Resected bearing steel structure and reinforcing construction method thereof

Abstract

The invention discloses a cut load-bearing steel structure and a reinforcement construction method thereof, by using isotropic mechanical properties of steel of a steel structure, firstly, a hinged joint of a steel column and a steel beam to be cut is changed into rigid connection, so that the hinged joint becomes a part of the steel beam, and then the interior of a steel frame column and a new steel beam are reinforced; and finally, secondary reinforcement is carried out on the lower flange of the new integral steel beam, so that deformation and cracking of an upper structure caused by continuous stress release of the reinforced new integral steel beam after the steel column is cut off along with time are avoided. The method is easy and safe to operate and short in period, saves labor and has good economic benefits.

Description

Technical Field

[0001] The invention relates to the technical field of existing building reconstruction, and in particular to a method for removing a load-bearing steel structure and reinforcing the same. Background Art

[0002] my country's urbanization is nearing its end, and office and residential buildings are basically saturated. In the next few decades, a large number of old houses that are still useful will be reused after reinforcement and renovation. When the process involves reinforcement or functional changes, the lower steel columns are often removed under the load-bearing state without demolishing the upper structure; however, according to incomplete statistics from relevant departments, more than 2 / 3 of engineering structure collapse accidents in my country occur during the construction stage, especially demolition projects are more dangerous, so the use of safe and economical removal technology is imperative.

[0003] There are currently two main ways to remove load-bearing steel columns. Method 1: The scaffolding is re-topped and re-topped on multiple floors below. This method is because after the steel column is removed and before the steel beam is reinforced, the upper floor structural load is borne entirely by the scaffolding, which has a high safety risk, a long disassembly and assembly cycle, and a high cost. It is easy to cause structural deformation and cracking. The scaffolding position occupies the working surface and seriously affects the subsequent decoration and installation construction. Method 2: Before removing the steel column, use customized special temporary steel supports on both sides of the steel column to temporarily replace the steel column to be removed and bear the upper load. This method has a long demonstration, component processing and disassembly cycle; the cost is high; the strength of the temporary support re-topping is not easy to control. Too much strength may cause deformation of the steel beam above or below the steel support and cracking of the concrete structure. Too little strength may cause deformation and sinking of the upper steel beam and cracking of the concrete structure after the steel column is removed. The original upper floor load is transmitted to the lower floor through the steel column. Because the steel support is re-topped and transmitted to the lower floor beam, the beam may not be able to bear the transmitted load; partial occupation of the working surface affects the subsequent decoration and installation construction. Summary of the invention

[0004] The present invention provides a method for cutting out a load-bearing steel structure and reinforcing the same to solve the above problems.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: The present invention provides a method for cutting off a load-bearing steel structure and reinforcing the same, comprising the following steps: Step 1: Change the hinged node between the steel column to be cut and the steel beam to a rigid node, so that the original steel beams on both sides of the steel column to be cut are connected to form a new integral steel beam; Step 2: Strengthen the steel beam by increasing the cross section; Step 3: Cut the steel column to be removed.

[0006] The present invention provides a method for cutting a load-bearing steel structure and reinforcing the same. Further, in step 1, the edges of the connecting plates where the steel columns to be cut are bolted to the steel beams are welded with double-sided fillet welds to achieve the transformation from hinged connection to rigid connection.

[0007] The present invention provides a method for cutting off a load-bearing steel structure and reinforcing the same. Further, in step 2, a reinforcing structure is welded on the lower flange of the steel beam.

[0008] The present invention discloses a load-bearing steel structure to be cut off and a reinforcement construction method thereof. Furthermore, the reinforcement structure comprises a reinforcing beam web and a reinforcing beam flange. The reinforcing beam web is arranged on the lower flange of the steel beam, and its position corresponds to the position of the web of the steel beam. The upper part is connected to the lower flange of the steel beam, and the two ends are connected to the steel frame columns on both sides of the steel column to be cut off; the top surface of the reinforcing beam flange is connected to the reinforcing beam web, and the two ends are connected to the steel frame columns.

[0009] The present invention provides a method for cutting out a load-bearing steel structure and reinforcing the same. Further, the steel frame column is provided with an inner stiffening plate, and the inner stiffening plate and the flange of the reinforcing beam are located at the same elevation.

[0010] The invention discloses a method for cutting off a load-bearing steel structure and reinforcing the same. Furthermore, a continuous reinforcing flange is welded at the lower part of the flange of the reinforcing beam.

[0011] The present invention discloses a method for cutting off a load-bearing steel structure and reinforcing the same. Furthermore, steel beam stiffening plates are respectively welded to the steel beams on both sides of the steel column to be cut off and the formed cross-section reinforcement structure, and the steel beam stiffening plates are arranged at intervals along the length direction of the steel beam.

[0012] The present invention discloses a method for cutting a load-bearing steel structure and reinforcing the same. Furthermore, a static cutting process is adopted to cut a steel column to be cut.

[0013] The present invention provides a method for cutting a load-bearing steel structure and reinforcing the same. Furthermore, before cutting the steel column to be cut, the newly added weld is inspected.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This application utilizes the isotropic mechanical properties of steel structure steel. First, the hinged node between the steel column to be removed and the steel beam is changed to a rigid connection, so that it becomes a part of the steel beam. Then, the interior of the steel frame column and the new steel beam are reinforced so that they can independently bear the upper load when the steel column is removed. Finally, the lower flange of the new integral steel beam is reinforced twice to avoid deformation and cracking of the upper structure due to the continuous release of stress over time of the new integral steel beam reinforced after the steel column is removed. 2. The construction is convenient and safe, and the upper load is transmitted through the predetermined beams and columns of the structural components at each step; 3. Simple operation, high efficiency, short cycle, does not occupy the work surface of decoration and installation, and does not affect the decoration period; 4. Will not cause quality or safety hazards such as structural deformation and cracking; 5. The economic benefits are very considerable, saving a lot of labor, materials, machinery and transportation costs for disassembly and assembly.

[0015] The present invention will be further described below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the present invention's structure status; Figure 2 This is a schematic diagram of the web of the welded reinforcement beam of the present invention; Figure 3 This is a schematic diagram of installing the reinforcement beam flange and the inner stiffening plate of the present invention; Figure 4 This is a schematic diagram of installing a steel beam stiffening plate according to the present invention; Figure 5 This is a schematic diagram of the completion of cutting the steel column to be removed according to the present invention; Figure 6 This is a schematic diagram of installing a reinforced flange according to the present invention.

[0017] Reference numerals: 1. Steel columns to be removed; 2. Steel beams; 3. Strengthened beam webs; 4. Strengthened beam flanges; 5. Internal stiffening plates; 6. Steel beam stiffening plates; 7. Strengthened flanges; 8. Steel frame columns. DETAILED DESCRIPTION

[0018] like Figure 1-Figure 6 As shown, the present invention discloses a method for cutting off a load-bearing steel structure and reinforcing the same, comprising the following steps: Step 1: First, clean the fire retardant coating at the bolted position between the steel column 1 to be cut and the steel beam 2, and then use double-sided fillet welds to weld the edges of the connecting plates where the steel column 1 to be cut and the steel beam 2 are bolted, so that the original core area of ​​the beam and column is transformed from a hinged connection to a rigid connection, so that the steel column 1 to be cut becomes a part of the steel beam 2, and the original steel beams 2 on both sides of the steel column 1 to be cut are connected to form a new integral steel beam.

[0019] Step 2: A reinforcement structure is welded to the lower flange of the steel beam 2 to enhance the bearing capacity of the steel beam 2. The reinforcement structure includes a reinforcing beam web 3 and a reinforcing beam flange 4. The reinforcing beam web 3 and the reinforcing beam flange 4 are installed at the bottom of the steel beam 2 in an inverted "T" shape. The reinforcing beam web 3 is arranged on the lower flange of the steel beam 2, and its position corresponds to the position of the web of the steel beam 2. The upper part is welded to the lower flange of the steel beam 2, and the two ends are welded to the steel frame columns 8 on both sides of the steel column 1 to be cut off; the top surface of the reinforcing beam flange 4 is welded to the reinforcing beam web 3, and the two ends are welded to the steel frame columns 8.

[0020] Then, inner stiffening plates 5 are arranged in the steel frame columns 8 at both ends. The inner stiffening plates 5 and the reinforcing beam flanges 4 are located at the same elevation, so that the reinforcing beam flanges 4 are connected to the newly added inner stiffening plates 5 in the steel frame columns 8, effectively transmitting the horizontal force of the newly added reinforcing beam flanges 4.

[0021] Step 3: Steel beam stiffening plates 6 are welded between the steel beams 2 on both sides of the steel column 1 to be cut and the flanges of the reinforcement structure. The steel beam stiffening plates 6 are arranged at intervals along the length direction of the steel beam 2. After completion, the newly added welds are inspected and meet the design requirements.

[0022] Step 4: The steel column 1 to be cut is cut by a static cutting process. Before cutting, the steel column 1 to be cut is firmly tied by a truck crane. After the cutting is completed, the truck crane hoists the steel column 1 to be cut downstairs.

[0023] Step 5: A full-length reinforcing flange 7 is welded at the bottom of the reinforcing beam flange 4, the weld is inspected again, the weld is polished and rust-removed, zinc-rich anti-rust primer is sprayed, and then epoxy micaceous iron intermediate paint is sprayed, and fire-retardant paint is sprayed after it is completely dry; by welding a full-length reinforcing flange 7 at the bottom of the reinforcing beam flange 4, it is avoided that the steel beam 2 will continue to release stress over time after the steel column is removed in the later stage, thereby preventing deformation or cracks.

[0024] The embodiments described above are merely descriptions of preferred implementation modes of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for removing a load-bearing steel structure and reinforcing it, characterized in that: The following steps are involved: Step 1: Change the hinged node between the steel column to be cut and the steel beam to a rigid node, so that the original steel beams on both sides of the steel column to be cut are connected to form a new integral steel beam; Step 2: Strengthen the steel beam by increasing the cross section; Step 3: Cut the steel column to be removed.

2. A method for removing a load-bearing steel structure and reinforcing it according to claim 1, characterized in that: In step 1, the edge of the connecting plate where the steel column to be cut is bolted to the steel beam is welded with double-sided fillet welds to achieve the transformation from hinged connection to rigid connection.

3. The method for removing a load-bearing steel structure and reinforcing it according to claim 1, characterized in that: In step 2, a reinforcement structure is welded to the lower flange of the steel beam.

4. The method for removing a load-bearing steel structure and reinforcing it according to claim 3, characterized in that: The reinforcement structure includes a reinforced beam web and a reinforced beam flange. The reinforced beam web is arranged on the lower flange of the steel beam, and its position corresponds to the position of the web of the steel beam. The upper part is connected to the lower flange of the steel beam, and the two ends are connected to the steel frame columns on both sides of the steel column to be cut off; the top surface of the reinforced beam flange is connected to the reinforced beam web, and the two ends are connected to the steel frame columns.

5. The method for removing a load-bearing steel structure and reinforcing the same according to claim 4, characterized in that: The steel frame column is provided with an inner stiffening plate, and the inner stiffening plate and the flange of the reinforcing beam are located at the same elevation.

6. The method for removing a load-bearing steel structure and reinforcing it according to claim 4, characterized in that: A full-length reinforcing flange is welded at the lower part of the reinforcing beam flange.

7. The method for removing a load-bearing steel structure and reinforcing it according to claim 1, characterized in that: Steel beam stiffening plates are welded respectively on the steel beams on both sides of the steel column to be cut off and on the formed cross-section reinforcement structure, and the steel beam stiffening plates are arranged at intervals along the length direction of the steel beam.

8. The method for removing a load-bearing steel structure and reinforcing it according to claim 1, characterized in that: The steel column to be cut is cut using static cutting technology.

9. A method for removing a load-bearing steel structure and reinforcing it according to any one of claims 1 to 7, characterized in that: Before cutting the steel column to be removed, the newly added welds should be inspected.

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