Reverse construction method for reserving original old wall structure of traditional building

Abstract

The invention provides a reverse construction method for reserving an original old wall structure of a traditional building, belongs to the technical field of historical building transformation construction, and aims to solve the problems that an original old wall is prone to instability and damage and new and old structures are difficult to cooperatively stress when an internal structure is dismantled. According to the technical scheme, two-way stable frame bodies are erected on the inner side and the outer side of an original old wall to achieve rigid fixing; horizontal bearing components (wood beams, joists and purlines) connected with the outer wall and an internal to-be-transformed structure are cut and removed; a newly-built beam column structure is constructed on the inner side of the outer wall, and an overall stress system is formed through node tying; constructing a newly-built roof structure by taking the stabilizing frame body as a supporting carrier; and dismantling the internal frame body units layer by layer from top to bottom and synchronously pouring the newly-built floor slab structures layer by layer. The method is mainly used for safely retaining the integrity of the original masonry or rammed earth outer wall in historical building reconstruction.

Description

Technical Field

[0001] This invention relates to the field of historical building renovation and construction technology. More specifically, this invention relates to a method for reverse-construction of traditional buildings while preserving the original old wall structure. Background Technology

[0002] In traditional building renovation and reinforcement projects, preserving the original brick or rammed earth exterior walls with high historical value is a key requirement. However, existing construction methods face significant technical bottlenecks when dealing with such structures: 1) Instability of old walls: When removing horizontal wooden components (such as beams, floor joists, and purlins) rigidly connected to the original old walls, the walls are prone to cracking, tilting, or even collapse due to sudden unloading. This is because traditional temporary supports are mostly unidirectional and cannot effectively constrain bidirectional deformation of the walls; internal damage to the old walls (such as weathering and voids) is difficult to identify accurately in advance, and the support scheme lacks specificity. Existing technologies have attempted to use full-span scaffolding for reinforcement, but the self-weight of the scaffolding increases the foundation load and cannot solve the problem of stress mutation at the moment of cutting. 2) Difficulty in controlling structural safety during the cutting process: Cutting horizontal load-bearing components will cause the original stress path to be interrupted, and the wood will produce uncontrollable cracks due to elastic rebound. Existing technologies use steel brackets at the bottom of components for temporary load-bearing, but these methods have significant drawbacks: bracket installation requires drilling or welding, which may damage the original components; they cannot compensate for axial stress loss caused by cutting, and the ends of the components are still prone to splitting. In engineering practice, prestressed steel straps have been used for reinforcement, but uneven stress distribution due to the uneven surface of the wood has led to frequent localized debonding. 3) The accuracy of old wall condition assessment is not high. 4) Achieving coordinated load-bearing between new and old structures is difficult: during reverse construction, the load of the new roof needs to be transferred to the old wall through a temporary scaffold, but existing methods suffer from unclear load transfer paths.

[0003] The aforementioned problems have hampered the safety and reliability of the preservation and renovation of historical buildings, necessitating the development of refined construction methods that are tailored to the characteristics of old walls and possess quantitative control capabilities. Summary of the Invention

[0004] One objective of this invention is to solve at least the aforementioned problems and to provide a method for reverse construction of traditional buildings while preserving the original old wall structure. This method addresses the issues that, during the demolition of internal structures in traditional building renovations, the original old walls become unstable and collapse due to the loss of horizontal structural support; and that the new and old structures cannot form a coordinated load-bearing system, leading to cracking or deformation of the old walls in the later stages.

[0005] This addresses the issue of wood splitting or breaking due to sudden stress release during the cutting of horizontal wooden components (beams, joists, etc.); and the inability of temporary reinforcement measures to compensate for axial stress loss caused by cutting, which affects the safety of the structure during the transition period.

[0006] This solution addresses the problems of weak bonding and uneven stress transfer between carbon fiber boards and wood surfaces due to cracks or unevenness; and the slow curing and tendency of traditional adhesives to delaminate, which reduces the reliability of temporary reinforcement.

[0007] The problem is that the internal damage (weathering, cavities) of old walls is not accurately identified, resulting in insufficient targeted support solutions; uniform reinforcement measures may lead to inadequate treatment of weak areas, causing localized damage during construction.

[0008] This addresses the problems of low efficiency and insufficient coverage (>500mm spacing) of manual tapping inspection, which easily leads to the omission of local damage; and the risk assessment bias caused by subjective judgment, which affects the effectiveness of reinforcement measures.

[0009] The problem is that the penetration depth of silicon-based slurry cannot be quantified and verified non-destructively, and core drilling can cause secondary damage to the wall. Empirical judgment of penetration effect can easily lead to insufficient reinforcement or over-construction.

[0010] This addresses the issues of uneven load distribution during roof concrete pouring, leading to uneven loading of temporary scaffolding or localized overloading of old walls; and the lag in manual monitoring and adjustment, making it impossible to control the load transfer path in real time.

[0011] This addresses the issues of sudden structural deformation caused by the unformed concrete floor slabs during the dismantling of internal scaffolding, and the lack of tiered unloading control in traditional support dismantling, which increases the risk of cracking in newly constructed components.

[0012] To achieve these objectives and other advantages according to the present invention, a method for reverse construction of traditional buildings that preserves the original old wall structure is provided, comprising the following steps: S1. Erect stable frames on the inner and outer sides of the original old wall that needs to be preserved, and fix the original old wall with bidirectional support; S2. Cut the horizontal load-bearing components that are rigidly connected to the original old wall. The horizontal load-bearing components include wooden beams, wooden floor joists, and roof purlins. After cutting, remove all structures to be modified within the inner area of ​​the original old wall. The inner area refers to the building interior space enclosed by the original old wall. S3. Construct a new beam-column structure inside the original old wall, and set fixed tie measures at the floor nodes and roof nodes of the new beam-column structure to make the original old wall and the new beam-column structure form an overall load-bearing system of the building. S4. Using the stable frame from step S1 as a support carrier, construct the new roof structure on top of the new beam and column structure. S5. Dismantle the stabilizing frame units located inside the building layer by layer from top to bottom, and simultaneously pour new floor slab structures layer by layer until all construction is completed.

[0013] Preferably, before cutting the horizontal load-bearing member in step S2, a prestress compensation and reinforcement process is performed, which specifically includes the following steps: A1. Install a reinforcement system on the target horizontal load-bearing component that needs to be cut. The reinforcement system includes a load-bearing bracket fixed on the stable frame, a carbon fiber plate covering the outer surface of the target horizontal load-bearing component, and a hydraulic tensioning device connecting the load-bearing bracket and the carbon fiber plate. A2. Start the hydraulic tensioning device to apply an axial preload of 5~10kN to the target horizontal load-bearing component using carbon fiber plates; After completing the cutting operation in step S2, the axial preload is maintained unchanged; after the new floor slab structure at the same height as the target horizontal load-bearing component in step S5 is poured and the strength is ≥70% of the design value, the hydraulic tensioning device is released and the reinforcement system is dismantled.

[0014] Preferably, when installing the carbon fiber plate in step A1, an interface strengthening treatment is performed, specifically including the following steps: A11. Apply a thixotropic epoxy resin interface agent to the surface of the target horizontal load-bearing component to form an interface agent coating. A12. Press the carbon fiber plate onto the interface agent coating, apply a negative pressure of -0.10~-0.08MPa through a vacuum bag to fill the cracks on the surface of the target horizontal load-bearing component with the interface agent, and allow the interface agent to cure naturally. A13. Monitor the interface resistance value between the carbon fiber plate and the component in real time. When the resistance value fluctuates by ≤±5%, it is determined that the stress transmission is uniform.

[0015] Preferably, in step S1, before erecting the stable frame, the following safety pre-assessment and enhancement process is performed: B1. A pulse vibration meter was used to conduct a grid-based knocking test on the installation area where the original old wall was connected to the stable frame. The vibration decay time τ was collected at each test point and defined as the time required for the amplitude to decay to 10% of the initial value. B2. Based on the τ value, the installation area is divided into a first risk zone and a second risk zone. The τ value of the first risk zone is: τ≥0.8s, and the τ value of the second risk zone is: τ<0.8s. B3. For the first risk zone, lay a buffer layer directly; for the second risk zone, spray nano-silica reinforcing agent slurry. B4. After treatment, allow the area to stand for ≥48 hours for curing. Only after the increase in the τ value of the second risk zone is ≥50% can a stable frame be erected. If the standard is still not met after the retest, reinforcement measures must be added to the corresponding risk area and the curing and testing must be repeated.

[0016] Preferably, in step B1, an array-type automated vibration robot is used to perform the tapping test. The robot includes a mobile platform equipped with a 32-channel piezoelectric sensor, a laser positioning module, and an adaptive tapping force control system. The robot scans the wall along a preset path and automatically completes one test for every 100mm×100mm grid.

[0017] Preferably, in step B3, when spraying the nano-silica reinforcing agent slurry, magnetic iron oxide nanoparticles are simultaneously incorporated. After the slurry is cured for 24 hours, a portable magnetic flux imaging instrument is used to perform the following operations: C1, Magnetic flux value of the measurement and processing area B m The unit is μT; C2. Retrieve the background magnetic flux value B0 stored before the same point processing, in μT; C3. Calculate the penetration depth d: d = k × [(B m -B0) / B0]×100%; where k is the calibration coefficient, which takes the value of 15mm / %, and d is in mm; C4. When d < 15mm, spray grout in the corresponding area until d ≥ 15mm.

[0018] Preferably, in step S4, when constructing the new roof structure, load gradient transfer control is implemented, as follows: D1. Install an adjustable tilting spherical support on the top of the stable frame, and install a pressure sensor array on the spherical support. The pressure sensors are in direct contact with the roof formwork support system. D2. The roof structure is poured in four stages: Stage 1: Pour the 300mm wide ring beam around the perimeter of the roof; Stage 2: Pour the central grid beam after an interval of 24 hours; Stage 3: Pour the secondary beam area after another 48 hours; Stage 4: Pour the roof slab after 7 days of curing. D3. When the pressure sensor shows a load deviation > 5%, adjust the inclination angle of the corresponding spherical support until the load deviation ≤ 1.5%.

[0019] Preferably, in step S5, prestressed equivalent support control is implemented for each layer of scaffold dismantling and pouring operations, specifically including the following steps: E1. 48 hours before dismantling the internal frame unit of a certain floor, install self-locking ring brackets on the newly built columns of that floor. The top surface of the brackets should be 50mm lower than the bottom formwork of the floor slab to be poured. E2. Install pressure servo jacks between the corbel and the bottom formwork of the floor slab; E3. Dismantle the frame unit in stages, and simultaneously reduce the pressure of the jacks in stages to control the load transfer rate to ≤5% / min; E4. When the concrete strength of the floor slab is ≥C20, remove the jacks and retain the corbels until the project is completed.

[0020] The present invention has at least the following beneficial effects: First, the original old wall is rigidly fixed by a two-way stabilizing frame, which effectively prevents the wall from becoming unstable or collapsing when cutting horizontal load-bearing components; the reverse construction process (first dismantling the internal structure → new beams and columns → roof construction → pouring floor slabs layer by layer from top to bottom) preserves the original old wall structure to the greatest extent and avoids the drawback of traditional renovations that require complete demolition; the new beams and columns form an integrated load-bearing system with the old wall, which significantly improves structural safety and extends the building's lifespan.

[0021] Second, apply axial preload (5~10kN) to the target component before cutting to compensate for stress loss caused by cutting and prevent the wood from cracking or breaking due to sudden unloading; the reinforcement system (carbon fiber plate + hydraulic device) provides a temporary load transfer path to ensure structural stability during construction; the reinforcement system is removed after the new floor slab reaches the strength requirements to achieve a smooth transition between the old and new structures.

[0022] Third, the thixotropic epoxy resin interface agent fully fills the cracks in the wood under negative pressure, improving the bonding integrity between the carbon fiber board and the component; interface resistance monitoring (fluctuation ≤ ±5%) ensures uniform stress transmission and prevents reinforcement failure caused by local debonding.

[0023] Fourth, based on the vibration decay time τ, a grid-based zoning assessment (first risk zone / second risk zone) is conducted to accurately identify weak points in the wall; targeted reinforcement measures (buffer layer / nano silica reinforcing agent slurry) significantly improve the integrity and damage resistance of the wall; construction is carried out only after the τ value is retested and meets the standard (the increase in the second risk zone is ≥50%), ensuring that the old wall has a safety reserve to bear the subsequent construction load.

[0024] Fifth, the array-type robot enables automated high-precision detection (100mm×100mm grid), and the 32-channel sensor fully captures the dynamic response of the wall; the adaptive impact force control system avoids human operation errors, and laser positioning ensures the spatial accuracy of the data; greatly improving detection efficiency and reliability, and providing a scientific basis for wall reinforcement.

[0025] Sixth, the slurry incorporating magnetic iron oxide nanoparticles has both reinforcing and magnetic marking functions; the change in magnetic flux directly reflects the penetration depth of the slurry; the mandatory requirement of a penetration depth of ≥30mm ensures that the reinforcing slurry fully strengthens the interior of the wall.

[0026] Seventh, the concrete is poured in four stages (ring beam → grid beam → secondary beam → roof panel) in combination with adjustable spherical supports to precisely control the load transfer path; pressure sensors monitor load deviation in real time and dynamically adjust the support inclination angle (deviation ≤1.5%) to avoid local overloading during roof construction, which could lead to deformation of old walls or instability of the frame.

[0027] Eighth, the self-locking ring bracket and the pressure servo jack form a prestressed equivalent support system to achieve a smooth transfer of load during dismantling (rate ≤5% / min); the staged dismantling and staged pressure reduction are controlled simultaneously to prevent sudden stress on the structure before the floor slab is poured; the bracket is retained until completion to provide long-term safety redundancy to cope with unexpected loads.

[0028] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0030] This invention provides a method for reverse construction of traditional buildings while preserving the original old wall structure, comprising the following steps: S1. Erect stable frames on the inner and outer sides of the original old wall that needs to be preserved, and fix the original old wall with bidirectional support; S2. Cut the horizontal load-bearing components that are rigidly connected to the original old wall. The horizontal load-bearing components include wooden beams, wooden floor joists, and roof purlins. After cutting, remove all structures to be modified within the inner area of ​​the original old wall. The inner area refers to the building interior space enclosed by the original old wall. S3. Construct a new beam-column structure inside the original old wall, and set fixed tie measures at the floor nodes and roof nodes of the new beam-column structure to make the original old wall and the new beam-column structure form an overall load-bearing system of the building. S4. Using the stable frame from step S1 as a support carrier, construct the new roof structure on top of the new beam and column structure. S5. Dismantle the stabilizing frame units located inside the building layer by layer from top to bottom, and simultaneously pour new floor slab structures layer by layer until all construction is completed.

[0031] In the above technical solution, in step S1, frame scaffolding or disc-lock scaffolding can be erected on the inner and outer sides of the original old wall (e.g., brick wall, stone wall) that needs to be preserved, as a stable framework. Adjustable top support devices (e.g., screw jacks, hydraulic jacks) can be installed between the framework and the wall to form bidirectional support for the wall. The horizontal distance between the uprights of the framework and the wall can be controlled within the range of 100mm to 300mm. The supporting force applied by the top support device can be set according to the estimated load of the wall to ensure the stability of the wall during subsequent construction.

[0032] In step S2, the horizontal load-bearing components that are rigidly connected to the original old wall and need to be demolished (such as wooden beams with a cross-section of 100mm×200mm, wooden floor joists of 50mm×150mm, and round log roof purlins with a diameter of 80mm) are cut. The cutting operation can be carried out using a handheld diamond wire saw or a chainsaw. After the cutting is completed, all structures planned to be modified (such as internal partitions, old floor slabs, non-load-bearing components, etc.) within the interior space of the building enclosed by the original old wall (i.e., the inner area) are completely demolished, leaving only the original old wall and the stable frame.

[0033] In step S3, a new reinforced concrete frame structure or steel frame structure can be constructed as a beam-column structure on the inside of the original old wall. The newly constructed frame columns can be set adjacent to the inside of the old wall. At the floor nodes (such as beam-column connections) and roof nodes (such as column tops and beam ends) of the new beam-column structure, steel connecting plates or tie bars can be fixed to the new structure using chemical anchors or expansion bolts, with the other end anchored into the original old wall, so that the old wall and the new structure form a cohesive whole system through tie measures.

[0034] In step S4, the stable frame erected and fixed in step S1 is used as the main support structure. A roof structure formwork support system (e.g., timber, formwork) is laid on the top beams or adjustable supports of the stable frame. Then, reinforcing bars are tied to this formwork support system, and concrete is poured to complete the construction of the new roof structure. The tops of the newly constructed beams and columns also contribute to supporting the new roof structure.

[0035] In step S5, the process proceeds layer by layer downwards, starting from the top floor. First, the scaffolding units (e.g., the inner rows of uprights and horizontal bars) of the stable scaffolding within the current construction floor are dismantled. Simultaneously with the dismantling of these internal scaffolding units, the reinforcing steel for the newly constructed floor slab is immediately tied, and the concrete slab is poured. Once the concrete slab has reached a certain strength (e.g., is walkable), the dismantling of the internal scaffolding units for the next floor and the simultaneous pouring of the corresponding floor slab are continued. This cycle is repeated until all internal scaffolding units have been dismantled and all newly constructed floor slabs have been poured.

[0036] The beneficial effects of adopting this technical solution are that it can effectively protect the historical value carrier of the original traditional building—the original old wall structure—during the renovation and construction process. Through a step-by-step and orderly construction process, and by using temporary supports and combining the old and new structures, the stability and safety of the old wall during the demolition of the internal structure and the construction of the new structure are ensured, and the collaborative work of the old and new structures is ultimately achieved.

[0037] In another technical solution, before cutting the horizontal load-bearing component in step S2, a prestress compensation and reinforcement process is performed, specifically including the following steps: A1. Install a reinforcement system on the target horizontal load-bearing component that needs to be cut. The reinforcement system includes a load-bearing bracket fixed on the stable frame, a carbon fiber plate covering the outer surface of the target horizontal load-bearing component, and a hydraulic tensioning device connecting the load-bearing bracket and the carbon fiber plate. A2. Start the hydraulic tensioning device to apply an axial preload of 5~10kN to the target horizontal load-bearing component using carbon fiber plates; After completing the cutting operation in step S2, the axial preload is maintained unchanged; after the new floor slab structure at the same height as the target horizontal load-bearing component in step S5 is poured and the strength is ≥70% of the design value, the hydraulic tensioning device is released and the reinforcement system is dismantled.

[0038] In the above technical solution, in step A1, a reinforcement system is installed before cutting the target horizontal load-bearing component (such as a wooden beam with a cross-sectional dimension of 150mm × 300mm or a round log purlin with a diameter of 100mm). This reinforcement system includes: load-bearing supports (e.g., triangular supports welded from channel steel or H-beams) that can be fixed to the uprights or crossbars of the stabilizing frame; precast carbon fiber plates that can cover the outer surface of the target component (such as a wooden beam, with a thickness of 1.2mm or 1.4mm); and a hydraulic tensioning device, such as a single-acting or double-acting hydraulic cylinder, that can connect the load-bearing supports to the carbon fiber plates. The load-bearing supports should ensure that their force transmission path acts stably on the main load-bearing members of the stabilizing frame.

[0039] In step A2, the hydraulic pump station of the hydraulic tensioning device is activated, causing the piston rod of the cylinder to extend or retract, pulling or pushing the connecting rod, thereby applying tension to the carbon fiber plate wrapped around the target component. The axial preload applied to the target horizontal load-bearing component is controlled by adjusting the pressure of the hydraulic system to a specific value of 5kN, 7kN, or 10kN. This pressure value can be monitored and set in real time using a pressure gauge or pressure sensor installed in the hydraulic circuit.

[0040] After the target horizontal load-bearing component reaches the set preload (e.g., 7kN), the cutting operation is carried out (e.g., using a chainsaw to cut the wooden beam along the predetermined cutting line). During and after the cutting process, the pressure of the hydraulic system needs to be kept constant to ensure that the axial preload applied to the component remains unchanged (e.g., by continuously locking the hydraulic valve or using a pressure-holding pump) until the release conditions for subsequent steps are met.

[0041] In step S5 of the construction process, the hydraulic system can only be operated to release pressure when the newly constructed reinforced concrete floor slab, which is at the same floor height as the target horizontal load-bearing component, is completed and its compressive strength reaches more than 70% of the design strength grade (e.g., C30) (i.e., ≥21MPa) as tested by on-site test blocks cured under the same conditions. Subsequently, the connection of the hydraulic tensioning device is disconnected, and the carbon fiber plate and load-bearing support are removed in sequence.

[0042] The beneficial effects of this technical solution are that by applying and maintaining a controllable axial preload on the horizontal load-bearing components before cutting, the process can effectively counteract the stress release or deformation that may occur during cutting, significantly reducing the risk of disturbance to the stability of the original old wall during cutting, preventing sudden instability or displacement of the components during cutting, and ensuring the safety and controllability of the construction process. At the same time, the continuous effect of this preload also provides a smooth transition for the subsequent load-bearing of the newly constructed floor slab structure.

[0043] In another technical solution, when installing the carbon fiber plate in step A1, an interface strengthening treatment is performed, which specifically includes the following steps: A11. Apply a thixotropic epoxy resin interface agent to the surface of the target horizontal load-bearing component to form an interface agent coating. A12. Press the carbon fiber plate onto the interface agent coating, apply a negative pressure of -0.10~-0.08MPa through a vacuum bag to fill the cracks on the surface of the target horizontal load-bearing component with the interface agent, and allow the interface agent to cure naturally. A13. Monitor the interface resistance value between the carbon fiber plate and the component in real time. When the resistance value fluctuates by ≤±5%, it is determined that the stress transmission is uniform.

[0044] In the above technical solution, in steps A11-A12, a two-component epoxy resin interface agent with thixotropic properties (such as an epoxy resin adhesive containing fumed silica thickener) can be applied to the surface area of ​​the target horizontal load-bearing component (such as a wooden beam) where the carbon fiber board needs to be bonded. A scraper or trowel is used to ensure uniform coverage, forming an interface agent coating 1 mm to 2 mm thick. Subsequently, the pre-fabricated carbon fiber board is placed over the coating. A vacuum bag (e.g., made of nylon or polyamide film) is used to seal the carbon fiber board and the component surface. A vacuum pump is started, and the pressure inside the vacuum bag is evacuated to a specific negative pressure value of -0.08 MPa, -0.09 MPa, or -0.10 MPa, and this negative pressure is maintained for 15 to 30 minutes. The negative pressure promotes better penetration of the interface agent into the micropores and cracks of the wood surface. Under the maintained vacuum negative pressure, the interface agent is allowed to cure naturally.

[0045] In step A13, during the natural curing process of the interface agent, a resistance tester is used for real-time monitoring. The probe of the tester can be connected to a pre-placed conductive copper foil electrode on the surface of the carbon fiber board and a microelectrode embedded in the surface of the wood to measure the interfacial resistance between them. The monitoring system continuously records the changes in the resistance value. When the monitoring data shows that the fluctuation range (the percentage difference between the maximum and minimum values ​​relative to the average value) of the resistance value is stable within ±5% for two consecutive minutes (e.g., the fluctuation range is between 95Ω and 105Ω, with an average value of 100Ω), it is determined that the interfacial stress transmission is uniform, and the curing process is complete. It should be noted that the carbon fiber board has intrinsic piezoresistive characteristics—its resistance value changes with internal stress. Therefore, the uniformity of stress transmission can be determined by measuring the interfacial resistance value. The beneficial effects of this technical solution are that the interface strengthening process, by applying controllable negative pressure to promote resin penetration and combining it with real-time monitoring of interface resistance as a criterion for curing uniformity, can effectively improve the interfacial bonding performance between carbon fiber boards and old wooden load-bearing components. This ensures the effective transfer of prestress in the reinforcement system, enhances the reliability of the reinforcement, and provides a more stable foundation for subsequent cutting and load transfer.

[0046] In another technical solution, before erecting the stable frame in step S1, the following safety pre-assessment and enhancement process is performed: B1. A pulse vibration meter was used to conduct a grid-based knocking test on the installation area where the original old wall was connected to the stable frame. The vibration decay time τ was collected at each test point and defined as the time required for the amplitude to decay to 10% of the initial value. B2. Based on the τ value, the installation area is divided into a first risk zone and a second risk zone. The τ value of the first risk zone is: τ≥0.8s, and the τ value of the second risk zone is: τ<0.8s. B3. For the first risk zone, lay a buffer layer directly; for the second risk zone, spray nano-silica reinforcing agent slurry. B4. After the treatment is completed, allow the structure to stand for ≥48 hours for curing. Only after the increase in the τ value of the second risk zone is ≥50% can the stable frame be erected.

[0047] In the above technical solution, in steps B1-B2, before erecting the stabilizing frame, a handheld pulse vibration device (e.g., a device equipped with a force hammer and an acceleration sensor) is used to conduct a hammering test on the installation area of ​​the original old wall connected to the stabilizing frame. The installation area is divided into a 100mm × 100mm grid, and a single hammering is performed at the center point of each grid. The vibration waveform is recorded by a sensor. The vibration decay time τ at each measuring point is calculated, which is the time (in seconds) required for the initial amplitude to decay to 10% of the amplitude. Risk areas are divided according to the τ value: when τ ≥ 0.8 seconds, it is determined as the first risk area; when τ < 0.8 seconds, it is determined as the second risk area (indicating serious damage or structural weakness). The test results can generate a risk distribution map of the installation area.

[0048] In step B3, differentiated enhancement measures are implemented based on risk zones: First risk zone: A flexible buffer layer (such as a 5mm thick closed-cell polyethylene foam board or rubber pad) can be directly laid between the contact surface of the subsequent stabilizing frame's top support device (such as screw top support) and the wall surface.

[0049] Second risk zone: A commercially available nano-silica reinforcing agent slurry can be sprayed (this is a diluted nano-silica reinforcing agent, such as Sika brand nano-silica reinforcing agent (InjectoCream 2000), using the matching Sika brand thinner (Diluent C), with a dilution ratio of 5%~10% (by volume)). Using a mortar spraying machine, evenly spray the slurry onto the marked second risk zone wall surface, forming a 2mm to 3mm thick covering layer. The spraying pressure can be controlled at 0.15MPa.

[0050] In step B4, after completing the reinforcement treatment of all areas (first risk zone and second risk zone), allow them to cure for at least 48 hours. After the curing period, retest the original second risk zone using the same pulse vibration meter: for the measuring points in the original second risk zone, the τ value must increase by more than 50% compared to the τ value before treatment. Only if this condition is met is the next step of erecting the stabilizing frame allowed. If the standard is not met, additional reinforcement measures must be added to the corresponding area, and the curing and testing must be repeated.

[0051] The beneficial effects of this technical solution are that, before erecting temporary supports, the process can systematically identify potential weak points in the installation area where the original old wall connects to the stable frame, and then use differentiated pretreatment measures (buffering, reinforcement) to specifically improve its load-bearing capacity and stability. This effectively reduces the risk of localized collapse or instability of the wall during subsequent support erection and structural modification, providing important early protection for the safe implementation of the entire reverse construction process.

[0052] In another technical solution, step B1 uses an array-type automated vibration robot to perform the impact test. The robot includes a mobile platform equipped with 32-channel piezoelectric sensors, a laser positioning module, and an adaptive impact force control system. The robot scans the installation area along a preset path and automatically completes one test for every 100mm×100mm grid.

[0053] In the above technical solution, during the impact test in step B1, an array-type automated vibration robot can be used. This robot comprises a movable platform (e.g., a tracked or wheeled chassis) with a detection arm mounted on it. On the contact surface of the detection arm, 32 independent piezoelectric sensors can be integrated to form a sensor array. The robot is also equipped with a laser positioning module (e.g., a two-dimensional laser scanner) for accurately identifying the position and distance of the installation area. Simultaneously, the robot integrates an adaptive impact force control system, which may include a servo motor-driven adjustable-stroke vibration hammer. The entire robot is connected to a field control host via cable or wirelessly.

[0054] In this technical solution, the operator pre-sets the boundary coordinates of the installation area to be tested in the control software. After the robot is started, its laser positioning module first scans the installation area, establishes a spatial coordinate system, and plans a preset path (usually a "bow" shaped path) covering the entire installation area. The robot moves automatically along the preset path. Whenever it moves to a new 100mm×100mm grid center point, the robot automatically stops. The adaptive impact force control system dynamically adjusts the stroke and impact force of the vibrating hammer (e.g., adjustable within the range of 1N to 10N) based on a preset program or the test results of the previous adjacent grid (e.g., the τ value). The vibrating hammer applies a blow to the wall. Simultaneously, a 32-channel piezoelectric sensor array synchronously acquires the vibration response signal of that grid point. After acquisition, the data is transmitted to the control host in real time for processing, calculating the vibration decay time τ value of that point. The robot then automatically moves to the next grid point, repeating the above-mentioned knocking, acquisition, and calculation process until all grids in the entire installation area are tested.

[0055] Data Processing and Output: Dedicated software on the control host receives and stores the τ value data of all grid points. Based on set thresholds (τ ≥ 0.8 seconds for first-risk, τ < 0.4 seconds for second-risk), the software automatically generates a risk level distribution map of the installation area. This map visually displays the location and extent of different risk areas, providing a basis for the subsequent zoning enhancement processing in step B3. Test data (including the coordinates, impact force, τ value, and risk level of each grid point) is stored and output in a structured format.

[0056] The beneficial effects of adopting this technical solution are that the application of this automated vibration robot enables automated, standardized, and high-precision operation of grid-based tapping tests on the installation area of ​​the original old wall. Its multi-channel sensor array and adaptive tapping system can acquire more reliable τ-value data, reducing human error. Automated grid coverage and data processing significantly improve detection efficiency, ensure the comprehensiveness and consistency of risk area identification, and provide efficient and accurate basic data support for subsequent wall safety pre-assessment and enhancement processes.

[0057] In another technical solution, during step B3, magnetic iron oxide nanoparticles are simultaneously incorporated into the sprayed nano-silica reinforcing agent slurry. After the slurry is cured for 24 hours, a portable magnetic flux imaging instrument is used to perform the following operations: C1, Magnetic flux value of the measurement and processing area B m The unit is μT; C2. Retrieve the background magnetic flux value B0 stored before the same point processing, in μT; C3. Calculate the penetration depth d: d = k × [(B m -B0) / B0]×100%; where k is the calibration coefficient, which takes the value of 15mm / %, and d is in mm; C4. When d < 15mm, spray grout in the corresponding area until d ≥ 15mm.

[0058] In the above technical solution, the slurry preparation and spraying are as follows: In step B3, when spraying the nano-silica reinforcing agent slurry onto the second risk zone, magnetic iron oxide nanoparticles (e.g., particle size ranging from 50nm to 200nm) can be simultaneously incorporated during the slurry mixing process. The proportion of these particles can be 1.5% to 2.5% of the total slurry volume. After thorough mixing using a conventional mortar mixer, the mixed slurry is evenly sprayed onto the installation area on the original old wall surface marked as the second risk zone using a mortar spraying machine (a plunger pump or screw pump can be selected). After spraying, allow it to cure naturally for 24 hours.

[0059] The magnetic flux detection and calculation are as follows: After 24 hours of slurry curing, a portable magnetic flux imager (e.g., a device based on a Hall effect sensor) is used for detection. The imager's probe is placed in close contact with the wall of the treatment area (formerly the second risk zone). The instrument is operated to measure and record the current magnetic flux value B in that area. m The unit is microtesla (μT). Simultaneously, the background magnetic flux value B0 stored at the same location before treatment (before slurry injection) is retrieved from the instrument's memory or external database; the unit is also μT. The slurry penetration depth d (in millimeters) is calculated using the formula: d = 15 × [(B m-B0) / B0] × 100%. The calibration coefficient k in the formula is a fixed value of 15 mm per percentage (mm / %).

[0060] The penetration depth assessment and re-spraying process is as follows: After calculating the penetration depth d value, it is compared with the preset acceptable threshold of 15 mm. If the calculated d value is less than 15 mm (i.e., d < 15 mm), the slurry penetration depth of the treated area is deemed insufficient. In this case, a slurry containing magnetic iron oxide nanoparticles and a nano-silica reinforcing agent needs to be re-sprayed in the corresponding area with insufficient penetration depth (d < 15 mm). After the re-spraying is completed, the area is allowed to stand for curing for another 24 hours, and the above magnetic flux measurement and B are repeated. m The process involves reading the penetration depth and calculating the d-value. This process is repeated until the calculated penetration depth d-value for the area reaches or exceeds 15 mm (d ≥ 15 mm). Areas with d ≥ 15 mm are considered to meet the requirements and do not require additional spraying.

[0061] The beneficial effects of this technical solution are that by incorporating magnetic markers such as magnetic iron oxide nanoparticles into the nano-silica reinforcing agent slurry and utilizing convenient non-destructive magnetic flux detection technology, the process can quantitatively and objectively assess the penetration depth of the slurry inside old walls. This overcomes the limitations of traditional visual or tapping inspections, which are difficult to judge the internal penetration effect. Setting a clear penetration depth threshold (d ≥ 15mm) and guiding the re-spraying operation accordingly ensures that the reinforcing slurry achieves the predetermined goals in filling and reinforcing internal defects (such as micro-cracks and loose areas) in the second-risk wall zone, improving the reliability and consistency of wall reinforcement treatment.

[0062] In another technical solution, during step S4, load gradient transfer control is implemented when constructing the new roof structure, as follows: D1. Install an adjustable tilting spherical support on the top of the stable frame, and install a pressure sensor array on the spherical support. The pressure sensors are in direct contact with the roof formwork support system. D2. The roof structure is poured in four stages: Stage 1: Pour the 300mm wide ring beam around the perimeter of the roof; Stage 2: Pour the central grid beam after an interval of 24 hours; Stage 3: Pour the secondary beam area after another 48 hours; Stage 4: Pour the roof slab after 7 days of curing. D3. When the pressure sensor shows a load deviation > 5%, adjust the inclination angle of the corresponding spherical support until the load deviation ≤ 1.5%.

[0063] In the above technical solution, the installation and monitoring of the spherical bearing are as follows: During the construction of the new roof structure in step S4, an adjustable tilt spherical bearing can be installed on the top beam or support of the stabilizing frame. The upper spherical crown and lower base of the spherical bearing are allowed to rotate relative to each other within a certain angle range. A pressure sensor array can be installed on the top surface of the spherical bearing, which can contain multiple (e.g., 4 or 8) independent high-precision pressure sensor units. The top surface of the pressure sensor array directly contacts the bottom of the roof formwork support system (e.g., timber or steel support beams) to ensure accurate measurement of the load value transmitted to the support point. All pressure sensors are connected to the on-site data acquisition unit and monitoring display via data cables.

[0064] The specific process of phased pouring and load monitoring is as follows: The roof structure concrete pouring is carried out in the following four phases: Phase 1: First, pour the reinforced concrete ring beams with a width of 300 mm around the perimeter of the roof. Phase 2: After an interval of 24 hours, pour the grid-shaped main beams in the central area of ​​the roof. Phase 3: After another interval of 48 hours, pour the secondary beams connecting the main beams. Phase 4: After the concrete in the secondary beam area has cured for 7 days, finally pour the roof slab. During the pouring process of each phase and in the initial hardening stage after pouring (such as within 24 hours after pouring), the load values ​​displayed by each pressure sensor array are monitored in real time. The load readings of each monitoring point within the same phase are compared with the theoretical expected load value of that phase or the average load value of adjacent monitoring points, and the relative deviation (percentage) is calculated.

[0065] The load deviation adjustment process is as follows: When the monitoring system detects that the load value deviation displayed by one or more pressure sensors exceeds 5% of the theoretical value or average value (i.e., deviation > 5%), the operator adjusts the inclination angle of the corresponding spherical support using an adjustment mechanism (such as a manual or electric adjusting screw). By changing the relative angle between the spherical crown and the base, the height and force direction of the support point are fine-tuned, thereby altering the load distribution transmitted to that support point. Continuous monitoring and adjustment are performed until the load deviation displayed by the pressure sensor stabilizes within the range of ≤ 1.5%. This adjustment process is carried out promptly after the load deviation occurs and ensures that the load deviation of each support point meets the requirements before subsequent pouring stages.

[0066] The beneficial effects of this technical solution are that, by installing adjustable spherical supports and a real-time pressure monitoring array, combined with a phased and orderly roof structure pouring process, this load gradient transfer control method can dynamically sense and actively adjust the actual load borne by each support point of the stabilizing frame. This effectively avoids uneven load distribution caused by differences in concrete pouring sequence, hardening shrinkage deformation, or stiffness differences in the support system, prevents local support point overload instability, ensures controlled deformation and overall stability of the new roof structure during construction, and also protects the original old walls that need to be preserved below.

[0067] In another technical solution, the dismantling and pouring operations at each level in step S5 are controlled by prestressed equivalent supports, specifically including the following steps: E1. 48 hours before dismantling the internal frame unit of a certain floor, install self-locking ring brackets on the newly built columns of that floor. The top surface of the brackets should be 50mm lower than the bottom formwork of the floor slab to be poured. E2. Install pressure servo jacks between the corbel and the bottom formwork of the floor slab; E3. Dismantle the frame unit in stages, and simultaneously reduce the pressure of the jacks in stages to control the load transfer rate to ≤5% / min; E4. When the concrete strength of the floor slab is ≥C20, remove the jacks and retain the corbels until the project is completed. In the above technical solution, the installation of the corbel and jacks is specifically as follows: In step S5, 48 hours before the planned removal of the stable frame unit of a certain floor (e.g., the third floor) of the building's interior, self-locking ring-shaped corbels are installed on the newly constructed reinforced concrete frame columns of that floor. These corbels can be steel ring-shaped clamps with self-locking bolts, which are tightened to securely fasten to the column. The top surface of the corbel is installed at an elevation measured using a level, ensuring it is 50 mm lower than the lower surface of the bottom formwork (such as wooden or steel formwork) of the newly constructed floor slab to be poured on that floor. Subsequently, a pressure servo jack, such as a hydraulic jack with a digital pressure display and servo control valve, can be installed between the top surface of the installed corbel and the lower surface of the floor slab bottom formwork above. The piston rod of the jack should be firmly pressed against the floor slab bottom formwork at the top, and the bottom should be stably supported on the corbel. After installation, an initial pre-jacking force (approximately 10% of the expected transfer load) is applied to the jack to ensure tight contact.

[0068] The dismantling of the internal stabilizing frame units (such as the vertical and horizontal supports of that floor) then begins. The dismantling operation is carried out in stages: the internal frame is divided into several small area units (e.g., dismantling the area supported by 1 to 2 vertical supports and their associated horizontal supports at a time). Only one small area unit is dismantled at a time. Simultaneously with the dismantling of a small area unit, the operator reduces the pressure of the corresponding pressure servo jack via a control console. The pressure reduction operation is also multi-stage (e.g., reducing the current remaining pressure by 20% each time). The key control point is that during the dismantling of a single small area unit and its corresponding multi-stage pressure reduction, the rate at which the load is transferred from the dismantled frame unit to the jacks and the new structure must be strictly controlled to not exceed 5% of the unit's expected total load transfer per minute. This rate is ensured by monitoring the pressure reduction rate of the jacks and data from displacement sensors (if installed).

[0069] After the concrete for the newly constructed floor slab is poured and cured for a period of time, compressive strength tests are conducted on concrete test blocks cured under the same conditions on-site. When the test results of the test blocks reach or exceed the C20 grade (i.e., ≥20MPa), it indicates that the floor slab has a certain self-supporting capacity. At this point, the servo system can be operated to slowly release the oil pressure inside the jacks, allowing the piston rods to fully retract. Subsequently, the jacks are removed from between the top surface of the corbel and the bottom formwork of the floor slab. The self-locking ring-type corbel remains in its original installation position (clamped onto the newly constructed column) and does not need to be removed until the entire project is completed.

[0070] The beneficial effects of this technical solution are as follows: This prestressed equivalent support control method, by pre-installing corbels and jacks as temporary supports before dismantling the scaffolding, and strictly controlling the load transfer rate (≤5% / min) during dismantling, achieves a smooth and gradual unloading of the internal support frame units. This effectively avoids the risk of excessive deformation or subsidence of the new floor slab formwork system due to sudden support removal, ensuring the molding quality of the floor slab concrete. Simultaneously, it provides a smoother load transfer path for the original old walls to be retained below (and for both the old and new structural systems), reducing construction disturbance. Retaining the corbels until completion also simplifies the construction process.

[0071] <Example 1> In the renovation project of a two-story brick-and-wood structured residential building (8m wide, 6m deep) in the Jiangnan region, the method of this invention was used to preserve the eastern exposed brick exterior wall (360mm thick). First, a pre-assessment of wall safety was performed: an array-type automated vibration robot was used to conduct impact tests on the installation area on the wall connected to the stabilizing frame along the eastern exterior wall in a 100mm×100mm grid. The robot's 32-channel piezoelectric sensor recorded the vibration decay time τ at each point. Based on the test results, areas were divided: a first risk zone (65% of the wall surface) with τ≥0.8s, and a second risk zone (35%, corner efflorescence areas) with τ<0.8s. A 5mm thick closed-cell rubber buffer layer was laid in the first risk zone; a nano-silica reinforcing agent slurry containing magnetic iron oxide nanoparticles (2.0 vol%) was sprayed into the second risk zone. After 48 hours of curing, a retest was conducted, and the τ value in the second risk zone increased from 0.32s to 0.51s (an increase of 59%), meeting the standard.

[0072] A modular scaffolding system was erected on both the inner and outer sides of the wall, with the inner and outer uprights 200mm from the wall surface. The wall was secured by bidirectional screw bracing. Before cutting the second-floor wooden joists (50mm x 150mm cross-section), prestressing compensation reinforcement was performed: a thixotropic epoxy resin interface agent was applied to the surface of the target joists, covered with a 1.2mm thick carbon fiber board, and then a vacuum negative pressure of -0.09MPa was applied. Natural curing was allowed, and bonding was completed after the interface resistance fluctuation was monitored in real time to be ≤3%. Load-bearing supports and hydraulic tensioning devices were installed on the scaffolding, and a 7kN axial preload was applied before cutting the joists. The pressure was maintained until the construction of the new floor slab on the same floor.

[0073] After dismantling the internal structure, a new reinforced concrete frame was constructed adjacent to the inner side of the old wall, with column sections of 300mm×300mm and beams of 250mm×400mm. L-shaped steel tie plates were anchored into the old wall (120mm deep) using chemical anchors, with the other end welded to the new beam-column joint. Spherical supports and a pressure sensor array were installed at the top of the frame to support the roof formwork. The roof was poured in four stages: first, a 300mm wide ring beam was poured; 24 hours later, the grid beams were poured; 48 hours later, the secondary beams were poured; and 7 days later, the roof slab was poured. During the pouring process, the support inclination angle was adjusted in real time to control the load deviation to ≤1.3%.

[0074] Starting from the top floor, dismantle the scaffolding and pour the concrete: Install self-locking ring brackets on the second-floor columns, with the top surface 50mm lower than the bottom formwork of the floor slab. Install pressure servo jacks between the brackets and the bottom formwork, with an initial pre-jacking force of 15kN. Dismantle the internal scaffolding units in stages, simultaneously reducing pressure in stages, controlling the load transfer rate at 3% / min. After the floor slab is poured and cured to a strength of 22MPa (73% of C30), remove the jacks, leaving the brackets in place. Complete the bottom floor work using the same method.

[0075] Technical effectiveness verification: 1) Old wall displacement monitoring: Lateral wall displacement ≤1.8mm throughout construction (laser displacement meter data); 2) Structural safety: The static load test deflection value of the newly built floor slab complies with GB 50204 standard; 3) Preservation of historical value: The exposed brick wall has no new damage and the original grouting is well preserved.

[0076] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A traditional building construction method that preserves the original old wall structure through reverse construction, characterized by: Includes the following steps: S1. Erect stable frames on the inner and outer sides of the original old wall that needs to be preserved, and fix the original old wall with bidirectional support; S2. Cut the horizontal load-bearing components that are rigidly connected to the original old wall. The horizontal load-bearing components include wooden beams, wooden floor joists, and roof purlins. After cutting, remove all structures to be modified within the inner area of ​​the original old wall. The inner area refers to the building interior space enclosed by the original old wall. S3. Construct a new beam-column structure inside the original old wall, and set fixed tie measures at the floor nodes and roof nodes of the new beam-column structure to make the original old wall and the new beam-column structure form an overall load-bearing system of the building. S4. Using the stable frame from step S1 as a support carrier, construct the new roof structure on top of the new beam and column structure. S5. Dismantle the stabilizing frame units located inside the building layer by layer from top to bottom, and simultaneously pour new floor slab structures layer by layer until all construction is completed.

2. The traditional building construction method for preserving the original old wall structure as described in claim 1, characterized in that, Before cutting the horizontal load-bearing component in step S2, a prestress compensation and reinforcement process is performed, which specifically includes the following steps: A1. Install a reinforcement system on the target horizontal load-bearing component that needs to be cut. The reinforcement system includes a load-bearing bracket fixed on the stable frame, a carbon fiber plate covering the outer surface of the target horizontal load-bearing component, and a hydraulic tensioning device connecting the load-bearing bracket and the carbon fiber plate. A2. Start the hydraulic tensioning device to apply an axial preload of 5~10kN to the target horizontal load-bearing component using carbon fiber plates; After completing the cutting operation in step S2, the axial preload is maintained unchanged; after the new floor slab structure at the same height as the target horizontal load-bearing component in step S5 is poured and the strength is ≥70% of the design value, the hydraulic tensioning device is released and the reinforcement system is dismantled.

3. The traditional building construction method for preserving the original old wall structure as described in claim 2, characterized in that, When installing the carbon fiber plate in step A1, interface strengthening treatment is performed, which specifically includes the following steps: A11. Apply a thixotropic epoxy resin interface agent to the surface of the target horizontal load-bearing component to form an interface agent coating. A12. Press the carbon fiber plate onto the interface agent coating, apply a negative pressure of -0.10~-0.08MPa through a vacuum bag to fill the cracks on the surface of the target horizontal load-bearing component with the interface agent, and allow the interface agent to cure naturally. A13. Monitor the interface resistance value between the carbon fiber plate and the component in real time. When the resistance value fluctuates by ≤±5%, it is determined that the stress transmission is uniform.

4. The traditional building construction method for preserving the original old wall structure as described in claim 3, characterized in that, In step S1, before erecting the stable frame, the following safety pre-assessment and enhancement procedures are performed: B1. A pulse vibration meter was used to conduct a grid-based knocking test on the installation area where the original old wall was connected to the stable frame. The vibration decay time τ was collected at each test point and defined as the time required for the amplitude to decay to 10% of the initial value. B2. Based on the τ value, the installation area is divided into a first risk zone and a second risk zone. The τ value of the first risk zone is: τ≥0.8s, and the τ value of the second risk zone is: τ<0.8s. B3. For the first risk zone, lay a buffer layer directly; for the second risk zone, spray nano-silica reinforcing agent slurry. B4. After treatment, allow the area to stand for ≥48 hours for curing. Only after the increase in the τ value of the second risk zone is ≥50% can a stable frame be erected. If the standard is still not met after the retest, reinforcement measures must be added to the corresponding risk area and the curing and testing must be repeated.

5. The traditional building construction method for preserving the original old wall structure as described in claim 4, characterized in that, In step B1, an array-type automated vibration robot is used to perform the impact test. The robot includes a mobile platform equipped with a 32-channel piezoelectric sensor, a laser positioning module, and an adaptive impact force control system. The robot scans the installation area along a preset path and automatically completes one test for every 100mm×100mm grid.

6. The traditional building construction method for preserving the original old wall structure as described in claim 4, characterized in that, In step B3, magnetic iron oxide nanoparticles are simultaneously incorporated into the sprayed nano-silica reinforcing agent slurry. After the slurry is cured for 24 hours, the following operations are performed using a portable magnetic flux imaging instrument: C1, Magnetic flux value of the measurement and processing area B m The unit is μT; C2. Retrieve the background magnetic flux value B0 stored before the same point processing, in μT; C3. Calculate the penetration depth d: d = k × [(B m -B0) / B0]×100%; where k is the calibration coefficient, which takes the value of 15mm / %, and d is in mm; C4. When d < 15mm, spray grout in the corresponding area until d ≥ 15mm.

7. The traditional building construction method for preserving the original old wall structure as described in claim 1, characterized in that, In step S4, when constructing a new roof structure, load gradient transfer control is implemented, as follows: D1. Install an adjustable tilting spherical support on the top of the stable frame, and install a pressure sensor array on the spherical support. The pressure sensors are in direct contact with the roof formwork support system. D2. The roof structure is poured in four stages: Stage 1: Pour the 300mm wide ring beam around the perimeter of the roof; Stage 2: Pour the central grid beam after an interval of 24 hours; Stage 3: Pour the secondary beam area after another 48 hours; Stage 4: Pour the roof slab after 7 days of curing. D3. When the pressure sensor shows a load deviation > 5%, adjust the inclination angle of the corresponding spherical support until the load deviation ≤ 1.5%.

8. The traditional building construction method for preserving the original old wall structure as described in claim 1, characterized in that, In step S5, prestressed equivalent support control is implemented for each layer's scaffolding removal and pouring operations, specifically including the following steps: E1. 48 hours before dismantling the internal frame unit of a certain floor, install self-locking ring brackets on the newly built columns of that floor. The top surface of the brackets should be 50mm lower than the bottom formwork of the floor slab to be poured. E2. Install pressure servo jacks between the corbel and the bottom formwork of the floor slab; E3. Dismantle the frame unit in stages, and simultaneously reduce the pressure of the jacks in stages to control the load transfer rate to ≤5% / min; E4. When the concrete strength of the floor slab is ≥C20, remove the jacks and retain the corbels until the project is completed.