CN115058976A - Aluminum alloy internal mold system containing diaphragm plate and variable cross-section cast-in-place box girder and construction method thereof - Google Patents

Abstract

The invention discloses an aluminum alloy internal mold system containing a diaphragm plate and a variable cross-section cast-in-place box girder, which consists of a template system and a supporting system which are arranged in the box girder. The template system comprises a standard template, a special-shaped template and an initial block template which are respectively arranged at the linear straight part of the box girder, the variable cross section and the center of the end part of the top plate template. The supporting system comprises a base beam, a base beam base and a steel pipe support built on the base beam, the front end of the base beam is suspended on the front upper cross beam of the hanging basket through a suspension rod, the rear end of the base beam is installed on the base beam base, and the base beam base is supported on a bottom plate of a poured beam section; the top of the steel pipe support is provided with a keel through a top support, and the keel supports a template. The construction method comprises the following steps: (1) analyzing the box girder structure; (2) designing an aluminum alloy internal mold; (3) mounting an aluminum alloy inner die; (4) and (5) removing the aluminum alloy inner die. The aluminum alloy internal mold system is applied to construction of variable-section cast-in-place box girders containing diaphragm plates, and can solve the problems of troublesome assembly and turnover of the existing steel or wood templates, long construction period, large material waste and the like.

Description

Aluminum alloy internal mold system containing diaphragm plate and variable cross-section cast-in-place box girder and construction method thereof

Technical Field

The invention relates to the technical field of bridge construction, in particular to an aluminum alloy internal mold system containing a diaphragm plate and a variable cross-section cast-in-place box girder and a construction method thereof.

Background

The box girder is one of bridge engineering, and the inside is hollow, and upper portion both sides have the flange, similar box, therefore obtains the name. The prestressed concrete cast-in-place box girder is a main bridge span structure type of the current girder bridge, has the advantages of high rigidity, low maintenance amount, low noise and the like after being built, and is a preferred main girder structure system of expressways, high-speed railways and municipal traffic bridges.

The main girder of the large-span bridge mostly adopts a variable cross-section box girder, and the two-dimensional size of a hollow box chamber in the box girder and the structural sizes of an upper chamfer, a lower chamfer and the like are constantly changed along with the length of the girder; meanwhile, due to the blocking of the diaphragm plates, the turnover of the templates can only be carried out from the man holes in the box chamber containing the diaphragm plates, and the two modes bring great inconvenience to the construction of the templates. For the variable cross-section cast-in-situ box girder containing the diaphragm plate, a wooden template or a steel template is mostly adopted as an inner mold. At present, the wood formwork is constructed in a mode of continuously cutting the formwork according to the size change of an inner box of a box girder by adopting on-site loose assembly, so that the mounting and positioning precision of the formwork is difficult to control, and the pouring appearance quality is poor; in the construction process, the template needs to be continuously adjusted, so that the construction period is long; meanwhile, the template has short service cycle and can not be recycled, thus increasing the cost and being not beneficial to environmental protection. The steel template is used as the inner mold, and the steel template is heavy in weight, needs to pass through a manhole and is difficult to use mechanical assistance in template turnover, so that the template is very inconvenient to install, dismantle and turnover, and the safety problem is easily caused. Therefore, there is a need to develop an internal mold system that has high standardization, can be recycled, has light weight, is convenient to use, and can adapt to a variable cross-section box girder.

Disclosure of Invention

The invention aims to provide an aluminum alloy internal mold system suitable for a variable cross-section cast-in-place box girder containing a diaphragm plate and a construction method thereof, and solves the problems of troublesome assembly and turnover of the existing steel and wood templates, long construction period, large material waste and the like.

In order to realize the purpose of the invention, the technical scheme is as follows:

an aluminum alloy internal mold system containing a diaphragm plate variable cross-section cast-in-place box girder consists of a template system installed in the box girder and a supporting system used for supporting the fixed template; the template system comprises a standard template, a special-shaped template and an initial block template; the standard template is made of rectangular aluminum templates with uniform size and is arranged at the linear straight positions of the top plate, the web plate and the diaphragm plate of the box girder; the special-shaped templates are arranged at the top chamfer and the inner bottom chamfer of the hollow box chamber of the box girder, and are designed independently, and the special-shaped templates of each specification and model are only suitable for chamfer construction with corresponding sizes and cannot be used in a mixed manner; the first-dismantling block template is arranged at the end part of the box girder top plate template and consists of two right-angle trapezoid templates and an isosceles trapezoid template, and the long edge of the isosceles trapezoid template faces the outer end part of the template during installation; the supporting system comprises a base beam, a base beam base and a steel pipe support built on the base beam, the front end of the base beam is suspended on an upper front cross beam of the hanging basket through a suspension rod, the rear end of the base beam is placed on the base beam base and is hinged and fixed with the base beam base through a pin shaft, the base beam base is supported on a bottom plate of a poured beam section, and the base beams are connected into a whole in a mode of welding a profile steel cross beam; the top of the steel pipe bracket is provided with a jacking support; the top support is provided with a keel, and the keel directly supports the box girder top plate template; corner connecting pieces are installed at two ends of the keel and connected with the back edges, and the box girder web plate template is attached and fixed on the back edges.

Further preferred is: the base beam is made of profile steel, the base of the base beam comprises two upright columns formed by double splicing of two channel steels, a cylindrical bearing is arranged between the channel steels and used for bearing the base beam, a steel bottom plate is welded at the bottom of each upright column, structural reinforcement is carried out between each upright column and the corresponding bottom plate in a steel batten welding mode, bolt holes are formed in the bottom plates, and the base plates are fixedly connected with the bottom plates of the poured box beams in a bolt beating mode; the upright post is provided with a hinge hole for being hinged and fixed with the base beam through a pin shaft.

Further preferred is: the standard template, the special-shaped template and the first-dismantling block template are connected in a bolt and taper pin combined connection mode.

Further preferred is: the template system is provided with a plurality of counter-pulling screw rods on the box girder web template, and two ends of the counter-pulling screw rods are fastened on the back edges through nuts.

Further preferred is: the keel, the corner connecting piece and the back edge are made of profile steel, the keel and the back edge are made in a segmented mode according to construction convenience requirements, and the segments are connected through flange bolts.

Further preferred is: the keel is connected with the corner connecting piece through a pin shaft, the corner connecting piece is connected with the back edge through a bolt, and the back edge is connected with the template system through a connecting buckle.

The construction process of the variable cross-section cast-in-place box girder aluminum alloy internal mold system with the diaphragm plate comprises the following steps:

1) and analyzing the box girder structure: according to a drawing of a cast-in-place continuous box girder, the section change of a box girder inner box and the design parameters and the heterogeneity of structural parts of a web plate, a diaphragm plate, a top plate, a chamfer angle, a manhole and a tooth block are analyzed, and the section change condition of a full-bridge box girder segment is synthesized to determine the combination mode and the quantity of the aluminum alloy inner molds.

2) And designing an aluminum alloy inner die: the box girder internal mold is subjected to integral modeling and gridding partition mold distribution design, the plane structures of a web plate, a diaphragm plate and a top plate adopt standard templates, the space structures of a manhole, a chamfer and a tooth block adopt special-shaped template combination, and various templates are designed according to the size convenient for combination, assembly, disassembly and transfer; the pull rod holes of the standard templates of the top plate and the web plate are distributed in a matrix manner, and the pull rod holes can be aligned in the transverse direction and the vertical direction through all combinations of the standard templates; the template at the middle end part of the top plate adopts the structural design of the first-dismantling block template, so that the template is convenient to dismantle and transfer.

3) And installing an aluminum alloy inner die:

a. installing a bottom plate and a web steel bar of the box girder segment, a prestressed pipeline, an embedded part and a foundation beam base and hoisting a foundation beam;

b. measuring lofting and positioning the central line position of the side mold of the diaphragm plate;

c. installing transverse partition plates and web plate templates, and assembling the transverse partition plates and the web plates from the middle of the transverse partition plates to the two sides of the transverse partition plates in a block-by-block mode sequentially according to a design block-module combination mode, wherein the assembling height of each cycle is about m-m;

d. mounting a back edge and penetrating through a split screw fixing template;

e. erecting a layer of steel pipe support from the foundation beam, laying an operation platform on the support, and erecting the steel pipe support to be consistent with the height of the template for subsequent template installation operation;

f. repeating the steps c to e until the diaphragm plate and the web plate template are installed at the chamfer of the inner top mold;

g. a top support is arranged at the top of the bracket, and a keel is arranged on the top support;

h. installing a top die template and an upper chamfer angle template, assembling the templates from the top chamfer angles of the webs at two sides to the middle of the top plate, and assembling the dies by adopting a first-disassembling block template in the middle;

i. adjusting the jacking to enable the lap joint part of the top die to be tightly attached to the top plate of the upper section, and simultaneously measuring lofting and adjusting the elevation of the front end of the top die to meet the design requirement;

j. mounting a connecting piece to connect the keel and the back edge, so that the inner top die, the side die and the diaphragm plate die plate are connected into a whole;

k. and (3) installing box girder top plate steel bars, prestressed pipelines and embedded parts, pouring girder section concrete, completing girder section construction, and beginning to dismantle the inner mold after the strength of the girder section concrete meets the requirement of mold removal.

4) And dismantling the aluminum alloy inner die:

a. dismantling the counter-pulling screw rod and the back edge by utilizing the original erected steel pipe bracket and the operation platform;

b. removing the web plate and the diaphragm plate template layer by layer from bottom to top;

c. removing the top plate first-removing block template, and then sequentially removing the rest block templates of the top plate;

d. removing the keel, and then removing the steel pipe bracket from top to bottom;

e. and transferring the workpiece to the construction position of the next beam section for installation through the transverse clapboard and the manhole.

Compared with the prior art, the technology of the application has the following characteristics and advantages:

1. the aluminum alloy template is designed in advance, the proportion of the special-shaped template is reduced to the minimum by deep template matching, about 80 percent of the template is a reusable universal standard template, and the circulation utilization rate of the aluminum template is maximized; simultaneously, the template adopts first fast design of tearing open, and first quick template of tearing open takes off after connecting the nut, and the pulling force of exerting toward the outside can easily deviate from, has avoided concrete placement back, and the template is connected too closely can't be demolishd and demolish the fragile problem that leads to, has reduced the engineering time promptly, has saved the template maintenance cost again.

2. The steel pipe support is erected on the foundation beam and does not contact the box girder bottom plate, construction of all parts of the box girder can be carried out simultaneously, the trouble that bottom plate concrete needs to be poured firstly in a traditional support method, and a support construction web plate and a top plate can be erected after the concrete is solidified is avoided, and the construction period is shortened.

3. Compared with a wood template, the aluminum alloy internal mold system has high installation flatness and good concrete pouring appearance quality; the aluminum alloy template can be recycled, the service cycle is long, the material waste is less, and the environment is protected; the special-shaped template is designed and manufactured in advance, the template does not need to be adjusted continuously in the construction process, and the construction period is short.

4. Compared with a steel template, the aluminum alloy internal mold adopts a small-block design, is light in weight, is convenient to install, dismantle and transport, and does not need to rely on large-scale mechanical equipment; meanwhile, the aluminum alloy template is not rusted, and compared with a steel template, the maintenance cost in the construction process can be reduced, and the template maintenance time is shortened.

Drawings

FIG. 1 is a schematic view of the installation structure of the aluminum alloy internal mold system;

FIG. 2 is a schematic right-side view of FIG. 1;

FIG. 3 is a schematic view of the layout of the foundation beam;

FIG. 4 is a schematic view of the installation and connection of the foundation beam, the steel pipe bracket and the foundation beam base;

FIG. 5 is a schematic view of the installation and connection of the aluminum alloy inner mold system and the support system;

FIG. 6 is a schematic view of a connection structure of a standard template and a back edge;

FIG. 7 is a schematic view taken along line A-A of FIG. 6;

FIG. 8 is an installation schematic of a first break block template;

FIG. 9 is a schematic view of the base beam base;

FIG. 10 is a left side schematic view of FIG. 9;

FIG. 11 is a top view of FIG. 9;

FIG. 12 is a schematic view of the structure of the connector;

FIG. 13 is a schematic structural diagram of a special-shaped template;

the names corresponding to the sequence numbers in the figure are:

1. a standard template; 2. a special-shaped template; 3. a right-angled trapezoidal template; 4. an isosceles trapezoid template; 5. a base beam; 6. a steel pipe bracket; 7. a boom; 8. a front upper cross beam; 9. a base beam base; 10. jacking; 11. a keel; 12. a corner connector; 13. back corrugation; 14. a column; 15. a cylindrical bearing; 16. a base plate; 17. a steel gusset plate; 18. oppositely pulling the screw rod; 19. a steel beam.

Detailed Description

For a more clear description of the present technology, the present technology is further described in detail below with reference to the accompanying drawings and examples.

Example 1

An aluminum alloy internal mold system containing a diaphragm plate variable cross-section cast-in-place box girder consists of a template system installed in the box girder and a supporting system used for supporting the fixed template; the template system comprises a standard template 1, a special-shaped template 2 and an initial block template; the standard template 1, the special-shaped template 2 and the first-disassembled template are connected in a bolt and taper pin combined connection mode. The standard template 1 is made of rectangular aluminum templates with uniform size and is arranged at the linear straight positions of a box girder top plate, a web plate and a diaphragm plate; the special-shaped templates 2 are arranged at the inner top chamfer and the inner bottom chamfer of the box girder hollow box chamber, and are independently designed, and the special-shaped templates of each specification and model are only suitable for chamfer construction with corresponding sizes and cannot be used in a mixed manner; the first-dismantling block template is arranged at the end part of the box girder top plate template and consists of two right-angle trapezoid templates 3 and an isosceles trapezoid template 4, and the long side of the isosceles trapezoid template faces the outer end part of the template during installation; the supporting system comprises a base beam 5, a base beam base 9 and a steel pipe support 6 built on the base beam 5, the front end of the base beam 5 is suspended on a front upper cross beam 8 of the hanging basket through a suspension rod 7, the rear end of the base beam is placed on the base beam base 9 and is hinged and fixed with the base beam base 9 through a pin shaft, the base beam 5 is made of profile steel, the base beam base 9 comprises a stand column 14 formed by splicing two channel steels, a cylindrical bearing 15 is installed between the channel steels and used for bearing the base beam 5, a steel bottom plate 16 is welded at the bottom of the stand column 14, structural reinforcement is carried out between the stand column 14 and the bottom plate 16 in a steel gusset plate 17 welding mode, bolt holes are formed in the bottom plate 16, and the bolt holes are fixedly connected with a poured box beam bottom plate in a bolt punching mode; the upright post 14 is provided with a hinge hole for hinging and fixing the base beam 5 through a pin shaft; the foundation beam base 9 is supported on a bottom plate of a poured beam section, and the foundation beams 5 are connected into a whole in a mode of welding the section steel cross beam 19; the top of the steel pipe bracket 6 is provided with a jacking 10; the top support 10 is provided with a keel 11 which directly supports the box girder top plate template; corner connecting pieces 12 are installed at two ends of the keel 11, the corner connecting pieces 12 are connected with back ridges 13, and the box girder web plate template is attached and fixed on the back ridges 13. Fossil fragments 11, corner connecting piece 12, back of the body stupefied 13 are made by shaped steel, fossil fragments 11 and the stupefied 13 of the back of the body need adopt the segmentation preparation according to the construction convenience condition, adopt flange bolted connection between the segmentation. The keel 11 and the corner connecting piece 12 are connected through a pin shaft, the corner connecting piece 12 and the back edge 13 are connected through a bolt, and the back edge 13 and the template system are connected through a connecting buckle.

The template system is provided with a plurality of counter-pulling screw rods 18 on a box girder web template, and two ends of the counter-pulling screw rods 18 are fastened on the back ridge 13 through nuts.

The construction process of the variable cross-section cast-in-place box girder aluminum alloy internal mold system with the diaphragm plate comprises the following steps:

1) and analyzing the box girder structure: according to a drawing of a cast-in-place continuous box girder, the section change of a box girder inner box and the design parameters and the heterogeneity of structural parts of a web plate, a diaphragm plate, a top plate, a chamfer angle, a manhole and a tooth block are analyzed, and the section change condition of a full-bridge box girder segment is synthesized to determine the combination mode and the quantity of the aluminum alloy inner molds.

2) And designing an aluminum alloy inner die: the box girder internal mold is subjected to integral modeling and gridding partition mold distribution design, the plane structures of a web plate, a diaphragm plate and a top plate adopt a standard template 1, the space structures of a manhole, a chamfer and a tooth block adopt a special-shaped template 2 combination, and various templates are designed according to the size convenient for combination, assembly, disassembly and transfer; the pull rod holes of the standard templates of the top plate and the web plate are distributed in a matrix manner, and the pull rod holes can be aligned horizontally and vertically by means of all-directional combination of the standard templates; the template at the middle end part of the top plate adopts the structural design of the first-dismantling block template, so that the template is convenient to dismantle and transfer.

3) And installing an aluminum alloy inner die:

a. installing a bottom plate and a web steel bar of the box girder segment, a prestressed pipeline, an embedded part and a foundation beam base 9 and hoisting a foundation beam 5;

b. measuring lofting and positioning the central line position of the side mold of the diaphragm plate;

c. installing transverse partition plates and web plate templates, and assembling the transverse partition plates and the web plates from the middle of the transverse partition plates to the two sides one by one according to a design block-module combination mode, wherein the assembling height of each cycle is about 1m-1.5 m;

d. mounting a back edge 13 and fixing a template by penetrating through a counter-pulling screw 18;

e. erecting a layer of steel pipe support 6 from the foundation beam 5, laying an operation platform on the support, and erecting the steel pipe support with the height consistent with that of the template for subsequent template installation operation;

f. repeating the steps c to e until the diaphragm plate and the web plate template are installed at the chamfer of the inner top mold;

g. a top support 10 is arranged at the top of the bracket 6, and a keel 11 is arranged on the top support;

h. installing a top die template and an upper chamfer angle template, assembling the templates from the top chamfer angles of the webs at two sides to the middle of the top plate, and assembling the dies by adopting a first-disassembling block template in the middle;

i. adjusting the jacking 10 to make the overlapping part of the top die tightly attached to the top plate of the upper section, and simultaneously measuring lofting and adjusting the elevation of the front end of the top die to meet the design requirement;

j. installing a connecting piece 12 to connect the keel 11 with the back edge 13, so that the inner top die, the side die and the diaphragm plate die plate are connected into a whole;

k. and (3) installing box girder top plate steel bars, prestressed pipelines and embedded parts, pouring girder section concrete, completing girder section construction, and beginning to dismantle the inner mold after the strength of the girder section concrete meets the mold dismantling requirement.

4) And dismantling the aluminum alloy inner die:

a. the oppositely pulling screw rods 18 and the back edges 13 are removed by utilizing the original erected steel pipe bracket 6 and the operation platform;

b. removing the web plate and the diaphragm plate template layer by layer from bottom to top;

c. removing the top plate first-removing block template, and then sequentially removing the rest block templates of the top plate;

d. removing the keel 11, and then removing the steel pipe bracket 6 from top to bottom;

e. and transferring the workpiece to the construction position of the next beam section for installation through the transverse clapboard and the manhole. .

The above description is not intended to limit the present application, and the present application is not limited to the above examples, and those skilled in the art should understand that they can make various changes, modifications, additions and substitutions within the spirit and scope of the present application.

Claims (7)

1. The utility model provides a contain cast-in-place case roof beam aluminum alloy centre form system of cross slab variable cross section which characterized in that: the supporting system is composed of a template system arranged in the box girder and a supporting system used for supporting the fixed template; the template system comprises a standard template (1), a special-shaped template (2) and an initial-dismantling block template; the standard template (1) is made of rectangular aluminum templates with uniform size and is arranged at the linear straight positions of a box girder top plate, a web plate and a diaphragm plate; the special-shaped templates (2) are arranged at the top chamfer and the inner bottom chamfer of the box girder hollow box chamber, and are designed independently, and the special-shaped templates of each specification and model are only suitable for chamfer construction with corresponding sizes and cannot be used in a mixed manner; the first-dismantling block template is arranged at the end part of the box girder top plate template and consists of two right-angle trapezoid templates (3) and an isosceles trapezoid template (4), and the long side of the isosceles trapezoid template faces the outer end part of the template during installation; the supporting system comprises a base beam (5), a base beam base (9) and a steel pipe support (6) built on the base beam (5), the front end of the base beam (5) is suspended on a front upper cross beam (8) of the hanging basket through a suspender (7), the rear end of the base beam is placed on the base beam base (9) and is hinged and fixed with the base beam base (9) through a pin shaft, the base beam base (9) is supported on a poured beam section bottom plate, and the base beams (5) are connected into a whole in a mode of welding a section steel cross beam (19); the top of the steel pipe bracket (6) is provided with a jacking support (10); a keel (11) is arranged on the top support (10), and the keel directly supports the box girder top plate template; corner connecting pieces (12) are installed at two ends of the keel (11), the corner connecting pieces (12) are connected with back ridges (13), and the box girder web plate template is attached and fixed to the back ridges (13).

2. The aluminum alloy internal mold system containing the diaphragm plate and the variable-section cast-in-place box girder as claimed in claim 1, is characterized in that: the base beam (5) is made of profile steel, the base beam base (9) comprises an upright post (14) formed by double splicing of two channel steels, a cylindrical bearing (15) is installed between the channel steels and used for bearing the base beam (5), a steel bottom plate (16) is welded at the bottom of the upright post (14), the upright post (14) and the bottom plate (16) are structurally strengthened in a steel batten plate (17) welding mode, bolt holes are formed in the bottom plate (16), and the upright post and the poured box beam bottom plate are connected and fixed in a bolt hitting mode; the upright post (14) is provided with a hinge hole for being hinged and fixed with the base beam (5) through a pin shaft.

3. The cast-in-place box girder aluminum alloy internal mold system with the diaphragm plate and the variable cross section as claimed in claim 1, characterized in that: the standard template (1), the special-shaped template (2) and the head-disassembled block template are connected in a bolt and taper pin combined connection mode.

4. The aluminum alloy internal mold system containing the diaphragm plate and the variable-section cast-in-place box girder as claimed in claim 1, is characterized in that: the template system is provided with a plurality of counter-pulling screw rods (18) on a box girder web template, and two ends of the counter-pulling screw rods (18) are fastened on a back edge (13) through nuts.

5. The aluminum alloy internal mold system containing the diaphragm plate and the variable-section cast-in-place box girder as claimed in claim 1, is characterized in that: fossil fragments (11), corner connecting piece (12), back of the body stupefied (13) make by shaped steel, fossil fragments (11) and back of the body stupefied (13) adopt the segmentation preparation according to the construction convenience needs, adopt flange bolted connection between the segmentation.

6. The cast-in-place box girder aluminum alloy internal mold system with the diaphragm plate and the variable cross section as claimed in claim 1, characterized in that: the keel (11) is connected with the corner connecting piece (12) through a pin shaft, the corner connecting piece (12) is connected with the back edge (13) through a bolt, and the back edge (13) is connected with the template system through a connecting buckle.

7. The cast-in-place box girder aluminum alloy internal mold system with the diaphragm plate and the variable cross section as claimed in claim 1, characterized in that: the construction process of the aluminum alloy internal mold system comprises the following steps:

1) and analyzing the box girder structure: according to a drawing of a cast-in-place continuous box girder, analyzing the section change of a box girder inner box and the design parameters and the heterogeneity of structural parts of a web plate, a diaphragm plate, a top plate, a chamfer, a manhole and a tooth block, and determining the combination mode and the quantity of the aluminum alloy inner die by synthesizing the section change condition of a full-bridge box girder segment;

2) and designing an aluminum alloy inner die: the box girder internal mold is subjected to integral modeling and gridding partition mold distribution design, the plane structures of a web plate, a diaphragm plate and a top plate adopt standard templates (1), the space structures of a manhole, a chamfer and a tooth block adopt special-shaped template (2) combination, and various templates are designed according to the size convenient for combination, assembly, disassembly and transfer; the pull rod holes of the standard templates of the top plate and the web plate are distributed in a matrix manner, and the pull rod holes can be aligned horizontally and vertically by means of all-directional combination of the standard templates; the template at the middle end part of the top plate is designed by adopting a first-dismantling-block template structure, so that the template is convenient to dismantle and transfer;

3) and installing an aluminum alloy inner die:

a. installing a bottom plate and a web steel bar of the box girder segment, a prestressed pipeline, an embedded part and a foundation beam base (9) and hoisting a foundation beam (5);

b. measuring lofting and positioning the central line position of the side mold of the diaphragm plate;

c. installing transverse partition plates and web plate templates, and assembling the transverse partition plates and the web plates from the middle of the transverse partition plates to the two sides one by one according to a design block-module combination mode, wherein the assembling height of each cycle is about 1m-1.5 m;

d. a back edge (13) is installed and a fixing template of a counter-pulling screw rod (18) is arranged in a penetrating way;

e. erecting a layer of steel pipe support (6) from the base beam (5), laying an operation platform on the support, and erecting the steel pipe support to be consistent with the height of the template for subsequent template installation operation;

f. repeating the steps c to e until the diaphragm plate and the web plate template are installed at the chamfer of the inner top mold;

g. a top support (10) is arranged at the top of the bracket (6), and a keel (11) is arranged on the top support;

h. installing a top die template and an upper chamfer angle template, assembling the templates from the top chamfer angles of the webs at two sides to the middle of the top plate, and assembling the dies by adopting a first-disassembling block template in the middle;

i. adjusting a jacking (10) to enable the overlapping part of the top die to be tightly attached to the top plate of the upper section, and simultaneously measuring lofting and adjusting the elevation of the front end of the top die to meet the design requirement;

j. mounting a connecting piece (12) to connect the keel (11) with the back edge (13) and connect the inner top die, the side die and the diaphragm plate template into a whole;

k. installing box girder top plate steel bars, prestressed pipelines and embedded parts, pouring girder section concrete, completing girder section construction, and beginning to dismantle the inner mold after the strength of the girder section concrete meets the mold dismantling requirement;

4) and dismantling the aluminum alloy inner die:

a. the oppositely pulling screw rods (18) and the back edges (13) are removed by utilizing the original erected steel pipe bracket (6) and the operation platform;

b. removing the web plates and the diaphragm plate templates layer by layer from bottom to top;

c. removing the top plate first-removing block template, and then sequentially removing the rest block templates of the top plate;

d. removing the keel (11), and then removing the steel pipe bracket (6) from top to bottom;

e. and transferring the workpiece to the next beam section construction position through the transverse clapboard and the manhole for installation.

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