, compressive, and flexural moduli of the members without the need for open flame welding, fundamentally overcoming the engineering obstacle of traditional welding reinforcement in fire-restricted industrial areas.

Description

Technical Field

[0001] This invention relates to the field of space frame reinforcement, specifically to a construction method for reinforcing space frame members and a space frame reinforcement structure. Background Technology

[0002] To enhance the load-bearing capacity of space frame structures, existing technologies typically involve directly sleeved thickened steel pipes onto the outside of the original pipes, and then fixing the old and new pipes together through full welding or segmented welding along the longitudinal and circumferential directions. Construction workers must perform open-flame welding directly in the high-altitude work area of ​​the space frame, using high-temperature molten metal to create a rigid connection between the sleeve and the original components, thereby achieving load sharing.

[0003] In industrial areas such as fertilizer plants where there are flammable and explosive media, the heat input and sparks from open flame welding conflict with the fire-prohibited environment, making reinforcement work impossible or posing a great risk of explosion. This causes existing welding structures to be affected by fire safety regulations and the environment. If the process of replacing components as a whole is adopted, it will cause a large-scale transfer of live load, resulting in sudden changes in the stress of surrounding nodes and making it easy to cause unsafe local structural instability. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for reinforcing space frame members and a space frame reinforcement structure. This solves the problems in existing technologies where space frame reinforcement relies on open flame welding, which cannot be implemented in fire-restricted spaces, and where overall replacement can easily lead to structural instability.

[0005] The first objective of this invention is to provide a method for reinforcing space frame members, which employs the following scheme: include: Obtain the outer diameter of the original pipe fitting, and configure at least two reinforcing segments with an inner diameter larger than the outer diameter of the original pipe fitting according to the target reinforcement requirements; Clean the outer wall of the original pipe fitting, and fasten at least two reinforcing pipe pieces together to cover the outside of the original pipe fitting. A gap is formed between the inner wall of the assembled reinforcing pipe pieces and the outer wall of the original pipe fitting. Fasteners are installed on the outside of the reinforced tube segments to position the snap-fitted reinforced tube segments. Adhesive is applied to the gaps and joints where adjacent reinforcing segments are joined. After the adhesive cures, the reinforcing segments are connected to the original pipe fittings to form a cohesive whole that bears the load.

[0006] Furthermore, when applying the adhesive, the corresponding application process is selected based on the radial width of the gap, specifically including: When the radial width of the gap is within the first width range or the third width range greater than the first width range, after the fastener is positioned and tightened, a high-pressure injection process is used to inject adhesive into the gap and joint. When the radial width of the gap is in the second width range between the first width range and the third width range, an atmospheric pressure brushing process is adopted. Before fastening the reinforcing tube segment, adhesive is applied to the outer wall of the original tube and the inner wall of the reinforcing tube segment.

[0007] Furthermore, the specific operation when using the high-pressure injection process is as follows: The joints and both ends of the gaps in the reinforced pipe segments are sealed to create a closed gap environment; Reserve or open injection holes and venting holes that connect to the interior in enclosed gap environments; Adhesive is injected into the gaps and joints through the injection hole using an adhesive injection device until adhesive overflows from the vent hole.

[0008] Furthermore, when the difference between the inner diameter of the configured reinforcing segment and the outer diameter of the original pipe is greater than a preset value, radial ribs distributed radially are pre-installed on the inner wall of the reinforcing segment. When the at least two reinforcing tube pieces are fastened and wrapped around the outside of the original pipe, the inner end of the radial rib abuts against the outer wall of the original pipe to provide coaxial centering support for the reinforcing tube pieces, and an adhesive-filled gap is left between the inner wall of the reinforcing tube pieces and the outer wall of the original pipe.

[0009] Furthermore, the space frame where the original pipe fitting is located also includes node spheres and brackets located above the node spheres; when deformation causes displacement or assembly gaps between the brackets and node spheres, the construction method also includes a support reinforcement step: Insert a matching metal pad at the location of displacement deviation or assembly gap to eliminate assembly gap or correct displacement deviation; The joints between the metal backing plate and the node ball, and between the metal backing plate and the bracket, are sealed by welding.

[0010] A second objective of this invention is to provide a space frame reinforcement structure, comprising: Original pipe fittings; The reinforcement structure includes at least two reinforcing segments that are fastened together and cover the outside of the original pipe fitting, with a gap formed between the inner wall of the spliced ​​reinforcing segments and the outer wall of the original pipe fitting. Fasteners are installed around the outside of the reinforced tube segments to clamp and position the assembled reinforced tube segments. An adhesive layer is used to fill the gaps and joints where the reinforced pipe segments are joined, so that the reinforced pipe segments and the original pipe components are fixed together as a whole that can share the load.

[0011] Furthermore, the fastener is a clamp, which includes two semi-circular clamp plates, with sleeves fixed to both ends of the two clamp plates respectively; the two clamp plates are locked by bolts passing through the sleeves to press and position the reinforcing tube segment.

[0012] Furthermore, multiple clamps are distributed at intervals along the axial direction of the reinforced pipe segment, and the clamp plates of adjacent clamps are staggered and interleaved in the circumferential direction.

[0013] Furthermore, multiple radial ribs extending radially toward the original pipe are fixed on the inner wall of the reinforcing pipe segment. The inner ends of the radial ribs abut against the outer wall of the original pipe, and the adhesive layer fills the gaps between the radial ribs.

[0014] Furthermore, it also includes support nodes that connect to the original pipe fittings: The support node includes a node ball and a bracket located above the node ball, with a metal pad between the node ball and the bracket for filling deformation gaps or displacement deviations; The metal pad, node ball, and bracket are rigidly connected.

[0015] Compared with the prior art, the advantages and positive effects of this invention are: To address the current problem that space frame reinforcement relies on open-flame welding, which is impossible to implement in fire-restricted spaces, and that overall replacement can easily lead to structural instability, this invention addresses the issue by attaching segmented reinforcing segments to the outside of the original pipes, using external fasteners to provide initial clamping and positioning force, and filling the gaps and joints with adhesive. This transforms the traditional high-temperature metallurgical bonding into a composite force transmission path of room-temperature high-strength bonding and mechanical clamping. By utilizing the shear strength of the cured adhesive in conjunction with radial constraint, the new and old pipes form a combined cross-section that shares the load, thereby improving the tensile, compressive, and flexural moduli of the members without the need for open flame welding. This fundamentally overcomes the engineering obstacle of traditional welding reinforcement being impossible in industrial fire-restricted areas. Attached Figure Description

[0016] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0017] Figure 1 This is a schematic diagram of the space frame reinforcement structure in one or more embodiments of the present invention.

[0018] Figure 2 This is a schematic diagram of a reinforced tube segment with ribs in a space frame reinforcement structure according to one or more embodiments of the present invention.

[0019] Figure 3 for Figure 1 A schematic diagram of the cross-section at point AA.

[0020] Figure 4 for Figure 2 A schematic diagram of the cross-section at point BB.

[0021] Figure 5This is a schematic diagram of a metal pad filling the deformation gap of a support node in one or more embodiments of the present invention.

[0022] Figure 6 This is a schematic diagram of the displacement deviation of the support node in one or more embodiments of the present invention.

[0023] Among them, 1. reinforced pipe segments; 2. fasteners; 3. original pipe fittings; 4. ribs; 5. hoop plates; 6. sleeves; 7. bolts; 8. joints; 9. adhesive gaps; 10. node balls; 11. brackets; 12. metal pads; 13. gaps. Detailed Implementation

[0024] Example 1 In a typical embodiment of the present invention, such as Figures 1-6 As shown, a method for reinforcing space frame members is presented.

[0025] Addressing the technical obstacles faced by steel structure roof trusses in high-risk industrial areas or existing building renovation projects, where fire safety regulations hinder the improvement of load-bearing capacity through traditional methods, this embodiment provides a fire-free reinforcement method for truss members. This method is suitable for industrial and civil building truss roofs with strict fire restrictions or environments where open flame work is not permitted. It utilizes ambient temperature adhesive injection equipment and fasteners to enhance the load-bearing capacity of the original structural members. By employing segmented pipe assembly, fastener clamping and positioning, and a gap-adaptive adhesive injection process, fire-free structural reinforcement is achieved. This provides equivalent or higher structural stiffness while reducing fire safety risks to the surrounding environment during construction.

[0026] like Figure 1 and Figure 3 As shown, this embodiment provides a space frame reinforcement structure, including the original pipe 3, a reinforcing structure, fasteners 2, and an adhesive layer. The reinforcing structure includes at least two reinforcing pipe segments 1 that are fastened together and cover the outside of the original pipe 3, forming a gap 13 between the inner wall of the assembled reinforcing pipe segment 1 and the outer wall of the original pipe 3. Fasteners 2 are installed around the outside of the reinforcing pipe segments 1 to clamp and position the assembled reinforcing pipe segments 1, thereby forming a radial constraint on the internal structure in space. The adhesive layer fills the gap 13 and the joint 8 at the splicing of the reinforcing pipe segments 1, so that the reinforcing pipe segments 1 and the original pipe 3 are fixed together as a whole that shares the load, constructing a composite section member composed of an internal steel pipe substrate, an intermediate structural adhesive force transmission medium, and an external steel pipe constraint body.

[0027] Based on the above-mentioned space frame reinforcement structure, this embodiment provides a space frame member reinforcement construction method, including: First, obtain the outer diameter of the original pipe fitting 3, and then customize at least two reinforcing pipe segments 1 with an inner diameter larger than the outer diameter of the original pipe fitting 3 according to the target reinforcement requirements.

[0028] Original pipe fitting 3 is usually a steel member in an existing space frame structure that has relatively insufficient tensile, compressive or bending bearing capacity due to the subsequent addition of equipment loads to the building roof or the increase in the standard value of wind and snow loads in the current building structure load code.

[0029] When determining the dimensions of the reinforced segment 1, the required additional cross-sectional area and moment of inertia are calculated based on the axial force envelope diagram and nodal displacement limitations at the location of the original pipe fitting 3. This allows for the reverse derivation of the wall thickness and outer diameter parameters of the reinforced segment 1. To facilitate handling, mechanical hoisting, and assembly positioning in confined high-altitude work spaces, the reinforced segment 1 is rationally divided according to the actual diameter of the original pipe fitting 3 and the on-site hoisting load limitations.

[0030] For the original pipe fitting 3 with a diameter within the normal range, the reinforced pipe segment 1 is divided into two semi-circular segments. The two-segment structure is made by symmetrically cutting a whole standard seamless steel pipe or straight seam welded pipe along the axis to ensure that the two halves of the pipe segment have a good splicing and restoration rate after being cut.

[0031] When facing large-diameter original pipe fittings 3 with large spans or heavy loads, the individual weight of the two-half reinforced pipe segment 1 will increase, potentially exceeding the safe lifting threshold for a single person or a small winch. To control the weight of individual pieces and reduce the risk of eccentric tipping during construction and assembly, the reinforced pipe segment 1 can be equally divided into three or four arc-shaped segments. The segmented design allows the reinforced pipe segment 1 to simultaneously fit the original pipe fitting 3 from different radial angles, avoiding the interference defect that forces the disassembly of the original grid structure's stress nodes due to the need for closed sleeves to be inserted from the end of the component.

[0032] Subsequently, the process begins with surface cleaning of the original pipe fitting 3 and assembly of the reinforced pipe segment 1.

[0033] Before carrying out the cleaning and fastening of the outer wall, in order to reduce the secondary stress redistribution caused by changes in structural stiffness during the load-bearing reinforcement process, the construction personnel need to set up temporary support frames under the space frame or use unloading equipment such as jacks to unload the live load and part of the dead load acting on the area where the space frame reinforcement structure is located.

[0034] By monitoring the changes in node elevation using displacement sensors, the axial stress level of the original pipe fitting 3 is reduced to a safe range, thereby ensuring that the newly added reinforced pipe segment 1 can be at a similar stress starting point as the original pipe fitting 3 during subsequent use, achieving synchronous stress distribution.

[0035] After unloading and confirmation, sandblasting equipment was used to perform deep surface treatment on the outer wall of the original pipe fitting 3 and the adjacent joint connection parts. High-pressure airflow carrying abrasive particles impacted the surface of the original pipe fitting 3 at high speed, peeling off the attached oxide and rust layer, the old anti-corrosion paint film, and the rolled iron sheet, revealing the metal with uniform roughness on its surface.

[0036] To meet the surface wetting and intermolecular van der Waals force bonding requirements of the structural adhesive, the quality level of the sandblasting treatment must be controlled at no less than Sa2.5 grade as specified in the standard, meaning that there are no visible grease, dirt, scale, rust, paint coatings, or other adhering substances on the surface. The increased roughness effectively amplifies the microscopic specific surface area of ​​the outer wall of the original pipe fitting 3, providing dense mechanical interlocking anchor points for the adhesive.

[0037] After cleaning, the surface is further wiped with industrial-grade cleaning agents such as industrial acetone or anhydrous ethanol to remove fine dust and grease residue left after sandblasting, and then dried by blowing with oil-free compressed air. The multiple reinforcing tube segments 1, after the above-mentioned pre-surface treatment, are lifted to a predetermined position and gradually fastened to the outside of the original tube 3 along its radial direction. Due to the pre-set tube diameter difference, a continuous annular gap 13 is formed between the inner wall of the fastened reinforcing tube segment 1 and the outer wall of the original tube 3.

[0038] After the reinforcement segment 1 is initially fastened, the construction workers install fasteners 2 on the outside of the reinforcement segment 1 to rigidly position the fastened reinforcement segment 1.

[0039] Fastener 2 provides a continuous and uniform radial centripetal compressive force, enabling the assembled reinforced tube segment 1 to overcome its own material weight, warping caused by residual processing stress, and gravity sagging during installation, and to hold tightly to the periphery of the original tube 3, forming a temporary and reliable mechanical constraint. This provides boundary conditions without relative displacement for subsequent liquid adhesive injection and long-term chemical curing processes.

[0040] Specifically, such as Figure 1 and Figure 3 As shown, fastener 2 is a set of independent clamps. Each clamp includes two semi-circular clamp plates 5, with sleeves 6 fixed to both ends of each clamp plate 5 for through-fastening. The two clamp plates 5 are locked together by bolts 7 passing through the sleeves 6 to press and position the reinforcing tube segment 1. When the bolts 7 apply preload and tighten, the inner wall of the semi-circular clamp plates 5 undergoes micro-elastic deformation along the outer circumference of the reinforcing tube segment 1, thereby converting the linear tensile force of the bolts 7 into a uniform radial centripetal compressive force distributed on the surface of the reinforcing tube segment 1. Compared to the conventional design of directly welding flanges to the edge of the reinforcing tube segment 1 and locking bolts, using sleeves 6 increases the structural thickness and bending section modulus at the bolt 7 connection, effectively reducing local buckling or tearing deformation of the plate caused by stress concentration during the locking process.

[0041] In the reinforcement of long straight space frame members, multiple fasteners 2 are distributed at intervals along the axial direction of the reinforcing tube segment 1 to provide segmented continuous radial constraints. To optimize the stress distribution of the overall composite member under complex stress conditions, the splicing positions of the hoop plates 5 of adjacent fasteners 2 are staggered circumferentially. If the locking joints of all fasteners 2 are arranged on the same straight line parallel to the axis, they can easily become weak stress zones in the entire hoop system when the member is subjected to bending moment or torsion. By staggering the joints of adjacent hoop plates 5 and distributing the joints of adjacent fasteners 2 by rotating them 90° or 120° circumferentially, the continuous strain concentration line can be effectively broken. The staggered arrangement makes the gradient change of the circumferential centripetal constraint force more gradual when it extends longitudinally along the tube, reducing the risk of slippage or delamination of the reinforcing tube segment 1 due to local clamping failure after deformation under stress.

[0042] After mechanical positioning is completed, adhesive is applied to the gap 13 and the joint 8 at the splicing of the reinforcing pipe segment 1. After the adhesive completes the curing and cross-linking reaction, the fluid medium is transformed into a solid adhesive layer with a high shear modulus, connecting the outer reinforcing pipe segment 1 and the inner original pipe component 3 into a cohesive whole that bears the load.

[0043] To ensure the long-term safety of the building structure, the selected adhesive must meet the corresponding specifications, employing a Class A structural reinforcement adhesive that meets the 50-year design service life requirement. Its bond shear strength standard value is set based on high confidence levels and high guarantee rates of mathematical statistics to ensure that fatigue failure does not occur within the material under long-term dynamic and static loads. For anti-aging and shrinkage control considerations, unsaturated polyester resin or alkyd resin is prohibited as a base material. Furthermore, to ensure sufficient initial setting time for injection and venting adjustments during high-altitude operations, fast-setting structural adhesives are not used.

[0044] In addition, based on the historical meteorological data and ambient temperature of the project location, it is necessary to select an adhesive type that matches the temperature tolerance range. For example, for cold northern or outdoor environments, a structural adhesive that is suitable for a working temperature range of -45°C to 60°C should be selected.

[0045] In the actual application of adhesive, for the gap 13 formed between different original pipe fittings 3 and reinforcing pipe segments 1 due to dimensional differences or deformation, this solution adopts a control logic that adaptively selects the corresponding adhesive application process based on the radial width of the gap 13. This adaptive selection logic aims to match the optimal process path based on fluid dynamic characteristics, specifically including: When the radial width of the gap 13 is within the first width range or the third width range greater than the first width range, after the fastener 2 is positioned and locked, the adhesive is injected into the gap 13 and the joint 8 using a high-pressure injection process.

[0046] For example, the radial width of the gap corresponding to the first width range is 0 to 5 mm. Within this narrow, confined space, the adhesive fluid experiences increased viscous resistance due to capillary action and surface tension. If a normal pressure brushing and fastening method is used at this time, a large amount of air is easily trapped at the moment the two tube surfaces come together, forming closed air bubbles that are difficult to expel, resulting in a sharp reduction in the actual effective bonding area. Therefore, a high-pressure injection process can utilize the continuous fluid pressure generated by the injection equipment to forcibly overcome the frictional resistance, gradually displacing the air within the gap 13, allowing the adhesive to densely fill the tiny gaps without any dead corners.

[0047] The radial width of the gap corresponding to the third width range is 15 to 20 mm or even greater. In this larger cavity, if a normal pressure process of applying adhesive before fastening is used, the thicker uncured adhesive is prone to flowing downwards or dripping under the influence of gravity, making it difficult to maintain the designed adhesive layer thickness on the upper semicircle of the original fitting 3. In this case, a high-pressure injection process is also used. By pre-establishing a sealed environment at both ends and joints, and utilizing the closed cavity structure to provide support, the adhesive can fill the entire wide gap under static pressure and remain stable until curing, thus ensuring the integrity and uniformity of the adhesive layer in the large gap.

[0048] When the radial width of the gap 13 is in the second width range between the first width range and the third width range, the normal pressure brushing process is adopted. Before fastening the reinforcing tube 1, adhesive is uniformly applied to the outer wall of the original tube 3 and the inner wall of the reinforcing tube 1.

[0049] For example, the radial width of the gap in the second width range is 5 to 15 mm. Within this thickness range, the gap width is moderate. The fluid resistance is insufficient to obstruct the exhaust at normal pressure, and the thixotropic and viscous properties of the adhesive itself are sufficient to overcome the downward dripping caused by gravity. At this point, multiple coats can be applied directly to the surface of the pipe fitting using a brush or a special roller to ensure that the adhesive fully wets the micropores on the surface before the reinforcement segment 1 is fastened and the fastener 2 is installed. This eliminates the cumbersome procedures required for high-pressure adhesive injection, such as the construction of a sealing cavity, the pre-embedding of the injection nozzle, and the waiting for pressurization, thereby improving the efficiency of on-site construction while ensuring bonding quality.

[0050] For scenarios employing high-pressure injection molding, the specific implementation steps include: First, the joints 8 and the two openings at both ends of the gap 13 of the reinforced segment 1 are airtightly sealed to create a closed gap environment isolated from the outside world.

[0051] Using a sealant with rapid curing properties and high initial strength, apply it continuously along the linear path of joint 8 and the annular openings at both ends, compacting it with a tool during application to prevent leakage under subsequent pressure. After sealing is complete and the sealant reaches the specified strength, leave or drill injection holes and vent holes in the sealed gap to connect to the internal cavity.

[0052] To allow the fluid to displace air from low to high under gravity, the injection holes are located at lower elevations within the space where the reinforcing segment 1 is situated, such as the bottom of horizontal members or the lower end of inclined members. The vent holes are located at corresponding higher elevations. Subsequently, construction personnel connect specialized injection equipment and, using the pressure parameters set on the equipment, smoothly inject the proportioned adhesive into the gap 13 and joint 8 through the injection holes.

[0053] During the adhesive injection process, the adhesive liquid is evenly advanced from bottom to top, gradually compressing and expelling any remaining air until a stable flow of air-free adhesive is observed from the vent holes. This serves as a reliable indication that the internal air has been completely replaced and the adhesive has densely filled the voids within the adhesive. Pressurization is then stopped, and all vent holes are sealed. The mixture is then allowed to stand and wait for the adhesive to cure at room temperature.

[0054] like Figure 2 and Figure 4 As shown, in certain special load-bearing space frame sections, the outer diameter of the original pipe 3 is designed to be relatively small, while the outer diameter of the reinforcing pipe segment 1 required to improve load-bearing capacity is larger. This results in the difference between the inner diameter of the reinforcing pipe segment 1 and the outer diameter of the original pipe 3 exceeding the preset construction standard limit. Under such conditions of large dimensional difference, simply increasing the wall thickness of the reinforcing pipe segment 1 or increasing the adhesive layer thickness to compensate for the dimensional difference will not only increase the cost of adhesive materials but also affect the bonding strength due to the increased shrinkage rate of the adhesive layer. Furthermore, the significantly increased steel weight will impose additional dead load on the original space frame structure. Based on these mechanical and economic considerations, this embodiment pre-installs multiple radially distributed ribs 4 on the inner wall of the reinforcing pipe segment 1 before assembly. By fixing the steel ribs 4 to the inner wall of the reinforcing pipe segment 1, the moment of inertia and bending section modulus of the reinforcing pipe segment 1 can be significantly increased with a slight increase in the overall component weight, thereby improving the stiffness of the individual unit.

[0055] like Figure 2 and Figure 4 As shown, during the process of fastening and covering the reinforcing tube 1 with ribs 4 onto the outside of the original pipe fitting 3, the operator makes the inner end of the ribs 4 directly abut against the outer wall of the original pipe fitting 3, which generates a coaxial centering support for the reinforcing tube 1, forcing the outer reinforcing tube 1 to self-align during assembly, and automatically leaving a uniformly sized adhesive-filled gap 9 between the inner wall of the reinforcing tube 1 and the outer wall of the original pipe fitting 3.

[0056] In the subsequent adhesive injection process, the adhesive layer will densely fill the adhesive voids 9 and the separation positions formed between adjacent ribs 4. In the final working state, the ribs 4, as a transmission structure, can directly transfer the lateral shear force or external local impact load applied to the reinforcing tube 1 to the original tube 3, reducing the peel stress of the adhesive layer under transient radial impact. At the same time, the ribs 4, as permanent internal positioning supports, ensure that the reinforcing tube 1 and the original tube 3 are always coaxially distributed, preventing the reinforcing tube 1 from eccentrically displacing when the fasteners 2 are locked or when the adhesive is not cured, ensuring that the centroid of the combined section coincides with the original force axis, and avoiding additional bending moments caused by eccentricity.

[0057] like Figure 5 and Figure 6 As shown, the spatial stress performance of the space frame is highly dependent on the stiffness continuity of each converging node. The space frame system where the original pipe 3 is located not only includes straight members, but also support nodes that connect multiple members. This support node, as the core hub for transferring the load of the roof panel or equipment suspension to the members, mainly includes the node ball 10 and the bracket 11 located above the node ball 10.

[0058] The node ball 10 is a bolt ball widely used in space frame engineering. Under the combined effects of long-term environmental temperature alternating stress, roof dynamic and static loads, and uneven foundation settlement, the space frame structure as a whole may undergo slight deflection deformation. This macroscopic deformation accumulates locally, causing displacement deviations between the flange faces of the bracket 11 and the node ball 10, such as lateral misalignment, or assembly gaps, such as longitudinal separation. When such defects occur, the roof load cannot be evenly distributed to the node ball 10 through the bracket 11, thereby inducing destructive secondary stresses in adjacent members.

[0059] Therefore, the construction method of this embodiment also includes a support reinforcement step specifically for this defect.

[0060] First, the displacement deviation or assembly gap thickness is accurately measured using feeler gauges and visual inspection. Then, a metal pad 12 with a matching thickness and shape is inserted at the location of the displacement deviation or assembly gap to eliminate the assembly gap or correct the lateral displacement deviation.

[0061] In this embodiment, the metal pad 12 can be a 6mm thick strip steel plate, or it can be composed of multiple thin steel plates of a specific thickness stacked together. It is forcibly inserted into the gap between the bracket 11 and the node ball 10 using external force. By utilizing the incompressible rigidity of steel, the node ball 10 restores the solid structural support of the bracket 11 to the bracket, so that the force transmission path is closed again.

[0062] After the metal pad 12 is inserted and leveled, due to the fire restrictions in the industrial site, the traditional open flame three-sided welding sealing operation was not used in this embodiment. Instead, structural adhesive bonding combined with cold mechanical connection was used for anchoring and sealing.

[0063] Specifically, before inserting the metal pad 12 or on its contact surface, a layer of structural reinforcement adhesive with high shear strength is pre-applied. After the metal pad 12 is initially positioned, at the connection boundaries between the metal pad 12 and the node ball 10, and between the metal pad 12 and the bracket 11, through-bolt connections, high-strength blind rivets, or threaded connectors pre-tapping the node ball 10 are used to mechanically clamp and chemically bond the metal pad 12, node ball 10, and bracket 11.

[0064] The use of a non-flammable connection process not only effectively avoids the damage to the preload of the original node ball 10 high-strength bolts caused by the heat input of welding, but also, through the dual mechanism of filling micro gaps with adhesive and providing pull-out restraint with mechanical fasteners, the structural stiffness and connection stability of the support node are reliably restored under the condition of no fire source interference, ensuring the smooth transfer of the load of the space frame roof.

[0065] After completing the wrapping and reinforcement of all original pipe fittings 3, the gap reinforcement of support nodes, and the complete curing of adhesive, in order to cope with the corrosive gas media in the complex industrial environment and the fire resistance limit requirements of fire protection regulations, the construction method also includes a subsequent anti-corrosion and fireproofing treatment process of applying a protective coating to the exterior of the space frame reinforcement structure.

[0066] Construction workers used grinding tools to roughen the outer wall of reinforced pipe segment 1, the surface of fastener 2, and the exposed metal components of each cold connection node, and cleaned the dust. Then, they applied multiple layers of heavy-duty anti-corrosion system material to the surface in sequence.

[0067] The coating consists of three layers: a first layer of epoxy zinc-rich anti-rust primer, approximately 70 μm thick, providing cathodic protection to block the electron pathways for electrochemical corrosion of steel; a second layer of epoxy micaceous iron oxide intermediate coat, approximately 60 μm thick, providing a flake-like shielding effect and enhancing the coating's resistance to moisture and oxygen penetration; and an outermost layer of polyurethane topcoat, approximately 70 μm thick, offering excellent weather resistance and UV resistance. Through the synergistic layering of these three coatings, the overall anti-corrosion dry film thickness is no less than 200 μm, forming a dense oxygen- and moisture-proof barrier.

[0068] After the anti-corrosion layer has fully dried, an ultra-thin fire-retardant coating for steel structures is uniformly applied to the outer surface of the anti-corrosion layer to meet the fire protection requirements of the building components. At room temperature, this coating is only a small film thickness, not affecting the overall geometry of the reinforced structure. However, when exposed to the high temperatures of a fire, the foaming agent and charring agent inside the fire-retardant coating rapidly undergo a chemical expansion reaction, forming a heat-insulating carbonized foam layer tens of times thicker than the original coating. This carbonized layer slows down the rate at which heat is conducted to the steel structure substrate, thus delaying the decrease in the load-bearing capacity of the reinforced space frame structure in a fire environment. This ensures that its fire resistance rating meets the requirements of building design fire protection codes, such as achieving a fire resistance requirement of 1.5 hours. This systematic multi-layered protection ensures that the space frame structure reinforced using fire-free technology can maintain its expected mechanical properties and structural safety for a long period in industrial environments with high risks and stringent restrictions.

[0069] Example 2 In another typical embodiment of the present invention, such as Figures 1-6 As shown, a space frame reinforcement structure is provided to implement the space frame member reinforcement construction method as described in Example 1, including: Original pipe fitting 3; The reinforcing structure includes at least two reinforcing tube segments 1 that are fastened together and cover the outside of the original pipe fitting 3, and a gap 13 is formed between the inner wall of the assembled reinforcing tube segment 1 and the outer wall of the original pipe fitting 3. Fasteners are installed around the outside of the reinforcing tube segment 1 to clamp and position the assembled reinforcing tube segment 1. An adhesive layer is filled in the gap 13 and the joint 8 at the splicing of the reinforcing pipe segment 1, so that the reinforcing pipe segment 1 and the original pipe 3 are fixed together as a whole that can share the load.

[0070] In this embodiment, the fastener is a clamp, which includes two semi-circular clamp plates 5, with sleeves 6 fixed to both ends of the clamp plates 5. The two clamp plates 5 are locked together by bolts 7 passing through the sleeves 6 to press and position the reinforcing tube segment 1. Multiple clamps are distributed at intervals along the axial direction of the reinforcing tube segment 1, and the clamp plates 5 of adjacent clamps are staggered circumferentially. Multiple radial ribs 4 extending radially toward the original tube fitting 3 are fixed on the inner wall of the reinforcing tube segment 1. The inner ends of the radial ribs 4 abut against the outer wall of the original tube fitting 3, and the adhesive layer fills the gaps between the radial ribs 4.

[0071] It also includes a support node connected to the original pipe fitting 3. The support node includes a node ball 10 and a bracket 11 located above the node ball 10. A metal pad 12 is provided between the node ball 10 and the bracket 11 to fill the deformation gap 13 or displacement deviation. The metal pad 12, the node ball 10 and the bracket 11 are rigidly connected.

[0072] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for reinforcing space frame members, characterized in that, include: Obtain the outer diameter of the original pipe fitting, and configure at least two reinforcing segments with an inner diameter larger than the outer diameter of the original pipe fitting according to the target reinforcement requirements; Clean the outer wall of the original pipe fitting, and fasten at least two reinforcing pipe pieces together to cover the outside of the original pipe fitting. A gap is formed between the inner wall of the assembled reinforcing pipe pieces and the outer wall of the original pipe fitting. Fasteners are installed on the outside of the reinforced tube segments to position the snap-fitted reinforced tube segments. Adhesive is applied to the gaps and joints where adjacent reinforcing segments are joined. After the adhesive cures, the reinforcing segments are connected to the original pipe fittings to form a cohesive whole that bears the load.

2. The method for reinforcing space frame members as described in claim 1, characterized in that, When applying adhesive, the appropriate application process should be selected based on the radial width of the gap, specifically including: When the radial width of the gap is within the first width range or the third width range greater than the first width range, after the fastener is positioned and tightened, a high-pressure injection process is used to inject adhesive into the gap and joint. When the radial width of the gap is in the second width range between the first width range and the third width range, an atmospheric pressure brushing process is adopted. Before fastening the reinforcing tube segment, adhesive is applied to the outer wall of the original tube and the inner wall of the reinforcing tube segment.

3. The method for reinforcing space frame members as described in claim 2, characterized in that, The specific operation when using the high-pressure injection process is as follows: The joints and both ends of the gaps in the reinforced pipe segments are sealed to create a closed gap environment; Reserve or open injection holes and venting holes that connect to the interior in enclosed gap environments; Adhesive is injected into the gaps and joints through the injection hole using an adhesive injection device until adhesive overflows from the vent hole.

4. The method for reinforcing space frame members as described in claim 1, characterized in that, When the difference between the inner diameter of the reinforced tube segment and the outer diameter of the original tube is greater than the preset value, radial ribs distributed radially are pre-installed on the inner wall of the reinforced tube segment. When the at least two reinforcing tube pieces are fastened and wrapped around the outside of the original pipe, the inner end of the radial rib abuts against the outer wall of the original pipe to provide coaxial centering support for the reinforcing tube pieces, and an adhesive-filled gap is left between the inner wall of the reinforcing tube pieces and the outer wall of the original pipe.

5. The method for reinforcing space frame members as described in claim 1, characterized in that, The space frame where the original pipe fitting is located also includes node spheres and brackets located above the node spheres; when deformation causes displacement or assembly gaps between the brackets and node spheres, the construction method also includes a support reinforcement step: Insert a matching metal pad at the location of displacement deviation or assembly gap to eliminate assembly gap or correct displacement deviation; Mechanical connection treatment is performed at the joints between the metal pad and the node ball, and between the metal pad and the bracket.

6. A space frame reinforcement structure applied to any one of claims 1-5, characterized in that, include: Original pipe fittings; The reinforcement structure includes at least two reinforcing segments that are fastened together and cover the outside of the original pipe fitting, and a gap is formed between the inner wall of the spliced ​​reinforcing segments and the outer wall of the original pipe fitting. Fasteners are installed around the outside of the reinforced tube segments to clamp and position the assembled reinforced tube segments. An adhesive layer is used to fill the gaps and joints where the reinforced pipe segments are joined, so that the reinforced pipe segments and the original pipe components are fixed together as a whole that can share the load.

7. The space frame reinforcement structure as described in claim 6, characterized in that, The fastener is a clamp, which includes two semi-circular clamp plates, with sleeves fixed at both ends of the two clamp plates; the two clamp plates are locked by bolts passing through the sleeves to press and position the reinforcing tube segment.

8. The space frame reinforcement structure as described in claim 7, characterized in that, The clamps are distributed at intervals along the axial direction of the reinforced pipe segment, and the clamp plates of adjacent clamps are staggered and interleaved along the circumferential direction.

9. The space frame reinforcement structure as described in claim 6, characterized in that, Multiple radial ribs extending radially toward the original pipe are fixed on the inner wall of the reinforced pipe segment. The inner ends of the radial ribs abut against the outer wall of the original pipe, and the adhesive layer fills the gaps between the radial ribs.

10. The space frame reinforcement structure as described in claim 6, characterized in that, It also includes support nodes that connect to the original pipe fittings: The support node includes a node ball and a bracket located above the node ball, with a metal pad between the node ball and the bracket for filling deformation gaps or displacement deviations; The metal pad, node ball, and bracket are rigidly connected.

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