Formwork system suitable for core tube cross section shrinkage platform retreating and construction method of formwork system

Abstract

The invention discloses a formwork system suitable for core tube section shrinkage and retreating and a construction method of the formwork system. The formwork system mainly comprises at least one single-truss formwork which is arranged on a supporting face and forms a three-dimensional supporting frame through stand columns, horizontal structures and inclined struts; the modularized space truss is detachably connected to the stand columns of at least one single-truss formwork and used for transverse connection and platform erection between the single-truss formworks. Through modular design of the formwork, high-altitude quick disassembly and change and real-time process monitoring, it can be guaranteed that formwork construction is safe and efficient, operation is easy, the construction cost is saved, and the construction period is shortened.

Description

Technical Field

[0001] The present invention belongs to the technical field of building construction, and relates to a formwork system applicable to the core tube cross-section shrinkage and stepped-back platform and a construction method thereof. Background Art

[0002] In general, the core tube structures of high-rise and super high-rise buildings have large cross-section stepped-back platforms, and the formwork for core tube construction needs to be demolished and rebuilt at high altitude according to structural changes; the formwork design for core tube construction and high-altitude structural conversion are factors that need to be considered key. At present, the demolition and reconstruction of formwork for high-rise and super high-rise buildings generally choose high-altitude cutting and on-site demolition and reconstruction, which are high-altitude operations and are relatively dangerous.

[0003] There are two traditional methods. One is to use a tower crane to hoist the formwork to the ground for demolition, assembly, and then hoist it to the variable cross-section position for reinstallation after the demolition is completed; this method occupies the on-site construction site and the tower crane usage time, and each demolition causes great damage to the formwork, with large deformations of steel columns and steel beams, and they need to be replaced in time. The other is that the formwork uses trusses as the main beam connections and is demolished and rebuilt in the air, increasing the loose assembly of columns and steel beams; there is a lack of effective protection, the operation risk is relatively large, there is a possibility of high-altitude falling and object hitting, and it occupies a large amount of tower crane usage time, affecting the flowing water construction of the lower horizontal structure.

[0004] CN204781929U relates to the field of core tube construction formwork systems for high-rise buildings, specifically referring to a convenient-to-assemble standard Bailey truss intelligent hydraulic lifting formwork system. It includes a Bailey truss platform system, a suspension system, and a power support lifting system; the Bailey truss platform system is assembled using standard Bailey trusses, the power support lifting system is fixed between the core tube walls for lifting the Bailey truss platform system, and the suspension system is slidably hung at the lower end of the Bailey truss platform system. This formwork system is composed of standard Bailey trusses, with a simpler and more reliable structure, fast and convenient construction assembly, reusable, strong adaptability, and large load capacity; this system provides a truss platform assembled from standard Baileys as a material and temporary facility storage yard, facilitating material transportation and turnover, and reducing the tower crane usage time for core tube structure construction.

[0005] CN206289963U relates to a climbing formwork system for variable cross-section core tube construction, which system includes: an attached wall guide rail attached to the core tube; a climbing formwork rail connected to the attached wall guide rail; a support platform laid on the top of the climbing formwork rail, the support platform being hinged to the climbing formwork rail; an adjusting support rod provided between the support platform and the climbing formwork rail; and a climbing formwork body provided on the support platform.

[0006] CN106401174A relates to a climbing formwork system for the construction of a variable cross-section core tube and a construction method thereof. The system includes: an attached wall guide rail attached to the core tube; a climbing formwork rail connected to the attached wall guide rail; a supporting platform laid on the top of the climbing formwork rail, the supporting platform being hinged to the climbing formwork rail; an adjusting support rod provided between the supporting platform and the climbing formwork rail; and a climbing formwork frame body provided on the supporting platform.

[0007] The above support system pays more attention to how to deal with the situation of the inclination of the core tube wall or small cross-section changes. Basically, it cannot solve the problem of the rapid demolition and modification of the formwork in the air under the large cross-section setback shrinkage of the core tube. Therefore, it is necessary to optimize and adjust the existing formwork system so that under the large cross-section setback shrinkage of the core tube, the formwork system can be quickly demolished and modified at high altitude, the position of the stress point does not change, and the formwork system is safe and reliable; the form of sectional and zonal demolition and modification reduces the impact on the critical construction period of the core tube; the stress and strain monitoring and warning system and the uneven settlement monitoring system increase the intelligent means of the formwork system; generally, it is safe and reliable, ensuring the construction period and saving costs. Summary of the Invention

[0008] In view of the above problems, the present invention provides a formwork system applicable to the setback shrinkage of the core tube cross-section and a construction method thereof. The unit formwork is adopted, and the formwork platform is connected by bolts. At the position of the variable cross-section setback of the core tube, the formwork platform can be demolished and installed in zones and sections; the columns and machine positions are considered in advance, and the high-altitude demolition and modification do not affect the force of the machine position and the safety of the formwork; the formwork stress system is made of lightweight and high-strength steel, and is modularly assembled and disassembled to improve the refitting efficiency. Through the high-altitude modular rapid demolition and modification of the formwork, the safety, efficiency and simplicity of the formwork construction are ensured, and the construction cost and construction period are saved.

[0009] The technical solution of the present invention provides a formwork system applicable to the setback shrinkage of the core tube cross-section and a construction method thereof, which includes: At least one single-panel formwork is arranged on the support surface and forms a three-dimensional support framework through columns, horizontal structures and diagonal braces; A modular space truss is detachably connected to the columns of at least one single-panel formwork for transverse connection and platform erection between single-panel formworks.

[0010] Further, the single-panel formwork includes: A plurality of formwork columns, the bottoms of which are fixed to the floor slab or the lower formwork; A plurality of formwork horizontal beams are spaced and connected to the plurality of formwork columns; A plurality of formwork diagonal braces are fixed between the plurality of formwork columns and the plurality of formwork horizontal beams; At least one formwork walkway plate is arranged on at least one formwork horizontal beam for walking and operation transportation.

[0011] Further, the modular space truss includes: Multiple truss columns; Multiple horizontal truss beams, which are connected to the multiple truss columns at intervals, and the top horizontal truss beam is fixed to the formwork horizontal beam; Multiple diagonal truss braces, which are fixed between the multiple truss columns and the multiple horizontal truss beams; At least one truss walkway plate, which is arranged on at least one horizontal truss beam and is used for walking and operation transportation.

[0012] Further, the formwork system applicable to the core tube section shrinkage and setback also includes a modular protection system, including: Multiple rectangular enclosing keels, one end of which is fixedly connected to the formwork columns or truss columns through connecting members; The standardized perforated mesh is installed between the multiple rectangular enclosing keels to form a lateral closed surface to cover the side area of the single formwork or modular space truss.

[0013] Further, the formwork system applicable to the core tube section shrinkage and setback also includes: A stress and strain monitoring system, which is installed at the stress points of the single formwork to monitor the structural stress changes in real time; A static level, which is installed at the top horizontal truss beam of the modular space truss and is used to monitor uneven settlement.

[0014] Further, the horizontal truss beam and the formwork horizontal beam adopt a detachable bolt connection structure, including U-bolts, through screws or lock washers.

[0015] The present invention also provides a construction method based on the formwork system applicable to the core tube section shrinkage and setback, including the steps of: S1: Assemble multiple single formworks, hoist them to the Nth floor support surface and fix them; S2: Assemble multiple modular space trusses, hoist and fix them on the multiple single formworks fixed in S1 to form multiple formworks that meet the construction requirements of the Nth floor; S3: Use the multiple formworks assembled in S2 to construct the Nth floor of the building; S4: After the concrete of the Nth floor reaches the design strength and part of the structure is completed and capped, the single formworks and modular space trusses in the area where the section has not shrunk are integrally lifted up one floor and continue to be used as the support system for the next floor; S5: Above the concrete capping part of the Nth floor that has been poured and above the formworks that have been lifted, reassemble new single formworks and modular space trusses to form multiple formworks that meet the construction requirements of the N+1th floor; S6: Use the multiple formworks assembled in S5 to construct the N+1th floor of the building; S7: Demolish the single - bay formwork and modular space truss that no longer bear the supporting role in the Nth layer; S8: Repeat the construction steps from S4 to S7 until the construction is completed.

[0016] Furthermore, a stress - strain monitoring system is used to monitor the stress - strain state of the stress points of the single - bay formwork during the installation process, use process, and demolition process. When the set warning threshold is exceeded, the system alarms.

[0017] Furthermore, in step S7, the demolition process adopts a zoning and sectional method, and preferentially demolishes the formwork in the shrinkage area after the set - back.

[0018] Furthermore, in step S7, the single - bay formwork and modular space truss after demolition are used for repeated assembly of the formwork system on other floors after passing the inspection. Beneficial effects

[0019] Compared with the traditional truss connection, this design adopts a combined connection form of single - bay trusses. In the middle, a welded H - shaped steel beam is used to hang the modular space truss. After one side of the formwork system is demolished, the other side can continue to climb; after the modular space truss is integrally demolished, only the modular protection system needs to be hoisted. The modular protection system can be hoisted and demolished as a whole, improving the refitting efficiency.

[0020] The formwork vertical poles are processed from double channel steels, and the guide rails are H - shaped steels; the steel beams and steel columns of each platform of the formwork are connected by bolts, which can facilitate the demolition and movement of the steel beam positions; it is suitable for structural shrinkage and frame segmentation, avoiding vertical protruding structures, and has strong adaptability.

[0021] The improvements of a formwork system and its construction method applicable to the high - altitude rapid demolition and modification of the core tube of super high - rise buildings of the present invention are as follows: Design the position of the stress points according to the structural conditions after the variable - section shrinkage, unitized design, and integral demolition and installation.

[0022] The present invention has the following advantages compared with the prior art: (1) The present invention solves the problem that the traditional formwork cannot be safely and quickly demolished and modified in the air under the condition of the large - section set - back and shrinkage of the core tube. It adopts a formwork system and its construction method applicable to the set - back and shrinkage of the core - tube section, enabling the formwork system to be safely and quickly demolished and modified at high altitude under the condition of the large - section set - back and shrinkage of the core tube.

[0023] (2) The modular space truss, single - bay formwork, multi - bay formwork, and modular protection system are all connected by bolts, which can be easily assembled, demolished, and moved, and are suitable for working conditions where the structure shrinks multiple times and the frame needs to control the demolition and modification. Avoid aerial cutting, and the overall aerial demolition and modification efficiency is high. At the same time, it reduces the damage to the frame and the occupation time of the tower crane and the storage yard, can significantly improve the construction efficiency, and reduce the labor intensity.

[0024] (3) For the formwork system applicable to the core tube cross-section shrinkage and stepped-back and its construction method of the present invention, during the in-air assembly, disassembly, and movement of the formwork system, the positions of the stress points do not change, and the overall stress system does not change.

[0025] (4) For the formwork system applicable to the core tube cross-section shrinkage and stepped-back and its construction method of the present invention, according to the construction conditions, the formwork system can be assembled and disassembled in zones and sections in the air, and basically does not occupy the critical construction period of the core tube.

[0026] (5) For the formwork system applicable to the core tube cross-section shrinkage and stepped-back and its construction method of the present invention, during the process of high-altitude modification of the variable cross-section, the stress and strain monitoring system monitors the stress and strain states of the stress points of multiple formwork bays and single formwork bays. When the set warning threshold is exceeded, the system alarms and feeds back to the stress and strain monitoring platform to conduct real-time safety monitoring and warning on the stress points during the entire assembly and modification.

[0027] (6) For the formwork system applicable to the core tube cross-section shrinkage and stepped-back and its construction method of the present invention, during the process of high-altitude modification of the variable cross-section, the uneven settlement monitoring system monitors the uneven settlement states of multiple formwork bays and single formwork bays. When the set warning threshold is exceeded, the system alarms and feeds back to the uneven settlement monitoring system platform to conduct real-time safety monitoring and warning on the uneven settlement of the entire formwork system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] For the convenience of those skilled in the art to understand, the present invention will be further described below with reference to the accompanying drawings.

[0029] Figure 1 It is an elevation view of the formwork system applicable to the high-altitude rapid modification under the large cross-section shrinkage of the super high-rise core tube according to an embodiment of the present invention; Figure 2 It is a plan view of the formwork system applicable to the high-altitude rapid modification under the large cross-section shrinkage of the super high-rise core tube of the present invention; Figure 3 It is an elevation view of the modular space truss; Figure 4 It is a front view of the node A of the modular space truss; Figure 5 It is a side view of the node A of the modular space truss; Figure 6 It is an elevation view of a single formwork bay; Figure 7 It is a front view of the node B of a single formwork bay; Figure 8 It is a plan view of the formwork at the Nth floor in the variable cross-section area; Figure 9 It is a plan view of the formwork at the (N + 1)th floor in the variable cross-section area; Figure 10 Schematic plan view of the N+2 layer formwork support in the variable cross-section area; Figure 11 Schematic plan view of the N+2 layer formwork support in the variable cross-section area; Figure 12 Schematic plan view of the N+3 layer formwork support in the variable cross-section area; Figure 13 Schematic plan view of the N+4 layer formwork support in the variable cross-section area; Figure 14 Schematic plan view of the N+5 layer formwork support in the variable cross-section area; Figure 15 Schematic plan view of the position of the support force points in the N layer of the variable cross-section area; Figure 16 Schematic plan view of the position of the support force points in the N+5 layer of the variable cross-section area.

[0030] In the figure: 101 - modular space truss; 102 - single formwork support; 103 - multi-formwork support; 104 - modular protection system; 105 - stress and strain monitoring system; 106 - high-speed static level; 107 - core tube shear wall; 1011 - 12# channel steel; 1012 - M20*140 bolt; 1013 - ¨100*100mm square steel tube; 1014 - diagonal brace; 1015 - BH210*350*8*12 welded section steel; 1016 - 16*220*100 gasket; 1017 - 20# channel steel, 1018 - M16*550 through screw rod, 1019 - double 14# channel steel; 10110 - walkway board; 10111 - M16*200*300 U-bolt; 10112 - 20# light C-channel steel; 10113 - 14# channel steel; 1021 - force point; 1022 - double 20# channel steel; 1041 - standardized punched mesh; 1042 - Z-shaped connecting plate; 1043 - M18 U-bolt; 1044 - 80*40*3 rectangular enclosure keel; 1 - single formwork support one; 2 - modular space truss two; 3 - single formwork support three; 4 - single formwork support four; 5 - single formwork support five; 6 - single formwork support six; 7 - modular space truss seven; 8 - single formwork support eight; 9 - modular space truss nine; 10 - single formwork support ten; 11 - modular space truss eleven. Detailed implementation manners

[0031] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0032] Please refer to Figures 1 - 16, the technical solution of the present invention provides a formwork system applicable to the core tube section shrinkage and stepped-back platform and its construction method, which includes: At least one single-frame formwork, which is arranged on the supporting surface and forms a three-dimensional support framework through columns, horizontal structures and diagonal braces; A modular space truss, which is detachably connected to the columns of at least one single-frame formwork and is used for the lateral connection between single-frame formworks and the erection of platforms.

[0033] Furthermore, the single-frame formwork includes: Multiple formwork columns, the bottoms of which are fixed to the floor slabs or the lower formwork; Multiple formwork horizontal beams, which are spaced and connected to multiple formwork columns; Multiple formwork diagonal braces, which are fixed between multiple formwork columns and multiple formwork horizontal beams; At least one formwork walkway plate, which is arranged on at least one formwork horizontal beam and is used for walking and operation transportation.

[0034] Furthermore, the modular space truss includes: Multiple truss columns; Multiple truss horizontal beams, which are spaced and connected to multiple truss columns, and the top truss horizontal beam is fixed to the formwork horizontal beam; Multiple truss diagonal braces, which are fixed between multiple truss columns and multiple truss horizontal beams; At least one truss walkway plate, which is arranged on at least one truss horizontal beam and is used for walking and operation transportation.

[0035] Furthermore, the formwork system applicable to the core tube section shrinkage and stepped-back platform further includes a modular protection system, which includes: Multiple rectangular enclosing keels, one end of which is fixedly connected to the formwork columns or truss columns through connecting members; A standardized punched mesh, which is installed between the multiple rectangular enclosing keels to form a lateral closed surface to cover the side area of the single-frame formwork or the modular space truss.

[0036] Furthermore, the formwork system applicable to the core tube section shrinkage and stepped-back platform further includes: A stress and strain monitoring system, which is installed at the stress points of the single-frame formwork to monitor the structural stress changes in real time; A static level, which is installed at the top truss horizontal beam of the modular space truss and is used to monitor uneven settlement.

[0037] Furthermore, the truss horizontal beam and the formwork horizontal beam adopt a detachable bolt connection structure, including U-bolts, through screws or lock washers.

[0038] The present invention also proposes a construction method based on the formwork system applicable to the core tube section shrinkage and stepped-back platform, including the steps: S1: Assemble multiple single-frame formworks, hoist them to the Nth floor support surface and fix them. S2: Assemble multiple modular space trusses, hoist and fix them on the multiple single-frame formworks fixed in S1 to form multiple-frame formworks meeting the construction requirements of the Nth floor. S3: Use the multiple-frame formworks assembled in S2 to construct the Nth floor of the building. S4: After the concrete of the Nth floor reaches the designed strength and partial structures are capped, the single-frame formworks and modular space trusses in the area where the cross-section has not shrunk are lifted up one floor as a whole and continue to be used as the support system for the next floor. S5: Above the concrete capping part of the Nth floor that has been poured and above the formworks that have been lifted, reassemble new single-frame formworks and modular space trusses to form multiple-frame formworks meeting the construction requirements of the (N + 1)th floor. S6: Use the multiple-frame formworks assembled in S5 to construct the (N + 1)th floor of the building. S7: Demolish the single-frame formworks and modular space trusses in the Nth floor that no longer bear the support function. S8: Repeat the construction steps of S4 to S7 until the construction is completed.

[0039] Furthermore, a stress-strain monitoring system is adopted to monitor the stress-strain states of the stress points of the single-frame formworks during the installation process, use process and demolition process. When the set warning threshold is exceeded, the system alarms.

[0040] Furthermore, in step S7, the demolition process adopts a zoning and sectional method, and preferentially demolishes the formworks in the shrunk area after the set-back.

[0041] Furthermore, in step S7, the single-frame formworks and modular space trusses to be demolished are used for repeated assembly of the formwork systems on other floors after passing the inspection.

[0042] Refer to Figure 1 、 2 As shown in

[0043] Refer to Figure 1 、 2 、3, the formwork system of the present invention applicable to high-altitude rapid demolition and modification of large cross-section shrinkage set-back in the super high-rise core tube includes modular space trusses, single-frame formworks, multiple-frame formworks, modular protection systems, stress-strain monitoring systems, and high-speed static level gauges.

[0044] Refer to Figure 6 、7 As shown in the figure, for the removed single formwork, the modular facade protection can be directly installed, so that the single formwork or multiple formworks form a closed safety protection system.

[0045] Refer to Figure 8 、 9 As shown in Figures 10, 11, 12, 13, 14, at the variable cross-section position, the modification can be carried out in sections and subsections. The entire modification spans the construction periods of N, N + 1, N + 2, N + 3, N + 4, N + 5 floors of the core tube, etc., without affecting the key construction period of the core tube.

[0046] Refer to Figure 15 、 16 As shown in the figure, the entire process is supervised and pre-warned in real time through the support point monitoring system and the uneven settlement system. The data is stored and analyzed through the twin space analysis and prediction module, and monitored in real time. When potential unsafe factors may occur, pre-control measures are automatically given, and the pre-control measures are realized through the real-time pre-control and alarm module to adjust and pre-warn the formwork system.

[0047] Such as Figure 3 、 4 、5, the modular space truss 101 includes columns 1013, 4 horizontal structures, diagonal braces 1014, and high-speed static level gauges 106. Among them, the vertical poles adopt square steel pipes 1013 of ¨100*100mm; the topmost horizontal structure successively adopts welded steel sections 1015 of BH210*350*8*12, 20# channel steels 1017, and double 14# channel steels 1019 from top to bottom. Patterned steel plates 10110 are laid on the upper part of the 20# channel steel 1017 as the walkway plates. The welded steel section 1015 of BH210*350*8*12 is fixedly connected to the 20# channel steel 1017 through M16*550 through screws 1018. The 20# channel steel 1017 is fixedly connected to the double 14# channel steel 1019 through M16*200*300 U-shaped bolts 101011.

[0048] The remaining 3 horizontal structures successively adopt 20# light C-shaped channel steels 10112 and double 14# channel steels 1019 from top to bottom. Patterned steel plates 10110 are laid on the upper part of the 20# light C-shaped channel steel 10112 as the walkway plates. The 20# light C-shaped channel steel 10112 is fixedly connected to the double 14# channel steel 1019 through M16*200*300 U-shaped bolts 10111; the diagonal braces 1014 adopt 14# channel steels 10113 and are connected to the columns 1013 through M20*200 bolts 1012.

[0049] Such as Figure 6 、 7, a single-frame formwork 102 includes columns 1013, 5 horizontal structures, diagonal braces 10113, stress points 1021, and a stress and strain monitoring system 105. Among them, the vertical poles adopt square steel pipes 1013 of ¨100*100mm; the top horizontal structure from top to bottom successively adopts double-channel steel 1022 of 20# and double-channel steel 1019 of 14#, and diamond plate 10110 is laid on the upper part of the double-channel steel 1022 of 20# as a walkway plate. The double-channel steel 1022 of 20# and the double-channel steel 1019 of 14# are fixedly connected by welding; the remaining 5 horizontal structures from top to bottom successively adopt light C-channel steel 10112 of 20# and double-channel steel 1019 of 14#, and diamond plate 10110 is laid on the upper part of the light C-channel steel 10112 of 20# as a walkway plate. The light C-channel steel 10112 of 20# and the double-channel steel 1019 of 14# are fixedly connected by M16*200*300 U-bolts 10111; the diagonal braces 10113 adopt 14# channel steel 10113 and are connected to the columns 1013 by M20*200 bolts 1012.

[0050] As Figure 7 , the modular protection system 104 includes a standardized punched mesh 1041, a Z-shaped connecting plate 1042, an M18 U-bolt 1043, and a 80*40*3 rectangular enclosure keel 1044. Among them, the 80*40*3 rectangular enclosure keel 1044 is connected to the column 1013 through the Z-shaped connecting plate 1042 by M18 U-bolts 1043, and the 80*40*3 rectangular enclosure keel 1044 and the standardized punched mesh 1041 are connected by M18 U-bolts 1043.

[0051] The top of the modular space truss 101 is connected to the single-frame formwork 102 through a welded steel section 1015 of BH210*350*8*12, and the connection method is bolt connection with M16*550 through screws 1018; the columns of each lower platform are connected into a whole by 12# channel steel 10101, and the connection bolts are M20*140 bolts 1012.

[0052] The modular space truss 101, the single-frame formwork 102, the multi-frame formwork 103, and the modular protection system 104 are all connected by bolts, which can be easily assembled, disassembled, and moved, and are suitable for working conditions where the structure shrinks multiple times and the frame needs to control disassembly and modification.

[0053] During the first assembly, the single-frame formwork 102 is first installed. Among them, the modular protection system 104 can not be installed. The welded steel section 1015 of BH210*350*8*12 on the upper part of the modular space truss 101 is connected to the support of the single-frame formwork 102, and all the M20*140 bolts 1012 and M16*550 through screws 1018 are tightened. During this process, the position of the stress point 1021 does not change.

[0054] When constructing to the variable cross-section floor, all the M20*140 bolts 1012 and M16*550 through screws 1018 are loosened. The modular space truss 101 can be directly demolished or assembled in the air, and the single-piece formwork 102 can continue to climb. During this process, the position of the stress point 1021 does not change, and the safety factor of the stress point 1021 increases. It is only necessary to add a modular protection system 104 outside the single-piece formwork 102.

[0055] A stress and strain monitoring system 105 is used to monitor the stress and strain states of the stress points 1021 of multiple-piece formworks 103 and single-piece formworks 102 during the installation process, use process, and demolition process. When the set warning threshold is exceeded, the system alarms and feeds back to the stress and strain monitoring platform to conduct real-time safety monitoring and early warning on the stress points 1021 during the entire assembly, disassembly, and modification.

[0056] The high-speed static level 106 is installed at the web position of the BH210*350*8*12 welded steel section 1015 on the upper part of the modular space truss 101 to monitor the uneven settlement of the multiple-piece formworks 103 during the use process in real time. Embodiment

[0057] In this embodiment, taking the N-layer variable cross-section disassembly and modification as an example, the technical solution of the present invention is specifically described. Key points need to consider the modular design of the formwork in the early stage, the rapid disassembly and modification at high altitude at the variable cross-section position, the sectional and segmented disassembly and modification at the variable cross-section position, etc.

[0058] First modular formwork assembly: According to the front and back changes of the entire structure, modular design and on-site first assembly are carried out. The single-piece formworks are assembled on the ground in sequence, and the upper and lower frameworks are hoisted into the inner and outer sides of the core tube. The modular space truss is hoisted into the inner and outer sides of the core tube as a whole. The modular space truss and the single-piece formwork are connected by U-shaped bolts to form inner and outer multiple-piece formwork groups.

[0059] (1) Ground assembly and single-piece hoisting of the single-piece formwork The single-piece formwork is assembled on the ground framework. The framework is made of lightweight and high-strength steel. The vertical poles are processed from double channel steels, and the guide rails are H-shaped steels. Other connecting frameworks are made of C-shaped steels and channel steels. The connecting nodes of the framework are mainly bolt connections, and columns and crossbeams can be added according to needs. When the single-piece formwork is constructed for the first time, a tower crane is used to hoist the formwork framework to the installation position.

[0060] (2) Overall hoisting of the modular space truss The modular space truss is assembled on the ground and all are connected by bolts, and then hoisted into the inner side of the core tube as a whole. The modular space truss and the single-piece formwork are connected by U-shaped bolts to form inner and outer multiple-piece formwork groups.

[0061] 2. Construction of the Nth layer of the formwork: After the construction of the Nth layer is completed and concrete is poured, some structures shrink and reach the top. At this time, each single formwork or modular space truss 1 - 11 is ready for demolition and modification.

[0062] 3. Construction of the (N + 1)th layer of the formwork: After the concrete pouring of the Nth layer is completed, in order to reduce the delay of the critical path time of the core tube, the structures with unshrunk cross-sections continue to be constructed upward. Among them, each single formwork or modular space truss 1 - 5 climbs up one more time; for the structures with shrunk cross-sections, the attached single formworks or modular space trusses six - 11 stop climbing and wait for assembly and conversion.

[0063] 4. Construction of the (N + 2)th layer of the formwork: After the construction of the (N + 1)th layer is completed and before the concrete pouring of the (N + 2)th layer, at this time, the areas where single formworks one - four are located need to be assembled and converted to ensure the continuous construction of some parts of the core tube; during this stage, modular space truss two and single formwork three are removed in sequence. Subsequently, single truss eight is shifted to the original position of "modular space truss two, single formwork three, single formwork four" for assembly and conversion.

[0064] 5. Construction of the (N + 3)th layer of the formwork: During the construction of the (N + 3)th layer, at this time, single formworks five and six can be removed in sequence as needed.

[0065] 6. Construction of the (N + 4)th layer of the formwork: During the construction of the (N + 4)th layer, at this time, modular space truss nine and modular space truss eleven are assembled. At this time, the formwork system modification conditions in different regions and stages at the variable cross-section position have been completed.

[0066] 7. Construction of the (N + 5)th layer of the formwork: During the construction of the (N + 5)th layer, at this time, single formwork ten can be removed in sequence as needed.

[0067] 8. Intelligent monitoring, early warning and supervision: The intelligent control system of the formwork is a control system for data monitoring and safety protection during the climbing of the formwork frame. This system has functions such as climbing stroke setting, displacement synchronization monitoring and alarm, pressure overlimit monitoring and alarm, and data display, so as to meet the requirements of synchronous climbing of the formwork and achieve the control of displacement accuracy.

[0068] The above - disclosed preferred embodiments of the present invention are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, according to the content of this specification, many modifications and changes can be made. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art in the relevant technical field can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A formwork system applicable to the core tube cross-section shrinkage and stepped-back platform, characterized in that, It mainly includes: At least one single-frame formwork, which is arranged on the supporting surface and forms a three-dimensional support framework through columns, horizontal structures and diagonal braces; A modular space truss, which is detachably connected to the columns of at least one single-frame formwork and is used for the lateral connection between single-frame formworks and the erection of platforms.

2. The formwork system applicable to the core tube cross-section shrinkage and stepped-back platform according to claim 1, wherein The single-frame formwork includes: Multiple formwork columns, the bottoms of which are fixed to the floor slab or the lower formwork; Multiple formwork horizontal beams, which are connected to multiple formwork columns at intervals; Multiple formwork diagonal braces, which are fixed between multiple formwork columns and multiple formwork horizontal beams; At least one formwork walkway board, which is arranged on at least one formwork horizontal beam and is used for walking and operation transportation.

3. The formwork system applicable to the core tube cross-section shrinkage and stepped-back according to claim 2, characterized in that The modular space truss includes: Multiple truss columns; Multiple truss horizontal beams, which are connected to multiple truss columns at intervals, and the top truss horizontal beam is fixed to the formwork horizontal beam; Multiple truss diagonal braces, which are fixed between multiple truss columns and multiple truss horizontal beams; At least one truss walkway board, which is arranged on at least one truss horizontal beam and is used for walking and operation transportation.

4. A formwork system applicable to the core tube cross-section shrinkage and stepped-back platform according to claim 3, characterized in that, The formwork system applicable to the core tube section shrinkage and setback also includes a modular protection system, which includes: Multiple rectangular enclosure keels, one end of which is fixedly connected to the formwork column or truss column through a connecting member; A standardized punched mesh, which is installed between the multiple rectangular enclosure keels to form a lateral closed surface to cover the side area of the single-frame formwork or modular space truss.

5. A formwork system applicable to the core tube cross-section shrinkage and stepped-back platform according to claim 3, characterized in that, The formwork system applicable to the core tube section shrinkage and setback also includes: A stress and strain monitoring system, which is installed at the stress points of the single-frame formwork to monitor the structural stress changes in real time; A static level, which is installed at the top truss horizontal beam of the modular space truss and is used to monitor uneven settlement.

6. The formwork system applicable to the core tube cross-section shrinkage and stepped-back platform according to claim 3, characterized in that, The truss horizontal beam and the formwork horizontal beam adopt a detachable bolt connection structure, including U-bolts, through screws or lock washers.

7. The construction method based on the formwork system applicable to the core tube cross-section shrinkage and stepped-back platform as described in claim 1, characterized in that, It includes the steps: S1: Assemble multiple single-frame formworks, hoist them to the Nth layer supporting surface and fix them; S2: Assemble multiple modular space trusses, hoist and fix them on the multiple single-frame formworks fixed in S1 to form multiple-frame formworks that meet the construction requirements of the Nth layer; S3: Use the multiple-frame formworks assembled in S2 to construct the Nth layer of the building; S4: After the concrete of the Nth layer reaches the design strength and part of the structure is completed and capped, the single-frame formwork and modular space truss in the non-shrinking area of the section are lifted up one layer as a whole and continue to be used as the next layer of the support system; S5: Above the concrete capping part of the Nth layer that has been poured and the lifted formwork, reassemble new single-frame formworks and modular space trusses to form multiple-frame formworks that meet the construction requirements of the N+1th layer; S6: Use the multiple-frame formworks assembled in S5 to construct the N+1th layer of the building; S7: Demolish the single-frame formworks and modular space trusses in the Nth layer that no longer bear the support function; S8: Repeat the construction steps of S4 to S7 until the construction is completed.

8. The construction method of the formwork system applicable to the core tube cross-section shrinkage and stepped-back platform according to claim 7, characterized in that, Use the stress and strain monitoring system to monitor the stress and strain states of the stress points of the single-frame formwork during the installation process, use process and demolition process. When the set warning threshold is exceeded, the system alarms.

9. The construction method of the formwork system applicable to the core tube cross-section shrinkage and stepped-back platform according to claim 7, characterized in that In step S7, the demolition process adopts a partitioned and sectionalized method, and the formwork in the shrunk area after the setback is preferentially demolished.

10. The construction method of the formwork system applicable to the core tube cross-section shrinkage and stepped-back platform according to claim 7, characterized in that, In step S7, after the single-piece formwork and modular space truss removed are inspected and qualified, they are used for repeated assembly of the formwork system on other floors.

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