A high-altitude rapid dismantling method of a whole lifting platform assembled by a bailey frame

Abstract

The present application relates to the technical field of super high-rise and high-rise building construction equipment, and particularly relates to a high-altitude rapid dismantling method for a whole lifting platform of a Bailey frame assembly, comprising: S100, preparation before dismantling and dismantling of auxiliary facilities: stopping the lifting operation of the lifting platform, dismantling the pipelines and equipment of the hydraulic system, and dismantling the auxiliary facilities and the floor layer on the top of the platform; the present application converts the originally loose and easily deformed thin-wall hanging rack system into a rigid module that can be stably hoisted and dismantled as a whole by pre-setting a steel support frame inside the hanging rack for overall reinforcement and scientifically arranging lifting points, thereby transferring the complicated high-altitude dismantling operation to ground disassembly, greatly reducing the high-altitude operation time and personnel exposure risk; at the same time, in combination with the dynamic symmetrical dismantling principle of the large-span steel truss of the Bailey frame and the traction prestress buffer mechanism before dismantling of the heavy support system, the center of gravity deviation instability and heavy object sudden drop impact hidden danger in the platform disassembly process are effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of construction equipment technology for super high-rise and high-rise buildings, specifically to a method for rapid high-altitude dismantling of a Bailey bridge prefabricated integral lifting platform. Background Technology

[0002] As the height of supertall buildings continues to break records, "sky-building machines," which integrate steel truss platforms, hydraulic jacking systems, formwork systems, and safety protection facilities, have become the mainstream technical equipment for supertall building construction. These machines not only provide a construction platform and structural support, but more importantly, they serve as high-altitude carriers for various construction equipment and facilities. Modern sky-building machine platforms require the integration of increasingly more auxiliary facilities, including concrete placing booms, construction elevators, unloading platforms, canopy protection, spray curing systems, control rooms, and various material storage yards.

[0003] A search revealed the following problems with existing building construction machine auxiliary facility integration technologies: (1) The integration method is singular, and the facilities are isolated from each other: Currently, the auxiliary facilities on building construction platforms mainly adopt a "point-to-point" mounting method—the concrete placing boom sits directly on the steel platform, the construction elevator is connected to the platform via an attachment frame, and the unloading platform is independently installed on the structure. There is a lack of collaborative design among these auxiliary facilities; they operate independently and fail to form an integrated functional cluster. For example, CN120291707B discloses a "highly integrated intelligent construction platform for building main structure construction," which integrates a concrete placing boom, prefabricated house, canopy, and sprinkler system above a Bailey bridge, achieving high integration of multiple functions. However, the collaborative mechanism between these integrated functions still needs further improvement; the concrete placing boom, construction elevator, and unloading platform still operate as independent modules, failing to form a systematic collaborative workflow.

[0004] (2) The load on the concrete placing machine is concentrated, and the platform is subjected to excessive local stress: Hydraulic placing booms generate significant concentrated loads and overturning moments during operation (single unit weight 5.4t, counterweight 800kg, system pressure 22MPa). Existing technologies often place the placing boom directly on a steel truss platform without optimizing load distribution, easily leading to localized stress concentration and deformation on the platform. CN112096056B discloses an "Integrated Steel Platform Formwork and Large Tower Crane Building Construction Equipment," which integrates a large tower crane onto a platform; however, its method for handling concentrated loads is through reinforcing the support frame structure, without addressing a technical solution for distributing the load to multiple crane positions via a distributed base. While CN114030073A also relates to hydraulic placing booms, it primarily focuses on the structural design of the boom itself, rather than its integration method on the platform.

[0005] (3) The lack of synchronous control between the construction elevator and the platform limits the efficiency of vertical transportation: As the building construction machine ascends layer by layer during structural construction, the construction elevator needs to be added in parallel to maintain efficient connection with the work surface. Existing construction elevators are mainly connected to the building structure through independent attachment systems. When the building construction machine ascends, the construction elevator cannot keep up, forcing personnel to climb scaffolding from the elevator exit to the platform work surface, severely impacting vertical transportation efficiency. CN222207304U discloses "a shaft-type construction elevator and building construction machine connection structure," which solves the connection problem between the elevator and the building construction machine. However, its technical solution focuses on the mechanical design of the connection structure and does not address the control method for the synchronous lifting of the elevator and platform.

[0006] (4) The unloading platform has low integration with the platform, and there are blind spots in material transfer. In existing building construction machine technologies, unloading platforms are mostly installed independently on pre-reserved openings in the building structure and connected to the upper structure for unloading via steel wire ropes. There is a lack of direct connection between the unloading platform and the building construction machine's mounting frame; materials must pass through multiple temporary passages to be transferred from the unloading platform to the construction surface, resulting in low efficiency and poor safety. CN119877865A discloses a "liftable automatic transfer cantilever unloading platform system," which enables the unloading platform to rise and fall with the guide rail frame; however, its lifting mechanism is independent of the building construction machine's jacking system and does not achieve integrated, coordinated lifting with the building construction machine.

[0007] (5) Insufficient integration depth of the canopy and sprinkler systems: While existing building construction machines have integrated canopy and sprinkler systems, their opening and closing rely on manual operation and lack automatic linkage with construction progress and weather changes. The technology of integrating sprinkler curing, dust suppression, and cooling systems at the platform bottom has been applied in residential building construction machines, but their control methods remain primarily manual, and their level of intelligence needs improvement.

[0008] (6) Lack of systematic design for platform load management: The top platform of the building jacking machine has a large area and many functional zones, with significant differences in load-bearing capacity between different areas (5kN / m² for centralized loading area and 3kN / m² for temporary loading area). Disorderly stacking is a major hidden danger to the safe operation of the platform. Although existing technologies differentiate the load-bearing capacity of each area of ​​the platform through calculations, a visualized load zoning management and dynamic monitoring system has not been established at the platform level. Material cleaning before lifting mainly relies on manual inspection, resulting in management blind spots.

[0009] In summary, existing building construction machine auxiliary facility integration technologies suffer from the fundamental problem of "excessive functional overlap and insufficient system collaboration," and there is an urgent need for a fully integrated auxiliary facility system that can organically integrate, deeply merge, and collaboratively work various auxiliary facilities. Summary of the Invention

[0010] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for rapid high-altitude dismantling of a Bailey bridge prefabricated integral lifting platform, including the following steps: S100, preparation before dismantling and removal of auxiliary facilities: stop the lifting operation of the lifting platform, remove the pipelines and equipment of the hydraulic system, and remove the auxiliary facilities and paving layer on the top of the platform; S200, Overall reinforcement and dismantling of the hanging rack system: A support frame is preset inside the hanging rack, and the loose hanging rack components are fixedly connected to the support frame to form a rigid whole hanging rack unit, and lifting points are set on the support frame; the connection between adjacent hanging rack units is released, and the hanging rack unit is lifted and dismantled as a whole through the lifting points on the support frame; S300, Bailey bridge steel truss platform symmetrical dismantling: After the entire hanging system is dismantled, the Bailey bridge and connecting parts of each hanging area are dismantled one by one in the reverse order of installation; during the dismantling process, the principle of symmetrical dismantling is followed, and the dismantling progress on both sides of the platform is advanced simultaneously to maintain the overall stability of the remaining platform structure; S400, Support System Dismantling: After the Bailey bridge steel truss platform is dismantled, the heightened columns, guide rail assemblies, and load-bearing seats of the support system are dismantled in sequence.

[0011] Furthermore, in step S100, the process of dismantling the hydraulic system's pipelines and equipment includes: Before dismantling the hydraulic hoses, gradually release the internal pressure of the hoses by adjusting the relief valve and collect the residual oil inside the hoses; then dismantle the hydraulic cylinders and pump stations of each machine position in sequence. The dismantling of hydraulic system pipelines and equipment follows the order of first disconnecting electrical control lines and then disconnecting hydraulic oil pipes.

[0012] Furthermore, in S100, the process of removing the ancillary facilities and paving layer on top of the platform includes: The hydraulic concrete placing boom, canopy protection system, spray curing pipes, unloading platform, and control room on the top of the platform were dismantled in sequence; then the platform top decking and the keel beams below it were dismantled.

[0013] Furthermore, in step S200, the specific process of pre-setting a support frame inside the hanger to form a rigid whole is as follows: According to the planar dimensions of the hanging unit, a rectangular support frame made of welded steel sections is prefabricated; the support frame is installed on the first layer of walkway plate from top to bottom of the hanging unit, and the longitudinal beams and transverse beams of the support frame are respectively welded to the vertical keel and walkway plate of the hanging unit to form the rigid whole; The provision of suspension points on the support frame includes: Lifting lugs are welded at the four corners of the upper chord edge and the midpoint of the long side of the support frame. The lifting lugs are used to connect with the rigging of the lifting equipment for attitude adjustment and main load lifting.

[0014] Furthermore, the hanging system is pre-divided into multiple independent hanging units according to the structural joints, and adjacent hanging units are fixed together by connecting bolts; the disconnection between adjacent hanging units specifically includes: removing all the connecting bolts at the structural joints, so that each hanging unit is separated from the others; In step S200, if the load of the entire hanging frame unit exceeds the lifting equipment's capacity, a segmented dismantling scheme is adopted, specifically including: The bracket unit is divided into multiple sub-units, and the support frame is set in corresponding segments. The support frames of adjacent segments are detachably connected by bolts to form an overall reinforced structure. During the lifting and dismantling process, first remove the bolts between the support frames of the adjacent sections to disconnect them, and then lift and dismantle each subunit separately.

[0015] Furthermore, in S200, the removal steps for the internal mounting bracket located inside the core tube specifically include: A hoisting hole is reserved in the area of ​​the top floor slab of the core tube directly opposite the internal hanging frame, and a temporary lifting device is erected above the hoisting hole; After the inner hanging frame unit is reinforced by the support frame, the hanging frame unit is lifted to above the hoisting hole by the temporary lifting equipment, and then moved horizontally out and picked up by the tower crane and hoisted to the ground.

[0016] Furthermore, in S300, the dismantling progress on both sides of the synchronous propulsion platform to maintain the overall stability of the remaining platform structure specifically includes: The process begins from one end of the platform and proceeds towards the other, while maintaining the difference in the number of Bailey bridges removed from symmetrical positions on both sides of the platform within a preset range. During the dismantling process, the tilt of the remaining platform structure is monitored in real time. If the tilt exceeds the allowable range, the dismantling is suspended and counterweight measures are taken on the tilted side before the dismantling operation is resumed.

[0017] Furthermore, in S300, the specific operational steps for dismantling the Bailey bridge scaffolding in each lifting area sequentially include: The Bailey bridge unit to be dismantled is connected to the reserved remaining platform structure by safety ropes; The lifting equipment is used to hook the lifting points of the Bailey bridge unit to be dismantled; Sequentially remove the lower chord connecting pins and upper chord connecting pins between the Bailey bridge unit to be dismantled and the adjacent unit; After confirming that the connection has been released, the Bailey bridge unit to be dismantled is lifted and separated using the lifting equipment. The suspension points of the Bailey bridge unit are located at the nodes where the upper and lower chords and web members of the Bailey bridge unit intersect.

[0018] Furthermore, in S400, the specific steps for sequentially lifting and dismantling the heightened column, guide rail assembly, and load-bearing base of the support system include: Remove the connecting bolts between the heightening column and the top of the guide rail, and use lifting equipment to lift and separate the heightening column as a whole. Disconnect the guide rail from the load-bearing base, and disassemble the guide rail and the upper and lower reversing boxes as a whole as the guide rail assembly. Remove the load-bearing bases and related embedded parts attached to the building structure, and seal the reserved holes.

[0019] Furthermore, before disconnecting the guide rail from the load-bearing seat, the guide rail assembly is pre-tensioned by a traction device, and then the guide rail assembly is lowered smoothly after the load-bearing connecting parts are removed. Beneficial effects

[0020] This invention transforms the originally loose and easily deformable thin-walled hanging frame system into a rigid module that can be stably lifted and dismantled as a whole by pre-setting a steel support frame inside the hanging frame for overall reinforcement and scientifically arranging the lifting points. This transfers the tedious high-altitude dismantling work to ground dismantling, significantly reducing the time spent working at height and the risk of personnel exposure. At the same time, by combining the dynamic symmetrical dismantling principle of Bailey bridge large-span steel trusses and the traction prestressing buffer mechanism before dismantling the heavy support system, it effectively avoids the risk of instability due to center of gravity shift and sudden impact of heavy objects during the platform dismantling process. The overall solution forms a modular standard dismantling process of "from the outside to the inside, and reverse layer by layer", which significantly improves the construction efficiency, structural stability and overall safety of high-altitude dismantling operations of super high-rise jacking platforms while reducing the dependence on the ultimate lifting capacity of a single lifting device. Attached Figure Description

[0021] Figure 1 This is an overall flowchart of the high-altitude rapid demolition method of the present invention; Figure 2 This is a detailed flowchart illustrating the overall reinforcement and dismantling process of the mounting system of the present invention; Figure 3 This is a flowchart of the dynamic balance dismantling and individual unit stripping process of the Bailey bridge according to the present invention.

[0022] Figure 4 This is a safety control logic architecture diagram of the high-altitude rapid demolition method of the present invention. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0024] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but includes other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0025] The present invention will now be described in further detail with reference to the accompanying drawings: Example

[0026] like Figure 1-4 As shown, a method for rapid high-altitude dismantling of a Bailey bridge prefabricated integral lifting platform includes the following steps: S100. Preparations before dismantling and dismantling of ancillary facilities: Stop the jacking operation of the jacking platform, dismantle the pipelines and equipment of the hydraulic system, and dismantle the ancillary facilities and paving layer on the top of the platform. S200, Overall reinforcement and dismantling of the hanging rack system: A support frame is pre-set inside the hanging rack, and the loose hanging rack components are fixedly connected to the support frame to form a rigid whole hanging rack unit, and lifting points are set on the support frame; the connection between adjacent hanging rack units is disconnected, and the hanging rack unit is lifted and dismantled as a whole through the lifting points on the support frame. S300, Bailey bridge steel truss platform symmetrical dismantling: After the entire hanging system is dismantled, the Bailey bridge and connecting parts of each hanging area are dismantled one by one in the reverse order of installation; during the dismantling process, the principle of symmetrical dismantling is followed, and the dismantling progress on both sides of the platform is advanced simultaneously to maintain the overall stability of the remaining platform structure; S400, Support System Dismantling: After the Bailey bridge steel truss platform is dismantled, the heightened columns, guide rail assemblies, and load-bearing seats of the support system are dismantled in sequence.

[0027] Furthermore, the specific implementation process of step S100 is as follows: Once the prefabricated integral lifting platform reaches the designated top elevation along with the main structure, the system is first locked. Operators cease all hydraulic lifting commands and disconnect the main control power supply to the hydraulic power system, ensuring the entire lifting platform's support system is in a static, anchored state.

[0028] Subsequently, the hydraulic control system pipelines and equipment were dismantled sequentially. This process strictly followed the technical execution sequence of first dismantling electrical control lines and then hydraulic oil pipes, while adhering to the principle of dismantling branch lines before main lines during hydraulic pipeline dismantling. Specifically, the operation was as follows: First, the signal cables and power cables connecting the PLC control cabinet in the control room to each pump station on the platform were disconnected and removed, and the cables were stripped, sorted, and bundled. Next, the high-pressure oil pipes were dismantled. Before disconnecting the high-pressure oil pipes between each double-acting hydraulic cylinder and the pump station, the motor was started in advance, and the static hydraulic pressure inside the high-pressure oil pipes was slowly released by gradually adjusting the opening degree of the system relief valve. After the internal pressure of the pipeline reached atmospheric pressure, the pipe joints were unscrewed, and the remaining working hydraulic oil inside the oil pipes was guided into a special sealed container for centralized collection using a guide tool. After the pipeline interfaces were disconnected, plastic caps were immediately used to physically seal the open hydraulic interfaces of the cylinders and pump stations to prevent external impurities from entering the system.

[0029] After the hydraulic pipeline system is completely disconnected and sealed, the heavy-duty hydraulic drive equipment is mechanically separated. The mounting pins of the double-acting hydraulic cylinders at each machine position are removed from the load-bearing joints of the guide rail reversing box, causing them to detach from their original positions. These cylinders are then hoisted and lowered using slings connected to the cylinder lifting points. Simultaneously, the anchor bolts of the base of each independent pump station unit are released, and the integrated pump station assembly, including the motor, hydraulic pump, and oil tank, is lifted and moved out of the working area as a whole.

[0030] Subsequently, the various auxiliary facilities on the top steel platform were dismantled and lifted. Operators sequentially disconnected the hydraulic placing boom, the canopy protection system, the spray curing pipes, the unloading platform, and the rigid connections between the control room and the top frame of the steel truss platform. For the hydraulic placing boom, which has an asymmetrical center of gravity, a four-point balancing hoisting method was used to lock its stable center of gravity position before the entire unit was lifted and moved. Before lifting the control room, its sensitive electrical control components were pre-disassembled, and moving components such as doors and windows were mechanically locked to ensure geometric stability during the hoisting process.

[0031] The final stage involves dismantling the steel truss top platform cladding and protective structure. Workers remove the surface patterned steel cladding and the supporting beams beneath it. The cladding removal is carried out linearly, span by span, along a predetermined single direction on the platform plane. The dismantled patterned steel plates and individual beams are sorted, stacked, and then hoisted down in batches. Simultaneously, the safety netting and guardrail posts located on the outer and inner sides of the top platform are cut and removed.

[0032] Furthermore, the specific implementation process of step S200 is as follows: First, remove any residual debris from the surface of each layer of the walkway slab and the internal passageways of the hanging frame to ensure there are no scattered, uncontrollable loads. The hanging frame system is pre-divided into several independent hanging frame units along the building facade according to structural joints, and adjacent hanging frame units are mechanically fastened together with connecting bolts. For hanging frame units that are in a state of splicing loose thin-walled rods, a rigid overall reinforcement structure is pre-constructed in the internal space of the hanging frame unit. The specific technical implementation is as follows: based on the planar outer contour dimensions of a single hanging frame unit, a rectangular support frame is prefabricated, which is orthogonally spliced ​​and fully penetrated welded from hot-rolled steel longitudinal beams and transverse beams. The support frame is horizontally hoisted and placed at the position of the first layer of walkway slab from top to bottom of the hanging frame unit, so that the bottom surface of the lower chord of the support frame is close to the upper surface of the metal walkway slab. Subsequently, fillet welds are used to connect the longitudinal beams and transverse beams of the support frame to the upper ends of the thin-walled vertical keels around the hanging frame unit using multi-sided perimeter welding, and continuous fillet welds are used to fully cover the lower chord of the support frame with the base surface of the walkway slab.

[0033] Considering that the vertical keel and walkway panels of the bracket unit are thin-walled components (typically with a wall thickness of about 3mm), while the supporting frame is made of medium-thick hot-rolled steel, to prevent the risk of burn-through of the thin-walled base material and thermal stress deformation caused by excessive welding heat input, the above welding process is forced to adopt a low-heat-input gas shielded welding process, and multi-layer multi-pass welding and segmented back-welding method are applied. For the connection nodes between the vertical keel and the frame beam, a metal transition liner is pre-welded to the thin-walled stress surface of the vertical keel, and then the frame steel and the transition liner are fully penetrated and welded, thereby effectively dispersing the residual welding stress and multiplying the local shear resistance area, ensuring the absolute mechanical reliability of the rigid connection of components with different thicknesses.

[0034] By constructing this multi-point rigid welded joint surface, the vertical keel, hanger rod and walkway plate, which were originally subjected to dispersed forces and were prone to shear deformation, are forcibly anchored together with the support frame with high cross-sectional moment of inertia and bending stiffness. This reconstructs the force transmission path of the hanger unit, transforming it into a rigid integral module that can withstand local concentrated lifting dynamic loads without structural instability.

[0035] Based on the rigid anchoring of the support frame, hoisting anchor points are constructed on the upper chord plane of the support frame. Thick-walled metal plate lifting lugs with pre-drilled load-bearing circular holes are fixed at the four end corners of the support frame's geometric configuration and at the longitudinal midpoints of the two side longitudinal beams using a single-sided bevel full-penetration welding process. The four lifting lugs at the corners primarily serve as the main load-bearing lifting points for docking with the main lifting slings of the hoisting equipment, bearing the absolute load of the target hanger unit's vertical lifting. The lifting lug located at the midpoint of the long side serves as an auxiliary adjustment lifting point for connecting with flexible traction slings such as chain hoists, specifically used for leveling compensation and micro-motion intervention for minor shifts in the center of gravity and spatial posture at the moment the hanger unit detaches from the main building structure.

[0036] After the reinforced frame and lifting points were constructed and passed non-destructive testing, workers intervened in the structural joint areas of the hanging unit. Using a screwdriver, they removed all connecting bolts penetrating the boundaries between adjacent hanging units, completely eliminating the lateral mechanical constraints between the hanging units at the physical structural level. This allowed the target hanging unit to form a physically separated independent lifting module, completely avoiding the destructive separation steps involving open flames or thermal cutting equipment at height. Subsequently, the main hook of the lifting equipment was connected to the lifting lugs on the support frame via high-strength steel wire ropes and shackle assemblies. The lifting mechanism applied an initial preload to keep the lifting wire ropes slightly tensioned. Then, the mechanical response of the stressed welds at each lifting lug and the overall stiffness of the support frame were rechecked. After confirming no signs of stress yielding, the lifting equipment slowly output lifting power, allowing the hanging unit to vertically detach from the building wall interface. During lifting and aerial rotation, the horizontal stability of the module structure was maintained by adjusting the lifting points. Finally, the hanging unit was smoothly lowered to the designated dismantling area on the ground.

[0037] For special application scenarios where the rated lifting load of the main lifting equipment at the work site cannot meet the full-load working conditions of the overall lifting and dismantling of large-size hanging frame units, this method further introduces a modular segmented dismantling structure.

[0038] Under this condition, the original target hanger unit is geometrically divided into multiple sub-units along the horizontal extension direction, and corresponding segmented splicing support frames are configured. The splicing end faces of adjacent segmented support frames are assembled using detachable mechanical connections consisting of structural butt plates and high-strength bolt arrays. After completing the cross-segment and cross-area welding reinforcement operation of the overall hanger unit to maintain the stability of the high-altitude structure, before the lifting mechanism applies force, all butt bolts between the segmented support frames are mechanically removed to release internal rigid constraints. This decomposes the original large-volume hanger unit into lightweight sub-units that meet the safe load threshold of the lifting equipment, and then independently lifts and separates them in sequence.

[0039] For internal hanging frame units concealed within the narrow shaft space inside the core tube, their dismantling faces a technical barrier due to the blind spots covered by external lifting equipment. To address this issue, a pre-reserved, vertically penetrating, closed-frame lifting hole with a metal frame is constructed in the solid area of ​​the top floor slab of the core tube, directly opposite the vertical trajectory projected from the geometric center of the internal hanging frame unit. A temporary lifting gantry and a follow-up electric hoist system are installed across the structural work surface above the lifting hole. After the internal hanging frame unit is rigidly reinforced by embedding it into the support frame as described above, the solidified internal hanging frame unit is lifted along the vertical shaft axis by the temporary lifting system until it passes through the lifting hole and reaches the exposed space at the top floor. It is then horizontally pushed and slid out of the projection area of ​​the hole, and finally hoisted to the ground by the external main lifting equipment.

[0040] Furthermore, the specific implementation process of step S300 is as follows: After the hanging system was completely stripped and the Bailey bridge load-bearing frame of the main steel truss platform was fully exposed, the system systematically entered the reverse lifting and dismantling phase of the Bailey bridge units. Before the dismantling operation, the weight of local components in each spatial lifting area was extracted based on the spatial installation topology diagram and load distribution data of the original truss platform, thereby constructing a structural dismantling matrix that is a strict mirror image of the initial installation sequence. In the actual dismantling execution, the principle of dynamic symmetrical dismantling of the structure was forcibly introduced and implemented throughout the process to suppress the severe shift of the global center of gravity and torsional instability induced by the local mass loss of the large-span suspended platform. Specifically, the operation instructions advanced from one end boundary of the platform to the other end, requiring alternating synchronous dismantling in two symmetrical functional areas of the platform (e.g., corresponding north and south areas). Through the interleaving of physical processes, the difference in the number of Bailey bridge units dismantled on both sides was strictly controlled within a very small preset safety threshold range, thereby maintaining the geometric balance of the remaining suspended steel truss at the macroscopic mechanical level.

[0041] To ensure absolute safety during the symmetrical dismantling process, this embodiment introduces a real-time attitude closed-loop feedback mechanism based on precision instruments. During continuous physical dismantling cycles, high-precision optical surveying equipment such as total stations are used to measure the horizontal elevation of multiple key spatial coordinate points of the remaining platform's load-bearing structure at high frequency, thereby calculating the overall spatial tilt of the platform in real time. Once the monitoring system determines that the current relative tilt is approaching or exceeding the preset limit allowable deformation control line (e.g., one-thousandth of the span), the on-site control center will immediately trigger an interruption command, freezing all current high-altitude structure separation operations. Subsequently, on the non-settlement side where the elevation shift has occurred, pre-prepared high-density counterweight modules are manually stacked or mounted, using static potential energy to forcibly reverse the tilt trend until the platform returns to within the safe baseline horizontal threshold. Only then can the lock be released and the normal dismantling sequence resume.

[0042] The loading position of the counterweight module is not randomly selected, but strictly based on the real-time spatial moment calculation model of the remaining platform. When a tilt alarm occurs, the system locks the outermost cantilever node on the tilted lifting side (i.e., the lighter side) and loads a standardized liquid counterweight box or prefabricated counterweight block at the core intersection node of that cantilever area. By maximizing the effective lever arm of the counterweight load, the system outputs the maximum reverse recovery bending moment with the minimum absolute counterweight mass. In addition, the counterweight loading adopts a step-by-step stacking mode, and an optical elevation remeasurement is performed after each standard equivalent is loaded to avoid secondary tilting or even structural fatigue of the platform caused by a one-time overload.

[0043] For the high-altitude mechanical separation of individual Bailey bridge units, an irreversible, standardized stripping process was developed. Before physical disconnection, workers first securely anchor one end of a flexible safety restraint cable to the main frame of the Bailey bridge unit to be dismantled, and then attach and lock the other end to a rigid node of the remaining platform that is confirmed to be safe and not involved in this round of dismantling, thus constructing the final physical line of defense against falls. Subsequently, the vertical lifting mechanism of the external lifting equipment is lowered to connect the main lifting sling with a pre-set dedicated lifting point on the Bailey bridge unit to be dismantled. This critical lifting point is precisely positioned in the core area of ​​the Bailey bridge unit's geometric structure where multiple components, including the upper and lower chords and internal intersecting diagonal braces, converge in the same plane. This specific location has extremely high shear and tear resistance, ensuring that the internal stress of the entire Bailey bridge remains within the elastic range during lifting, preventing local yielding deformation.

[0044] After the lifting mechanism applies a precisely calculated initial preload to tension the lifting cables, the operators must retreat completely to the inside of the geometric safety boundary of the retained structure to perform the mechanical retraction of the node pins. The retraction sequence follows a gravity-based self-locking release logic prioritizing the lower section: first, a powerful impact tool is used to forcefully push out and remove the connecting metal pins between the lower chord of the unit to be dismantled and the lower chord of the adjacent retained unit; at this time, the upper chord pins at the top of the Bailey bridge continue to maintain a temporary hinged steady state due to the local torque generated by the component's own weight. Immediately afterwards, all connecting pins of the upper chord are simultaneously knocked back and removed along the direction of force release. At the instant all interface pins are completely cleared and absolute physical separation is achieved between the structures, the lifting equipment immediately executes a slow, low-speed vertical lifting procedure to ensure that the Bailey bridge unit to be dismantled completely detaches from the spatial interference envelope of the original structural array in a frictionless state, and is finally guided by the control system to smoothly descend to the ground-based logistics transfer center.

[0045] Furthermore, the specific implementation process of step S400 is as follows: After the Bailey bridge steel truss platform was completely dismantled and removed from the site, the heavy vertical support system, originally hidden at the bottom of the platform, was fully exposed to the working surface. For the dismantling of the support system, the demolition sequence first cut into the heightened column components extending vertically at the top of the system. Workers intervened at the flange end face splicing area between the heightened column and the lower main guide rail, using specialized high-torque dismantling tools to remove the high-strength anchor bolts evenly distributed along the circumferential array one by one. After the mechanical and physical constraints at the end face were completely removed, the main load-bearing slings of the external lifting equipment were connected to the pre-installed metal lifting lugs on the heightened column body. The lifting equipment, using a unidirectional upward lifting method along the vertical axis, smoothly pulled the extremely heavy heightened column from the top end face of the guide rail and transported it as a whole to the ground dismantling site.

[0046] After the heightened columns are removed, the core operation shifts to the removal of the heavy-duty guide rail assembly attached to the surface of the building's shear wall. This assembly highly integrates the core hydraulic actuators, such as the metal main guide rail and the upper and lower reversing boxes, and is massive in weight, suspended vertically against the wall. To prevent destructive downward impact due to its enormous weight when the wall anchoring joint is removed, this embodiment forcibly introduces an anti-gravity prestressed buffer control process before removing the rigid connection between the guide rail and the wall support. Specifically, flexible traction equipment such as chain hoists is pre-configured in the effective stress zone above the top structure of the guide rail, ensuring a reliable closed-loop anchorage between the working end of the traction equipment and the specially designed load-bearing lugs on the upper part of the guide rail. Simultaneously, the stationary fixed end of the traction equipment must be reliably attached to and anchored to the corresponding retained embedded part of the building's shear wall above the guide rail or to the concrete solid floor slab joint of the previous floor that has reached its design strength. By constructing a temporary vertical force path independent of the original load-bearing base between the robust main building structure and the suspended guide rail components, the upward preload output by the traction equipment is ensured to have solid mechanical reaction support. This allows the gravity load of the guide rail to be seamlessly and smoothly transferred to the temporary force path at the moment the main bolts of the wall are released.

[0047] Subsequently, the mechanical drive of the traction equipment applies a vertically upward preload force to the guide rail components, strictly opposite to the direction of gravity. This preload continues until the lifting cable exhibits rigid tension and slightly replaces the load-bearing seat in bearing the localized actual load of the guide rail, thereby eliminating the potential vertical free fall tendency of the guide rail assembly at the moment of anchorage from the source of stress. After the aforementioned preload safety system is established and confirmed by dynamic mechanical verification to have no abnormal slippage, the operators can safely intervene at the rear load-bearing seat connection node to completely unload the main load-bearing bolts or load-bearing pins passing through the guide rail flange and the wall load-bearing seat. After the structural constraints are released, the operators simultaneously control the top traction equipment to release the vertical tension force extremely slowly, guiding the heavy guide rail assembly to descend gently along the main wall with a small stroke and move it to the safe space release zone, where it is finally handed over to the main hoisting equipment on site to fully take over its gravity load and complete the lowering and hoisting.

[0048] After the guide rail assembly is safely detached from the main structure, the system enters the final unloading and structural restoration operation at the wall attachment point of the support system. Operators mechanically dismantle the high-strength load-bearing seats attached to the main structural beams or shear walls, removing the through-wall anchor bolts at their base one by one using a rotary tool. All remaining metal inserts, such as load-bearing climbing cones and tension sleeves, deeply embedded in the concrete matrix, are then pulled out in the reverse direction. After the load-bearing base and all embedded parts are cleaned, the remaining penetrating structural holes in the original concrete wall are filled and permanently sealed using high-grade micro-expansion cement mortar or high-strength non-shrink grout in multiple layers. This process completely cuts off potential water vapor penetration paths from the internal dense structural level, restoring the waterproof and seepage-resistant performance and surface geometric flatness of the main building components, marking the completion of the dismantling of all high-altitude components of the prefabricated integral lifting platform.

[0049] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for rapid high-altitude dismantling of a Bailey bridge prefabricated integral lifting platform, characterized in that, Includes the following steps: S100. Preparations before dismantling and dismantling of ancillary facilities: Stop the jacking operation of the jacking platform, dismantle the pipelines and equipment of the hydraulic system, and dismantle the ancillary facilities and paving layer on the top of the platform. S200, Overall reinforcement and dismantling of the hanging rack system: A support frame is preset inside the hanging rack, and the loose hanging rack components are fixedly connected to the support frame to form a rigid whole hanging rack unit, and lifting points are set on the support frame; the connection between adjacent hanging rack units is released, and the hanging rack unit is lifted and dismantled as a whole through the lifting points on the support frame; S300, Bailey bridge steel truss platform symmetrical dismantling: After the entire hanging system is dismantled, the Bailey bridge and connecting parts of each hanging area are dismantled one by one in the reverse order of installation; during the dismantling process, the principle of symmetrical dismantling is followed, and the dismantling progress on both sides of the platform is advanced simultaneously to maintain the overall stability of the remaining platform structure; S400, Support System Dismantling: After the Bailey bridge steel truss platform is dismantled, the heightened columns, guide rail assemblies, and load-bearing seats of the support system are dismantled in sequence.

2. The method for rapid high-altitude dismantling of a Bailey bridge prefabricated integral lifting platform according to claim 1, characterized in that, In step S100, the process of dismantling the pipelines and equipment of the hydraulic system includes: Before dismantling the hydraulic hoses, gradually release the internal pressure of the hoses by adjusting the relief valve and collect the residual oil inside the hoses; then dismantle the hydraulic cylinders and pump stations of each machine position in sequence. The dismantling of hydraulic system pipelines and equipment follows the order of first disconnecting electrical control lines and then disconnecting hydraulic oil pipes.

3. The method for rapid high-altitude dismantling of a Bailey bridge prefabricated integral lifting platform according to claim 2, characterized in that, In step S100, the process of removing the ancillary facilities and paving layer on top of the platform includes: The hydraulic concrete placing boom, canopy protection system, spray curing pipes, unloading platform, and control room on the top of the platform were dismantled in sequence; then the platform top decking and the keel beams below it were dismantled.

4. The method for rapid high-altitude dismantling of a Bailey bridge prefabricated integral lifting platform according to claim 3, characterized in that, In step S200, the specific process of pre-setting a support frame inside the hanger to form a rigid whole is as follows: According to the planar dimensions of the hanging unit, a rectangular support frame made of welded steel sections is prefabricated; the support frame is installed on the first layer of walkway plate from top to bottom of the hanging unit, and the longitudinal beams and transverse beams of the support frame are respectively welded to the vertical keel and walkway plate of the hanging unit to form the rigid whole; The provision of suspension points on the support frame includes: Lifting lugs are welded at the four corners of the upper chord edge and the midpoint of the long side of the support frame. The lifting lugs are used to connect with the rigging of the lifting equipment for attitude adjustment and main load lifting.

5. A method for rapid high-altitude dismantling of a Bailey bridge prefabricated integral lifting platform according to claim 4, characterized in that, The hanging system is pre-divided into multiple independent hanging units according to the structural joints, and adjacent hanging units are fixed together by connecting bolts; the release of the connection between adjacent hanging units specifically includes: removing all the connecting bolts at the structural joints, so that each hanging unit is separated from the others; In step S200, if the load of the entire hanging frame unit exceeds the lifting equipment's capacity, a segmented dismantling scheme is adopted, specifically including: The bracket unit is divided into multiple sub-units, and the support frame is set in corresponding segments. The support frames of adjacent segments are detachably connected by bolts to form an overall reinforced structure. During the lifting and dismantling process, first remove the bolts between the support frames of the adjacent sections to disconnect them, and then lift and dismantle each sub-unit separately.

6. A method for rapid high-altitude dismantling of a Bailey bridge prefabricated integral lifting platform according to claim 5, characterized in that, In step S200, the removal steps for the internal mounting bracket located inside the core tube specifically include: A hoisting hole is reserved in the area of ​​the top floor slab of the core tube directly opposite the internal hanging frame, and a temporary lifting device is erected above the hoisting hole; After the inner hanging frame unit is reinforced by the support frame, the hanging frame unit is lifted to above the hoisting hole by the temporary lifting equipment, and then moved horizontally out and picked up by the tower crane and hoisted to the ground.

7. A method for rapid high-altitude dismantling of a Bailey bridge prefabricated integral lifting platform according to claim 6, characterized in that, In step S300, the dismantling progress on both sides of the synchronous propulsion platform is maintained to ensure the overall stability of the remaining platform structure, specifically including: The process begins from one end of the platform and proceeds towards the other, while maintaining the difference in the number of Bailey bridges removed from symmetrical positions on both sides of the platform within a preset range. During the dismantling process, the tilt of the remaining platform structure is monitored in real time. If the tilt exceeds the allowable range, the dismantling is suspended and the dismantling operation is resumed after counterweight measures are taken on the tilted side.

8. A method for rapid high-altitude dismantling of a Bailey bridge prefabricated integral lifting platform according to claim 7, characterized in that, In S300, the specific operational steps for dismantling the Bailey bridge scaffolding in each lifting area sequentially include: The Bailey bridge unit to be dismantled is connected to the reserved remaining platform structure by safety ropes. The lifting equipment is used to hook the lifting points of the Bailey bridge unit to be dismantled; Sequentially remove the lower chord connecting pins and upper chord connecting pins between the Bailey bridge unit to be dismantled and the adjacent unit; After confirming that the connection has been released, the Bailey bridge unit to be dismantled is lifted and separated using the lifting equipment. The suspension points of the Bailey bridge unit are located at the nodes where the upper and lower chords and web members of the Bailey bridge unit intersect.

9. A method for rapid high-altitude dismantling of a Bailey bridge prefabricated integral lifting platform according to claim 8, characterized in that, In S400, the specific steps for sequentially lifting and dismantling the heightened column, guide rail assembly, and load-bearing base of the support system include: Remove the connecting bolts between the heightening column and the top of the guide rail, and use lifting equipment to lift and separate the heightening column as a whole. Disconnect the guide rail from the load-bearing base, and disassemble the guide rail and the upper and lower reversing boxes as a whole as the guide rail assembly. Remove the load-bearing bases and related embedded parts attached to the building structure, and seal the reserved holes.

10. A method for rapid high-altitude dismantling of a Bailey bridge prefabricated integral lifting platform according to claim 9, characterized in that, Before disconnecting the guide rail from the load-bearing base, the guide rail assembly is pre-tensioned by a traction device. After the load-bearing connecting parts are removed, the guide rail assembly is then lowered smoothly.

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