Design method for large space reconstruction of brick-concrete structure house

Abstract

The application relates to the technical field of building engineering reconstruction, and provides a design method for large-space reconstruction of brick-concrete structure houses, which comprises the following steps: S1, checking calculation of steel supports needed in reconstruction; S2, checking calculation of construction stages of U-shaped steel plates needed in reconstruction; S3, checking calculation of use stages of combined beams needed in reconstruction; and S4, design of other related components needed in reconstruction. The application checks and designs each component, and ensures the safety and reliability of construction.

Description

Technical Field

[0001] This invention relates to the field of building renovation technology, specifically a design method for large-space renovation of brick-concrete structure houses. Background Technology

[0002] Residents' demand for the renovation of living spaces in brick-concrete houses has increased significantly. Due to administrative factors and construction costs, the feasibility of complete demolition and reconstruction is low. Traditional large-space renovations can only achieve a single widening of the span or depth, which cannot fully meet people's needs for large-space renovations.

[0003] Traditional renovation methods suffer from several drawbacks: first, they lack scientific calculation and analysis, rendering them unsuitable for widespread application; second, their force transmission methods are unreasonable and fail to meet current standards; and third, their key construction steps are flawed, lacking safety guarantees. Therefore, to achieve truly meaningful large-space renovations of brick-concrete structures, it is urgent to propose a scientific and reliable design method, develop a frame combination form for this type of structure based on the design results, and summarize safe and convenient construction methods. Summary of the Invention

[0004] The purpose of this invention is to provide a design method for large-space renovation of brick-concrete structure houses, which can at least solve some of the defects in the existing technology.

[0005] To achieve the above objectives, embodiments of the present invention provide the following technical solution: a design method for large-space renovation of brick-concrete structure houses, comprising the following steps:

[0006] S1, begin with foundation construction.

[0007] S2, After the foundation construction is completed, the frame columns will be constructed.

[0008] S3. After the frame columns are constructed, openings are made in the load-bearing walls inside the building. Simultaneously, openings are also made in the floor slabs corresponding to these load-bearing walls. Steel supports are installed at these openings, positioned between the upper and lower longitudinal walls of the load-bearing walls.

[0009] S4. After the steel support construction is completed, the frame composite beams will be constructed. These frame composite beams will be located below the floor slabs of the building.

[0010] S5, finally remove the load-bearing wall.

[0011] Furthermore, foundation reinforcement or additional foundation treatment shall be carried out at the locations where load-bearing walls are to be demolished and frame composite columns are to be installed, and at the locations where new reinforced concrete columns are to be installed in the outward openings; new reinforced concrete columns shall be added in the outward expansions, and steel plates shall be pre-embedded at the beam-column joints; and frame composite columns shall be reinforced in the existing openings.

[0012] Furthermore, before constructing the frame composite beam, the wall surface layer at the location of the frame composite beam to be constructed is first removed, and the opening is made at the center of each precast slab of the floor panel.

[0013] Furthermore, the beam segment flush with the support is chiseled away, and the upper and lower longitudinal bars and stirrups of the frame composite beam are installed. The upper and lower longitudinal bars are welded to the reserved longitudinal bars and angle steel. An opening is made at the junction of the transverse wall and the longitudinal wall for the U-shaped steel plate of the frame composite beam to pass through.

[0014] Furthermore, the side plates of the U-shaped steel plate are positioned and marked, pre-embedded bolt holes are opened, steel plates on both sides of the U-shaped steel plate and tie rods are installed, and finally the bottom steel plate of the U-shaped steel plate is installed; after the newly added reinforced concrete column reaches the required strength, the formwork is removed, and the U-shaped steel plate is welded together with the pre-embedded steel plate of the newly added reinforced concrete column, the gusset plate of the frame composite column, and the stiffening plate.

[0015] Furthermore, concrete is poured into the frame composite beam and repeatedly vibrated with a vibrator until it is completely compacted; the pre-embedded bolts are tightened, and after the design strength is reached, the bolt ends are cut off, and the lower longitudinal wall is removed.

[0016] Furthermore, the original transverse walls of the load-bearing walls are removed to increase the bay opening, and the gaps between the frame composite beams are filled with precast slabs using high-strength polymer mortar or steel wedges.

[0017] Furthermore, the steel support used consists of two rigid planes, upper and lower, and four compression bars.

[0018] Compared with the prior art, the beneficial effects of the present invention are: to verify and design each component, ensuring safe and reliable construction. Attached Figure Description

[0019] Figure 1 A design flowchart for altering a large local space in a brick-concrete structure house, as provided in an embodiment of the present invention;

[0020] Figure 2 This is a schematic elevation view of the frame assembly form before the walls are removed, provided in an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of the frame assembly after the walls have been removed.

[0022] Figure 4 for Figure 2 AA section view;

[0023] Figure 5 for Figure 2 BB cross-sectional view;

[0024] Figure 6 for Figure 2 CC section view;

[0025] Figure 7 for Figure 2 DD sectional view;

[0026] Figure 8 Top view of the connection node between the angle steel and the upper and lower longitudinal bars;

[0027] Figure 9 A three-dimensional perspective view of the composite beam of the frame before the concrete was poured.

[0028] Figure 10 This is a three-dimensional schematic diagram of the steel support.

[0029] Figure 11 This is a side view of the embedded steel plate;

[0030] Figure 12 This is a top view of the embedded steel plate;

[0031] In the attached diagram, the following are the reference numerals: 1. Frame composite beam; 101. Concrete; 102. Bottom longitudinal reinforcement; 102a. Bottom longitudinal reinforcement of the reserved section; 103. Top longitudinal reinforcement; 103a. Top longitudinal reinforcement of the reserved section; 104. Stirrups; 105. Through bolts; 106. Equivalent reinforcement; 107. U-shaped steel plate; 107a. Side plate of the U-shaped steel plate; 107b. Bottom plate of the U-shaped steel plate; 109. High-strength polymer mortar or steel wedges; 2. Frame column; 2a. Newly added reinforced concrete column; 2b. Frame composite column; 3. Floor slab; 3a. Cast-in-place slab; 3b. Precast slab; 114. Steel support; 114a. Upper steel plate of steel support; 114b. Lower steel plate of steel support; 114c. Compression member; 121a. Stiffening plate of newly added column; 121b. Stiffening plate of frame composite column; 122. Embedded steel plate; 124. Angle steel; 125. Draping plate; 126. Embedded steel bar; 141. Pouring port; 4. Load-bearing wall; 4a. Upper longitudinal wall; 4b. Lower longitudinal wall; 4c. Existing transverse wall; 41. Transverse wall opening. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Please see Figures 1 to 12 This invention provides a design method for large-space renovation of brick-concrete structure houses, specifically comprising the following steps:

[0034] I. Calculation of steel support 114:

[0035] 1.1 Determine the stress model of steel support 114:

[0036] 1) In the first construction stage, steel support 114 is considered to bear all the loads. The loads in this stage mainly include the design value of the upper wall 4a line load, the design value of the floor slab 3 line load, and the design value of the construction live load. The load intensity q of the sub-load is calculated according to the relevant clauses of the "General Specification for Engineering Structures" GB55001-2021.

[0037] 2) A single steel support 114 is considered as a four-point support system formed by the upper and lower rigid planes 114a and four vertical members 114c. When embedded in the wall, it is considered as a compression member at both ends.

[0038] 3) No impacts or vibrations are allowed during the construction of large-space renovations, therefore loads generated by dynamic effects are not considered;

[0039] 4) Remove the wall within the beam height range. The load of the upper wall 4a is transferred to the lower wall 4b by the steel support 114. The steel supports 114 are arranged densely. The included angle of stress transfer is generally within the rigid angle range, so it can be exempted from verification.

[0040] 1.2 Compressive strength verification of a single steel support (114): qs / (4φa)≤[f]

[0041] In the above formula: q - distributed load intensity, unit kN / m; s - steel support spacing, unit m; φ - stability coefficient of steel support member, which can be approximately taken as 0.9~0.95; a - cross-sectional area of ​​steel support member, unit kN; f - compressive strength of steel support member, unit MPa;

[0042] 1.3 Verification of local compressive strength of the wall: qs≤ηγf t A

[0043] In the above formula: η - effective contact coefficient of the steel plate, which can be approximately taken as 0.7 to 0.9; γ - the coefficient for increasing the compressive strength of the masonry, which can be taken as 2 according to the relevant clauses of the "Code for Design of Masonry Structures"; f t - Design value of compressive strength of masonry; when no relevant data is available, the measured value can be used, unit: MPa; A - Cross-sectional area of ​​steel pad, unit: mm² 2 ;

[0044] II. Verification of U-shaped steel plate 107 during construction phase:

[0045] 2.1 Determine the stress model of U-shaped steel plate 107:

[0046] 1) Before the steel support 114 of the partial wall fails to be removed and the concrete strength has not reached the design strength, the second construction stage considers that the U-shaped steel plate 107 bears the entire load. The load in this stage mainly includes the design value of the line load of the upper wall 4a, the design value of the line load of the floor slab 3, the design value of the self-weight load of the steel plate 107, the design value of the self-weight load of the reinforced concrete 1, the design value of the self-weight load of the partial support 114, and the design value of the construction live load. The load intensity q of the sub-section is calculated according to the relevant clauses of the "General Specification for Engineering Structures" GB55001-2021.

[0047] 2) The bending capacity, shear capacity, local stability and deformation of the U-shaped steel plate 107 can be verified separately for the second construction stage as an inverted channel steel beam.

[0048] 3) After the inverted channel steel beam is filled with concrete, only the bending moment in the strong axis direction needs to be checked.

[0049] 3) Add stiffening plates at the beam supports to prevent instability caused by torsion of the beam end section; after the inverted C-shaped steel beam is filled with concrete, the concrete can effectively prevent instability caused by lateral displacement of the steel plate, so the overall stability does not need to be verified.

[0050] 4) For the local instability of the web of U-shaped steel plate 107 calculated as an inverted channel steel beam, the ratio of the unsupported width to the thickness of the compression flange of the box section steel beam between the two webs can be used as a reference in the current "Steel Structure Design Standard" (GB50017-2017) and "General Specification for Steel Structures" (GB55006-2021).

[0051] 5) Under the load during the construction phase, the U-shaped steel plate is in the elastic stage and cannot produce excessive deformation that would affect the use of the composite beam during the service phase. Therefore, its deformation is calculated based on the elastic method.

[0052] 2.2 Calculation of the bending capacity of U-shaped steel plate: M x / W nx ≤[f u ]

[0053] In the above formula: M x - Bending moment about the x-axis under construction stage loads, in N*mm; W nx - The net section modulus about the x-axis under construction stage loads can be found in the steel tool table, unit mm. 3 ;[f u A - Material strength and bending design value of the inverted channel steel, in MPa; A - Cross-sectional area of ​​the steel pad, in mm² 2 ;

[0054] 2.3 Shear bearing capacity calculation of U-shaped steel plate: VS / It w ≤[f V ]

[0055] In the above formula: V - shear force under load during construction stage, unit N; S - area moment of the gross section about the neutral axis above the calculated shear stress, which can be found in the steel profile tool table, unit mm. 3 I - Gross moment of inertia of the inverted channel beam, unit mm 4 ;t w -Thickness of the web of the inverted channel beam, in mm; [f] v - Material strength and shear design value of inverted channel steel, in MPa;

[0056] 2.4 Local stability calculation of U-shaped steel plate: b0 / t≤40*(235 / f) y ) (1 / 2)

[0057] In the above formula: b0 - width between webs, in mm; t - flange thickness, in mm; f y - Gross yield strength of inverted channel beam, in mm 4 ;t w -Thickness of the web of the inverted trough beam, in mm; f y - The material yield design value of the inverted channel steel, in MPa;

[0058] 2.5 Deformation calculation of U-shaped steel plate: △1=αM x l 2 / (E ss I)≤[△ lim ]

[0059] In the above formula: △1 - mid-span deflection, in mm; α - a coefficient related to support conditions and load type, which can be approximately taken as 0.104; L - span of the inverted channel steel, in mm; Ess - elastic modulus of the inverted channel steel, in MPa; △ lim - The deflection limit of the inverted channel steel can be taken from the allowable deflection value of the bending member in Table 4-2 of the current "Steel Structure Design Standard" (GB50017-2017).

[0060] III. Verification of Frame Composite Beam 1 during Service Stage

[0061] 3.1 After the concrete strength reaches the design requirements, the U-shaped steel plate and reinforced concrete are considered to work together to form a whole, forming a frame composite beam 1;

[0062] 3.2 Using YJK structural calculation software, appropriate composite beam specifications and dimensions were selected. The U-shaped steel plate-reinforced concrete beam was equivalent to a box-shaped concrete beam with a custom cross-section. The key step was to set the upper thickness of the box section to 0 and verify the internal forces and deformations of the composite beam during the service stage.

[0063] IV. Design of related components:

[0064] 4.1 Foundation and Substructure Design

[0065] After the renovation of the large space, the live load increased. The frame structure replaced the brick-concrete structure, and the foundation of the brick-concrete structure changed from strip footing under the wall to strip footing under the column. The original superstructure underwent additional deformation, and stress concentration occurred in the foundation and substructure. If the foundation and substructure do not meet the requirements after verification, the foundation can be reinforced with anchor static pressure piles, and the substructure can be reinforced by increasing the cross section. The specific design can be carried out according to the relevant clauses of the "Technical Specification for Reinforcement of Existing Building Foundations" JGJ123-2012.

[0066] 4.2 Frame Column Design

[0067] In the renovation of large spaces, to address the issues of insufficient compaction, poor integrity, and low construction efficiency when demolishing load-bearing walls, a frame composite column 2b reinforced with angle steel and self-compacting concrete is designed. The specific design can be carried out according to the relevant clauses of the "Technical Specification for Self-Compacting Concrete Reinforced Structures" DBJ-T13-150-2012.

[0068] Please see Figures 2-12 This invention provides a frame structure for the renovation of a large space in a brick-concrete structure house, characterized by: a frame composite beam 1, a floor slab 3, and frame columns 2; the frame composite beam 1 is set at the bottom of the original floor slab 3 and includes a U-shaped steel plate 107, concrete 101, upper longitudinal reinforcement 103, lower longitudinal reinforcement 102, stirrups 104, and through bolts 105; the floor slab 3 is a cast-in-place reinforced concrete slab 3a in the outer expansion bay and a precast reinforced concrete slab 3b in the original bay; the frame columns 2 are newly added reinforced concrete columns 2a in the outer expansion bay and frame composite columns 2b in the original bay.

[0069] As an optimized embodiment of the present invention, the joints of the upper longitudinal reinforcement 103 and the lower longitudinal reinforcement 102 of the frame composite beam 1 are set at the point of minimum stress, and all longitudinal reinforcements are pre-anchored in the newly added reinforced concrete column 2a in the outer expansion space.

[0070] Preferably, the anchorage length of the upper longitudinal reinforcement 103a and the lower longitudinal reinforcement 102a of the frame composite beam 1 into the cast-in-place frame column 2a of the original bay shall not be less than 12d, where d is the diameter of the stressed longitudinal reinforcement.

[0071] As an optimized solution of the present invention, the newly added reinforced concrete column 2a should be pre-embedded with steel plate 122. After reaching the strength, it should be welded with the U-shaped steel plate 107 of the frame composite beam 1 to form an integral whole. Finally, two stiffening plates 121a are added to the bottom 107b of the U-shaped steel plate and the side of the pre-embedded steel plate 122.

[0072] Preferably, the embedded steel plate 122 is composed of two L-shaped steel plates 122 that are flush together. Four embedded steel bars 126 are added to the inner side of the L-shaped steel plate in the direction of beam height and are anchored into the newly added reinforced concrete column 2a.

[0073] Preferably, there is a certain gap between the two L-shaped steel plates 122 of the pre-embedded steel plate to ensure that the bottom 107b of the U-shaped steel plate is firmly welded to the pre-embedded steel plate 122;

[0074] Preferably, the height of the stiffening plate can be set below the U-shaped steel plate 107 and above the lower edge of the embedded steel plate 122 by 25mm; the width is 1-3mm smaller than the thickness of the U-shaped steel plate 107 and the embedded steel plate 122; and the steel grade can be set to the minimum strength of the U-shaped steel plate 107 and the embedded steel plate 122.

[0075] Preferably, the frame composite column 2b is formed by external angle steel 124, horizontally added gusset plates 125, and internal self-compacting concrete.

[0076] As an optimized embodiment of the present invention, the U-shaped steel plate 107 of the frame composite beam 1 is welded to the angle steel 124 of the original frame composite column 2b to form an integral whole; the upper longitudinal reinforcement 103 and the lower longitudinal reinforcement 102 are bent to the surface of the angle steel 124 and welded to it on both sides, and the welding length shall not be less than 5d, where d is the diameter of the stressed longitudinal reinforcement; two stiffening plates 121b are added to the bottom 107b of the U-shaped steel plate and the gusset plate 125, and the three are welded to form an integral whole;

[0077] As an optimized solution of the present invention, the frame composite beam 1 and the frame composite column 2b are connected at the beam-column junction by using equivalent steel reinforcement 106 instead of gusset plate 125.

[0078] As an optimized solution of the present invention, before the lower wall 4b is demolished for construction, a transverse wall opening 41 with a width of 200mm to 250mm and a height of (beam height - slab thickness) is opened in the lower part of the precast slab 3b of the original bay in the frame composite beam 1, and a steel support 114 is added at the transverse wall opening 41 so that the steel support 114 can tightly support the precast slab 3b.

[0079] As an optimized solution of the present invention, before the lower wall 4b is demolished for construction, a 200mm×250mm pouring opening 141 is opened in the upper masonry wall 4a of the original bay of the frame composite beam 1, and is filled with grout 109 after all construction is completed.

[0080] Preferably, the width of the angle steel 124 of the frame composite column 2b must be more than 10mm wider than the width of the U-shaped steel 107, and the thickness of the angle steel must differ from the thickness of the U-shaped steel plate 107 by 2-5mm, so as to ensure the welding effect.

[0081] As an optimized embodiment of the present invention, there is a gap between the U-shaped steel plate 107 and the precast plate, which can be filled with high-strength polymer mortar or steel wedges; the strength of the high-strength polymer mortar 109 is not lower than M20, and the steel wedge is of type not lower than Q355B, with a thickness slightly greater than the gap thickness by 2-5mm.

[0082] Preferably, the weld between the embedded steel plate 122 and the reserved reinforcing bar 126 is in tension, and the steel support and the compression rod are in compression, with a weld height of 8mm.

[0083] Preferably, the steel support 114 is composed of two rigid planes 114a and four compression bars 114c; the rigid plane 114a is made of steel plate 114b, the thickness of the steel plate 114a shall not be less than 8mm, the width shall be 50mm to 80mm less than the beam width, the height of the steel plate 114a shall be 100mm greater than the width of the steel plate, and the strength grade shall be Q355B; the compression bars 114c are made of thick steel bars, the diameter shall not be less than 22mm, the length shall be based on the beam height and beam block, and the strength grade shall be HRB400.

[0084] This invention also provides a construction method for large-space renovation of a brick-concrete structure house, including the following steps: S1, first carry out foundation construction; S2, after the foundation construction is completed, construct the frame columns; S3, after the frame columns are constructed, open holes in the load-bearing walls inside the house, and at the same time, open holes in the floor slabs of the corresponding load-bearing walls, and install steel supports at the openings, the steel supports being located between the upper and lower longitudinal walls of the load-bearing walls; S4, after the steel supports are constructed, construct the frame composite beams, the frame composite beams being located below the floor slabs of the house; S5, finally demolish the load-bearing walls.

[0085] Specifically, foundation reinforcement or additional foundation treatment will be carried out at the locations where load-bearing wall 4b is to be demolished and frame composite column 2b is to be installed, and at the locations where new reinforced concrete columns 2a are to be installed in the outward-opening space; new reinforced concrete columns 2a will be added in the outward-opening space, and steel plates 122 will be pre-embedded at the beam-column joints; reinforcement construction of frame composite column 2b will be carried out at the original opening.

[0086] Specifically, the wall surface and plaster at the location of the pre-added frame composite beam 1 are removed, and an opening with a width of 200mm to 250mm and a height of (beam height - slab thickness) is made at the center of each precast slab 3b; steel supports 114 are added at the opening so that each steel support 114 can tightly support the precast slab 3b.

[0087] Specifically, the beam segment flush with the support is chiseled out, and the upper 103, lower longitudinal reinforcement 102, and stirrups 104 of the frame composite beam 1 are installed. The upper 103, lower longitudinal reinforcement 102 are welded to the reserved longitudinal reinforcement 103a (102a) and angle steel 124. At the junction of the transverse wall 4c and the longitudinal wall 4b, a 400mm×500mm transverse wall opening 41 is opened to ensure that the U-shaped side plate 107a can pass through.

[0088] Specifically, the U-shaped steel plate side plate 107a is positioned and marked, pre-embedded bolt holes are opened, the steel plates 107a on both sides of the U-shaped steel plate and the tie rods 105 are installed, and finally the bottom steel plate 107b of the U-shaped steel plate is installed; after the newly added reinforced concrete column 2a reaches the required strength, the formwork is removed, and the U-shaped steel plate 107 is welded together with the pre-embedded steel plate 122 of the newly added reinforced concrete column 2a, the gusset plate 125 of the frame composite column, and the stiffening plate 121b.

[0089] Specifically, concrete 101 is poured into the pouring port 141 and repeatedly vibrated with a vibrator until it is completely compacted. Then, grouting material is used to seal the pouring port 141. The pre-embedded screw is tightened. After the design strength is reached, the end of the screw is cut off and the lower wall 4b is removed.

[0090] Specifically, the original transverse wall 4c was finally removed to increase the bay opening. The gap between the precast slab 3b and the U-shaped steel plate 107 was filled with high-strength polymer mortar or steel wedges 109. All steel components were coated with anti-rust paint and fireproof paint.

[0091] Preferably, the welding sequence of the frame column and the frame composite beam is: side plate 107a of U-shaped steel plate → bottom plate 107b of U-shaped steel plate → stiffening plate 121a.

[0092] Preferably, the demolition sequence is: lower longitudinal wall 4b opening → lower transverse wall 4b opening → longitudinal wall beam segment → lower longitudinal wall 4b → original transverse wall 4c.

[0093] As an optimized embodiment of the present invention, this method can be applied to the simultaneous expansion of the bay and depth in the renovation of large spaces in brick-concrete buildings, realizing large-space renovation. This frame structure utilizes steel supports and U-shaped steel plates to fully support the stress characteristics of different construction stages, ensuring the construction quality of the supporting structure and the overall safety throughout the construction process. The steel plates in this frame-beam composite structure provide high tensile and compressive strength and can also constrain the concrete, improving its load-bearing performance. The concrete can prevent local buckling and overall instability of the beam, thereby increasing the beam's strength and reducing deflection. This construction method combines the stress characteristics of welding and dismantling parts to achieve an effective construction sequence, ensuring construction speed, and eliminating the need for scaffolding, making construction very simple.

[0094] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A design method for large-space renovation of brick-concrete structure houses, characterized in that, The steps include the following: S1, Verify the steel supports required for the renovation; S2, to verify the construction stage of the U-shaped steel plates required for the renovation; S3, verify the service stage of the composite beams to be used in the renovation; S4, design other related components needed for the renovation; In step S1, S10, First determine the force model of the steel support. S11, then the compressive strength of a single steel support is checked: qs / (4φa)≤[f], In the above formula: q - distributed load intensity, unit kN / m; s - steel support spacing, unit m; φ - Stability coefficient of the steel support member, taken as 0.9~0.95; a - Cross-sectional area of ​​the steel support member, in kN; f - Compressive strength of the steel support member, in MPa; S12, Next, the local compressive strength of the wall is checked: qs≤ηγftA, In the above formula: η - effective contact coefficient of steel plate, taken as 0.7~0.9; γ - enhancement coefficient of masonry compressive strength, taken as 2; ft - design value of masonry compressive strength, taken as measured value when no relevant data is available, unit MPa; A - cross-sectional area of ​​steel pad, unit mm. 2 ; In step S10, S101, In the first construction stage, the steel supports are considered to bear the entire load. The loads in this stage include the design values ​​of the upper wall line load, the floor slab line load, and the construction live load. Calculate the load intensity q of the sub-loads. S102, a single steel support is considered as a four-point support system formed by the upper and lower rigid planes and four vertical members. When embedded in the wall, it is considered as a compression member at both ends. S103, There shall be no impact or vibration during the construction of large space renovation, therefore the load generated by dynamic effects shall not be considered. S104, Remove the wall within the beam height range, the load of the upper wall is transferred to the lower wall by steel supports, the steel supports are densely arranged, the included angle of stress transfer is within the rigid angle range, and the calculation is exempted. In step S3, S30, after the concrete strength reaches the design requirements, consider the U-shaped steel plate and reinforced concrete to work together to form a whole, forming a frame composite beam; S31. Using YJK structural calculation software, select appropriate composite beam specifications and dimensions, and equate the U-shaped steel plate-reinforced concrete beam to a box-shaped concrete beam with a custom cross-section. The key step is to set the upper thickness of the box-shaped cross-section to 0 and verify the internal forces and deformations of the composite beam during the service stage.

2. The design method for large-space renovation of brick-concrete structure houses as described in claim 1, characterized in that: In step S2, S20, First determine the stress model of the U-shaped steel plate: S21, Next, verify the bending capacity of the U-shaped steel plate: Mx / Wnx ≤ [fu] In the above formula: Mx - bending moment about the x-axis under construction stage load, unit N. mm; Wnx - Net section modulus about the x-axis under construction stage loads, refer to the steel tool table, unit mm. 3 [fu] - Material strength and bending design value of inverted channel steel, in MPa; A - Cross-sectional area of ​​steel pad, in mm. 2 ; S22, Next, verify the shear capacity of the U-shaped steel plate: VS / Itw ≤ [fV] In the above formula: V - shear force under load during construction stage, unit N; S - area moment of the gross section about the neutral axis above the calculated shear stress, from the steel profile tool table, unit mm. 3 I - Gross moment of inertia of the inverted channel beam, unit mm 4 ;tw - web thickness of the inverted channel beam, in mm; [fv] - material strength shear design value of the inverted channel steel, in MPa; S23, then the local stability of the U-shaped steel plate is checked: b0 / t≤40 (235 / fy) (1 / 2) In the above formula: b0 - width between webs, in mm; t - flange thickness, in mm; fy - gross yield strength of the inverted channel beam, in mm. 4 ;tw - web thickness of the inverted channel beam, in mm; fy - material yield design value of the inverted channel steel, in MPa; S24, Finally, the deformation calculation of the U-shaped steel plate is as follows: △1=αMxl2 / (EssI)≤[△lim] In the above formula: △1 - mid-span deflection, in mm; α - coefficient related to support conditions and load form, taken as 0.104; L - span of the inverted channel steel, in mm; Ess - elastic modulus of the inverted channel steel, in MPa; △lim - deflection limit of the inverted channel steel.

3. The design method for large-space renovation of brick-concrete structure houses as described in claim 1, characterized in that: In step S20, S201, before the partial wall steel support fails and the concrete strength reaches the design strength, the second construction stage considers the U-shaped steel plate to bear the entire load. The load in this stage includes the design value of the upper wall line load, the design value of the floor slab line load, the design value of the steel plate self-weight load, the design value of the reinforced concrete self-weight load, the design value of the local support self-weight load, and the design value of the construction live load. Calculate the load intensity q of the sub-section. S201, the bending capacity, shear capacity, local stability and deformation of the U-shaped steel plate in the second construction stage are checked respectively according to the inverted channel steel beam; S202, after the inverted channel steel beam is filled with concrete, only the bending moment in the strong axis direction needs to be checked; S203, stiffening plates are added at the beam supports to prevent instability caused by torsion of the beam end section; after the inverted C-shaped steel beam is filled with concrete, the concrete effectively prevents instability caused by lateral displacement of the steel plate, so the overall stability is not checked. S204, the local instability of the web of the U-shaped steel plate is calculated as that of the inverted channel steel beam; S205, under the load during the construction phase, the U-shaped steel plate is in the elastic stage and cannot produce excessive deformation that would affect the use of the composite beam during the service phase. Therefore, its deformation is calculated based on the elastic method.

4. The design method for large-space renovation of brick-concrete structure houses as described in claim 1, characterized in that: In step S4, S40, the foundation and substructure design will be carried out first; S41, then proceed with the design of the frame columns.

5. The design method for large-space renovation of brick-concrete structure houses as described in claim 4, characterized in that: In step S40, the live load increased after the large space renovation, the frame structure replaced the brick-concrete structure, and the brick-concrete foundation changed from strip footing under the wall to strip footing under the column. The original superstructure underwent additional deformation, and stress concentration occurred in the foundation and substructure. After verifying the foundation and substructure, if the requirements are not met, the foundation is reinforced with anchor static pressure piles, and the substructure is reinforced by increasing the cross section.

6. The design method for large-space renovation of brick-concrete structure houses as described in claim 4, characterized in that: In step S41, to address the issues of insufficient compaction, poor integrity, and low construction efficiency in the demolition of load-bearing walls during large-space renovation, a combined column reinforced with angle steel and self-compacting concrete is designed.

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