Variable cross-section high pier column lifting frame reverse mold structure suitable for rapid construction and construction method

Abstract

According to the variable cross-section high pier column lifting frame reverse formwork structure suitable for rapid construction and the construction method, an operation platform, a lateral support and a formwork system are separated, and structural separation and function recombination are conducted on the basis of a traditional formwork; the slope of the formwork is preset, a flange and a long round hole are arranged on the edge of the wide formwork, continuous slope collection is achieved in the climbing process through a chain block, and meanwhile synchronous removal of an invalid formwork formed after section contraction is achieved. The lifting system bears the load of the working face of the operation platform, the weight of the formworks is borne by the pier columns, the two layers of formworks are cyclically overturned in the enclosure and the platform, the influence of the age of concrete is small, the overall construction progress is fast, opposite pull rods in the traditional technology are omitted through lateral supporting of the enclosure truss, the concrete appearance quality is good, and the structure is reliable and easy and convenient to operate. According to the invention, lifting of the variable-cross-section thin-wall pier template outer frame and mold reversing circulation operation are realized, and the construction efficiency and the safety are greatly improved. According to the technology, high-quality, continuous and efficient construction of the variable-cross-section thin-wall pier of the bridge can be achieved.

Description

Technical Field

[0001] The invention belongs to the field of bridge engineering pier construction, and in particular relates to a variable-section bridge high pier frame lifting mold structure suitable for rapid construction and a construction method. Background Art

[0002] With the vigorous development of highway construction, bridge projects need to adopt high pier construction methods to support bridge structures when crossing large rivers, canyons and other terrain obstacles. The height of the bridge is often more than 40 meters. The high pier construction method has become a key factor in ensuring the safety, stability and economy of bridges. In the face of key issues in the design and construction of high piers, the safety and durability of bridge high pier construction can be significantly improved by adopting advanced construction methods and strict construction processes. Among them, variable-section high bridge domains are the most common substructure forms in mountain highways and general roads, especially when the bridge is relatively high. The large-space specific cross-sectional deformation of high piers in the height direction makes the steel formwork not universal. It is difficult to accurately control in actual construction. Slight deviations will lead to the accumulation of high pier construction errors, affecting the appearance of the pier. Usually, in order to ensure the overall stiffness of the formwork system, strong reinforcement treatment is required. In addition, the combined steel formwork has a small area, many joints, and an unsightly appearance. Common construction methods are slow and time-consuming. At present, the flip formwork construction used in high piers has great safety risks. The large workload of template installation and disassembly leads to low construction efficiency. The construction speed is limited by the age of concrete. The average speed during construction is difficult to exceed 1m per day. The slipform process will lead to poor appearance quality and reduced durability of the piers. Although roller formwork and hanging formwork technologies have been developed in recent years, they are only partial improvements of different formwork technologies, and the application of new plastic materials in pier formwork is also very rare. At present, bridge construction, especially high piers, is constrained by conditions such as short construction period and large volume. An efficient and safe construction method is urgently needed to improve this problem. Summary of the invention

[0003] The purpose of the present invention is to provide a high-efficiency bridge variable-section thin-wall pier construction template and to explain its construction method. The use of this set of templates can realize the rapid and efficient construction of hollow piers with uniform cross-sections, greatly reduce the influence of concrete age on construction efficiency, and ensure the construction quality and safety of the pier columns.

[0004] The present invention is implemented through the following technical scheme: a variable-section thin-wall pier lifting frame type inverted mold structure, including an upper operating platform, a lower operating platform, a circle truss structure, a closed guardrail, a hanger, an outer template, an inner template, an outer template lifting system, an inner template lifting system and a maintenance platform, the circle truss structure is connected with four trusses in sequence by high-strength bolts to form a rectangular truss circle around the pier column, the closed guardrail is directly connected to the circle truss structure with high-strength bolts, the upper operating platform is arranged on the circle truss structure, the hanger is connected with the lower part of the circle truss structure by bolts, the lower part of the hanger is arranged, the bottom of the hanger is arranged with a maintenance platform, the lower end of the hanger is arranged with a support roller and can roll upward along the pier column, the outer side of the hanger is opened with a plurality of holes on the lower operating platform and the maintenance platform, steel bars are inserted into the holes, and the circle truss structure is connected to the outer template by bolt top support; The outer formwork lifting system includes an outer formwork lifting frame, a supporting steel pipe and a wedge jack, the outer formwork lifting frame is connected to the enclosure truss structure by bolts, and the outer formwork lifting frame is connected to the supporting steel pipe inserted into the concrete by the wedge jack; The inner formwork lifting system comprises an inner formwork lifting frame, a supporting steel pipe and a wedge jack. The inner formwork lifting frame is connected to the supporting steel pipe inserted into the concrete through the wedge jack, and the inner formwork lifting frame is connected to the inner formwork crossbeam through high-strength bolts.

[0005] Furthermore, the enclosure truss structure is composed of 100*10 equilateral angle steels as chord members and 63*63*6 angle steels as web members, forming a truss with a cross-sectional outer contour of 1.2m*1.3m. The closed guardrail is made of 50*50*5 steel pipes, and the upper operating platform is a 2.5mm patterned steel plate laid on the enclosure truss structure; the bolt top support is made of φ28 fine-rolled threaded steel, and a grooved top support is welded at the end to tighten the outer formwork beam, and the tail end is supported on the open steel of the enclosure truss structure with a nut.

[0006] Furthermore, the bracket adopts 80*6 equilateral angle steel with a length of 4.8m. A 50*5 double-angle steel crossbeam is set 2.8m below the bracket and a 2.5mm patterned plate is laid to form a lower operating platform. The bottom of the bracket adopts a 50*5 double-angle steel crossbeam and a 2.5mm patterned plate is laid to form a maintenance platform. The outer side of the bracket has holes every 60cm on the two platforms.

[0007] Furthermore, the outer formwork is an integral large steel formwork with a height of 2.25m and a thickness of 5mm. The four corners are arc-shaped formworks. The large surface is composed of two 2.95 wide steel formworks and the small surface is composed of a 2.9m wide steel formwork assembled with arc formworks respectively. There are two sets of 20 outer formworks in total. The vertical surface of a single formwork is flat and smooth, and the vertical back ribs are arranged with No. 5 channel steel at a spacing of 30cm. Angle steels are welded around the formworks and holes are punched as bolt holes for connecting the formworks to each other. The two ends of the back ribs are firmly welded to the angle steels. A formwork crossbeam formed by double No. 14 channel steels is set 1 / 5 inward at both ends of the back ribs. After the formwork is installed in place, it is tightened by a top support supported by bolts. There are two sets of outer formworks in total. First, one set is installed and after the concrete is poured, the other set is installed and concrete is poured. Subsequently, the lower set of outer formworks is disassembled piece by piece and lifted to the top by a tower crane for reinstallation and use. During the entire construction process, two sets of outer formworks are used. The formwork is cycled through continuous disassembly and assembly from bottom to top. The slope of the outer formwork is reduced by clamping the large formwork with the small formwork. A flange and an oblong hole are set at the end of the large formwork. The corresponding small formwork plane is perpendicular to the large formwork and has bolt holes with a spacing of 120-140mm, which are bolted to the oblong holes of the outer formwork through high-strength bolts. The first cycle of the outer formwork is when the operating platform is hoisted to a height of 4.8m and the remaining steel bars are tied. At the same time, the internal formwork system is installed and the slope of the inner formwork is debugged. After checking the formwork, concrete can be poured. After the concrete is initially set, the bolt support can be removed to form a space for the formwork to be transported back and forth between the truss and the formwork. At this time, the lower formwork is removed for the first time and installed on the top with bolt support. The inner formwork is lifted with the pouring to form a new thin-wall pouring space. When the lower space reaches the installation height, the hanging platform can be installed. The inner formwork determines the overall size of the formwork according to the cross-sectional contour of the inner cavity of the thin-walled pier, uses 5mm steel plate as the panel, has a height of 2.25m, and the vertical back ribs are arranged with No. 5 channel steel at a spacing of 30cm. Angle steel is welded to the upper and lower ends for locking. The division and connection of the formwork blocks are all in the plane position. Double No. 14 channel steels are set at the 1 / 5 position inward at both ends of the vertical back ribs of the inner formwork as formwork beams. The large-surface formwork is set into 2 modules, and 4 supports are used in opposite directions. The end corner formwork is divided into 3 modules, and the connection between the formworks can only be achieved outside the corner. Lateral supports are set on the formwork beams and connected to the nearest supports to form a skeleton. When in use, after all supports are connected, bamboo plywood can be laid on them to form an operating platform for the inner formwork.

[0008] Furthermore, the external formwork lifting frame is composed of 2 pieces of I18 channel steel support tips welded to form a vertical bar with a rectangular cross-section, and the cross bar is composed of 2 pieces of I18 channel steel back to back and connected by a tie plate at a distance of 50mm-60mm to form a lattice truss, and I100 channel steel is used as a diagonal brace to connect with the vertical bar at the top. After installation, the external formwork lifting frame is connected as a whole through the truss welded by the channel steel tie plate; four holes are punched on the cross bar of the external formwork lifting frame by welding steel plates as a base, a wedge jack is placed on the base, and the supporting steel pipe is a φ48*3.5 seamless steel pipe.

[0009] Furthermore, the inner formwork lifting frame is composed of two pieces of I18 channel steel support tips welded to form a vertical bar with a rectangular cross-section, and the cross bar is formed by two pieces of I18 channel steel back to back and connected by a tie plate at a distance of 50mm-60mm to form a lattice truss. The vertical bar and the cross bar are welded orthogonally, and the channel steel tie plate is used as a diagonal rod at the formed inner corner. Four holes are punched on the crossbeam of the inner formwork lifting frame by welding steel plates as a jack base, and a wedge jack is placed on the base. The supporting steel pipe 10 is a φ48*3.5 seamless steel pipe.

[0010] The present invention also provides a construction method for a variable-section thin-wall pier lifting frame type inverted mold structure, the steps of which are as follows: (1) After the cap is poured and the main reinforcement of the pier column is embedded, the outer edge of the pier column is positioned and measured, and the stirrups are tied. The steel formwork is dusted and the release agent is applied. The first layer of the outer formwork and the enclosure truss structure, closed guardrail, and upper operating platform are assembled. The outer formwork lifting frame and wedge jack are installed, and the inner formwork is adjusted. The hydraulic pipeline is connected and the hydraulic system is debugged. The support steel pipe is inserted above the wedge jack until the steel pipe contacts the cap. The bolts are adjusted to support the top support so that the top support is tight against the formwork beam, and the formwork is checked; (2) After checking that the formwork is correct, pour the solid section concrete; (3) Extend the main reinforcement; (4) Adjust the bolts to support the beams of the first layer of outer formwork. At this time, the time since the last concrete pouring should be more than 12 hours. Lift the outer frame and tie the stirrups simultaneously. (5) Install the second layer of formwork and adjust the bolts to support the formwork beams; (6) Position and install the inner formwork system and verify its accuracy, and debug the inner formwork's slope reduction and lifting hydraulic system; (7) Pour the thin-walled section concrete. During the pouring process, the inner formwork system is lifted intermittently after a delay of 2 hours, and step (4) is repeated; (8) Remove the lower formwork and use a tower crane to lift each piece to the top and install it, adjust the bolts to support the formwork beam, and check the position of the formwork; (9) Repeat steps (7), (4), and (8) until the pier column diaphragm is reached, then raise the inner formwork by 1.2 m and set up the diaphragm bottom formwork using the traditional wooden formwork process; (10) Repeat steps (8), (7), and (4) to the next diaphragm. Continue this cycle until the solid section at the top of the pier is reached. After lifting, use a tower crane to remove the inner formwork and hoist it to the ground. Install the bottom formwork of the solid section at the top of the pier using the traditional formwork process. (11) Repeat step (8) again and pour the pier top concrete; (12) Use a tower crane to dismantle the outer formwork in preparation for the construction of the next pier.

[0011] Furthermore, in step (2), 2 m of solid section concrete is poured; in step (3), the main reinforcement is extended by 4.5 m; in step (4), the cumulative lifting and tying of stirrups is performed upward by 2.25 m; in step (7), 2.25 m of thin-wall section concrete is poured, and the cumulative lifting is performed by 2.1 m within 2 hours after the pouring is completed; Furthermore, in step (4), the main reinforcement is synchronously extended when necessary.

[0012] The inner formwork of the present invention is separated from the outer frame. The outer frame of the outer formwork integrates a truss structure, upper and lower operation and maintenance platforms, and the lifting system realizes the lifting of the entire outer frame, which provides an integrated operation platform and working surface and provides lateral support for the formwork. The inner formwork is formed by ring assembly of formwork blocks and reinforced by supports. The inner formwork lifting system is directly connected to the formwork to form an inner formwork system. The inner and outer formwork systems together constitute a uniform cross-section thin-walled pier lifting frame type inverted mold structure.

[0013] The enclosure truss structure of the present invention serves as a horizontal force-bearing structure of the thin-walled pier formwork, and as a force-bearing carrier of the operating platform, enclosure structure, and pylon. The closed guardrail forms a safety protection for the formwork system. The upper operating platform serves as a platform for installing and binding steel bars and pouring concrete. The lower operating platform serves as a working surface for removing the formwork. The maintenance platform serves as a platform working surface for maintenance and maintenance. The support rollers enhance the stability of the entire pylon and platform. The outer side of the pylon is opened with a hole, and steel bars are inserted into the hole to form the enclosure system of the platform.

[0014] The invention discloses a variable-section high pier column lifting frame reverse mold structure and construction method suitable for rapid construction, which realizes the variable-section thin-wall pier cyclic operation mainly through lifting frame and reverse mold cycle, so that the operating platform, lateral support and formwork system are separated, and the entire operating platform and lateral support structure are separated from the formwork, and the connection is reliable, the structure is light, and the safety is high. The weight of the formwork is borne by the pier column, and the two-layer cycle is less affected by the age of concrete, and the overall construction progress is fast. The lateral support of the enclosure truss cancels the tie rod in the traditional process, so that the appearance quality of the concrete is good. The entire lifting frame reverse mold structure performs functional decomposition and recombination of the traditional formwork, and the structure is reliable and easy to operate, and can be widely promoted and applied in variable-section thin-wall piers. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1This is the overall model diagram of the variable-section high pier frame mold structure system; Figure 2 This is a schematic diagram of the external formwork system structure of the variable-section high pier frame reverse mold structure; Figure 3 This is a schematic diagram of the internal formwork system structure of the variable-section high pier frame reverse mold structure; Figure 4 Plan view of the frame-turning structural system for variable-section high pier columns; Figure 5 It is a schematic diagram of a flat steel module; Figure 6 This is a schematic diagram of the lifting system of the variable-section high pier frame and reverse mold structure; Figure 7 This is a schematic diagram of the hydraulic system for the variable-section high pier frame casting structure; Figure 8 This is a schematic diagram of the construction section of the variable-section high pier frame reverse formwork structure construction where the solid section transitions to the thin-walled section; Fig. 9 This is a schematic diagram of the construction section of the standard thin-wall section of the variable-section high pier frame reverse mold structure construction; Fig.10 This is a schematic diagram of the construction section of the partition board for the variable-section high pier frame reverse mold structure construction; Fig.11 This is a schematic diagram of the construction section of the solid section of the pier top for the variable-section high pier column frame reverse mold structure; Fig.12 This is a schematic diagram of the construction flow chart of the variable-section high pier frame reverse formwork structure; In the figure: 1-circle truss structure, 2-enclosed guardrail, 3-upper operating platform, 4-hanging bracket, 5-lower operating platform, 6-maintenance platform, 7-support roller, 8-bolt support, 9-external formwork lifting frame, 10-support steel pipe, 11-wedge jack, 12-external formwork lifting system, 13-external formwork, 14-inner formwork, 15-inner formwork lifting frame, 16-inner formwork lifting system, 17-short side truss, 18-long side truss, 19-hydraulic system, 20-high-strength bolts, 21-end plate bolt holes, 22-back ribs, 23-oil cylinders, 24-mold adjustment segments. DETAILED DESCRIPTION

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work. Example 1

[0017] like Figure 1 — Figure 7 The variable cross-section high pier column lifting frame inverted mold structure of this embodiment is composed of an upper operating platform 3, a lower operating platform 5, a circle truss structure 1, a closed guardrail 2, a hanger 4, a maintenance platform 6, an inner template 14, an outer template 13, an outer template lifting system 12, an inner template lifting system 16 and other structures, which are specifically as follows: The enclosure truss structure 1 is composed of 100*10 equilateral angle steel as chord and 63*63*6 angle steel as web. The cross-sectional outer contour of the truss is 1.2m*1.3m. The enclosure truss structure 1 connects 4 trusses in sequence through high-strength bolts to form a rectangular truss enclosure around the pier column, which serves as the horizontal force-bearing structure of the thin-walled pier formwork and as the force-bearing carrier of the operating platform, enclosure structure and bracket. The closed guardrail 2 is made of 50*50*5 steel pipe to form the safety protection of the formwork system and is directly connected to the enclosure truss structure 1 with high-strength bolts. The upper operating platform 3 is a 2.5mm patterned steel plate laid on the enclosure truss structure 1, which serves as a platform for steel bar installation and binding and concrete pouring. The hanger 4 is made of 80*6 equilateral angle steel with a length of 4.8m. It is connected to the welded cross arm under the enclosure truss structure 1 by bolts. A 50*5 double-angle steel cross arm is set 2.8m below the hanger 4 and a 2.5mm patterned plate is laid to form a lower operating platform 5 as a demoulding working surface. The bottom of the hanger 4 is made of 50*5 double-angle steel cross arm and a 2.5mm patterned plate is laid to form an inspection platform 6 as a platform working surface for inspection and maintenance. The support roller 7 is set at the bottom of the hanger 4 and can roll upward along the pier to enhance the stability of the entire hanger 4 and the platform. The outer side of the hanger 4 is opened every 60cm above the two platforms, and steel bars are inserted into the holes to form the enclosure system of the platform. The bolt top support 8 is made of φ28 precision-rolled threaded steel and a groove-type top support is welded at the end. The tail end is supported on the open-hole steel of the enclosure truss with a special nut. When in use, the top support is tightened against the template beam by tightening the special bolts.

[0018] The external formwork lifting frame 9 is composed of two I18 channel steel support tips welded to form a vertical bar with a rectangular cross-section. The crossbar is composed of two I18 channel steels back to back and connected by a tie plate at a distance of 50mm-60mm to form a lattice truss, and an I100 channel steel is used as a diagonal brace to connect it with the vertical bar above. After installation, the external formwork lifting frame 9 is connected as a whole through the truss welded by the channel steel tie plate. The external formwork lifting frame 9 is connected to the supporting steel pipe 10 inserted into the concrete through the wedge jack 11. Four holes are punched on the crossbeam of the external formwork lifting frame 9 by welding steel plates as the jack base, and the wedge jack 11 is placed on the base. The supporting steel pipe 10 is a φ48*3.5 seamless steel pipe. The aforementioned external formwork lifting frame 9, the supporting steel pipe 10, and the wedge jack 11 together constitute the external formwork lifting system 12, and the external formwork lifting system 12 is connected to the enclosure truss structure 1 through high-strength bolts. During lifting, the wedge jack 11 climbs on the supporting steel pipe 10 and drives the entire outer formwork lifting system 12 and the outer frame to rise.

[0019] The outer template 13 is 2.25m high and is a large integral steel template with a thickness of 5mm. The four corners are arc-shaped templates. The large surface is composed of two 2.95 wide steel templates and the small surface is composed of 2.9m wide steel templates, which are assembled with arc templates to form the outer template 13. There are two sets of 20 outer templates in total. The vertical surface of a single template is flat and smooth. The vertical back ribs are arranged with a spacing of 30cm using No. 5 channel steel. The angle steels are welded around the templates and holes are punched as bolt holes for connecting the templates. The two ends of the back ribs are firmly welded to the angle steels. A template crossbeam formed by double No. 14 channel steels is set at 1 / 5 of the inner side of the two ends of the back ribs. After the template is installed in place, it is tightened by the top support of the bolt top support 8. There are two sets of outer templates 13 in total. One set is installed first and after the concrete is poured, the upper set is installed and concrete is poured. The lower set of outer templates is disassembled piece by piece and lifted to the top by a tower crane for re-installation and use. During the entire construction process, the two sets of outer templates are circulated by continuous disassembly and assembly from bottom to top. The slope of the outer formwork 13 is reduced by "clamping" the large formwork with the small formwork, wherein flanges and oblong holes are provided at the ends of the large formwork, and the corresponding small formwork plane is perpendicular to the large formwork and has bolt holes with a spacing of 120-140mm, which are bolted to the oblong holes of the outer formwork through high-strength bolts. The first cycle of the outer formwork 13 is that the operating platform is cumulatively lifted to a height of 4.8m and the remaining steel bar binding is completed. At the same time, the internal formwork system is installed and the slope reduction of the inner formwork is debugged. After checking the formwork, concrete can be poured. When the concrete is initially set, the bolt top support 8 can be removed to form a space for the formwork to be reversed between the truss and the formwork. At this time, the lower layer of the formwork is removed for the first time and installed on the top with bolt top support 8 for fixation. After the inner formwork is lifted with the pouring, a new thin-walled pouring space is formed. The suspended platform can be installed when the lower space reaches the installation height. At this point, the installation of all platforms for the lifting frame reverse formwork is completed, and subsequent construction can be carried out according to standard processes.

[0020] The structure of the inner formwork 14 is similar to that of the outer formwork 13. The overall size of the formwork is determined according to the cross-sectional profile of the inner cavity of the thin-walled pier. A 5mm steel plate is used as the panel with a height of 2.25m. The vertical back ribs are arranged with a spacing of 30cm using No. 5 channel steel. The upper and lower ends are welded with angle steel lock edges. The division and connection of the formwork blocks are all in the plane position. Double No. 14 channel steels are set at the inner 1 / 5 position of both ends of the vertical back ribs of the inner formwork 14 as the formwork beam. The large-surface formwork is set as 2 modules, and 4 supports are used in opposite directions. The end corner formwork is divided into 3 modules, and the connection between the formworks can only be realized outside the corner. Lateral supports are set on the formwork beams and connected to the nearest supports to form a skeleton. When in use, bamboo plywood can be laid on them after all supports are connected to form the operating platform of the inner formwork.

[0021] The inner formwork lifting frame 15 is composed of two pieces of I18 channel steel support tips welded to form a vertical bar with a rectangular cross-section. The crossbar is composed of two pieces of I18 channel steel back to back and connected by a tie plate at a distance of 50mm-60mm to form a lattice truss. The vertical bar and the crossbar are welded orthogonally, and the channel steel tie plate is used as a diagonal tie rod at the formed inner corner. The inner formwork lifting frame 15 is connected to the supporting steel pipe 10 inserted into the concrete through a wedge jack. Four holes are punched on the crossbeam of the inner formwork lifting frame 15 by welding steel plates as a jack base, and a wedge jack 11 is placed on the base. The supporting steel pipe 10 is a φ48*3.5 seamless steel pipe. The aforementioned inner formwork lifting frame 9, supporting steel pipe 10, and wedge jack 11 together constitute the inner formwork lifting system 16, and the inner formwork lifting system 16 is connected to the inner formwork crossbeam through high-strength bolts. During the lifting process, the wedge jack 11 climbs on the supporting steel pipe 10 and drives the entire inner formwork lifting system 16 and the inner formwork 14 to rise. The inner formwork 14 is lifted into place intermittently according to the sliding formwork process during the pouring process and for a period of time after the pouring is completed, depending on the setting state of the concrete, or after the concrete is fully solidified, the hydraulic system 19 is used to recover the demoulding, and the formwork is lifted and checked after lifting. Figure 7 The hydraulic system 19 shown is composed of a cylinder 23 and a mold adjustment segment 24. The inner mold is put in place first, and has a lap length of at least 15 cm with the poured concrete. The outer template 13 is turned over and put in place, and the outer template 13 is supported by bolts (screws) and after verification, the pouring of the 2.4m concrete in this section can be started. During the pouring process and after completion, the inner template 14 is lifted according to the sliding template process; 4-6 hours after the pouring, the concrete is completely initially set, and the bolt support can be removed, and the enclosure truss structure 1 is lifted, and the steel bars are tied synchronously. This is a complete standard thin-wall section construction operation cycle. During the process, each template is checked by two 15kg plumb bobs to check the distance between the template and the center plumb line to ensure the accuracy of template installation and slope reduction. At the same time, a horizontal pipe is used to mark the horizontal plane on the supporting steel pipe 10 to control the horizontal height of the entire template installation. Example 2

[0022] like Figure 1 — Fig.12 The variable-section high pier column lifting frame inverted mold structure and its construction process in this embodiment include a solid section at the bottom of the pier, a standard thin-walled section in the middle, a solid section at the top of the pier and a cross-partition construction. One pier column only needs to be installed and dismantled once for the working platform.

[0023] The details are as follows: It includes a circle truss structure 1, a closed guardrail 2, an upper operating platform 3, a bracket 4, a lower operating platform 5, a maintenance platform 6, a support roller 7, a bolt top support 8, an inner formwork 14, an outer formwork 13, an outer formwork lifting system 12 and an inner formwork lifting system 16. The circle truss structure 1 is composed of 100*10 equilateral angle steels as chords and 63*63*6 angle steels as webs, and the cross-sectional outer contour of the truss formed is 1.2m*1.3m. The circle truss structure 1 connects 4 trusses in sequence through high-strength bolts to form a rectangular truss circle around the pier column, which serves as a horizontal force-bearing structure of the thin-walled pier formwork and as a force-bearing carrier for the operating platform, the enclosure structure and the bracket. The closed guardrail 2 is made of 50*50*5 steel pipes to form a safety protection for the formwork system and is directly connected to the circle truss structure 1 with high-strength bolts. The upper operating platform 3 is laid with 2.5mm patterned steel plates on the circle truss structure 1, which serves as a platform for installing and binding steel bars and pouring concrete. The hanger 4 is made of 80*6 equilateral angle steel with a length of 4.8m. It is connected to the welded cross arm under the enclosure truss by bolts. A 50*5 double-angle steel cross arm is set 2.8m below the hanger 4 and a 2.5mm patterned plate is laid to form a lower operating platform as a demoulding working surface. The bottom of the hanger 4 is made of 50*5 double-angle steel cross arm and a 2.5mm patterned plate is laid to form an inspection platform 6 as a platform working surface for inspection and maintenance. The support roller 7 is set at the bottom of the hanger 4 and can roll upward along the pier to enhance the stability of the entire hanger 4 and the platform. The outer side of the hanger 4 is opened every 60cm above the two platforms, and steel bars are inserted into the holes to form the enclosure system of the platform. The bolt top support 8 is made of φ28 precision-rolled threaded steel and a groove-type top support is welded at the end. The tail end is supported on the open-hole steel of the enclosure truss with a special nut. When in use, the top support is tightened against the template beam by tightening the special bolts.

[0024] The external formwork lifting frame 9 is composed of two I18 channel steel support tips welded to form a vertical bar with a rectangular cross-section. The crossbar is composed of two I18 channel steels back to back and connected by a tie plate at a distance of 50mm-60mm to form a lattice truss, and an I100 channel steel is used as a diagonal brace to connect it with the vertical bar above. After installation, the external formwork lifting frame 9 is connected as a whole through the truss welded by the channel steel tie plate. The external formwork lifting frame 9 is connected to the supporting steel pipe 10 inserted into the concrete through the wedge jack 11. Four holes are punched on the crossbeam of the external formwork lifting frame 9 by welding steel plates as the jack base, and the wedge jack 11 is placed on the base. The supporting steel pipe 10 is a φ48*3.5 seamless steel pipe. The aforementioned external formwork lifting frame 9, the supporting steel pipe 10, and the wedge jack 11 together constitute the external formwork lifting system 12, and the external formwork lifting system 12 is connected to the enclosure truss structure 1 through high-strength bolts. During lifting, the wedge jack 11 climbs on the supporting steel pipe 10 and drives the entire outer formwork lifting system 12 and the outer frame to rise.

[0025] The outer template 13 is 2.25m high and is a large integral steel template with a thickness of 5mm. The four corners are arc-shaped templates. The large surface is composed of two 2.95m wide steel templates and the small surface is composed of 2.9m wide steel templates, which are assembled with arc templates to form the outer template 13. There are two sets of 20 pieces of outer templates 13 in total. The vertical surface of a single template is flat and smooth. The vertical back ribs 22 are arranged with a spacing of 30cm using No. 5 channel steel. Angle steels are welded around the templates and holes are punched as end plate bolt holes 21 for connecting the templates to each other. The two ends of the back ribs 22 are firmly welded to the angle steels. A template crossbeam formed by double-branched No. 14 channel steel is set at 1 / 5 of the inner side of both ends of the back rib 22. After the template is installed in place, it is tightened by the top support of the bolt top support 8. There are two sets of outer templates 13 in total. One set is installed first. After the concrete is poured, the upper set is installed and the concrete is poured. The lower set of outer templates is disassembled piece by piece and lifted to the top by a tower crane for reinstallation and use. During the entire construction process, the two sets of outer templates 13 are circulated by continuous disassembly and assembly from bottom to top. The slope of the outer template 13 is reduced by the small face template "clamping" the large face template, wherein flanges and oblong holes are set at the ends of the large face template, and the corresponding small face template plane is perpendicular to the large face template and has bolt holes with a spacing of 120-140mm, which are bolted to the oblong holes of the outer template 13 through high-strength bolts 20. The first cycle of the outer template 13 is that the operating platform is cumulatively lifted to a height of 4.8m and the remaining steel bar binding is completed. At the same time, the inner template system is installed and the slope reduction of the inner template 14 is debugged. After checking the template, concrete can be poured. After the concrete has initially set, the bolt support 8 can be removed to form a space for the template to be transported between the truss and the template. At this time, the lower template is removed for the first time and installed to the top with bolt support 8 to fix it. The inner template 14 is lifted with the pouring to form a new thin-wall pouring space. When the lower space reaches the installation height, the hanging platform can be installed. At this point, the installation of all platforms for the frame reverse mold is completed, and the subsequent construction can be carried out according to the standard process.

[0026] The structure of the inner formwork 14 is similar to that of the outer formwork 13. The overall size of the formwork is determined according to the cross-sectional profile of the inner cavity of the thin-walled pier. A 5mm steel plate is used as the panel with a height of 2.25m. The vertical back ribs 22 are arranged with a spacing of 30cm using No. 5 channel steel. The upper and lower ends are welded with angle steel lock edges. The division and connection of the formwork blocks are all in the plane position. Two No. 14 channel steels are set at the inner 1 / 5 position of both ends of the vertical back ribs 22 of the inner formwork 14 as the formwork beam. The large-surface formwork is set as 2 modules, and 4 supports are used in opposite directions. The end corner formwork is divided into 3 modules, and the connection between the formworks can only be realized outside the corner. Lateral supports are set on the formwork beams and connected to the nearest supports to form a skeleton. When in use, bamboo plywood can be laid on them after all supports are connected to form the operating platform of the inner formwork.

[0027] The inner formwork lifting frame 15 is composed of two pieces of I18 channel steel support tips welded to form a vertical bar with a rectangular cross-section. The crossbar is composed of two pieces of I18 channel steel back to back and connected by a tie plate at a distance of 50mm-60mm to form a lattice truss. The vertical bar and the crossbar are welded orthogonally, and the channel steel tie plate is used as a diagonal tie rod at the formed inner corner. The inner formwork lifting frame 15 is connected to the supporting steel pipe 10 inserted into the concrete through the wedge jack 11. Four holes are punched on the crossbeam of the inner formwork lifting frame 15 by welding steel plates as a jack base, and the wedge jack 11 is placed on the base. The supporting steel pipe 10 is a φ48*3.5 seamless steel pipe. The aforementioned inner formwork lifting frame 9, supporting steel pipe 10, and wedge jack 11 together constitute the inner formwork lifting system 16, and the inner formwork lifting system 16 is connected to the inner formwork crossbeam through high-strength bolts. During lifting, the wedge jack 11 climbs on the supporting steel pipe 10 and drives the entire inner template lifting system 16 and the inner template 14 to rise.

[0028] When the standard section is constructed to the diaphragm position, the inner formwork is directly lifted 1.2m (for the diaphragm thickness of 40cm, the upper and lower chamfers are 40cm), the thin-walled pre-buried bolts are used, the distribution beams are set, 10cm square wood is erected and bamboo plywood is laid, and the chamfered hanging formwork is set on the top. The manhole position is made of bamboo plywood and square wood. The template section of the diaphragm position is shown in the figure. Fig.10 . Insert the fixing bolts into the bolt sleeves pre-embedded in the thin-walled concrete, set up the load-bearing beams, distribute the wooden slats, and use wooden formwork to set up the permanent bottom formwork of the diaphragm, tie the diaphragm reinforcement, and install the chamfered side formwork after passing the inspection. After the inspection is correct, the diaphragm and thin-walled concrete are poured at the same time and exceed the chamfer by about 20cm. After the concrete is initially set, the construction can be carried out according to the standard thin-wall section cycle to the next diaphragm. The key point of diaphragm construction is that the lower embedded sleeve should be connected with embedded steel bars to ensure the bearing capacity. The bottom formwork uses 18 I-beams as beams to ensure the bearing capacity. The bottom formwork is set up with square wood and bamboo plywood. To ensure construction safety, the bottom formwork is no longer removed and used as a permanent formwork.

[0029] The installation of the bottom formwork of the solid section of the pier top is consistent with the bottom formwork of the diaphragm. It is connected to the crossbeam through embedded parts and set up square wood and bamboo plywood. The first pouring of concrete should exceed the chamfer and cover at least 40-50cm of the top surface of the permanent formwork. After the concrete solidifies, the working platform can be lifted and the outer formwork can be turned over to complete the pouring of the solid pier on the pier top. Fig.11 .

[0030] In summary, the outer frame of the outer mold integrates the truss structure, upper and lower operation and maintenance platforms, and the lifting system realizes the lifting of the entire outer frame, which provides an integrated operation platform and working surface and provides lateral support for the template. The inner mold is formed by the template blocks and reinforced by supports. The inner mold lifting system is directly connected to the template to form the inner mold system. The inner mold template together constitutes a uniform cross-section thin-walled pier lifting frame type inverted mold structure.

[0031] The construction method of the high pier lifting frame inverted formwork structure of the variable cross-section bridge for rapid construction of the present invention is that the foundation is cast and the main reinforcement of the pier is pre-buried, the outer edge line of the pier is positioned and measured, and the stirrups are tied. The first step is to remove dust from the steel mold, apply a mold release agent, assemble the first layer of the outer template and assemble the enclosure truss structure 1, the closed guardrail 2, and the upper operating platform 3. The outer template lifting frame 9 and the wedge jack 11 are installed, and the slope of the inner mold is debugged, the hydraulic pipeline is connected and the hydraulic system 19 is debugged. The hydraulic system 19 is composed of an oil cylinder 23 and a mold adjustment segment 24. The support steel pipe 10 is inserted above the wedge jack 11 until the steel pipe contacts the foundation, and the bolt support 8 is adjusted to support and tighten the template crossbeam. After checking that the template is correct, the second step is to cast the solid section concrete. 2m of soil; Step 3: Extend the main reinforcement by 4.5m; Step 4: Adjust the bolt top support 8 to disengage the crossbeam of the first layer (also called the lower layer) outer formwork. At this time, the time from the last concrete pouring should be greater than 12 hours. Lift the outer frame and tie the stirrups simultaneously. If necessary, extend the main reinforcement simultaneously. The cumulative lifting and plate tying stirrups are 2.25m upward; Step 5: Install the second layer (also called the lower layer) formwork and adjust the bolt top support 8 to support the formwork crossbeam. Step 6: Position and install the inner formwork system and verify its accuracy, and debug the inner formwork slope reduction and lifting hydraulic system 19. Step 7: Pour 2.25m of thin-walled section concrete. During the pouring process, the inner formwork system lags behind for 2 hours and is lifted intermittently. It is lifted cumulatively by 2.1m 2 hours after the pouring is completed. Repeat Step 4. Step 8: Remove the lower layer formwork and use a tower crane to lift it piece by piece to the top. Adjust the bolt top support 8 to support the formwork crossbeam and check the position of the formwork. Repeat steps 7, 4, and 8. When the pier column diaphragm is reached, perform step 9 to lift the inner formwork 1.2m and set up the bottom formwork of the diaphragm according to the traditional wooden formwork process. Repeat steps 8, 7, and 4 to the next diaphragm. Follow this cycle to the solid section of the pier top. After lifting in step 10, use a tower crane to remove the inner formwork and hoist it to the ground. Install the bottom formwork of the solid section of the pier top according to the traditional formwork process. Repeat step 8 again. Step 11 pours the pier top concrete. Step 12 uses a tower crane to remove the outer formwork in preparation for the next pier column construction.

[0032] The present invention provides a variable-section high pier column frame lifting and mold-turning structure and construction method suitable for rapid construction, which mainly realizes the variable-section thin-wall pier cyclic operation through frame lifting and mold-turning cycles, so that the operating platform, lateral support and formwork system are separated, and the entire operating platform and lateral support structure are separated from the formwork, and the connection is reliable, the structure is light, and the safety is high. The construction process is divided into the pier bottom solid section construction, standard thin-wall section construction, diaphragm construction and pier top solid section construction based on the pier column position. The corresponding formwork system completes the first layer formwork installation, enclosure truss installation, second formwork installation, operating platform installation, and inner formwork installation at the pier bottom section, and the pier top gradually completes the inner formwork removal, two-layer formwork removal, enclosure truss and platform removal. The construction flow chart of the variable-section high pier column frame lifting and mold-turning structure is shown in Fig.12 The invention discloses a variable-section high pier column lifting frame reverse formwork structure and construction method suitable for rapid construction, with fast overall construction progress. The lateral support of the enclosure truss eliminates the tie rods in the traditional process, so that the concrete appearance quality is good. The entire lifting frame reverse formwork structure functionally splits and recombines the traditional templates, has a reliable structure, is easy to operate, and can be widely promoted and applied in variable-section thin-wall piers.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A variable-section thin-walled pier lifting frame type inverted mold structure, characterized in that: The invention comprises an upper operating platform (3), a lower operating platform (5), a ring truss structure (1), a closed guardrail (2), a hanger (4), an outer formwork (13), an inner formwork (14), an outer formwork lifting system (12), an inner formwork lifting system (16) and an inspection platform (6), wherein the ring truss structure (1) is connected in sequence with four trusses by high-strength bolts to form a rectangular truss ring surrounding the pier column, the closed guardrail (2) is directly connected to the ring truss structure (1) by high-strength bolts, and the upper operating platform (3) is arranged on the ring truss structure (1). A ring truss structure (1), wherein the hanger (4) is connected to the lower part of the ring truss structure (1) by bolts, a lower operating platform (5) is arranged at the lower part of the hanger (4), a maintenance platform (6) is arranged at the bottom of the hanger (4), a support roller (7) is arranged at the lower end of the hanger (4) and can roll upward along the pier, a plurality of holes are opened on the outer side of the hanger (4) on the lower operating platform (5) and the maintenance platform (6), steel bars are inserted into the holes, and the ring truss structure (1) is connected to the outer formwork (13) by bolt top support (8); The outer formwork lifting system (12) comprises an outer formwork lifting frame (9), a supporting steel pipe (10) and a wedge jack (11); the outer formwork lifting frame (9) is connected to the enclosure truss structure (1) via bolts, and the outer formwork lifting frame (9) is connected to the supporting steel pipe (10) inserted into the concrete via the wedge jack (11); The inner formwork lifting system (16) comprises an inner formwork lifting frame (15), a supporting steel pipe (10) and a wedge jack (11); the inner formwork lifting frame (15) is connected to the supporting steel pipe (10) inserted into the concrete via the wedge jack (11); and the inner formwork lifting frame (15) is connected to the inner formwork (14) crossbeam via high-strength bolts.

2. A variable-section thin-walled pier lifting frame type inverted mold structure according to claim 1, characterized in that: The enclosure truss structure (1) is composed of 100*10 equilateral angle steels as chord members and 63*63*6 angle steels as web members, forming a truss with a cross-sectional outer contour of 1.2m*1.3m. The closed guardrail (2) is made of 50*50*5 steel pipes. The upper operating platform (3) is a 2.5mm patterned steel plate laid on the enclosure truss structure (1). The bolt top support (8) is made of φ28 fine-rolled threaded steel, and a grooved top support is welded at the end to tighten the cross beam of the outer template (13). The tail end is supported by a nut on the open-hole steel of the enclosure truss structure (1).

3. The variable-section thin-walled pier lifting frame type inverted mold structure according to claim 1 is characterized in that: The bracket (4) is made of 80*6 equilateral angle steel and has a length of 4.8 m. A 50*5 double-angle steel crossbar is arranged 2.8 m below the bracket (4) and a 2.5 mm patterned plate is laid to form a lower operating platform (5). A 50*5 double-angle steel crossbar is arranged at the bottom of the bracket (4) and a 2.5 mm patterned plate is laid to form a maintenance platform (6). The outer side of the bracket (4) has holes opened every 60 cm on the two platforms.

4. The variable-section thin-walled pier lifting frame type inverted mold structure according to claim 1 is characterized in that: The outer template (13) is an integral large steel template with a height of 2.25m and a thickness of 5mm. The four corners are arc-shaped templates. The large surface is composed of two 2.95m wide steel templates and the small surface is composed of 2.9m wide steel templates assembled with arc templates. The outer template (13) has two sets of 20 pieces in total. The vertical surface of a single template is flat and smooth. The vertical back ribs are arranged with a spacing of 30cm using No. 5 channel steel. The template periphery is welded with angle steel and holes are punched as bolt holes for connecting the templates. The two ends of the back rib are firmly welded to the angle steel. A template crossbeam formed by double No. 14 channel steel is set at 1 / 5 of the inner side of the two ends of the back rib. After the template is installed in place, it is tightened by the top support of the bolt top support (8). There are two sets of outer templates (13). One set is installed first and after the concrete is poured, the other set is installed and concrete is poured. Subsequently, the lower set of outer templates is disassembled piece by piece and lifted to the upper side by a tower crane for reinstallation and use. During the entire construction process, the two sets of outer templates are connected by The disassembly and assembly method is continuously circulated from bottom to top, and the outer template (13) is sloped by clamping the large template with the small template, wherein a flange and an oblong hole are set at the end of the large template, and the corresponding small template plane is perpendicular to the large template and has bolt holes with a spacing of 120-140mm, which are bolted to the oblong holes of the outer template through high-strength bolts; the first cycle of the outer template (13) is that the operating platform is cumulatively raised to a height of 4.8m and the remaining steel bars are tied, and at the same time, the internal template system is installed and the slope of the inner template is debugged. After checking the template, concrete can be poured; after the concrete is initially set, the bolt support (8) can be removed to form a space for template reversal between the truss and the template. At this time, the lower template is removed for the first time and installed to the top and fixed with the bolt support (8). The inner template (14) is raised with the pouring to form a new thin-wall pouring space, and the lower space can be installed when the installation height is reached. The inner template (14) has an overall size determined according to the cross-sectional profile of the inner cavity of the thin-walled pier, uses a 5 mm steel plate as a panel, has a height of 2.25 m, and uses a 5-channel steel with a spacing of 30 cm for the vertical back ribs. The upper and lower ends are welded with angle steel for locking. The template blocks are divided and connected all in a plane position. Two 14-channel steels are provided at the inner 1 / 5 position of both ends of the vertical back ribs of the inner template as template crossbeams. The large-surface template is arranged into 2 modules, and 4 supports are used in opposite directions. The end corner template is divided into 3 modules, and the connection between the templates can only be realized outside the corner. Lateral supports are provided on the template crossbeams and connected to the nearest supports to form a skeleton. When in use, bamboo plywood can be laid on them after all supports are connected to form an operating platform for the inner template.

5. The variable-section thin-walled pier lifting frame type inverted mold structure according to claim 1, characterized in that: The outer formwork lifting frame (9) is formed by welding two I18 channel steel support tips to form a vertical bar with a rectangular cross-section, and the cross bar is formed by connecting two I18 channel steels back to back and 50mm-60mm apart through a tie plate to form a lattice truss, and I100 channel steel is used as a diagonal brace to connect with the vertical bar at the top. After installation, the outer formwork lifting frame (9) is connected as a whole through the truss welded by the channel steel tie plate; four holes are punched on the cross bar of the outer formwork lifting frame (9) by welding a steel plate as a base, and a wedge jack (11) is placed on the base, and the supporting steel pipe (10) is a φ48*3.5 seamless steel pipe.

6. The variable-section thin-walled pier lifting frame type inverted mold structure according to claim 1, characterized in that: The inner formwork lifting frame (15) is composed of two pieces of I18 channel steel support tips welded to form a vertical bar with a rectangular cross-section, and the cross bar is composed of two pieces of I18 channel steel back to back and connected by a tie plate at a distance of 50mm-60mm to form a lattice truss. The vertical bar and the cross bar are orthogonally welded, and a channel steel tie plate is used as a diagonal rod at the formed inner corner. Four holes are punched on the crossbeam of the inner formwork lifting frame (15) by welding a steel plate as a jack base, and a wedge jack (11) is placed on the base. The supporting steel pipe 10 is a φ48*3.5 seamless steel pipe.

7. A construction method for a variable-section thin-walled pier frame-type reverse mold structure, characterized in that: The variable-section thin-walled pier lifting frame type inverted mold structure comprises the following steps: (1) After the foundation is poured and the main reinforcement of the pier column is embedded, the outer edge of the pier column is positioned and measured, and the stirrups are tied. After the steel formwork is dusted and a release agent is applied, the first layer of the outer formwork is assembled, and the enclosure truss structure (1), the closed guardrail (2), and the upper operating platform (3) are assembled. The outer formwork lifting frame (9) and the wedge jack (11) are installed, and the inner formwork is adjusted. The hydraulic pipeline is connected and the hydraulic system is adjusted. The support steel pipe (10) is inserted above the wedge jack (11) until the steel pipe contacts the foundation. The bolt support (8) is adjusted so that the support is tightly against the formwork beam, and the formwork is checked; (2) After checking that the formwork is correct, pour the solid section concrete; (3) Extend the main reinforcement; (4) Adjust the bolt top support (8) to disengage the crossbeam of the first layer of outer formwork (13). At this time, the time since the last concrete pouring should be greater than 12 hours. Lift the outer frame and tie the stirrups simultaneously. (5) Install the second layer of formwork and adjust the bolt top support (8) to support the formwork beam; (6) Position and install the inner mold (14) system and verify its accuracy, and debug the inner mold's slope reduction and lifting hydraulic system; (7) pouring the thin-walled section concrete, during which the inner formwork (14) system is lifted intermittently after a 2-hour delay, and step (4) is repeated; (8) Remove the lower formwork and use a tower crane to lift each piece to the top and install it piece by piece. Adjust the bolt top support (8) to support the formwork beam and check the position of the formwork; (9) Repeat steps (7), (4), and (8) until the pier column diaphragm is reached, then raise the inner formwork by 1.2 m and set up the diaphragm bottom formwork using the traditional wooden formwork process; (10) Repeat steps (8), (7), and (4) to the next diaphragm. Continue this cycle until the solid section at the top of the pier is reached. After lifting, use a tower crane to remove the inner formwork and hoist it to the ground. Install the bottom formwork of the solid section at the top of the pier using the traditional formwork process. (11) Repeat step (8) again and pour the pier top concrete; (12) Use a tower crane to remove the outer formwork (13) in preparation for the construction of the next pier.

8. The construction method of a variable-section thin-walled pier lifting frame type reverse mold structure according to claim 7, characterized in that: In step (2), 2 m of solid section concrete is poured; in step (3), the main reinforcement is extended by 4.5 m; in step (4), the cumulative lifting and tying of stirrups is performed upward by 2.25 m; in step (7), 2.25 m of thin-wall section concrete is poured, and the cumulative lifting is performed by 2.1 m within 2 hours after the pouring is completed.

9. The construction method of a variable-section thin-walled pier frame-lifting type reverse mold structure according to claim 7, characterized in that: In step (4), the main reinforcement is extended synchronously if necessary.

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