A method for widening reconstruction of a reinforced concrete frame structure

Abstract

A reinforced concrete frame structure widening reconstruction method, step one: dig open the ground to the foundation bottom surface on the side of the widening; step two: add new column independent foundation outside the corridor; step three: extend the original foundation beam of the original column independent foundation, add new foundation beam and new bottom floor slab; step four: support four groups of vertical support mechanisms one under the lower part of each layer original cantilever beam; step five: support the pouring formwork of the new added beam and the new added slab; step six: bind the new added beam reinforcement; step seven: embed square steel plates as shear keys on the contact surface of the original cantilever beam and the cantilever beam extension beam; step eight: bind the new added slab reinforcement; step nine: bind the new added column reinforcement; step ten: support the new added column formwork, and pour the new added beam slab column concrete; step eleven: after curing the concrete to the design strength, remove the formwork and remove the support. The method can provide more use space by widening the original building, and can meet the functional requirements of the building.

Description

Technical Field

[0001] This invention belongs to the field of building engineering and composite structure reinforcement technology, specifically relating to a method for widening and remodeling a reinforced concrete frame structure. Background Technology

[0002] Currently, my country's construction industry has entered a mature stage. While a large number of buildings are being constructed, existing buildings are also being renovated and upgraded to expand usable space or improve functionality. Some older buildings have already shown signs of damage and cracking before reaching their intended service life, affecting their normal use. Demolition and reconstruction are neither economical nor practical. Therefore, reinforcing older buildings to improve their safety is of great significance. With the development of society and the economy, people's requirements for building functions are constantly increasing. If the use of a building changes, the corresponding load-bearing capacity of beams, slabs, and columns will also change, requiring redesign and recalculation. For some newly constructed buildings, expansion, renovation, or reinforcement activities aimed at improving building safety are necessary to meet new usage requirements. For frame structures, a common industrial and civil building structure, widening and expanding the span of the original structure increases usable space, thereby meeting new functional requirements. Furthermore, single-span frame structures, lacking redundant constraints and exhibiting fewer statically indeterminate degrees, fail to meet the requirements of multi-layered seismic defense. Therefore, they urgently require reinforcement and retrofitting to improve their safety performance and functionality. In conclusion, building reinforcement technology is crucial for both existing reinforced concrete frame structures and single-span frame structures.

[0003] Commonly used reinforcement techniques for reinforced concrete structures include: cross-section enlargement, external prestressing, and bracing. While these methods offer good reinforcement for individual components, they lack a systematic approach for expanding usable space and enhancing overall structural integrity. External prestressing requires technicians to treat the oblique and normal sections of the reinforced concrete frame structure, making the construction process complex. Bracing requires adding numerous components, significantly impacting the building's usable space and functionality. Therefore, there is an urgent need for a new reinforcement technology to meet the needs of widening and renovating existing reinforced concrete frame structures. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a method for widening and renovating a reinforced concrete frame structure. This method is simple to implement and has good overall integrity. By widening the original building, more usable space can be provided, which can meet the functional requirements of the building, optimize space utilization, and increase the safety, stability, and seismic resistance of the building structure.

[0005] To achieve the above objectives, the present invention provides a method for widening and remodeling a reinforced concrete frame structure, comprising the following steps:

[0006] Step 1: Excavate the ground on one side of the expansion span down to the bottom of the foundation;

[0007] Remove the original walkway railings, excavate the ground on one side of the span down to the bearing layer of the existing foundation bottom, expose the foundation, and inspect the foundation. After ensuring that the foundation is not damaged or destroyed, proceed to step two.

[0008] Step 2: Add new independent foundations for the columns on the outside of the connecting corridor;

[0009] S21: Determine the location of the multiple new independent foundations to be added under the columns on the outer side of the connecting corridor, and ensure that the location of the multiple new independent foundations corresponds one-to-one with the multiple original independent foundations under the columns near the side of the extension.

[0010] S22: Pour foundation pad concrete at the location of the determined new column independent foundation, and vibrate the pad concrete during the pouring process to make it dense.

[0011] S23: First, tie the reinforcing bars of the new column independent foundation, then install the pouring formwork of the new column independent foundation, then pour the concrete of the new column independent foundation, and ensure that the height of the new column independent foundation is consistent with that of the original column independent foundation. After curing, remove the pouring formwork.

[0012] Step 3: Extend the original foundation beam of the original independent foundation under the column, and add a new foundation beam and a new ground floor slab;

[0013] S31: Extend the original foundation beam of the original independent column foundation in the direction of the corresponding new independent column foundation to form a foundation beam extension beam, and use the foundation beam extension beam to connect the original independent column foundation and the corresponding new independent column foundation.

[0014] S32: A new foundation beam shall be set between every two adjacent new column independent foundations, and the new foundation beam shall be used to connect the two adjacent new column independent foundations.

[0015] S33: Pour a new ground floor slab between the new independent column foundation and the original independent column foundation, and ensure that the steel bars inside the new ground floor slab are embedded inside the top of the original independent column foundation and inside the top of the new independent column foundation.

[0016] Step 4: Install four sets of vertical support mechanisms under the original cantilever beams on each floor;

[0017] Four adjustable supports (2) are installed securely and stably along the length of the original cantilever beam on the floor slab below it. Four vertical supports (1) are then erected on the four adjustable supports (2), ensuring a secure and stable connection between the vertical supports (1) and the adjustable supports (2). Next, the four adjustable supports (1) are installed on the upper ends of the four vertical supports (1), ensuring a secure and stable connection between the adjustable supports (1) and the vertical supports (1). Finally, four short steel pipe supports are erected between the four adjustable supports (1) and the original cantilever beam, and four pads are embedded between the four short steel pipe supports and the four adjustable supports (1). Plate 2: Four pads 1 are embedded between the four short steel pipe supports and the lower end face of the original cantilever beam, ensuring that the two ends of the short steel pipe supports are stably abutted between the upper end of the adjustable support 1 and the lower end face of the original cantilever beam through pads 2 and pads 1. The pads 1, short steel pipe supports, pads 2, adjustable support 1, upright support 1 and adjustable support 2 are connected from top to bottom to form a vertical support mechanism 1, and the four sets of vertical support mechanisms 1 are used to stably support the original cantilever beam. At the same time, the four short steel pipe supports serve as the main skeleton of the part to be heightened below the original cantilever beam.

[0018] Step 5: Erect the casting formwork for the new beams and slabs;

[0019] Using multiple sets of vertical support mechanisms, the casting templates for the extension beams of the cantilever beams are erected in the extension direction of the original cantilever beams, and the casting templates for the new inter-column frame beams are erected at the positions between the ends of the adjacent cantilever beam extension beams of the original frame beams, ensuring that both ends of the cantilever beam extension beams are connected to the original cantilever beams and the new inter-column frame beams.

[0020] Using multiple sets of vertical support mechanisms, the pouring formwork for the newly widened floor slab is partially erected between the sealing beam and the newly added inter-column frame beam, and the pouring formwork for the new walkway railing is erected above the newly added inter-column frame beam.

[0021] Step Six: Tie the reinforcing bars of the newly added beam;

[0022] S61: First, roughen the contact surface between the bottom surface of the original cantilever beam and the outer side of the web of the original cantilever beam. Then, tie stirrup 1 to the outer side of the main frame of the part to be heightened below the original cantilever beam and anchor stirrup 1 into the interior of the original cantilever beam. Then, tie stirrup 2 to the part of the corresponding cantilever beam extension beam and tie longitudinal steel bar 1 to the top and bottom parts of the corresponding extension beam. At the same time, insert longitudinal steel bar 1 into the interior of the original cantilever beam.

[0023] S62: First, tie stirrups three to the part of the newly added inter-column frame beam, and then tie longitudinal reinforcement two to the part of the upper and lower sides of the corresponding frame beam.

[0024] Step 7: Install square steel plates as shear keys at the contact surfaces of the original cantilever beam and the cantilever beam extension beam;

[0025] Square steel plates are horizontally installed at the contact surface between the original cantilever beam and the cantilever beam extension beam. One end of the square steel plate is horizontally inserted into the interior of the original cantilever beam, and the other end of the square steel plate is horizontally inserted into the reinforcing bars inside the cantilever beam extension beam. Structural adhesive is then injected at the rebar insertion site to utilize the square steel plate as a shear key.

[0026] Step 8: Tie the reinforcing bars of the newly added slab;

[0027] S81: First, roughen the outer contact surface of the original sealing beam, and tie longitudinal reinforcing bars in the top and bottom parts of the corresponding newly widened floor slab. At the same time, embed the longitudinal reinforcing bars into the reinforcing bars inside the sealing beam and the newly added inter-column frame beam. Then, tie transverse reinforcing bars in the top and bottom parts of the corresponding newly widened floor slab. At the same time, embed the transverse reinforcing bars into the reinforcing bars inside the extended beams of the cantilever beams at both ends.

[0028] S82: First, tie vertical steel bars on both sides of the corresponding new walkway railing, and insert the ends of the vertical steel bars into the steel bars inside the newly added inter-column frame beams. Then, tie horizontal steel bars on both sides of the corresponding new walkway railing, and tie tie bars at the double-row vertical steel bars.

[0029] Step 9: Tie the reinforcing steel bars of the newly added column;

[0030] Tie the vertical steel bars and stirrups four of the new column below the connection between the cantilever beam extension beam and the newly added column frame beam, and connect the upper end of the vertical steel bars in the new column with the longitudinal steel bar one in the cantilever beam extension beam and the longitudinal steel bar two in the newly added column frame beam, so that the lower end of the vertical steel bars in the new column is inserted into the inside of the top of the independent foundation under the new column or into the inside of the top of the new column below.

[0031] Step 10: Erect the formwork for the new columns and pour the concrete for the new beams, slabs and columns;

[0032] At the construction location of the new column, a support frame is erected, and the precast slabs of the column formwork are installed on the support frame. The column formwork is then fixed to the support frame with connectors. Then, the concrete for the new column, the new inter-column frame beam, the cantilever beam extension beam, the newly widened floor slab, and the new walkway railing is poured in sequence.

[0033] Step 11: After the concrete has cured to the design strength, remove the formwork and dismantle the supports;

[0034] After the concrete has cured to the designed age, the formwork should be removed first. The formwork removal order is: column side formwork, slab bottom formwork, beam side formwork, and beam bottom formwork. Then, the concrete strength should be tested. After the concrete strength test is qualified, the supports should be removed.

[0035] Step 12: Starting from the first floor, perform steps 4 through 11 layer by layer from low to high, repeating the work in sequence until the widening work of all floors is completed.

[0036] In step S41 of step four, the support strength of each set of vertical support mechanisms is adjusted by extending and retracting the adjustable support one and the adjustable support two to ensure that the original cantilever beam can be stably supported.

[0037] In step S41 of step four, the four upright supports are connected by multiple transverse connecting rods, forming an integral support after connection.

[0038] In step five, both vertical support mechanisms two and three consist of adjustable support three, upright support two, and adjustable support four connected sequentially from top to bottom.

[0039] Adjustable support 1, adjustable support 2, adjustable support 3, and adjustable support 4 have the same structure, each mainly consisting of a top fixed support, a bottom fixed support, and a middle adjusting rod. The top fixed support consists of an upper support block and an upper support sleeve fixedly connected to the lower center of the upper support block; the upper support sleeve has an internal thread structure 1. The bottom fixed support consists of a lower support block and a lower support sleeve fixedly connected to the upper center of the lower support block; the lower support sleeve has an internal thread structure 2. The middle adjusting rod consists of an adjusting block located in the middle, a... The system consists of an upper threaded rod and a lower threaded rod fixedly connected to the upper and lower centers of the adjusting block; a middle adjusting rod is positioned between the top and bottom fixed supports, with the upper threaded rod threadedly inserted into the upper support sleeve and the lower threaded rod threadedly inserted into the lower support sleeve; a cylindrical mounting groove is formed at the lower center of the lower support block, and an internal thread structure is provided in the mounting groove; an external thread structure is provided on the upper exterior of the first upright support; the mounting groove of the lower support block is fixedly fitted onto the outer side of the upper end of the first upright support through a threaded fit.

[0040] In step one, the foundation is first reinforced. Step two is then carried out only after the bearing capacity and stability of the foundation meet the requirements for the widening and reconstruction.

[0041] Furthermore, in order to effectively reduce the ground reaction force on the widened side and reduce ground settlement and deformation, in step two, it is ensured that the bottom area of ​​the new column independent foundation is larger than that of the original column independent foundation.

[0042] In this invention, the ground on one side of the expansion span is first excavated down to the bearing layer of the existing foundation bottom elevation, which facilitates effective inspection of the foundation on the expansion span side. Adding new independent column foundations only after ensuring the foundation is undamaged or uninjured effectively ensures the safety and stability of the widened side of the building during later use. When adding new independent column foundations, ensuring the height of the new foundations matches the original foundations, and then using foundation beam extension beams to connect the original and new independent column foundations, effectively ensures the overall stress balance after connection, significantly improving the stability and load-bearing capacity of the connecting corridor. Connecting two adjacent new independent column foundations using new foundation beams improves the overall integrity of several new independent column foundations, effectively increasing the load-bearing capacity of the new foundations and reducing the settlement and deformation of the foundation during subsequent use. After the new independent column foundations are added, a new ground floor slab is first poured between the new and original independent column foundations, which can be used as the initial support layer for the height increase. Four sets of vertical support mechanisms mounted on the new ground floor slab provide stable and reliable support for the original cantilever beam. Adjustable support brackets are installed at the bottom and top of each set of vertical support mechanisms, allowing for convenient adjustment of the length of the vertical support mechanism to accommodate different support heights and effectively improve its versatility. Short steel pipe supports are installed at the top of each set of vertical support mechanisms. These four short steel pipe supports, distributed sequentially along the length, can be directly cast into the raised section of the original cantilever beam during pouring. This not only reduces demolition work but also utilizes the four short steel pipe supports as the main framework of the raised section, increasing overall stability and preventing structural deformation. Furthermore, it helps reduce the vibration amplitude of the overall structure during typhoons and earthquakes. Roughening the contact surfaces of the bottom and outer sides of the original cantilever beam's web helps to significantly enhance the bonding strength between the original cantilever beam and the newly added / extended sections during the casting of the extended and heightened sections. This better ensures that the original sections can form an integral structure with the newly added / extended sections, ultimately creating a widened frame beam for the building. Simultaneously, combined with the frame beams added between the new columns, this effectively guarantees the stability and load-bearing capacity of the beam structure. When tying the reinforcing bars, anchoring the stirrups of the extended section into the original cantilever beam and embedding the longitudinal reinforcing bars at the top and bottom of the extended beam into the original cantilever beam significantly increases the connection strength between the extended and heightened sections, resulting in a stronger overall load-bearing capacity. Embedding square steel plates as shear keys at the contact surfaces of the original and extended cantilever beams, with both parts embedded inside, and then grouting the anchored areas with structural adhesive, effectively ensures the strong connection at the beam joint.When tying the reinforcing bars of the newly widened floor slab, the longitudinal reinforcing bars are embedded inside the sealing beams and the reinforcing bars inside the newly added inter-column frame beams, while the transverse reinforcing bars are embedded inside the reinforcing bars inside the extended beams of the cantilever beams at both ends. This ensures that the newly widened floor slab is firmly and reliably connected to the sealing beams, the newly added inter-column frame beams, and the extended beams of the cantilever beams on both sides. This ensures that after pouring, the load of the newly widened floor slab can be transferred to the surrounding frame beams and further to the frame columns, ensuring the safety of the newly widened floor slab during later use. The concrete pouring of the new columns, the new inter-column frame beams, the extended beams of the cantilever beams, the newly widened floor slab, and the new walkway railing is carried out sequentially. The newly poured columns provide effective support for the subsequently poured new inter-column frame beams and extended beams of the cantilever beams, which in turn provide effective support for the newly widened floor slab, ensuring the load-bearing capacity of the widened floor slab.

[0043] This invention, by widening the span of an existing building, provides more usable space, meets the building's functional needs, optimizes space utilization, improves the overall integrity of a single-span building structure, increases structural stability and seismic resistance, and reduces the safety hazard of structural overturning. This method is simple to implement, convenient for construction and hoisting, has good seismic performance, and a high degree of industrialization. It maintains the integrity of the original structure, is relatively cost-effective, and effectively solves problems caused by inadequate geological surveys, substandard design, typhoons, earthquakes, and changes in people's functional requirements for building construction. It enhances the value and sustainability of buildings, extends their service life, and conforms to the principles of sustainable development. Applying this method to the field of building reinforcement can generate significant economic and social benefits. Attached Figure Description

[0044] Figure 1 This is the original frame structure basic plan;

[0045] Figure 2 This is the foundation plan after the original frame structure was reinforced;

[0046] Figure 3 This is the plan view of the middle layer of the original frame structure;

[0047] Figure 4 This is a floor plan of the intermediate layer after the original frame structure was reinforced;

[0048] Figure 5 This is a supporting schematic diagram of the widening and modification process of the present invention;

[0049] Figure 6 This is an elevation view of the original cantilever beam bottom support in this invention;

[0050] Figure 7 This is an elevation view of the modified frame beam of this invention;

[0051] Figure 8 yes Figure 7 Sectional view along the middle AA direction;

[0052] Figure 9 yes Figure 7 Cross-sectional view along the BB direction;

[0053] Figure 10 In this invention Figure 3 DD-direction cross-section;

[0054] Figure 11 In this invention Figure 4 CC-direction cross-section.

[0055] In the diagram: 1. New independent column foundation; 2. Foundation beam extension beam; 3. Square steel plate; 4. New ground floor slab; 5. Original independent column foundation; 6. New foundation beam; 7. Original cantilever beam; 8. Short steel pipe support; 9. Pad plate one; 10. Pad plate two; 11. New inter-column frame beam; 12. Original frame beam; 13. Upright support one; 14. Cantilever beam extension beam; 15. Bottom surface of original cantilever beam; 16. Stirrup two; 17. Stirrup one; 18. Adjustable support one; 19. Outer contact surface of original sealing beam; 20. New widened floor slab; 21. New walkway railing; 22. Original walkway railing; 23. New column; 24. Sealing beam; 25. Adjustable support two; 26. Outer contact surface of original cantilever beam web. Detailed Implementation

[0056] The invention will now be further described with reference to the accompanying drawings.

[0057] like Figures 1 to 11 As shown, the present invention provides a method for widening and remodeling a reinforced concrete frame structure, comprising the following steps:

[0058] Step 1: Excavate the ground on one side of the expansion span down to the bottom of the foundation;

[0059] Remove the original walkway railing 22, excavate the ground on one side of the span down to the bearing layer of the existing foundation bottom surface, expose the foundation, and inspect the foundation. After ensuring that the foundation is not damaged or destroyed, proceed to step two.

[0060] Step 2: Add a new independent foundation 1 for the column on the outside of the connecting corridor;

[0061] S21: Determine the location of the multiple new independent foundations 1 to be added under the columns on the outer side of the connecting corridor, and ensure that the location of the multiple new independent foundations 1 corresponds one-to-one with the multiple original independent foundations 5 under the columns near the side of the extension.

[0062] S22: Pour foundation pad concrete at the location of the determined new column independent foundation 1, and vibrate the pad concrete during the pouring process to make it dense.

[0063] S23: First, tie the reinforcing bars of the new independent foundation 1 under the column, then install the pouring formwork of the new independent foundation 1 under the column, then pour the concrete of the new independent foundation 1 under the column, and ensure that the height of the new independent foundation 1 under the column is consistent with that of the original independent foundation 5 under the column. After curing, remove the pouring formwork.

[0064] Step 3: Extend the original foundation beam of the original independent foundation 5 under the original column, and add a new foundation beam 6 and a new ground floor slab 4;

[0065] S31: Extend the original foundation beam of the original independent foundation 5 in the direction of the corresponding new independent foundation 1 to form a foundation beam extension beam 2, and use the foundation beam extension beam 2 to connect the original independent foundation 5 and the corresponding new independent foundation 1.

[0066] S32: A new foundation beam 6 is set between every two adjacent new column independent foundations 1, and the new foundation beam 6 is used to connect the two adjacent new column independent foundations 1.

[0067] S33: Pour a new bottom floor slab 4 between the new independent column foundation 1 and the original independent column foundation 5, and ensure that the steel bars inside the new bottom floor slab 4 are inserted into the inside of the top of the original independent column foundation 5 and the inside of the top of the new independent column foundation 1.

[0068] Step 4: Install four sets of vertical support mechanisms under the original cantilever beams 7 on each floor;

[0069] Four adjustable supports 25 are installed securely and stably along the length of the original cantilever beam 7 on the floor slab below it. Four vertical supports 13 are then erected on the four adjustable supports 25, ensuring a secure and stable connection between the vertical supports 13 and the adjustable supports 25. Next, four adjustable supports 18 are installed on the upper ends of the four vertical supports 13, ensuring a secure and stable connection between the adjustable supports 18 and the vertical supports 13. Then, four short steel pipe supports 8 are erected between the four adjustable supports 18 and the original cantilever beam 7, and four short steel pipe supports 8 are embedded between the four short steel pipe supports 8 and the four adjustable supports 18. Pad 2 10, four pads 1 9 are embedded between the four short steel pipe supports 8 and the lower end face of the original cantilever beam 7, and ensure that the two ends of the short steel pipe supports 8 are stably abutted between the upper end of the adjustable support 18 and the lower end face of the original cantilever beam 7 through pads 2 10 and pads 1 9; the pads 1 9, short steel pipe supports 8, pads 2 10, adjustable support 18, upright support 13 and adjustable support 2 25 connected from top to bottom form a vertical support mechanism 1, and the four sets of vertical support mechanisms 1 formed stably support the original cantilever beam 7. At the same time, the four short steel pipe supports 8 serve as the main skeleton of the part to be heightened below the original cantilever beam 7.

[0070] Step 5: Erect the casting formwork for the new beams and slabs;

[0071] Using multiple sets of vertical support mechanisms, the casting template of the cantilever beam extension beam 14 is set up in the extension direction of the original cantilever beam 7, and the casting template of the new inter-column frame beam 11 is set up at the position between the ends of the adjacent cantilever beam extension beam 14 corresponding to the original frame beam 12, and ensures that both ends of the cantilever beam extension beam 14 are connected to the original cantilever beam 7 and the new inter-column frame beam 11.

[0072] Using multiple sets of vertical support mechanisms, the pouring formwork for the newly widened floor slab 20 is partially supported between the sealing beam 24 and the newly added inter-column frame beam 11, and the pouring formwork for the new walkway railing 21 is supported above the newly added inter-column frame beam 11.

[0073] Step Six: Tie the reinforcing bars of the newly added beam;

[0074] S61: First, roughen the contact surface 26 of the bottom surface 15 and the outer side of the web of the original cantilever beam. Then, tie the stirrup 17 to the outside of the main frame of the part to be heightened below the original cantilever beam 7 and anchor the stirrup 17 into the interior of the original cantilever beam 7. Then, tie the stirrup 26 to the part of the corresponding cantilever beam extension beam 14 and tie the longitudinal steel bar 1 to the top and bottom parts of the corresponding extension beam. At the same time, insert the longitudinal steel bar 1 into the interior of the original cantilever beam 7.

[0075] S62: First, tie stirrups 3 to the part of the newly added inter-column frame beam 11, and then tie longitudinal reinforcement 2 to the part of the upper and lower sides of the corresponding frame beam.

[0076] The dimensions of the cantilever beam extension beam 14 and the newly added inter-column frame beam 11, as well as the diameter of their internal steel bars, are determined by calculation based on the load-bearing capacity of the frame structure.

[0077] Step 7: Install square steel plates 3 as shear keys at the contact surfaces of the original cantilever beam 7 and the cantilever beam extension beam 14;

[0078] A square steel plate 3 is horizontally installed at the contact surface between the original cantilever beam 7 and the cantilever beam extension beam 14. One section of the square steel plate 3 is horizontally inserted into the interior of the original cantilever beam 7, and the other section of the square steel plate 3 is horizontally inserted into the reinforcing bars inside the cantilever beam extension beam 14. Structural adhesive is used to inject the reinforcing bar area to utilize the square steel plate 3 as a shear key.

[0079] Step 8: Tie the reinforcing bars of the newly added slab;

[0080] S81: First, roughen the outer contact surface 19 of the original sealing beam, and tie longitudinal reinforcing bars to the top and bottom parts of the corresponding newly widened floor slab 20. At the same time, embed the longitudinal reinforcing bars into the reinforcing bars inside the sealing beam 24 and the newly added inter-column frame beam 11. Then, tie transverse reinforcing bars to the top and bottom parts of the corresponding newly widened floor slab 20. At the same time, embed the transverse reinforcing bars into the reinforcing bars inside the cantilever beam extension beam 14 at both ends. The dimensions of the newly widened floor slab 20 and the diameter of its internal reinforcing bars are determined according to the load-bearing capacity of the frame structure.

[0081] S82: First, tie vertical steel bars on both sides of the corresponding new walkway railing 21, and insert the ends of the vertical steel bars into the steel bars inside the adjacent newly added inter-column frame beam 11. Then, tie horizontal steel bars on both sides of the corresponding new walkway railing 21, and tie tie bars at the double-row vertical steel bars.

[0082] Step 9: Tie the new column reinforcement bar 23;

[0083] Below the connection between the cantilever beam extension beam 14 and the newly added inter-column frame beam 11, tie the vertical reinforcing bars and stirrups four of the newly added column 23, and connect the upper end of the vertical reinforcing bars in the newly added column 23 with the longitudinal reinforcing bars one in the cantilever beam extension beam 14 and the longitudinal reinforcing bars two in the newly added inter-column frame beam 11, so that the lower end of the vertical reinforcing bars in the newly added column 23 is inserted into the interior of the top of the independent foundation under the new column or into the interior of the top of the newly added column 23 below; wherein, the dimensions of the newly added column 23 and the diameter of its internal reinforcing bars are determined according to the bearing capacity of the frame structure.

[0084] Step 10: Erect the formwork for the new column 23 and pour the concrete for the new beams, slabs and columns;

[0085] At the construction location of the newly added column 23, a support frame is erected, and the precast slab of the column formwork is installed on the support frame. The column formwork is then fixed to the support frame with connectors. Then, the concrete for the newly added column 23, the newly added inter-column frame beam 11, the cantilever beam extension beam 14, the newly widened floor slab 20, and the new walkway railing 21 is poured in sequence.

[0086] Step 11: After the concrete has cured to the design strength, remove the formwork and dismantle the supports;

[0087] After the concrete has cured to the designed age, the formwork should be removed first. The formwork removal order is: column side formwork, slab bottom formwork, beam side formwork, and beam bottom formwork. Then, the concrete strength should be tested. After the concrete strength test is qualified, the supports should be removed.

[0088] Step 12: Starting from the first floor, perform steps 4 through 11 layer by layer from low to high, repeating the work in sequence until the widening work of all floors is completed.

[0089] In step S41 of step four, the support strength of each set of vertical support mechanisms is adjusted by extending and retracting the adjustable support 18 and the adjustable support 25 to ensure that the original cantilever beam 7 can be stably supported.

[0090] In step S41 of step four, the four upright supports 13 are connected by multiple horizontal connecting rods, and after connection, they form an integral support.

[0091] In step five, both vertical support mechanisms two and three consist of adjustable support three, upright support two, and adjustable support four connected sequentially from top to bottom.

[0092] Adjustable support 18, adjustable support 25, adjustable support 3, and adjustable support 4 have the same structure, each mainly consisting of a top fixed support, a bottom fixed support, and a middle adjusting rod. The top fixed support consists of an upper support block and an upper support sleeve fixedly connected to the lower center of the upper support block; the upper support sleeve has an internal thread structure. The bottom fixed support consists of a lower support block and a lower support sleeve fixedly connected to the upper center of the lower support block; the lower support sleeve has an internal thread structure. The middle adjusting rod consists of an adjusting block located in the middle, a... The system consists of an upper threaded rod and a lower threaded rod fixedly connected to the upper and lower centers of the adjusting block; a middle adjusting rod is positioned between the top and bottom fixed supports, with the upper threaded rod threaded into the upper support sleeve and the lower threaded rod threaded into the lower support sleeve; a cylindrical mounting groove with an internal thread is provided at the lower center of the lower support block; an external thread is provided on the upper exterior of the upright support 13; and the mounting groove of the lower support block is fixedly fitted onto the outer side of the upper end of the upright support 13 via a threaded connection.

[0093] In step one, the foundation is first reinforced. Step two is then carried out only after the bearing capacity and stability of the foundation meet the requirements for the widening and reconstruction.

[0094] In order to effectively reduce the ground reaction force on the widened side and reduce ground settlement and deformation, in step two, it is ensured that the bottom area of ​​the new column independent foundation 1 is greater than the bottom area of ​​the original column independent foundation 5.

[0095] In this invention, the ground on one side of the expansion span is first excavated down to the bearing layer of the existing foundation bottom elevation, which facilitates effective inspection of the foundation on the expansion span side. Adding new independent column foundations only after ensuring the foundation is undamaged or uninjured effectively ensures the safety and stability of the widened side of the building during later use. When adding new independent column foundations, ensuring the height of the new foundations matches the original foundations, and then using foundation beam extension beams to connect the original and new independent column foundations, effectively ensures the overall stress balance after connection, significantly improving the stability and load-bearing capacity of the connecting corridor. Connecting two adjacent new independent column foundations using new foundation beams improves the overall integrity of several new independent column foundations, effectively increasing the load-bearing capacity of the new foundations and reducing the settlement and deformation of the foundation during subsequent use. After the new independent column foundations are added, a new ground floor slab is first poured between the new and original independent column foundations, which can be used as the initial support layer for the height increase. Four sets of vertical support mechanisms mounted on the new ground floor slab provide stable and reliable support for the original cantilever beam. Adjustable support brackets are installed at the bottom and top of each set of vertical support mechanisms, allowing for convenient adjustment of the length of the vertical support mechanism to accommodate different support heights and effectively improve its versatility. Short steel pipe supports are installed at the top of each set of vertical support mechanisms. These four short steel pipe supports, distributed sequentially along the length, can be directly cast into the raised section of the original cantilever beam during pouring. This not only reduces demolition work but also utilizes the four short steel pipe supports as the main framework of the raised section, increasing overall stability and preventing structural deformation. Furthermore, it helps reduce the vibration amplitude of the overall structure during typhoons and earthquakes. Roughening the contact surfaces of the bottom and outer sides of the original cantilever beam's web helps to significantly enhance the bonding strength between the original cantilever beam and the newly added / extended sections during the casting of the extended and heightened sections. This better ensures that the original sections can form an integral structure with the newly added / extended sections, ultimately creating a widened frame beam for the building. Simultaneously, combined with the frame beams added between the new columns, this effectively guarantees the stability and load-bearing capacity of the beam structure. When tying the reinforcing bars, anchoring the stirrups of the extended section into the original cantilever beam and embedding the longitudinal reinforcing bars at the top and bottom of the extended beam into the original cantilever beam significantly increases the connection strength between the extended and heightened sections, resulting in a stronger overall load-bearing capacity. Embedding square steel plates as shear keys at the contact surfaces of the original and extended cantilever beams, with both parts embedded inside, and then grouting the anchored areas with structural adhesive, effectively ensures the strong connection at the beam joint.When tying the reinforcing bars of the newly widened floor slab, the longitudinal reinforcing bars are embedded inside the sealing beams and the reinforcing bars inside the newly added inter-column frame beams, while the transverse reinforcing bars are embedded inside the reinforcing bars inside the extended beams of the cantilever beams at both ends. This ensures that the newly widened floor slab is firmly and reliably connected to the sealing beams, the newly added inter-column frame beams, and the extended beams of the cantilever beams on both sides. This ensures that after pouring, the load of the newly widened floor slab can be transferred to the surrounding frame beams and further to the frame columns, ensuring the safety of the newly widened floor slab during later use. The concrete pouring of the new columns, the new inter-column frame beams, the extended beams of the cantilever beams, the newly widened floor slab, and the new walkway railing is carried out sequentially. The newly poured columns provide effective support for the subsequently poured new inter-column frame beams and extended beams of the cantilever beams, which in turn provide effective support for the newly widened floor slab, ensuring the load-bearing capacity of the widened floor slab.

[0096] This invention, by widening and extending the span of a reinforced concrete frame structure, provides more usable space, meets the functional requirements of the building, optimizes space utilization, improves the safety and integrity of single-span building structures, increases the stability and seismic resistance of the building structure, and reduces the safety hazard of structural overturning. This method is simple to implement, convenient to construct, has good seismic performance, and a high degree of industrialization. It maintains the integrity of the original structure, is relatively cost-effective, and effectively solves problems caused by inadequate geological surveys, substandard design, typhoons, earthquakes, and changes in people's functional requirements for building construction. It enhances the value and sustainability of buildings, extends their service life, and conforms to the principles of sustainable development and carbon neutrality. Applying this method to the field of building reinforcement can generate significant economic and social benefits.

Claims

1. A method for widening and remodeling a reinforced concrete frame structure, characterized in that, Includes the following steps: Step 1: Excavate the ground on one side of the expansion span down to the bottom of the foundation; Remove the original walkway railing (22), excavate the ground on one side of the span to the bearing layer of the existing foundation bottom surface, expose the foundation, and inspect the foundation. At the same time, after ensuring that the foundation is not damaged or destroyed, proceed to step two. Step 2: Add new independent foundations under the columns on the outside of the connecting corridor (1); S21: Determine the location of the multiple new independent foundations (1) to be added under the columns on the outer side of the corridor, and ensure that the location of the multiple new independent foundations (1) corresponds one-to-one with the multiple original independent foundations (5) near the side of the extension. S22: Pour foundation pad concrete at the location of the determined new column independent foundation (1), and vibrate the pad concrete during the pouring process to make it dense; S23: First, tie the reinforcing bars of the new independent foundation (1) under the column, then install the pouring form of the new independent foundation (1) under the column, then pour the concrete of the new independent foundation (1) under the column, and ensure that the height of the new independent foundation (1) under the column is consistent with that of the original independent foundation (5) under the column. After the curing is completed, remove the pouring form. Step 3: Extend the original foundation beam of the original independent foundation (5) under the column, and add a new foundation beam (6) and a new ground floor slab (4). S31: Extend the original foundation beam of the original independent foundation (5) in the direction of the corresponding new independent foundation (1) to form a foundation beam extension beam (2), and use the foundation beam extension beam (2) to connect the original independent foundation (5) and the corresponding new independent foundation (1). S32: A new foundation beam (6) is set between each pair of adjacent new column independent foundations (1) to connect the two adjacent new column independent foundations (1); S33: Pour a new bottom floor slab (4) between the new independent column foundation (1) and the original independent column foundation (5), and ensure that the steel bars inside the new bottom floor slab (4) are inserted into the inside of the top of the original independent column foundation (5) and the inside of the top of the new independent column foundation (1); Step 4: Install four sets of vertical support mechanisms under the original cantilever beams (7) on each floor; Four adjustable brackets (25) are installed securely and stably along the length of the original cantilever beam (7) on the floor slab below the original cantilever beam (7). Four upright supports (13) are then installed on the four adjustable brackets (25), ensuring a secure and stable connection between the upright supports (13) and the adjustable brackets (25). Next, four adjustable brackets (18) are installed on the upper ends of the four upright supports (13), ensuring a secure and stable connection between the adjustable brackets (18) and the upright supports (13). Then, four short steel pipe supports (8) are installed between the four adjustable brackets (18) and the original cantilever beam (7), and four pads are embedded between the four short steel pipe supports (8) and the four adjustable brackets (18). 2 (10), four pads 1 (9) are embedded between the four short steel pipe supports (8) and the lower end face of the original cantilever beam (7), and ensure that the two ends of the short steel pipe supports (8) are stably abutted between the upper end of the adjustable support 1 (18) and the lower end face of the original cantilever beam (7) through the pads 2 (10) and the pads 1 (9); the pads 1 (9), short steel pipe supports (8), pads 2 (10), adjustable support 1 (18), upright support 1 (13) and adjustable support 2 (25) are connected from top to bottom to form a vertical support mechanism 1, and the four sets of vertical support mechanisms 1 formed are used to stably support the original cantilever beam (7), and at the same time, the four short steel pipe supports (8) serve as the main skeleton of the part to be raised below the original cantilever beam (7); Step 5: Erect the casting formwork for the new beams and slabs; Using multiple sets of vertical support mechanisms, the casting template of the cantilever beam extension beam (14) is set up in the extension direction of the original cantilever beam (7), and the casting template of the new inter-column frame beam (11) is set up at the position between the ends of the adjacent cantilever beam extension beam (14) corresponding to the original frame beam (12), and ensure that the two ends of the cantilever beam extension beam (14) are connected to the original cantilever beam (7) and the new inter-column frame beam (11); Using multiple sets of vertical support mechanisms, the casting formwork for the newly widened floor slab (20) is partially supported between the sealing beam (24) and the newly added inter-column frame beam (11), and the casting formwork for the new walkway railing (21) is supported above the newly added inter-column frame beam (11). Step Six: Tie the reinforcing bars of the newly added beam; S61: First, roughen the bottom surface (15) of the original cantilever beam and the outer contact surface (26) of the web of the original cantilever beam. Then, tie the first stirrup (17) to the outside of the main frame of the part to be heightened below the original cantilever beam (7) and anchor the first stirrup (17) into the interior of the original cantilever beam (7). Then, tie the second stirrup (16) to the part of the corresponding cantilever beam extension beam (14) and tie the first longitudinal steel bar to the part of the corresponding extension beam top and bottom. At the same time, insert the first longitudinal steel bar into the interior of the original cantilever beam (7). S62: First, tie the stirrups three in the part of the corresponding newly added inter-column frame beam (11), and then tie the longitudinal reinforcement two in the part of the upper and lower sides of the corresponding frame beam. Step 7: Install square steel plates (3) as shear keys on the contact surface between the original cantilever beam (7) and the cantilever beam extension beam (14); A square steel plate (3) is horizontally installed at the contact surface between the original cantilever beam (7) and the cantilever beam extension beam (14), and one section of the square steel plate (3) is horizontally inserted into the interior of the original cantilever beam (7), and the other section of the square steel plate (3) is horizontally inserted into the steel bars inside the cantilever beam extension beam (14), and structural adhesive is injected at the rebar insertion site to utilize the square steel plate (3) as a shear key; Step 8: Tie the reinforcing bars of the newly added slab; S81: First, roughen the outer contact surface (19) of the original sealing beam, and tie longitudinal reinforcing bars to the top and bottom of the corresponding newly widened floor slab (20). At the same time, insert the longitudinal reinforcing bars into the reinforcing bars inside the sealing beam (24) and the newly added inter-column frame beam (11). Then, tie transverse reinforcing bars to the top and bottom of the corresponding newly widened floor slab (20). At the same time, insert the transverse reinforcing bars into the reinforcing bars inside the cantilever beam extension beam (14) at both ends. S82: First, tie vertical steel bars on both sides of the corresponding new walkway railing (21) and insert the ends of the vertical steel bars into the steel bars inside the newly added inter-column frame beam (11) of the adjacent connection. Then, tie horizontal steel bars on both sides of the corresponding new walkway railing (21) and tie tie bars at the double-row vertical steel bars. Step 9: Tie the reinforcing bars of the newly added column (23); Tie the vertical steel bars and stirrups of the new column (23) below the connection between the cantilever beam extension beam (14) and the newly added inter-column frame beam (11), and connect the upper end of the vertical steel bars in the new column (23) with the longitudinal steel bar one in the cantilever beam extension beam (14) and the longitudinal steel bar two in the newly added inter-column frame beam (11), so that the lower end of the vertical steel bars in the new column (23) is inserted into the inside of the top of the independent foundation under the new column or into the inside of the top of the new column (23) below. Step 10: Erect the formwork for the new column (23) and pour the concrete for the new beam, slab and column; At the construction location of the new column (23), a support frame is erected, and the precast slab of the column formwork is installed on the support frame. The column formwork is then fixed on the support frame with connectors. Then, the concrete of the new column (23), the new inter-column frame beam (11), the cantilever beam extension beam (14), the new widened floor slab (20), and the new walkway railing (21) is poured in sequence. Step 11: After the concrete has cured to the design strength, remove the formwork and dismantle the supports; After the concrete has cured to the designed age, the formwork should be removed first. The formwork removal order is column side formwork, slab bottom formwork, beam side formwork, and beam bottom formwork. Then, the concrete strength test should be carried out. After the concrete strength test is qualified, the supports should be removed. Step 12: Starting from the first floor, perform steps 4 through 11 layer by layer from low to high, repeating the work in sequence until the widening work of all floors is completed.

2. The method for widening and remodeling a reinforced concrete frame structure according to claim 1, characterized in that, In step S41 of step four, the support strength of each set of vertical support mechanisms is adjusted by extending and retracting the adjustable support one (18) and the adjustable support two (25) to ensure that the original cantilever beam (7) can be stably supported.

3. A method for widening and remodeling a reinforced concrete frame structure according to claim 1 or 2, characterized in that, In step S41 of step four, the four upright supports (13) are connected by multiple transverse connecting rods and form an integral support after connection.

4. The method for widening and remodeling a reinforced concrete frame structure according to claim 3, characterized in that, In step five, both vertical support mechanisms two and three consist of adjustable support three, upright support two, and adjustable support four connected sequentially from top to bottom.

5. A method for widening and remodeling a reinforced concrete frame structure according to claim 4, characterized in that, The adjustable support 1 (18), adjustable support 2 (25), adjustable support 3, and adjustable support 4 have the same structure, each consisting of a top fixed support, a bottom fixed support, and a middle adjusting rod. The top fixed support consists of an upper support block and an upper support sleeve fixedly connected to the lower center of the upper support block; the upper support sleeve has an internal thread structure 1 inside. The bottom fixed support consists of a lower support block and a lower support sleeve fixedly connected to the upper center of the lower support block; the lower support sleeve has an internal thread structure 2 inside. The middle adjusting rod consists of an adjusting block located in the middle and a relative... The upper threaded rod and the lower threaded rod are fixedly connected to the center of the upper end and the center of the lower end of the adjusting block; the middle adjusting rod is set between the top fixed support and the bottom fixed support, and the upper threaded rod is inserted into the inside of the upper support sleeve through threaded engagement, and the lower threaded rod is inserted into the inside of the lower support sleeve through threaded engagement; a cylindrical mounting groove is opened at the center of the lower part of the lower support block, and an internal thread structure is provided in the mounting groove; an external thread structure is provided on the outer side of the upper end of the upright support one (13); the mounting groove of the lower support block is fixedly fitted onto the outer side of the upper end of the upright support one (13) through threaded engagement.

6. The method for widening and remodeling a reinforced concrete frame structure according to claim 5, characterized in that, In step one, the foundation is first reinforced. Step two is then carried out only after the bearing capacity and stability of the foundation meet the requirements for the widening and reconstruction.

7. A method for widening and remodeling a reinforced concrete frame structure according to claim 6, characterized in that, In step two, ensure that the base area of ​​the new column independent foundation (1) is greater than the base area of ​​the original column independent foundation (5).

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