Floor reinforcement construction method for old building renovation

Abstract

The present invention relates to a floor reinforcement construction method for old building renovation. While preserving the original appearance of exterior walls, the interior floors of a building can be demolished and reconstructed, interior walls are completely demolished, and a pile foundation, frame columns and frame beams are newly added to form a support frame system, thereby completing the conversion of a load-bearing system, and solving the problem of most conventional masonry structure construction methods not changing a structural load-bearing system of a building. The method of the present invention prolongs the service life of a building, and reduces the cost of demolition and reconstruction; besides, by means of optimizing a construction process, the construction period is shortened, and the efficiency and safety of the construction process are ensured. The method has wide application prospects.

Description

Old building reconstruction floor reinforcement construction method TECHNICAL FIELD

[0001] The present application relates to the technical field of building construction, in particular to an old building reconstruction floor reinforcement construction method. BACKGROUND

[0002] With the acceleration of urban renewal process, the supporting facilities of historical and cultural buildings gradually lag behind, the applicability decreases, the coordination with the surrounding environment decreases, the protection and updating of historical buildings are imminent, and the structural safety and overall stability have also been significantly reduced. Such buildings generally have safety hazards such as decreased load-carrying capacity and insufficient seismic grade. In order to ensure the safe use performance of the building, it needs to be systematically reinforced and reconstructed.

[0003] Traditional building-based reinforcement methods such as increasing section method and external steel reinforcement method can improve the bearing capacity, but also expose some defects in actual application. First, a large area of the original structure needs to be demolished during construction, resulting in a high loss rate of the internal space of the building. Secondly, the new and old structure coordination mechanism is weak, especially when the frame beam column joint is reinforced, there is a stress discontinuity phenomenon. In addition, the traditional masonry reinforcement method does not change the original stress system and the functional division of the internal space, and reinforces the original brick masonry engineering with reinforced concrete surface and cement mortar surface, but such reconstruction does not cause qualitative change to the building properties. In addition, although the patent "CN119373334A" discloses a steel frame overall replacement scheme, it still lacks a systematic solution for the reconstruction of the space after the removal of the non-load-bearing interior wall, the reinforcement and protection of the remaining exterior wall, and the construction of the concealed reinforcement system. Therefore, it is necessary to research an old building reconstruction floor reinforcement construction method. SUMMARY

[0004] In view of this, the purpose of the present application is to provide an old building reconstruction floor reinforcement construction method, which effectively solves the contradiction between the interior wall removal and structural reinforcement in the prior art, and overcomes the problems of concealed reinforcement system construction, exterior wall in-situ reinforcement protection, and frame joint.

[0005] In order to achieve the above object, the technical scheme adopted by the present application is: a construction method for reinforcing floors of old buildings, comprising the following steps: Step 1: new foundation construction; according to the construction drawing, a frame column construction area is laid out, a cast-in-place pile is poured around the new frame column, the frame column is located in the middle of the surrounding frame columns, the inside main beam operation hole is constructed, the overlapping part of the main beam and the outer wall foundation is cut off, the operation surface of the overpass beam is reserved, the pile head of the over-poured pile is cut, the pile head reinforcement and the pile cap reinforcement are anchored, the foundation concrete is poured, the beam reinforcement is pre-buried, and the pile cap main beam concrete is poured; Step 2: wall surface cleaning and positioning; the inside wall surface of the outer wall is spaded flat, and a surveying reference is marked on the wall; based on the surveying reference, a frame beam construction area and a reinforced wall construction area are laid out according to the construction drawing, the reinforced wall construction area is marked with a reinforcing point, and the frame column construction area and the frame beam construction area are marked with a shear key construction point; Step 3: drilling treatment is performed on the shear key construction point and the reinforcing point, and the corresponding hole grooves are cleaned; then the shear key is planted in the shear key construction point; and the tieback reinforcement is planted in the tieback reinforcement point on the masonry, and the steel mesh is hung on the tieback reinforcement outside the wall; Step 4: reinforced wall construction; the reinforced wall outer form is supported outside the steel mesh, the grouting hole is opened in the upper floor slab, and the grouting hole is used to pour grout from top to bottom into the outer form to form a reinforced wall; Step 5: remove the outer form and erect the temporary support; the temporary support is erected around the frame column construction area, and the top support is supported to the upper floor slab; Step 6: based on the frame column construction area, a hole is cut at the top floor slab, the frame column reinforcement is bound and then lowered to the frame column construction area, and the frame column is formed by pouring construction from bottom to top in a segmented formwork and pouring manner; Step 7: frame beam construction; based on the frame beam construction area, a hole is opened in the inner wall, the frame beam reinforcement is bound in sections and placed in the frame beam construction area, the formwork is poured to form the frame beam, and the frame beam and the frame column are connected to form a reinforced support system; Step 8: remove the inner wall; the indoor temporary support and the interlayer floor slab are removed, the indoor inner wall is removed, and the remaining gap of the reinforced wall is repaired.

[0006] Further, after the cast-in-place pile construction in step 1 is completed, the indoor part of the foundation is excavated, the ground rigid hardening layer is cut off using a cutting machine, and then the inside main beam operation hole overpass beam construction is performed.

[0007] Further, when the overpass beam construction is performed, a groove is first opened in the wall using a cutting machine, the groove is 1 / 2 thick, then the overpass beam reinforcement and formwork work are performed in the groove, and C50 high-strength grouting material is poured; after the inside grouting strength reaches the preset strength, the same method is used to perform the outside overpass beam operation.

[0008] Further, in step 3, the shear key hole is opened on the outer wall by using the jump warehouse method; the self-compacting grouting material is mixed according to the proportion, and is injected into the formwork from the pre-reserved grouting port.

[0009] Further, after the completion of the shear key construction, the anchor bar is implanted in the anchoring point on the masonry outer wall, and the steel bar net is hung on the anchor bar extending out of the wall.

[0010] Further, in step 4, a grouting hole is opened at the position of the top floor before pouring the reinforced wall, and then C25 self-compacting fine stone concrete is used to pour the reinforced concrete from the grouting hole to form the reinforced wall, and the slump degree is 180-220mm.

[0011] Further, in step 5, the double-row support scaffold is erected to support the top floor, and the lower part is provided with a pad, and the upper part is fixed with a square wood to the bottom position of the floor by a top wire.

[0012] Further, in step 6, the static cutting method is used to open a hole at the position where the new frame column coincides with the top floor, and the hole size is 100mm larger than the cross-sectional size of the frame column, and the structure column steel bar is bound synchronously.

[0013] Further, in step 6, the frame column is constructed by the skip method, and the main concrete of the frame column at each position is poured and constructed in three batches, and after the pouring is completed, the top of the frame column extends above the top floor.

[0014] Further, in step 7, the frame beam is arranged along the inner edge of the outer wall at the position corresponding to the frame column above the floor, and the frame beam is synchronously poured and constructed with the frame column, and after the construction of the new frame beam and the frame column is completed, the outer wall and the new structure are connected as a whole, and after the stress form is changed, the original indoor wall of the building is removed.

[0015] The beneficial effects of the above technical solution are: the old building reconstruction floor reinforcement construction method provided by the application adopts the technical route of "internal demolition and external protection", that is, the internal non-load-bearing wall of the building is completely removed, and the main load-bearing components such as the outer wall, the frame column and the frame beam are systematically reinforced, and finally the reinforced system is completely covered in the retained outer wall structure. This transformation method not only can significantly improve the overall structural strength of the building and meet the safety requirements of the current specification, but also can maximize the historical features of the building, realize the dual goals of building function improvement and historical value protection.

[0016] The reconstruction and removal method provided by the application can change the residential property building into a commercial property building under the premise of retaining the original appearance of the outer wall, remove all the internal walls, add pile foundations, frame columns and frame beams to form a support frame system, complete the conversion of the stress system, solve the problem that the traditional masonry structure construction method does not change the structural stress system, and the method can be widely applied under similar construction conditions and environment, and has wide application prospect.

[0017] In addition, the invention sets up a support column beam and a constructional tension beam between the pile caps, forms a net foundation structure, can redistribute the load through the bending stiffness of the beam when the foundation is unevenly settled, avoids overloading of a single pile, and the redundant design enhances the adaptability of the system to foundation deformation. The newly built reinforced concrete reinforcing wall not only bears the vertical load, but also is anchored with the frame column through horizontal reinforcement to form a double lateral force resisting system, and under the action of earthquake or wind load, the two work together, the dynamic response is optimized through the combination of different stiffness components, and finally the safety and durability are doubled in the functional reconstruction of historical buildings.

[0018] In the application, the new structure is a concrete frame structure, and a set of reinforcing construction method suitable for masonry structure is innovated by means of adding new beams, shear keys, planting reinforcement, pre-burying tension bolts in the original outer wall hole and the like, only the outer wall is reserved and reinforced, and the inner wall is completely removed, so that the three-story residential building of the original building is reconstructed into a two-story commercial building, and the reinforcing construction method of the existing historical building changing the whole stress system is changed.

[0019] The reinforcing construction method provided by the application prolongs the service life of the building under the condition that the disturbance to the original outer wall structure is minimum, reduces the cost of demolition and reconstruction, and through optimization of the construction process, the construction period is reduced, the efficiency and safety of the construction process are ensured, the seismic grade of the reinforced building is significantly improved, the building can better adapt to the seismic requirements of modern buildings, and an innovative solution is provided for the protective reconstruction of historical buildings in urban renewal. BRIEF DESCRIPTION OF DRAWINGS Fig. 1 is a schematic diagram of the cross-sectional structure of an embodiment of the application; Fig. 2 is a schematic diagram of the arrangement of foundation construction piles; Fig. 3 is a cross-sectional view of foundation construction earth excavation; Fig. 4 is a schematic diagram of the cross-sectional structure of beam construction; Fig. 5 is a schematic diagram of the layout of the reinforcing wall steel mesh; Fig. 6 is a schematic diagram of the construction structure of the reinforcing wall concrete pouring; Fig. 7 is a schematic diagram of the front view of the erected temporary support structure; Fig. 8 is a schematic diagram of the cross-sectional comparison of the old building before and after construction.

[0020] Reference signs: 1-outer wall, 2-reinforcing wall, 3-frame beam, 4-frame column, 5-roof, 7-pile, 8-new floor, 9-concrete pile cap, 10-concrete coupling beam, 11-shear key, 12-two-story floor, 13-temporary support. DETAILED DESCRIPTION

[0021] The application will be described in further detail below with reference to the drawings and specific embodiments: Embodiment 1, the embodiment aims to provide a method for reinforcing construction of old building reconstruction floors, mainly applicable to protective reinforcement engineering of historical masonry buildings, specifically, the internal wall structure of old masonry buildings is demolished and the external wall is reinforced, so that the old brick-concrete building internal structure is reconstructed and replaced under the premise of basically not changing the original appearance of the external wall, only the external facade wall is retained, a reinforcing wall is arranged on the inside of the building external wall (indoor), and the excess internal wall is demolished, so as to meet the structural requirements and functional needs of modern commercial use, relatively completely retain the original appearance of the external wall of the old building, significantly improve the overall structural strength of the building, and maximize the historical features of the old masonry building, effectively reducing the disturbance to the original building structure.

[0022] The old building reconstruction floor reinforcing construction method provided by the embodiment, as shown in FIG. 1, mainly aims to reinforce and demolish the original three-story building structure, retain and reinforce the external wall, and demolish the internal wall, so that the three-story residential building of the original building is reconstructed into a two-story commercial building. The embodiment takes the first floor as an example for introduction, and specifically includes the following construction steps: Step 1: new foundation construction; according to the original building structure status surveyed in advance, first, a bored pile method is used to perform pile foundation construction, according to the position of the frame column marked on the drawing in advance, the bored pile 7 is poured around the new frame column, so that the frame column 4 is located in the middle of the four surrounding frame columns, as shown in FIG. 2.

[0023] Then, the indoor part of the foundation is excavated, a cutting machine is used to cut the ground rigid hardening layer, and then the inside main beam operation hole lintel construction is performed. The lintel structure is specifically implemented by using a cutting machine to groove the external wall 1 / 2 thick inside the wall, then performing reinforcement, formwork work, and pouring C50 high-strength grouting material in the slot, as shown in FIG. 4. After the inside grouting strength reaches the preset strength, the same method is used to excavate the outside soil and perform the outside lintel construction, and angle steel lintel construction is performed at the outside of the external wall corner position. In addition, before the lintel construction, a settlement observation nail is arranged at 300 mm above the lintel, and in the embodiment, four settlement observation nails are arranged in a rectangular structure above the lintel, so as to avoid the local settlement of the original building structure due to the large amount of structure beam construction at the external wall foundation position before the hole is opened for operation, and thus the settlement amount of the building construction process is monitored through the settlement nail observation data.

[0024] Referring to FIGS. 2 and 3, after the overall construction of the lintel above the outer wall opening is completed, subsequent opening construction is performed; the overlapping part of the main beam and the outer wall foundation is cut off, an operation surface for the construction of the lintel is reserved, at the same time, the pile head is cut off, the pile head reinforcement is anchored with the pile top reinforcement, the foundation concrete is poured by using the brick formwork, then the foundation slab and the beam reinforcement are bound, the reinforcement of the two side structure beams is punched and anchored to the slab through the wall, after the construction is completed, the brick formwork is secondly built, the outer side is backfilled while being built, after the construction of the slab and the beam reinforcement is completed, the frame column position is measured and set on the reinforcement beam, the frame column reinforcement is anchored into the foundation beam according to the design requirements, at the same time, the concrete coupling beam 10 reinforcement is pre-buried, finally, the concrete is poured to the position of the lintel, and at this time, only the concrete of the slab and the main beam is poured. After the construction of the newly-built reinforcement body on the inner side of the first floor outer wall is completed, the opening construction of the remaining structure beam of the slab foundation is performed, the brick formwork, reinforcement binding, concrete pouring, curing and earthwork backfilling of the beam are performed according to the elevation required by the drawing.

[0025] The new foundation structure of the present application passes through the part of the outer wall of the original building, the formwork is cancelled, and only the brick formwork is built inside and outside the wall, which realizes the reduction of the opening area of the outer wall and the excavation area of the foundation soil while effectively ensuring the construction of the structure. Moreover, the cast-in-place concrete lintel is made twice inside and outside the room before the opening construction of the outer wall of the original building, which avoids the change of the stress form of the building caused by the one-time opening of the lintel opening, and reduces the disturbance of the whole lintel construction process to the building.

[0026] In this step, after the indoor and outdoor bored piles are constructed, the pile foundation slabs are connected through the coupling beam passing through the outer wall of the original building, the cast-in-place concrete lintel is made before the opening construction of the outer wall, which effectively ensures the stability of the outer wall foundation structure, and then the lintel opening and the reinforcement binding and concrete pouring of the slab are completed, which completes the construction of the newly-built pile foundation structure of the historical building.

[0027] In this embodiment, the newly-built structure foundation is a pile foundation; the foundation is composed of single-pile slabs and column-raising beam beams, specifically, for example, according to the structural characteristics of the original building, there are 18 foundation slabs in this embodiment, and the 18 foundation slabs are raised by 4 piles and 1 frame column, 3 foundation slabs are raised by 6 piles and 2 frame columns, and one slab is raised by 10 piles and 4 frame columns, and the column-raising beam beams between the bottom bored piles and the concrete slabs on the top of the piles are used as the foundation to support the frame columns above.

[0028] Step 2: wall cleaning and line laying; the inside wall of the outer wall 1 is removed, and after the wall is basically removed clean, the wall is washed with a high-pressure water gun; before construction, the axis and structure line are marked on the wall as the construction stage of the measurement reference, and based on the measurement reference, the frame column construction area, the frame beam construction area, and the reinforced wall construction area are laid out according to the construction drawing, and the reinforced wall construction area is marked with the embedded steel bar point, including the horizontal steel bar, the vertical steel bar and the tie steel bar laying position, and the shear key construction point is marked in the frame column construction area and the frame beam construction area.

[0029] Step 3: drilling treatment is performed on the shear key construction point and the embedded steel bar point, and the corresponding hole groove is cleaned; then the shear key is implanted in the shear key construction point, and in this embodiment, the shear key construction point is arranged on the masonry wall corresponding to the frame column and the frame beam, and is uniformly and spacedly arranged to ensure the stability of the outer wall.

[0030] When the shear key 11 is constructed, first, after the building elevation line and the axis are measured and introduced into the indoor wall, the frame column and the frame beam position line are laid out, the beam and column size line is laid out, and then the shear key position and size are marked on the wall according to the drawing. After that, the construction personnel cut and chisel around the shear key to ensure that the shear key hole size meets the requirements and to avoid deep construction as much as possible. After the shear key steel bar is pre-assembled, the formwork is supported, and a circular hole is opened in the middle of the formwork to facilitate the exposure of the shear key steel bar, and the formwork is fixed to the outer wall.

[0031] Then the mixed self-compacting grouting material (50 kg of grouting material is added with 5-6 kg of water, that is, 12% of water) is injected into the shear key formwork from the pre-prepared grouting port, and after the self-compacting grouting material is solidified, the formwork is removed and the surface is treated. It should be noted that when the shear key is opened, it cannot be done at one time, and the shear key holes corresponding to the frame beam and the frame column are divided into two times, and the construction is carried out by skipping the warehouse, that is, the holes are spaced apart, and after the first time the shear key is grouted and the strength reaches the requirement, the second time the hole is opened for construction.

[0032] After the shear key construction is completed, the tie steel bar is implanted in the embedded steel bar point on the masonry outer wall, and the steel mesh is hung on the tie steel bar extending out of the wall. In specific implementation, the position of the tie steel bar is marked according to the requirements, the hole is drilled and implanted into the original wall masonry, and the actual wall surface is treated according to the requirements. This embodiment provides a description of a method of implanting a steel bar, for example, full-length gluing within the thickness of the wall, and the implanting depth of the steel bar is 120 mm, the first row of steel bar is 80 mm away from the beam edge, the column edge and the window edge, and the steel bar spacing is 500 mm in principle, for example, if the distance between the window edge and the column is less than 500 mm, two rows of steel bars are implanted, and if the distance is less than 1000 mm, three rows of steel bars are implanted, and the like.

[0033] After the tie bar is implanted, the horizontal and vertical steel bars are bound in advance. The spacing of the vertical and horizontal steel bars is 250 mm in principle, which can be adjusted according to the actual situation. The horizontal steel bars of the reinforced concrete wall are anchored into the frame column, and the vertical steel bars are anchored into the frame beam, as shown in FIGS. 5 and 6.

[0034] Step 4: Reinforced wall construction; a reinforced wall outer form is provided outside the steel mesh. In order to ensure the accuracy of the shear wall thickness, 14 mm steel bars (length 150 mm, 180 mm) are used as formwork supports on the outer side of the steel mesh, with a spacing of 600*700 mm. The shear key 11 is opened at the side formwork of the frame column 4 and the frame beam 3, and the reserved steel bars are inserted and sealed. If a window is encountered, a side form is made around the window, i.e. the formwork gap is sealed with double-sided adhesive tape and foam clamps to prevent concrete from running during pouring. The back of the formwork is supported by double 40*80 mm wooden bars with a spacing of 300 mm, and horizontal steel pipes with a spacing of 450 mm are used to support the formwork on the inner wall. After the formwork construction is completed, it is inspected and accepted before pouring concrete.

[0035] Before pouring concrete, a grouting hole is opened above the top floor slab, and the reinforced wall 2 is formed by grouting from the top to the bottom of the outer form. Further, commercial C25 self-compacting fine aggregate concrete is used for pouring, with a slump of 180-220 mm. The concrete is continuously poured before initial setting, and one layer of reinforced concrete wall is poured to the bottom of the second floor slab at a time, as shown in FIG. 6.

[0036] Step 5: Remove the reinforced wall outer form and erect temporary support; a scaffold temporary support 13 is erected around the frame column construction area, and the top support is extended to the second floor slab 12. The temporary support is erected as shown in FIG. 7, and a double-row scaffold support is erected with a steel pipe in the frame column construction area, with a vertical distance of 600 mm and a horizontal distance of 900 mm. A pad is provided at the bottom of the support, and a square wood is fixed to the floor bottom position by a top wire at the top. Step 6: Frame column construction; the position and spacing of the column are determined based on the structure and load requirements of the building, to ensure that the column can bear and transfer the load and form a frame column construction area. Then, based on the frame column construction area, a static cutting method is used to open a hole at the position where the new frame column and the original second floor slab overlap, with a size of 100 mm larger than the cross-sectional size of the column. Then, the frame column steel bars are bound and lowered to the frame column construction area, with the top extending above the second floor slab. Then, a segmented formwork and segmented pouring method is used to pour and construct from bottom to top, forming a frame column 4.

[0037] M14 opposite pull bolts embedded in the reinforced wall at the column position are used to fix firmly during the framework column formwork setting, and one jump one construction is adopted, first, the positions of indoor framework columns are numbered, then concrete pouring is carried out according to the order of even first and then odd or odd first and then even; and during pouring, the principle of segmented pouring is adopted, for example, the first time pouring is carried out to 1.5m, the second time pouring is carried out to 3.2m above the beam bottom, the third time pouring is carried out to 3.7m, and the framework beam is poured at the same time, and after pouring, the framework column is removed.

[0038] Step 7: framework beam construction; in the above step 6, the framework column is constructed in sections, and the third time framework column concrete pouring is above the second floor slab, before the third time concrete pouring, first, the steel bar binding and formwork setting of the framework column are carried out, based on the preset framework beam construction area, a hole is opened on the inner wall, the framework beam steel bar is bound in sections and placed in the framework beam construction area, so that the third time framework column and the framework beam 3 are constructed at the same time, so that the formed framework beam and the framework column correspond and connect to form a reinforced support system.

[0039] Step 8: according to the above steps 2-7, the same construction process as the first floor is adopted to reinforce the second floor, the third floor and the roof 5, after the corresponding reinforcement is removed, the second floor new floor slab 8 is constructed, finally the indoor temporary support and interlayer floor slab are removed, the original second floor inner wall and floor slab are removed and construction waste is cleaned, and the scaffold system is removed at the same time; finally, the remaining structural wall gap repair construction is carried out, and the modified building structure is shown in Figure 8.

[0040] The old building reconstruction floor reinforcement construction method provided by the application adopts the technical route of "internal removal and external protection", that is, the non-load-bearing wall in the building is removed as a whole, and the main load-bearing members such as the outer wall, the framework column and the framework beam are systematically reinforced, and finally the reinforced system is completely wrapped in the retained outer wall structure. This reconstruction method not only can significantly improve the overall structural strength of the building and meet the safety use requirements of the current specification, but also can maximize the historical features of the building, realize the dual goals of building function improvement and historical value protection.

[0041] Further, through the reconstruction construction method of the application, a set of efficient, stable and collaborative stress system is formed, the reinforced wall is used as the main vertical load-bearing member, and the upper load is uniformly distributed to the foundation beam; the foundation beam transmits the load to the framework column through the pull beam system, and finally the load is borne by the deep bored pile, the newly applied load is transmitted step by step through the reinforced wall, the foundation beam, the framework column and the bored pile, the path is clear and the levels are distinct, this layered transmission mechanism avoids local stress concentration and improves the overall bearing efficiency.

[0042] The embodiment 2, the above embodiment 1 is only for the construction of a building structure, the embodiment is introduced to the operation of the second floor and the third floor in the step 8 in the embodiment 1, the construction mode of the second floor reinforced concrete reinforcing body, frame column and frame beam is same with the construction method of the first floor in the embodiment 1, and it needs to be noted that, after the construction of the frame beam and the frame column of the second floor and the third floor of the original building is completed, in order to ensure the stability of the whole structure when the interior wall is removed, the temporary steel structure support is installed first, and then the interior wall is removed. Then the inner wall, such as the T-shaped wall, is removed, the wall surface needs to be cleaned, the two sides are chiseled, the formwork is set after cleaning, the micro-expanding concrete is used for secondary pouring, the two sides of the inner wall reinforced concrete body are connected into a whole, before the original second floor slab is removed, the roof frame beam scaffold formwork is removed first, after the formwork and scaffold are removed and cleaned, the prefabricated slab floor is removed first, after the crane is fixed to the prefabricated slab, the static cutting saw is used to cut along the inner side of the outer wall at the floor slab, so that it is disconnected with the building wall, and finally the garbage is cleaned and transported.

[0043] The above-mentioned embodiments of the application do not constitute a limitation on the protection scope of the application, and the basic idea of the application is to transform and replace the internal structure of the old brick-concrete building under the premise of basically not changing the original appearance of the outer wall, only the outer facade wall is retained, the reinforcing wall is arranged inside the building outer wall, the excess interior wall is removed, the pile foundation, frame column and frame beam are newly added to form a support frame system, the stress system is converted, and the overall structural strength of the building is significantly improved. Any modification, equivalent replacement and improvement within the spirit and principles of the application shall be included in the protection scope of the claims of the application.

Claims

1. A method for reinforcing floors during the renovation of an old building, characterized in that: Includes the following steps: Step 1: New foundation construction; According to the construction drawings, mark out the construction area of ​​the frame columns, pour cast-in-place piles around the new frame columns, so that the frame columns are located in the middle of the surrounding frame columns, carry out the construction of the inner main beam working opening lintel, cut off the overlapping part of the main beam and the outer wall foundation, reserve the lintel construction working surface, cut off the over-poured pile heads, then anchor the pile head steel bars to the pile cap steel bars, pour the foundation concrete, carry out the pre-embedding construction of tie beam steel bars, and pour the pile cap main beam concrete; Step 2: Wall cleaning and layout positioning; level the inner wall surface of the exterior wall and mark the reference benchmark on the wall; based on the reference benchmark, lay out the frame beam construction area and the reinforced wall construction area according to the construction drawings, mark the rebar installation points in the reinforced wall construction area, and mark the shear key construction points in the frame column construction area and the frame beam construction area. Step 3: Drill holes at the shear key construction points and rebar installation points, and clean the corresponding holes and slots; then insert shear keys at the shear key construction points; and insert tie bars at the rebar installation points on the masonry, and hang steel mesh on the tie bars extending out of the wall. Step 4: Construction of the reinforced wall; Set up the outer formwork of the reinforced wall on the outside of the steel mesh, open grouting holes in the upper floor slab, and inject grout from top to bottom into the outer formwork to form the reinforced wall; Step 5: Remove the outer formwork and erect temporary supports; erect temporary scaffolding supports around the construction area of ​​the frame columns, with the top supports extending to the upper floor slab; Step 6: Based on the frame column construction area, cut holes at the top floor slab, and after the frame column reinforcement is tied, lower it to the frame column construction area. Use segmented formwork and segmented pouring method to pour from bottom to top to form the frame column. Step 7: Frame beam construction; Based on the frame beam construction area, make openings in the inner wall, tie the frame beam reinforcement in sections, place them in the frame beam construction area, support the formwork and pour the concrete to form the frame beam. The frame beam and the frame column are connected to form a reinforcement and support system. Step 8: Interior wall demolition; remove the temporary interior supports and floor slabs, demolish the interior walls, and then repair any remaining gaps in the reinforced walls.

2. The method for reinforcing floors in the renovation of old buildings according to claim 1, characterized in that: After the construction of the cast-in-place piles is completed in step 1, the soil excavation of the indoor foundation is carried out, the rigid hardened layer of the ground is removed using a cutting machine, and then the construction of the lintel of the inner main beam working opening is carried out.

3. The method for reinforcing floors in the renovation of old buildings according to claim 2, characterized in that: During the construction of the lintel, a cutting machine is first used to cut a groove on the inner side of the wall, which is half the thickness of the outer wall. Then, the reinforcement and formwork of the lintel are carried out in the groove, and C50 high-strength grout is poured in. After the grout strength on the inner side reaches the preset strength, the outer lintel is constructed in the same way.

4. The method for reinforcing floors in the renovation of old buildings according to claim 1, characterized in that: In step 3, the shear key opening is made on the outer wall using the skip-fill method; the self-compacting grout is mixed according to the ratio and injected into the template through the reserved grouting port.

5. The method for reinforcing floors in the renovation of old buildings according to claim 4, characterized in that: After the shear key construction is completed, tie bars are inserted at the anchor points on the masonry exterior wall, and steel mesh is hung on the tie bars extending out of the wall.

6. The method for reinforcing floors in the renovation of old buildings according to claim 1, characterized in that: In step 4, before pouring the reinforced wall, grouting holes are opened at the top floor slab. Then, C25 self-compacting fine stone concrete is used to pour the reinforced concrete reinforced wall through the grouting holes, with a slump of 180-220mm.

7. The method for reinforcing floors in the renovation of old buildings according to claim 1, characterized in that: In step 5, a double-row, socket-type scaffolding is erected to support the top floor slab. When erecting the support, a pad is placed underneath, and square timber is fixed to the bottom of the floor slab with top screws.

8. The method for reinforcing floors in the renovation of old buildings according to claim 1, characterized in that: In step 6, a static cutting method is used to make an opening at the position where the newly built frame column coincides with the top floor slab. The opening size is 100mm larger than one side of the frame column cross-section, and the structural column reinforcement is tied at the same time.

9. The method for reinforcing floors in the renovation of old buildings according to claim 1, characterized in that: In step 6, the frame column is constructed using the skip-pour method, and the main concrete of the frame column at each location is poured in three batches. After the pouring is completed, the top of the frame column extends to the top floor slab.

10. The method for reinforcing floors in the renovation of old buildings according to claim 1, characterized in that: In step 7, a frame beam is installed above the floor slab at the location corresponding to the frame column, along the inner edge of the exterior wall. The frame beam and frame column are poured and constructed simultaneously. Once the construction of the new frame beam and frame column is completed, the exterior wall and the new structure are connected as a whole. Then, the demolition of the original interior walls of the building begins.

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