Reinforcing structure for additionally arranging steel beam on historical building wood floor cover

Abstract

The utility model provides a reinforcing structure for adding a steel beam to a historical building wooden floor, the wooden floor comprises log grids, log floors and original diagonal bracings, first gaps and second gaps which are sequentially and alternately distributed are formed between the log grids, the original diagonal bracings are arranged in the first gaps, and reinforcing steel is arranged in the second gaps; the original wall is provided with a chiseling hole located in the second gap, a reinforced concrete beam pad is poured at the bottom of the chiseling hole, the end of the reinforcing steel is in lap joint with the upper surface of the reinforced concrete beam pad, and micro-expansion fine aggregate concrete covering the end of the reinforcing steel and the reinforced concrete beam pad is poured in the chiseling hole. According to the method, drilling or slotting on the wood grating is not needed, so that the effective section of the wood can be ensured not to be damaged, and the original bearing capacity of the wood is ensured not to be influenced. And part of the diagonal bracings are detached and reinforced through the reinforcing steel, so that the stability of the structure is ensured, and meanwhile, convenience is provided for future maintenance and adjustment.

Description

Technical Field

[0001] This utility model relates to building reinforcement, specifically to a reinforcement structure for adding steel beams to the wooden floor of a historical building. Background Technology

[0002] Shanghai, as a representative of treaty ports, boasts a large number of outstanding modern historical buildings whose architectural styles hold significant historical value. These buildings are generally multi-story houses with a mixed structure, primarily composed of brick and wood. The project development adheres to the principle of "preserving historical features while injecting modern functionality," retaining the facades, distinctive interior decorations, and construction methods to maintain the historical architectural style.

[0003] For brick-and-wood structures where the floor slabs are mainly supported by wooden lattice as horizontal load-bearing components, upgrades and renovations are required after a long period of use. On the one hand, the wooden lattice itself suffers from insufficient bending load-bearing capacity and deflection. On the other hand, the load-bearing capacity requirements increase. At this time, the floor slabs need to be reinforced as required.

[0004] Traditional methods of directly reinforcing steel beams involve adding channel steel, flat steel, or angle steel to the sides of the wooden grating using through bolts to increase the load-bearing capacity of the wooden components. The problem is that drilling directly into the wooden grating can cause irreversible damage to the wooden structure.

[0005] Steel cladding for timber structures: This method involves wrapping a timber grid with a U-shaped steel channel and securing it with chemical anchors to improve the load-bearing capacity of the timber components. The problem is that, with the timber grid enclosed within the U-shaped steel channel, the steel-timber interface is prone to deformation due to stress caused by temperature and humidity changes.

[0006] In summary, the main shortcomings of existing technologies are:

[0007] 1. Highly destructive to structure

[0008] Traditional methods require drilling or slotting into the wooden grid, resulting in a loss of the effective cross-section of the timber and weakening its original load-bearing capacity. When side steel members are used for reinforcement, the subsequent construction of scissor bracing to ensure the stability between the original wooden grids becomes difficult, easily leading to out-of-plane instability of the wooden grid.

[0009] 2. Poor interface consistency

[0010] The coefficients of linear expansion of steel and wood differ significantly, with steel having a coefficient of 11.7 × 10⁻⁶. -6 / ℃ vs. wood 3-5×10 -6 / ℃, when the temperature changes, the connection node is prone to a displacement difference of 3-5mm, which causes stress concentration.

[0011] 3. Insufficient anti-corrosion and insect-proof properties.

[0012] In existing technologies, the steel-wood contact surface is only coated with ordinary anti-rust paint. When the moisture content of the wooden components exceeds the standard, the average annual corrosion depth of the contact surface reaches 0.15mm, and the joint strength decreases.

[0013] 4. Irreversible defects

[0014] After reinforcement, it is rigidly connected to the wooden structure. Removing the reinforcement structure can easily cause damage to more than 30% of the wooden components, increasing maintenance costs. Utility Model Content

[0015] To achieve structural reinforcement while minimizing further damage to the building and reducing potential future hidden damage, this utility model provides a reinforcement structure for adding steel beams to the wooden floor slabs of historical buildings. Through reasonable structural design, it effectively overcomes the shortcomings of current historical building reinforcement methods. The specific solution is as follows:

[0016] A reinforcement structure for adding steel beams to the wooden floor slab of a historical building is disclosed. The wooden floor slab includes original wooden grids, original wooden flooring, and original scissor bracing. Several parallel and perpendicular wooden grids are installed within the original walls, with both ends of the wooden grids embedded in holes in the original walls. The wooden flooring is fixed to the upper surface of the wooden grids, and alternating first and second gaps are formed between the wooden grids.

[0017] The original scissor brace is installed in the first gap, and reinforcing steel is provided in the second gap;

[0018] The original wall has a drilled hole located in the second gap. A reinforced concrete beam pad is poured at the bottom of the drilled hole. The end of the reinforcing steel overlaps the upper surface of the reinforced concrete beam pad. Micro-expansion fine stone concrete is poured into the drilled hole to cover the end of the reinforcing steel and the reinforced concrete beam pad.

[0019] Furthermore, the reinforcing steel is Q235B grade steel.

[0020] Furthermore, the reinforcing steel is an I-beam or a U-shaped steel.

[0021] Furthermore, the reinforcing steel located within the same second gap is a single steel beam.

[0022] Furthermore, the depth of the hole inside the wall is 10cm-20cm.

[0023] Furthermore, the surfaces of the log grille and the reinforcing steel are coated with anti-rust paint and fire-retardant coating.

[0024] 1. Minimal damage to the original roof structure

[0025] When reinforcing or modifying the roof structure, this application preserves the original structure as much as possible and minimizes damage. Specifically, there is no need to drill holes or cut grooves in the wooden grid, which ensures that the effective cross-section of the wood is not lost, thereby ensuring that the original load-bearing capacity of the wood is not affected. In addition, this application preserves some of the construction space for the original scissor bracing, which can effectively prevent the wooden grid from experiencing out-of-plane instability.

[0026] 2. Strong interface compatibility

[0027] By avoiding a rigid connection between the steel and timber structural members—that is, by leaving gaps between the reinforcing steel and the log latticework on both sides—stress concentration problems that might arise due to differences in expansion coefficients are avoided. This design not only ensures structural stability but also facilitates future maintenance and adjustments.

[0028] 3. Simple procedures, convenient construction, and reversible reinforcement.

[0029] There's no need to remove the wooden grating and most of the original wood flooring; only a small amount of wood flooring needs to be removed from both sides of the added steel beams to make room for hoisting. This design not only simplifies the construction process but also makes the entire reinforcement process reversible, meaning it can be removed without damage when needed, thus ensuring a high reuse rate of wooden components and low maintenance costs.

[0030] 4. High durability

[0031] The retained wooden grating was treated with three protective measures (fireproofing, moisture-proofing, and insect-proofing), while the newly added steel beams were also treated with fireproofing and rust prevention. In addition, appropriate spaces were left between the materials to ensure good ventilation performance, thereby further enhancing the durability of the overall roof structure. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the addition of steel beams to the wooden floor slab of a historical building according to this utility model;

[0034] Figure 2 for Figure 1 Exploded structural diagram;

[0035] Figure 3 for Figure 1 Cross-sectional view in the X direction;

[0036] Figure 4 for Figure 1 Cross-sectional view in the Y direction;

[0037] Figure 5 This is a cross-sectional view of the reinforced concrete beam pad and reinforcing steel inside the drilled hole. Detailed Implementation

[0038] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid confusion with the present invention.

[0039] To fully understand this utility model, detailed steps and structures will be presented in the following description to illustrate the technical solution of this utility model. Preferred embodiments of this utility model are described in detail below; however, in addition to these detailed descriptions, this utility model may have other embodiments.

[0040] Reference Figure 1-5 As shown, this utility model provides a reinforcement structure for adding steel beams to the wooden floor of a historical building. The wooden floor includes a log grid 3, a log floor 2, and a scissor brace 4. Several log grids 3 that are parallel to each other and perpendicular to the ground are installed in the original wall 1. The two ends of the log grids 3 are embedded in the original holes 14 of the original wall 1. The log floor 2 is fixed on the upper surface of the log grid 3. The log floor 2 can be a double-layer floor composed of an upper log floor 22 and a lower log floor 21 with cross-laminated upper and lower layers.

[0041] A first gap 31 and a second gap 32 are alternately distributed between the original wooden grids 3. An "X"-shaped original scissor brace 4 is located in the first gap 31, and a reinforcing steel 5 is located in the second gap 32. The original wall 1 has a chisel hole 11 located in the second gap 32. The chisel hole 11 can be formed by continuing to chisel based on the holes left after the removal of the original wooden grids 3. A reinforced concrete beam pad 12 is poured at the bottom of the chisel hole 11. The end of the reinforcing steel 5 overlaps the upper surface of the reinforced concrete beam pad 12, and the reinforced concrete beam pad 12 provides bottom support for the reinforcing steel 5. Micro-expansion fine stone concrete 13 is poured into the chisel hole 11 to cover the end of the reinforcing steel 5 and the reinforced concrete beam pad 12. The micro-expansion fine stone concrete 13 fixes the reinforcing steel 5 to the wall.

[0042] In an optional embodiment, the reinforcing steel 5 is a single "I" or "U" shaped steel made of Q235B grade steel to ensure strength.

[0043] In an optional embodiment, the width and height of the hole 11 are determined according to the cross-sectional dimensions of the reinforcing steel, and the depth of the hole 11 inside the wall is preferably 10-20cm, so as to ensure the reinforcement strength while avoiding damage to the original wall due to excessive hole depth.

[0044] In an optional embodiment, the surfaces of the log grating 3 and the reinforcing steel 5 are coated with anti-rust paint and fire-retardant coating to provide rust prevention, fire prevention, and aesthetic benefits.

[0045] The construction process of this utility model is as follows:

[0046] S1. Half of the original building's scissor bracing is removed at intervals, and the gaps in the wooden lattice 3 from the removed scissor bracing are used as the second gap 32.

[0047] S2. A hole 11 is chiseled in the wall of the second gap 32, located below the wooden floor 2. The width, height and depth of the hole 11 are 15cm, 30cm and 15cm respectively.

[0048] S3. Place steel bars at the bottom of the drilled hole 11 and pour concrete, waiting for it to solidify to form a reinforced concrete beam pad 12 at the bottom of the drilled hole 11.

[0049] S4. Insert one end of the reinforcing steel 5 into the drilled hole 11 and place it on the upper surface of the reinforced concrete beam pad 12. Fill the gap between the reinforcing steel 5 and the drilled hole 11 with micro-expansion fine stone concrete 13.

[0050] The requirements for steel and welding materials during construction are as follows:

[0051] Steel and welding materials should be selected according to the requirements of the construction drawings. Their performance and quality must meet the requirements of national standards, and they should be accompanied by quality certificates or inspection reports. If other steel and welding materials are used as substitutes, the design unit must agree, and reliable test data and corresponding process documents must be available before welding can proceed.

[0052] The steel structure fabrication process is as follows:

[0053] 1) Material marking and cutting

[0054] Material marking: Material marking should be carried out after the steel has been straightened. Before marking, the specifications and material of the steel should be checked, and oil, dirt, rust, and other contaminants on the surface of the steel should be removed. Allowance should be made for cutting and processing, as well as welding shrinkage.

[0055] Cutting: Hot-rolled H-beams are cut using manual flame cutting. After cutting, burrs and slag must be removed. The cut surfaces are then ground and finished using a grinding wheel. The blanking error should not exceed ±2mm.

[0056] 2) The raw material assembly process is as follows:

[0057] The main material is profiles, and the splicing of profiles should be in accordance with the following requirements:

[0058] For hot-rolled H-beam splicing, the splicing method using connecting plates and welding is selected according to the construction drawings and standard drawings.

[0059] The welds must be of equal strength. If the design or the owner has requirements regarding the top elevation of the main and secondary beams, a 45° bevel joint can be used.

[0060] Straightening: Straightening of steel and semi-finished components should be carried out mechanically at room temperature whenever possible. When manual hammering is used, a pad hammer should be used to prevent dents and damage. The straightened steel surface should not have obvious dents or damage, and surface scratches should not exceed 0.5mm. When heat straightening is used, the heating temperature should not exceed 900℃, and water should not be poured on it during cooling to prevent steel deterioration.

[0061] Painting of steel components should be carried out after the fabrication and welding quality have passed inspection, and the fabrication quality records of the components should be kept.

[0062] Surface treatment: Shot blasting is used to remove rust, and the surface roughness must meet the Sa.2.5 requirement. Before rust removal, all spatter, burrs, weld spatter, and other debris on the surface of the component should be thoroughly removed.

[0063] Paint Management: The storage and safekeeping of paint shall be the responsibility of designated personnel. Paint shall be issued only as needed, and excessive amounts of paint should not be stored at the work site. No-smoking and no-fire warning signs and fire prevention equipment shall be provided. Paint prepared on the same day must be used on the same day. Records of material issuance shall be kept.

[0064] The painting specifications are as follows:

[0065] The coating materials used should have a factory quality certificate and meet the design requirements. The ambient temperature and relative humidity during coating should comply with the coating product instructions. If no specific requirements are specified, the ambient temperature should ideally be between 5 and 38°C, and the relative humidity should not exceed 85%. Coating should not be applied to components with condensation, and the surface must not be exposed to rain for four hours after coating. The coating should be uniform, without obvious wrinkles or runs, and should adhere well. Coating is not permitted within 50mm of areas requiring on-site welding; if accidentally applied, it should be removed before welding.

[0066] The following are the specifications for on-site paint touch-up during installation:

[0067] After the steel structure installation and on-site welding are completed, any coating worn or damaged during on-site construction, as well as areas left unpainted during fabrication, should be touched up with paint. Surface treatment should involve manual rust removal using hand tools, with a rust removal quality grade no lower than St2.0. The touch-up painting process should be consistent with the factory painting requirements.

[0068] The acceptance specifications for steel components are as follows:

[0069] After the components are manufactured, the quality inspection department shall inspect and accept the finished components in accordance with the construction drawings and specifications. When the steel components leave the factory, they shall be accompanied by a product certificate and a component shipping packing list.

[0070] The stacking, transportation, and delivery specifications are as follows:

[0071] 1) Stacking: The ground for stacking finished and semi-finished components should be flat, firm and well-drained. Finished components should be placed according to category and area. When stacking, wooden blocks should be added.

[0072] 2) Transportation: Flatbed trailers are used for transporting components. Components should be securely tied during transportation, and the wooden stakes should be correctly positioned and in appropriate quantities.

[0073] 3) Delivery: Each batch of components is shipped with a packing list. The personnel accompanying the shipment should check the components against the list with the receiving personnel. After confirming that everything is correct, the receiving personnel should sign to accept the shipment.

[0074] The on-site installation specifications are as follows:

[0075] 1) Beam hoisting: The heaviest beam should not exceed 1.4T. First, move it to the installation position. For beams with separate concrete columns at both ends, fix two 2T hand-operated hoists on the concrete columns at both ends of the main beam, lift it to the installation position, and then install it. For beams with only one concrete column at one end, use an A-frame to install the steel beam. The tripod height should not be less than 4m, and it should be made of materials such as Φ76 seamless steel pipes, which are easy to disassemble and move.

[0076] 2) Scaffolding facilities

[0077] The top of the steel beam is approximately 3 meters above the ground. A detachable steel pipe scaffold is erected on the flat surface, with wooden planks laid on top to create a working platform. The upper part of the scaffold must be securely tied to the concrete column. Where there are no concrete columns, someone should be on the ground to supervise. The wooden planks laid on the scaffold must be of appropriate size and securely tied to the scaffold. For personnel movement on the platform structure, Φ8 steel wire ropes are used as safety ropes for attaching safety belts. The safety ropes are fixed to the concrete column.

[0078] The preferred embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above. Devices and structures not described in detail herein should be understood as being implemented in a conventional manner within the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of this utility model using the disclosed methods and techniques, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of this utility model. This does not affect the essential content of this utility model. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model, without departing from the content of the technical solution of this utility model, still fall within the protection scope of the technical solution of this utility model.

Claims

1. A reinforcement structure for adding steel beams to a wooden floor slab of a historical building, the wooden floor slab comprising a log grid (3), a log floor (2), and original scissor bracing (4), wherein the two ends of the log grid (3) are embedded in holes in the original wall (1), the log floor (2) is fixed to the upper surface of the log grid (3), and a first gap (31) and a second gap (32) are alternately distributed between the log grids (3), characterized in that, The original scissor brace (4) is located in the first gap (31), and a reinforcing steel (5) is provided in the second gap (32); The original wall (1) has a drilled hole (11) located in the second gap (32). A reinforced concrete beam pad (12) is poured at the bottom of the drilled hole (11). The end of the reinforcing steel (5) overlaps the upper surface of the reinforced concrete beam pad (12). Micro-expansion fine stone concrete (13) is poured in the drilled hole (11) to cover the end of the reinforcing steel (5) and the reinforced concrete beam pad (12).

2. The reinforcement structure for adding steel beams to the wooden floor of a historical building as described in claim 1, characterized in that, The reinforcing steel (5) is Q235B grade steel.

3. A reinforcement structure for adding steel beams to the wooden floor of a historical building as described in claim 1 or 2, characterized in that, The reinforcing steel (5) is an "I"-shaped steel or a "U"-shaped steel.

4. The reinforcement structure for adding steel beams to the wooden floor of a historical building as described in claim 1, characterized in that, The reinforcing steel (5) located within the same second gap (32) is a single steel beam.

5. The reinforcement structure for adding steel beams to the wooden floor of a historical building as described in claim 1, characterized in that, The depth of the hole (11) inside the wall is 10cm-20cm.

6. The reinforcement structure for adding steel beams to the wooden floor of a historical building as described in claim 1, characterized in that, The surfaces of the log grille (3) and the reinforcing steel (5) are coated with anti-rust paint and fireproof coating.

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