Temporary support unloading process for multi-surface cutting type roof steel structure

Abstract

The invention relates to a temporary support unloading process for a multi-surface cutting type roof steel structure, which comprises the following steps: S1, after the closure of the roof steel structure is finished and an unloading condition is met, arranging a pressure detection device at each main truss section splicing node of a cantilever part of the roof steel structure; s2, a jacking support arranged on the temporary support in advance is used for jacking a truss lower chord of the overhanging part, then cutting equipment is used for cutting the top of an adjusting pipe of the temporary support, a deformation detection device is used for detecting the deformation state of the overhanging part in real time, and a pressure detection device is used for detecting the stress change at the splicing joint in real time; s3, the step S2 is repeated until the lower chord of the cantilever part truss is completely separated from the top of the adjusting pipe, and unloading is finished; according to the unloading process, active control and multi-dimensional real-time feedback in the unloading process are achieved, the crossing from passive bearing risk to active management risk is achieved, the structural safety of the overhanging part is guaranteed, and the forming precision is controlled.

Description

Technical Field

[0001] This invention relates to the field of steel structure construction technology, and in particular to a temporary support unloading process for a multi-faceted cut-type roof steel structure. Background Technology

[0002] Multi-faceted cut roof steel structure, such as Figure 1 As shown, the roof is composed of tubular members and tubular trusses with different cross-sections. The roof has numerous truss structures around its perimeter, with many nodes and branches, resulting in a complex structure, irregularly shaped components, and varied splicing angles. During construction, it experiences significant deformation and complex stress. Therefore, before the roof steel structure is fully integrated, temporary supports need to be erected at the bottom to bear its structural weight. Once the roof steel structure is installed and forms a unified whole, the temporary supports should be removed. This allows the load previously borne by the temporary supports to be transferred to the individual components within the roof steel structure system, where they enter a stress state according to the design intent, ultimately achieving force equilibrium. This conversion process is called unloading.

[0003] In the entire construction process of the multi-faceted cut roof steel structure, the unloading of temporary supports is a crucial procedure. Because the unloading process involves the transfer of force and the transformation of the load-bearing body, it is a dynamic process. The transfer of force and the transformation of the load-bearing body must be carried out in a reasonable, orderly, smooth, slow, and uniform manner. The multi-faceted cut roof steel structure has numerous cantilevered sections around its four edges, with the highest cantilever reaching 18.33m. It not only has a high installation height and large span, but also features irregular structural characteristics with multi-angle bending.

[0004] Traditional temporary support unloading methods employ a gradual cutting of temporary supports. This unloading process is discrete and discontinuous; each cut causes a sudden change and redistribution of stress. For cantilevered sections with multi-angle bends, the uneven stiffness distribution makes them extremely sensitive to changes in support points. Conventional jump-type unloading methods cannot simulate the actual behavior of the structure under continuous, slow, and uniform load transfer. This can lead to local members or nodes experiencing instantaneous impact stresses or deformations not considered in the design, posing safety hazards. Furthermore, traditional unloading processes often rely on total stations for monitoring. Total stations involve discrete, periodic manual measurements, typically performing static measurements before and after cutting. They cannot capture dynamic changes at the moment of cutting or during the process. The most dangerous state of the structure often occurs at the moment of load transfer, and critical nodes in cantilevered structures with multi-angle bends are often obscured, making comprehensive and dense monitoring impossible with total stations alone.

[0005] Therefore, this invention proposes a temporary support unloading process for multi-faceted cut roof steel structures to solve the above problems. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a temporary support unloading process for a multi-faceted cut roof steel structure, so as to realize active control and multi-dimensional real-time feedback in the unloading process, ensure the structural safety of the cantilever part, and control the forming accuracy.

[0007] To solve the above-mentioned technical problems, the technical solution of the present invention is: a temporary support unloading process for a multi-faceted cut roof steel structure, the innovation of which is: including the following steps: S1. After the roof steel structure is closed and the unloading conditions are met, pressure detection devices are arranged at the assembly nodes of each main truss segment of the cantilevered part of the roof steel structure. After the pressure detection devices are installed, the initial pressure value of each pressure detection device is recorded. S2. Using the top support brackets pre-installed on the temporary supports, the lower chord of the cantilevered truss is tightened. Then, the top of the adjustment tube of the temporary support is cut with cutting equipment. When cutting the top of the adjustment tube, the axial cutting height is 3cm first, and then 2 / 3 of the length is cut off along the perimeter. After that, the remaining length is cut off in multiple times along the perimeter. When cutting off the remaining length, cut 1~2cm along the perimeter each time until the top of the support tube is completely cut off. The top support bracket is slowly lowered. When the lower chord of the cantilevered truss slowly deforms and contacts the top of the adjustment tube again, one unloading is completed. Throughout the process, the deformation detection device is pre-installed at each structural inflection point or stress weak point of the cantilevered part to detect the deformation state of the cantilevered part in real time. The stress detection device is used to detect the stress change at each main truss segment assembly node of the cantilevered part in real time. S3. Repeat step S2 until the lower chord of the cantilevered truss is completely separated from the top of the regulating pipe. The unloading is then completed. After that, the top support is slowly lowered. When the stress value at the assembly node of each main truss segment of the cantilevered section is stable as detected by the pressure detection device, the bottom weld of the regulating pipe is cut open, the regulating pipe is removed, the pressure detection device is removed, and finally the top support is removed.

[0008] Furthermore, the unloading conditions include: The roof steel structure has been installed and the welds have passed inspection. Check that all connection nodes are intact; The roof steel structure is in a free state without additional constraints, avoiding the need for fixed connections between temporary supports and the roof steel structure.

[0009] Furthermore, the pressure detection device includes an upper support, a lower support, a flat plate pressure sensor, a guide rod, and a spring; The upper and lower supports are respectively installed on the two sides of the assembly node of the cantilevered main truss segment. The lower support is located below the upper support. The flat plate pressure sensor is installed on the lower support. The guide rod is fixed on the upper support. The spring is movably fitted on the outside of the guide rod. The top of the spring is fixedly connected to the upper support. The bottom of the spring is movably abutting against the pressure-bearing surface of the flat plate pressure sensor. The central axis of the spring is perpendicular to the pressure-bearing surface of the flat plate pressure sensor.

[0010] Furthermore, in step S3, when removing the pressure detection device, the spring is first cut to cancel the stress transmission between the spring and the platform-type pressure sensor, and then the lower support and the upper support are cut off.

[0011] Furthermore, the deformation detection device includes a windproof housing, a distance sensor, a signal receiving board, and two rotating supports; The windproof box is fitted outside the inflection point or stress-weak point of the cantilevered structure. Two rotating brackets are set inside the windproof box and are respectively installed on the poles on both sides of the inflection point or stress-weak point of the cantilevered structure by clamps. The clamps have a rotating shaft, and the rotating brackets are rotatably mounted on the rotating shaft. The ranging sensor and the signal receiving board are respectively installed on the two rotating brackets below the rotating shaft. The signal receiving board is set perpendicular to the ranging laser emitted by the ranging sensor. Each rotating bracket has a counterweight frame at its bottom, and several counterweight blocks are detachably installed in the counterweight frame.

[0012] Furthermore, when arranging the deformation detection device, it is necessary to ensure that there are no other structural interferences on the rotation trajectory of each rotating support, and to adjust the number of counterweight blocks in the counterweight frame at the bottom of each rotating support to ensure that the center of gravity of the cantilever structure remains stable before and after the installation of the deformation detection device.

[0013] Furthermore, the top support bracket includes a base, a jack, and a rotating bracket; The base is fixed in the middle of the temporary support. There are two jacks, which are respectively set on both sides of the temporary support. The bottom of the jacks is fixedly installed on the base. The rotating bracket is sleeved on the outside of the temporary support and set above the jacks. The bottom two sides of the rotating bracket are respectively hinged to the piston rod end of the jack. The top of the rotating bracket is provided with two V-grooves for placing segments. Fiber optic strain gauges are attached in the V-grooves. The two V-grooves are respectively set on both sides of the temporary support. There are two vertically set limit rods on both sides of each V-groove on the rotating bracket. Each limit rod is provided with an inclined guide plate at the top. The inclined guide plate is inclined from top to bottom towards the middle of the V-groove.

[0014] Furthermore, in step S2, when the lower chord of the cantilevered truss is tightened using the top support bracket, the tightening force applied to the lower chord of the truss by the rotating bracket is adjusted to the design value based on the data changes detected by the fiber optic strain gauge attached in the V-groove. During the adjustment process, it is necessary to ensure that the stress values ​​at the assembly nodes of each main truss segment of the cantilevered part detected by the pressure detection device remain stable.

[0015] Furthermore, in step S3, when repeating step S2, after each unloading is completed, the top support bracket continues to slowly lower the rotating bracket. When the stress detected by the fiber optic strain gauge attached in the V-groove returns to zero, the stress value at the assembly node of each main truss segment of the cantilever section detected by the pressure detection device is recorded, and the pressure value is compared with the initial pressure value. If the stress value change is within the safe range, unloading continues, and the pressure value is used as the new initial pressure value. If it exceeds the safe range, unloading stops, the top support bracket moves up, and the rotating bracket tightens the lower chord of the cantilever section truss, and the roof steel structure is inspected and repaired.

[0016] Further, in step S3, step S2 is repeated until the lower chord of the cantilevered truss is completely separated from the top of the adjusting pipe, and the unloading is completed. Then, when the top support is slowly lowered, the stress detected by the fiber optic strain gauge attached in the V-groove returns to zero, but the lower chord of the cantilevered truss is still between the limiting rods on both sides of the V-groove. After the adjusting pipe and pressure detection device are removed, the rotating bracket is lowered to make the lower chord of the cantilevered truss leave the limiting rods on both sides of the V-groove. Then the lifting support is removed.

[0017] The advantages of this invention are: During the unloading process, the multi-faceted cut roof steel structure of this invention utilizes deformation detection devices pre-positioned at structural inflection points or stress-weak points in the cantilever section to monitor the deformation state of the cantilever section in real time, dynamically providing feedback on the overall stability of the cantilever section's posture. Furthermore, a pressure detection device monitors stress changes at the assembly nodes of each main truss segment of the cantilever section in real time, providing feedback on the balanced distribution of stress within the cantilever section. By comparing data at various points in real time, the lifting and lowering speeds and strokes of the top support brackets are dynamically adjusted to ensure that the load on the cantilever section is smoothly transferred along the preset optimal path. This achieves proactive control and multi-dimensional real-time feedback during the unloading process, representing a shift from passively bearing risk to actively managing risk, ensuring the structural safety of the cantilever section, and controlling the forming accuracy. Attached Figure Description

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0019] Figure 1 This is a schematic diagram of the multi-faceted cut roof steel structure of the present invention.

[0020] Figure 2 This is a schematic diagram showing the arrangement of the pressure detection device, deformation detection device, and top support bracket of the present invention at the cantilevered portion.

[0021] Figure 3 This is a schematic diagram of the pressure detection device of the present invention.

[0022] Figure 4 This is a schematic diagram of the deformation detection device of the present invention.

[0023] Figure 5 This is a front view of the top support bracket of the present invention.

[0024] Figure 6 This is a side view of the top support bracket of the present invention.

[0025] Figure 7 This is a flowchart illustrating the cutting adjustment tube during the temporary support unloading process of the present invention. Detailed Implementation

[0026] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0027] Example This embodiment provides a temporary support unloading process for a multi-faceted cut-type roof steel structure, including the following steps: S1. After the roof steel structure is fully assembled and meets the unloading conditions, pressure detection devices 1 are installed at the assembly nodes of each main truss segment of the cantilevered part of the roof steel structure, such as... Figure 2 As shown, after the pressure detection device 1 is installed, the initial pressure value of each pressure detection device 1 is recorded.

[0028] The unloading conditions include: the roof steel structure is installed and the welds are inspected and found to be in good condition; all connection nodes are checked for integrity; the roof steel structure is in a free state without any additional constraints, and the temporary supports are not fixed to the roof steel structure.

[0029] like Figure 3As shown, the pressure detection device 1 includes an upper support 11, a lower support 15, a flat plate pressure sensor 14, a guide rod 12, and a spring 13. The upper support 11 and the lower support 15 are respectively installed on the two sides of the assembly node of the main truss segment of the cantilevered part. The lower support 15 is located below the upper support 11. The flat plate pressure sensor 14 is installed on the lower support 15. The guide rod 12 is fixed on the upper support 11. The spring 13 is movably fitted on the outside of the guide rod 12. The top of the spring 13 is fixedly connected to the upper support 11. The central axis of the spring 13 is perpendicular to the bearing surface of the flat plate pressure sensor 15. The bottom end of the spring 13 movably abuts against the bearing surface of the flat plate pressure sensor 15, ensuring that the cantilevered part of the roof steel structure is in a free state. The installation of the pressure detection device 1 does not impose any additional constraints on the cantilevered part.

[0030] S2. Using pre-installed top supports on the temporary supports, tighten the lower chord of the cantilevered truss. Then, use cutting equipment to cut the top of the adjusting pipe of the temporary supports. When cutting the top of the adjusting pipe, if... Figure 7 As shown, first, the axial cutting height is 3cm, then 2 / 3 of the length is cut off along the circumference. After that, the remaining length is cut off multiple times along the circumference, cutting 1~2cm each time along the circumference until the top of the support tube is completely cut off. The top support is slowly lowered, and the lower chord of the cantilevered truss slowly deforms until it contacts the top of the adjusting tube again, completing one unloading. Throughout the process, deformation detection devices are used to detect the deformation state of the cantilevered part in real time at each structural inflection point or stress weak point of the cantilevered part, and pressure detection devices are used to detect the stress at each main truss segment assembly node of the cantilevered part in real time.

[0031] like Figure 4 As shown, the deformation detection device 2 includes a windproof box 27, a ranging sensor 21, a signal receiving board 22, and two rotating brackets 23. The windproof box 27 is fitted onto the outside of the inflection point or stress weak point of the suspension structure. The two rotating brackets 23 are set inside the windproof box and are respectively installed on the rods on both sides of the inflection point or stress weak point of the suspension structure via clamps 24. The clamps 24 have a rotating shaft, and the rotating brackets 23 are rotatably fitted onto the rotating shaft. The ranging sensor 24 and the signal receiving board 22 are respectively installed below the rotating shaft on the two rotating brackets 23. The signal receiving board 22 is set perpendicular to the ranging laser emitted by the ranging sensor 21. Each rotating bracket 23 has a counterweight frame 25 at its bottom. Several counterweight blocks 26 are detachably installed in the counterweight frame 25. The counterweight blocks 26 are stacked in the counterweight frame 25 and fixed by bolts.

[0032] The two rotating supports 23 inside the windproof box 27 remain vertical under the action of the counterweight 26. If the structural inflection point or stress weak point on the cantilever section deforms, the distance between the two rotating supports 23 installed on both sides of the structural inflection point or stress weak point will change. As a result, the vertical distance signal detected by the distance sensor 24 between the sensor and the signal receiving board 22 will change. This allows for real-time detection of deformation during unloading, timely detection of abnormal deformation at nodes, and timely intervention before structural damage occurs.

[0033] When arranging the deformation detection device 2, it is necessary to ensure that there are no other structural interferences on the rotation trajectory of each rotating support 23, and to adjust the number of counterweight blocks 26 in the counterweight frame at the bottom of each rotating support 23 to ensure that the center of gravity of the cantilever structure remains stable before and after the installation of the deformation detection device 2.

[0034] like Figure 5-6 As shown, the top support bracket 3 includes a base 31, jacks 32, and a rotating bracket 33. The base 31 is fixed in the middle of the temporary support 4. There are two jacks 32, which are respectively arranged on both sides of the temporary support 4. The bottom of the jacks 32 is fixedly installed on the base 31. The rotating bracket 33 has a square frame structure. The rotating bracket 33 is sleeved on the outside of the temporary support 4 and is arranged above the jacks 32. The bottom sides of the rotating bracket 33 are respectively hinged to the piston rod ends of the two jacks 32. The top of the rotating bracket 32 ​​is provided with two sections for placing segments. The V-groove 331 is conducive to achieving precise positioning of the segment. Two V-grooves 331 are respectively set on both sides of the temporary support 4. Fiber optic strain gauges are attached in each V-groove. Two vertically set limit rods 34 are provided on both sides of each V-groove 331 on the rotating bracket 33. In order to facilitate the smooth entry of the lower chord of the cantilevered truss into the space between the two limit rods, an inclined guide plate 35 is provided at the top of each limit rod 34. The inclined guide plate 35 is inclined from top to bottom towards the middle of the V-groove 34 to guide the falling trajectory of the lower chord of the truss.

[0035] When the bottom chord of the cantilevered truss is tightened using the top support bracket 3, the tightening force applied to the bottom chord of the truss by the rotating bracket 33 is adjusted to the design value based on the data changes detected by the fiber optic strain gauge attached in the V-groove 331. During the adjustment process, it is necessary to ensure that the stress values ​​at the assembly nodes of each main truss segment of the cantilevered part detected by the pressure detection device 1 remain stable.

[0036] S3. Repeat step S2 until the lower chord of the cantilevered truss is completely separated from the top of the regulating pipe. Unloading is complete. After unloading is complete, the top support bracket is slowly lowered. When the stress value at the assembly node of each main truss segment of the cantilevered part is stable as detected by the pressure detection device, the bottom weld of the regulating pipe is cut open, the regulating pipe is removed, the pressure detection device is removed, and finally the top support bracket is removed.

[0037] When repeating step S2, after each unloading is completed, the top support bracket 3 continues to slowly lower the rotating bracket 33. When the stress detected by the fiber optic strain gauge attached in the V-groove 331 returns to zero, the stress value at the assembly node of each main truss segment of the cantilever section detected by the pressure detection device 1 is recorded, and the pressure value is compared with the initial pressure value. If the stress value change is within the safe range, unloading continues, and the pressure value is used as the new initial pressure value. If it exceeds the safe range, unloading stops, the top support bracket 3 moves the rotating bracket 33 upward to tighten the lower chord of the cantilever section truss, and the roof steel structure is inspected and repaired.

[0038] After unloading, the top support bracket is slowly lowered so that the stress detected by the fiber optic strain gauge attached to the V-groove 331 returns to zero. However, the lower chord of the cantilevered truss remains between the limiting rods 34 on both sides of the V-groove 331 to cope with sudden structural changes and improve safety. After the regulating pipe and pressure detection device 1 are removed, the rotating bracket 33 is lowered so that the lower chord of the cantilevered truss leaves the limiting rods 34 on both sides of the V-groove. Then the lifting support 3 is removed.

[0039] When removing the pressure detection device 1, first cut the spring 13 to cancel the stress transmission between the spring 13 and the platform-type pressure sensor 14, and then cut off the lower support 15 and the upper support 11.

[0040] During the unloading process of the multi-faceted cut roof steel structure, deformation detection devices 2, which are pre-placed at the inflection points or stress weak points of the cantilever section, are used to detect the deformation state of the cantilever section in real time and provide dynamic feedback on whether the overall posture of the cantilever section is stable. Pressure detection devices 1 are used to detect the stress changes at the assembly nodes of each main truss segment of the cantilever section in real time and provide feedback on whether the stress distribution within the cantilever section is balanced. By comparing the data at each point in real time, the lifting and lowering speed and stroke of the top support bracket 3 are dynamically adjusted to ensure that the load of the cantilever section is transferred smoothly along the preset optimal path. This achieves active control and multi-dimensional real-time feedback in the unloading process, and transforms the process from passively bearing risks to actively managing risks, ensuring the structural safety of the cantilever section and controlling the forming accuracy.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A temporary support unloading process for a multi-faceted cut-type roof steel structure, characterized in that: Includes the following steps: S1. After the roof steel structure is closed and the unloading conditions are met, pressure detection devices are arranged at the assembly nodes of each main truss segment of the cantilevered part of the roof steel structure. After the pressure detection devices are installed, the initial pressure value of each pressure detection device is recorded. S2. Using the top support brackets pre-installed on the temporary supports, the lower chord of the cantilevered truss is tightened. Then, the top of the adjustment tube of the temporary support is cut with cutting equipment. When cutting the top of the adjustment tube, the axial cutting height is 3cm first, and then 2 / 3 of the length is cut off along the perimeter. After that, the remaining length is cut off in multiple times along the perimeter. When cutting off the remaining length, cut 1~2cm along the perimeter each time until the top of the support tube is completely cut off. The top support bracket is slowly lowered. When the lower chord of the cantilevered truss slowly deforms and contacts the top of the adjustment tube again, one unloading is completed. Throughout the process, the deformation detection device is pre-installed at each structural inflection point or stress weak point of the cantilevered part to detect the deformation state of the cantilevered part in real time. The stress detection device is used to detect the stress change at each main truss segment assembly node of the cantilevered part in real time. S3. Repeat step S2 until the lower chord of the cantilevered truss is completely separated from the top of the regulating pipe. The unloading is then completed. After that, the top support is slowly lowered. When the stress value at the assembly node of each main truss segment of the cantilevered section is stable as detected by the pressure detection device, the bottom weld of the regulating pipe is cut open, the regulating pipe is removed, the pressure detection device is removed, and finally the top support is removed.

2. The temporary support unloading process for the multi-faceted cut roof steel structure according to claim 1, characterized in that: The uninstallation conditions include: The roof steel structure has been installed and the welds have passed inspection. Check that all connection nodes are intact; The roof steel structure is in a free state without additional constraints, avoiding the need for fixed connections between temporary supports and the roof steel structure.

3. The process for temporary bracing unloading of a multi-faceted cut type roof steel structure according to claim 1, characterized in that: The pressure detection device includes an upper support, a lower support, a flat plate pressure sensor, a guide rod, and a spring. The upper and lower supports are respectively installed on the two sides of the assembly node of the cantilevered main truss segment. The lower support is located below the upper support. The flat plate pressure sensor is installed on the lower support. The guide rod is fixed on the upper support. The spring is movably fitted on the outside of the guide rod. The top of the spring is fixedly connected to the upper support. The bottom of the spring is movably abutting against the pressure-bearing surface of the flat plate pressure sensor. The central axis of the spring is perpendicular to the pressure-bearing surface of the flat plate pressure sensor.

4. The process for temporary bracing unloading of a multi-faceted cut type roof steel structure according to claim 3, characterized in that: In step S3, when removing the pressure detection device, first cut the spring to cancel the stress transmission between the spring and the platform-type pressure sensor, and then cut off the lower support and the upper support.

5. The process for temporary bracing unloading of a multi-faceted cut type roof steel structure according to claim 1, characterized in that: The deformation detection device includes a windproof box, a distance sensor, a signal receiving board, and two rotating brackets. The windproof box is fitted outside the inflection point or stress-weak point of the cantilevered structure. Two rotating brackets are set inside the windproof box and are respectively installed on the poles on both sides of the inflection point or stress-weak point of the cantilevered structure by clamps. The clamps have a rotating shaft, and the rotating brackets are rotatably mounted on the rotating shaft. The ranging sensor and the signal receiving board are respectively installed on the two rotating brackets below the rotating shaft. The signal receiving board is set perpendicular to the ranging laser emitted by the ranging sensor. Each rotating bracket has a counterweight frame at its bottom, and several counterweight blocks are detachably installed in the counterweight frame.

6. The process for temporary bracing unloading of a multi-faceted cut type roof steel structure according to claim 5, characterized in that: When arranging the deformation detection device, it is necessary to ensure that there are no other structures interfering with the rotation trajectory of each rotating support, and to adjust the number of counterweights in the counterweight frame at the bottom of each rotating support to ensure that the center of gravity of the cantilever structure remains stable before and after the installation of the deformation detection device.

7. The process for temporary bracing unloading of a multi-faceted cut type roof steel structure according to claim 1, characterized in that: The top support bracket includes a base, a jack, and a rotating bracket; The base is fixed in the middle of the temporary support. There are two jacks, which are respectively set on both sides of the temporary support. The bottom of the jacks is fixedly installed on the base. The rotating bracket is sleeved on the outside of the temporary support and set above the jacks. The bottom two sides of the rotating bracket are respectively hinged to the piston rod end of the jack. The top of the rotating bracket is provided with two V-grooves for placing segments. Fiber optic strain gauges are attached in the V-grooves. The two V-grooves are respectively set on both sides of the temporary support. There are two vertically set limit rods on both sides of each V-groove on the rotating bracket. Each limit rod is provided with an inclined guide plate at the top. The inclined guide plate is inclined from top to bottom towards the middle of the V-groove.

8. The process for temporary bracing unloading of a multi-faceted cut type roof steel structure according to claim 7, characterized in that: In step S2, when the lower chord of the cantilevered truss is tightened using the top support bracket, the tightening force applied to the lower chord of the truss by the rotating bracket is adjusted to the design value based on the data changes detected by the fiber optic strain gauge attached in the V-groove. During the adjustment process, it is necessary to ensure that the stress values ​​at the assembly nodes of each main truss segment of the cantilevered part detected by the pressure detection device remain stable.

9. The process for temporary bracing unloading of a multi-faceted cut type roof steel structure according to claim 7, characterized in that: In step S3, when repeating step S2, after each unloading is completed, the top support bracket continues to slowly lower the rotating bracket. When the stress detected by the fiber optic strain gauge attached in the V-groove returns to zero, the stress value at the assembly node of each main truss segment of the cantilever section detected by the pressure detection device is recorded, and the pressure value is compared with the initial pressure value. If the stress value change is within the safe range, unloading continues, and the pressure value is used as the new initial pressure value. If it exceeds the safe range, unloading stops, the top support bracket moves up, the rotating bracket is tightened against the lower chord of the cantilever section truss, and the roof steel structure is inspected and repaired.

10. The process for temporary bracing unloading of a multi-faceted cut type roof steel structure according to claim 7, characterized in that: In step S3, after unloading is completed, the top support bracket is slowly lowered so that the stress detected by the fiber optic strain gauge attached to the V-groove returns to zero. However, the lower chord of the cantilevered truss remains between the limiting rods on both sides of the V-groove until the adjusting pipe and pressure detection device are removed. Then, the rotating bracket is lowered so that the lower chord of the cantilevered truss leaves the limiting rods on both sides of the V-groove. After that, the lifting support bracket is removed.

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