Modular bridge bent cap reinforcement and method of installation

Abstract

The application discloses a modular bridge bent cap steel reinforcement framework and a mounting method, mainly comprising the following steps: laying multiple I-shaped steels on a flat and solid cement concrete ground at equal intervals; laying flat bottom plates with the width of steel reinforcement framework modules for connecting sections and column top sections on the multiple I-shaped steels respectively; laying inclined bottom plates with the width of steel reinforcement framework modules for cantilever sections on one side of the flat bottom plates; welding multiple U-shaped positioning frames for the flat bottom plate side steel reinforcement framework and the inclined bottom plate side steel reinforcement framework on both sides of the multiple I-shaped steels respectively; meanwhile, the vertical rods on both sides of the multiple U-shaped positioning frames are fixed by crosspiece lengthwise welding on the top of the vertical rods; multiple inclined braces are welded on both sides of the vertical rods and the I-shaped steels respectively; and multiple horizontal rods for supporting longitudinal steel reinforcements of the steel reinforcement framework are arranged on the vertical rods. The structure has the advantages of convenient operation, reliable quality, labor saving, precision improvement, energy saving and environmental protection, and has high economic and social benefits in combination with the corresponding mounting method.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of energy-saving bridge construction, in particular to a modular bridge bent cap reinforcement framework and installation method. BACKGROUND

[0002] With the increasing environmental protection requirements and labor costs of engineering construction, the application of highway fabricated concrete bridge is gradually widespread, and the fabricated reinforced concrete bridge bent cap construction is one of the focuses. At present, the fabricated reinforced concrete bridge bent cap is mainly divided into three types: the first type is the overall prefabricated installation of the bent cap; the second type is the segmental prefabrication and installation connection of the bent cap to form a whole; and the third type is the overall fabrication and installation of the bent cap reinforcement framework and cast-in-place concrete. According to the engineering scale, construction site conditions, transportation and lifting capacity, and economic and technical requirements, the fabricated construction scheme of the reinforced concrete bridge bent cap is determined. In the third type of overall fabrication and installation of the bent cap reinforcement framework and cast-in-place concrete construction scheme, the overall bent cap is also disassembled into multiple segmental reinforcement frameworks for pouring concrete after assembly, but due to the factors such as lifting point, self-weight and the like in the process of fabrication, stacking, transportation and assembly, the segmental lifting of the bent cap reinforcement framework is prone to deformation, and the assembly quality is difficult to meet the design requirements, so it is necessary to analyze the causes of these problems and propose solutions. SUMMARY

[0003] The technical problem to be solved by the present application is to overcome the defects of the prior art and provide a modular bridge bent cap reinforcement framework and installation method which is convenient to operate, reliable in quality, saves labor, improves precision, saves energy and is environmentally friendly.

[0004] The technical problem of the present application is solved by the following technical scheme:

[0005] A modular bridge bent cap reinforcement framework, comprising multiple I-shaped steels laid at equal intervals on a flat and solid cement concrete ground surface, flat bottom plates of a connection segment reinforcement framework module width and a column top segment reinforcement framework module width are respectively laid on the multiple I-shaped steels, and inclined bottom plates of a cantilever segment reinforcement framework module width are laid on one side of the flat bottom plates, then U-shaped positioning frames for erecting flat bottom plate side reinforcement frameworks and inclined bottom plate side reinforcement frameworks are respectively welded on both sides of the multiple I-shaped steels; the vertical rod top portions of both sides of the multiple U-shaped positioning frames are fixed by longitudinal welding of crosspieces, multiple inclined braces are respectively welded on both sides of the vertical rods of the multiple U-shaped positioning frames and the I-shaped steels, and multiple crossbars for supporting longitudinal reinforcement frameworks are arranged on the vertical rods of the multiple U-shaped positioning frames.

[0006] The modular bridge cap beam reinforcement cage comprises two modular cantilever sections and one modular column top section reinforcement cage, fabricated by welding, binding, and sleeve connection between a sloping bottom plate, a flat bottom plate, and a U-shaped positioning frame. The cantilever and column top sections are hoisted and placed in the storage area for later use. The cantilever sections require support at cantilever A to maintain their dimensional stability and reduce deformation. When support is provided at cantilever A, the cantilever section reinforcement cage is considered a simply supported variable cross-section beam. During storage, the sagging deformation curve of the lowest layer of inclined reinforcement in the cantilever section reinforcement cage is as follows: Its maximum relaxation deformation When the cantilever section of the reinforcing steel cage is hoisted into the cap beam formwork and spliced ​​with the column top section of the reinforcing steel cage, the cantilever section of the reinforcing steel cage and the column top section of the reinforcing steel cage are connected at the connection section using a sleeve. o The end is the fixed end of the cantilever beam, and the sag deflection at mid-span of the cantilever beam is... ,Require That is, the maximum relaxation deformation during the stacking of the cantilever section steel reinforcement cage is approximately... The sag deflection after splicing with the cantilever section reinforcement cage and the column top section reinforcement cage using sleeves The sum must meet the splicing standard error requirements. ,or That is, the maximum downward deflection of the cantilever end after the cantilever section steel reinforcement cage and the column top section steel reinforcement cage are spliced ​​together with sleeves. The splicing standard error requirements must be met. ;

[0007] Formula 1: Calculation of characteristic parameters of the reinforcement cage in the cantilever section

[0008] The longitudinal, diagonal, and transverse reinforcing bars, stirrups I and II of the cantilever section's steel reinforcement cage are welded together to form a non-deformable cage. The cantilever section's steel reinforcement cage is considered a truss structure, and its main characteristic parameters are expressed in equivalent form, with equivalent unit weight... Equivalent elastic modulus E Equivalent self-weight load The moment of inertia is calculated using the following formula:

[0009] Formula 2: Relaxation Deformation of Cantilever Beam The cantilever end deflection after the modular cantilever section reinforcement cage is spliced ​​with the column top section reinforcement cage using sleeves. calculate

[0010] 1. Relaxation deformation of cantilever beam calculate

[0011] During the stacking period after the cantilever section steel reinforcement cage is fabricated, it is regarded as a simply supported variable cross-section beam;

[0012] Obtained by numerical calculation;

[0013] 2. The downward deflection of the cantilever end after the modular cantilever section reinforcement cage is spliced ​​with the column top section reinforcement cage using sleeves. calculate

[0014] The modular cantilever section steel cage and the column top section steel cage are spliced ​​together with sleeves and regarded as a cantilever beam.

[0015] Obtained by numerical calculation;

[0016] Formula 3: Quality Control Standards for the Installation of Reinforcing Steel Cages in Modular Bridge Cap Beams

[0017] The symbols in Formula 1, Formula 2, and Formula 3 are defined as follows:

[0018] —These represent the width of the steel reinforcement frame module, the length of the cantilever section, and the lengths of the connecting section and the column top section, respectively. ;

[0019] —These are the unit weight of the reinforcing bars and the unit weight of the reinforcing bar cage in the cantilever section, which are considered as equivalent to the unit weight of the truss structure. ;

[0020] —These are the elastic modulus of the reinforcing bars and the elastic modulus of the reinforcing bar cage in the cantilever section, which are considered equivalent to the elastic modulus of the truss structure. ;

[0021] —The relaxation deformation coefficient of the steel reinforcement cage of the cantilever section is regarded as the equivalent elastic modulus of the truss structure. It is determined by field tests or past engineering construction experience and is dimensionless.

[0022] —These are the steel reinforcement cages for the cantilever sections. The total area of ​​longitudinal reinforcement at the cross-section, ;

[0023] —These are the steel reinforcement cages for the cantilever sections. The distance between the center of the highest-level longitudinal reinforcement and the center of the lowest-level longitudinal reinforcement of the truss at the cross-section. ;

[0024] —The slope of the inclined bottom slab and the inclined reinforcement of the cantilever section, ;

[0025] —Cantilever section reinforced steel frame truss The first section The diameter of the longitudinal reinforcement bars in the layer, ;

[0026] —These are cantilevered steel frame trusses. The first section layer Total cross-sectional area of ​​longitudinal reinforcement bars, distance from the center of the bottom longitudinal reinforcement bars to the neutral axis height, ;

[0027] —These are cantilevered steel frame trusses. The first section The moment of inertia of the longitudinal reinforcement bars about themselves The moment of inertia at the cross section, and the factor for increasing the total moment of inertia considering the transverse reinforcement and stirrup I or stirrup II. Determined by on-site testing or by past engineering construction experience. , Dimensionless;

[0028] —When the cantilever section reinforcement cage is fabricated and stacked, it is considered as a simply supported variable cross-section beam. The bending moment at the section, and the modular cantilever section reinforcement cage and the column top section reinforcement cage are considered as cantilever beams after being spliced ​​together with sleeves. Bending moment at the cross section ;

[0029] —When the cantilever section reinforcement cage is fabricated and stacked, it is considered as a simply supported variable cross-section beam. Sag deformation curve at the cross section Relaxation deformation at the cross-section ;

[0030] —When the modular cantilever section reinforcement cage and the column top section reinforcement cage are spliced ​​together using sleeves and considered as a cantilever beam, Sag deformation curve at the cross section The amount of sagging deformation at the cross-section and the maximum deformation of the cantilever section. ;

[0031] —Standard quantity of allowable splicing error for modular bridge cap beam reinforcement cage installation. .

[0032] The inclined bottom plate and the flat bottom plate are both steel plates, and are welded to the middle part of a plurality of I-shaped steel as the bottom plate of the modular bridge bent cap steel reinforcement framework. The upper surface of the inclined bottom plate and the flat bottom plate is marked with grid lines according to the number and interval of the longitudinal reinforcement and stirrup I or stirrup II of the bridge bent cap steel reinforcement framework, as the position pattern of the longitudinal reinforcement; the slope of the inclined bottom plate is the same as the slope of the inclined reinforcement of the cantilever section.

[0033] The U-shaped positioning frame is the same in number as the I-shaped steel, and is used as a support for positioning the positions of the longitudinal reinforcement, the inclined reinforcement, the transverse reinforcement, the stirrup I and the stirrup II. The bottom of the two vertical rods in each U-shaped positioning frame is clamped between the two sides of the inclined bottom plate and the flat bottom plate and is welded to the top surface of the I-shaped steel. The top of the two vertical rods in each U-shaped positioning frame is electrically welded by a longitudinal crosspiece. The vertical rod is a closed L-shaped angle steel welded by two angle steels. The vertical rod is opened with a row of square holes along the height. The number and interval and height of the square holes are consistent with the vertical arrangement of the longitudinal reinforcement. The square hole opened in one of the vertical rods is a through hole, i.e. through the two angle steels of the closed L-shaped angle steel. The square hole opened in the other vertical rod is a non-through hole, i.e. only one angle steel is opened. The crosspiece is a square steel. The upper surface of the square steel is marked with a groove with the same number as the longitudinal reinforcement in each row, so as to position the longitudinal reinforcement. The number of the crosspiece in each U-shaped positioning frame is the same as the number of the square holes in each row. The square steel is inserted into the through hole of one vertical rod and the square hole of the other non-through vertical rod. The total length of each square steel is 5cm-10cm larger than the width of the U-shaped positioning frame. After the bridge bent cap steel reinforcement framework is completed, the square steel is extracted to hoist the bridge bent cap steel reinforcement framework and stack it in a predetermined place.

[0034] The longitudinal reinforcement, the inclined reinforcement, the transverse reinforcement, the stirrup I and the stirrup II are the constituent reinforcement of the bent cap steel reinforcement framework. The longitudinal reinforcement of the column top section and the cantilever section is distributed in multiple layers. The longitudinal reinforcement in each layer has the same diameter. The number of the longitudinal reinforcement in each layer is determined according to the stress condition of the structure by design. The lowermost row of longitudinal reinforcement in the cantilever section is the inclined reinforcement. Due to the slope of the cantilever section, the longitudinal reinforcement of the column top section extends along the cantilever section, and the number of layers of the longitudinal reinforcement is gradually reduced at a certain distance. In the connecting section between the column top section and the cantilever section, the longitudinal reinforcement in one layer is staggered in length. The upper and lower layers are also staggered in length. The staggered length is 50cm-100cm. The transverse reinforcement connects the longitudinal reinforcement transversely at a certain interval. The stirrup I and the stirrup II are used in the cantilever section and the column top section respectively. The shape is L-shaped. The bottom layer, the top layer and the left and right sides of the longitudinal reinforcement are wrapped inside. All the outer edges of the longitudinal reinforcement are wrapped as a single closed L-shaped double-leg stirrup. The same cross section with a wider cross section is wrapped with two closed stirrups and four steels staggered in the width direction as a four-leg stirrup. The stirrup I has different heights at different cross sections in the cantilever section due to the slope.

[0035] The sleeve is made of Q235 or Q345 steel pipe with internal threads, and the corresponding longitudinal reinforcing bars with different lengths are also made with external threads, so that the longitudinal reinforcing bars of the cantilever section and the column top section can be interlocked at the connection section.

[0036] The I-beams are structural steel, with multiple I-beams laid horizontally between the ground and the sloping or flat bottom plate. Each I-beam is laid at a certain distance apart. The two vertical rods of the U-shaped positioning frame are each welded firmly to the I-beams by two diagonal rods.

[0037] A method for installing a modular bridge cap beam reinforcement cage includes the following steps:

[0038] Step 1: Assembly of the modular bridge cap beam reinforcement cage fabrication formwork

[0039] ① Determine the initial dimensions of the modular bridge cap beam reinforcement cage fabrication formwork based on the construction drawings;

[0040] ② When the cantilever section reinforcement cage is fabricated and stacked after completion using Formula 1, Formula 2, and Formula 3, it is considered as a simply supported variable cross-section beam. Relaxation deformation at the cross section And when the modular cantilever section steel reinforcement cage and the column top section steel reinforcement cage are spliced ​​together with sleeves and regarded as a cantilever beam. at the cross section Sagging deformation Maximum deformation at the cantilever end ;

[0041] ③ Adjust the inclination angle of the inclined reinforcing bars and the inclined bottom plate to ensure that the installation and splicing error of the modular bridge cap beam reinforcing steel skeleton meets the requirements. At the same time satisfy ;

[0042] ④ Adjust the initial dimensions, design the modular bridge cap beam steel reinforcement skeleton fabrication formwork, select the raw materials for the steel reinforcement processing platform, and fabricate I-beams, inclined bottom plates, flat bottom plates, U-shaped positioning frames, vertical bars, diagonal braces, horizontal bars, supports, and crossbars;

[0043] ⑤ Install steel bases, arranged laterally along the length of the cap beam, with a certain length reserved according to construction needs;

[0044] ⑥ Assemble the modular bridge cap beam steel reinforcement cage to make the formwork, and check that the dimensions of each part meet the design requirements;

[0045] ⑦ Mark the positions of various reinforcing bars on the platform according to the reinforcing bar cage design drawings;

[0046] Step 2: Fabrication of the steel reinforcement cage for the cap beam

[0047] ① The longitudinal steel bars, inclined steel bars, transverse steel bars, stirrup I and stirrup II are prepared in standby, and the required quantity, specification and size are accurate;

[0048] ② The longitudinal steel bars of the cantilever section and the column top section are connected into a whole by sleeves at the cutting position;

[0049] ③ The horizontal rods are inserted into the reserved holes of the vertical rods of the U-shaped positioning frame, and the prepared stirrups I and II are placed on the inclined bottom plate and the flat bottom plate and temporarily fixed with the horizontal rods by binding wires;

[0050] ④ The longitudinal steel bars corresponding to each layer are pulled from one cantilever end to the other cantilever end by steel guide ropes from bottom to top;

[0051] ⑤ The transverse steel bars of each layer are placed;

[0052] ⑥ The intersection points of the longitudinal steel bars, inclined steel bars, transverse steel bars, stirrup I and stirrup II are fixed by binding wires or spot welding, and the protective layer cushion blocks are installed;

[0053] ⑦ The temporary binding wires of the stirrup I, stirrup II and horizontal rods are removed;

[0054] ⑧ The connecting sleeves of the longitudinal steel bars of the cantilever section and the column top section are rotated to any single side of the longitudinal steel bars, so that the modular cover beam steel framework of the cantilever section and the column top section is separated;

[0055] ⑨ The horizontal rods are pulled out by a small amount of lifting by a crane;

[0056] ⑩ The cantilever section and the column top section are respectively transported and orderly stacked on the site, and the small section of the cantilever section is supported by a cushion;

[0057] Step three, cover beam steel framework installation

[0058] ① The cover beam formwork is laid on the already constructed column top support, and the cover beam construction working platform is set;

[0059] ② The column top section module steel framework is hoisted and placed accurately, and then the two side cantilever section module steel frameworks are hoisted and placed, and the positions of the column top section and the two side cantilever sections are adjusted accurately;

[0060] ③ The longitudinal steel bar sleeves of the cantilever section and the column top section are rotated to connect the steel framework into a whole;

[0061] ④ The prestressed tendon corrugated pipe is installed according to the design requirements to ensure smooth line type;

[0062] ⑤ The position of the concrete protective layer cushion block is adjusted, and the error between the cover beam steel framework and the cover beam concrete formwork is detected to meet the standard design requirements;

[0063] ⑥ The cover beam cement concrete is poured and cured qualified.

[0064] Compared with the prior art, the present application mainly comprises the following steps: laying multiple I-shaped steel bars on the flat and solid cement concrete ground at equal intervals, laying flat bottom plates with the width of the connecting section steel reinforcement framework module and the column top section steel reinforcement framework module on the multiple I-shaped steel bars respectively, laying inclined bottom plates with the width of the cantilever section steel reinforcement framework module on one side of the flat bottom plates, and then welding multiple U-shaped positioning frames for erecting the side steel reinforcement framework of the flat bottom plates and the side steel reinforcement framework of the inclined bottom plates on both sides of the multiple I-shaped steel bars respectively; meanwhile, the vertical rods on both sides of the multiple U-shaped positioning frames are connected and fixed by the crosswise welding of the horizontal rods on the top of the vertical rods, multiple inclined braces are welded on both sides of the vertical rods and the I-shaped steel bars respectively, and multiple horizontal rods for supporting the longitudinal steel reinforcement of the steel reinforcement framework are arranged on the vertical rods. The modular bridge cap beam steel reinforcement framework has the following characteristics: 1. The long line modular bridge cap beam steel reinforcement framework is divided into multiple modules, which can be hoisted and installed in blocks, thus being flexible, reducing the labor intensity of the operators and saving the cost of hoisting and transportation machinery; 2. The modular bridge cap beam steel reinforcement framework is simple and effective in quality control, which is beneficial to improving the engineering quality and durability; 3. The provided modular bridge cap beam steel reinforcement framework installation quality control calculation method is clear, scientific, reasonable, practical and easy to implement, which can guide the engineering construction, improve the safety performance and improve the engineering quality. Therefore, the present application has the advantages of convenient operation, reliable quality, saving of labor, improvement of precision, energy saving and environmental protection, and has high economic and social benefits. BRIEF DESCRIPTION OF DRAWINGS

[0065] Figure 1 is a schematic view of the facade of the present application.

[0066] Figure 2 is a structure schematic view of the cantilever section (left), the connecting section and the column top section (right) in Figure 1 and the U-shaped positioning frame.

[0067] Figure 3 is an I-I sectional view of Figure 1 .

[0068] Figure 4 is a cross section characteristic calculation view of the cantilever section steel reinforcement framework x.

[0069] Figure 5 is a deformation calculation view of the cantilever section steel reinforcement framework. DETAILED DESCRIPTION

[0070] The embodiment of the present application will be described in detail below with reference to the above drawings.

[0071] As Figures 1-5As shown, 1. ground, 2. I-beam, 31. inclined bottom plate, 32. flat bottom plate, 4. U-shaped positioning frame, 41. vertical rod, 42. inclined brace, 43. cross rod, 44. support, 5. crosspiece, 6. cantilever section, 61. longitudinal reinforcement, 611. inclined reinforcement, 62. transverse reinforcement, 63. stirrup I, 64. stirrup II, 7. connecting section, 71. sleeve, 8. column top section.

[0072] A modular bridge bent cap reinforcement framework and installation method, as shown, Figure 1 mainly related to the field of energy-saving bridge construction, the structure includes laying a plurality of I-beams 2 on the flat and solid cement concrete ground 1 at equal intervals, laying flat bottom plates 32 of the connecting section 7 reinforcement framework module width and the column top section 8 reinforcement framework module width on the plurality of I-beams respectively, and laying inclined bottom plates 31 of the cantilever section 6 reinforcement framework module width on one side of the flat bottom plate, then welding a plurality of U-shaped positioning frames 4 on both sides of the plurality of I-beams 2, which stand the flat bottom plate 32 side reinforcement framework and the inclined bottom plate 31 side reinforcement framework.

[0073] The top of the vertical rod 41 on both sides of the plurality of U-shaped positioning frames 4 is connected and fixed by longitudinal welding of the crosspiece 5, the vertical rod 41 on both sides of the plurality of U-shaped positioning frames 4 is welded with a plurality of inclined braces 42 on both sides of the I-beam 2, and the vertical rod 41 on both sides of the plurality of U-shaped positioning frames 4 is provided with a plurality of cross rods 43 supporting the longitudinal reinforcement 61 of the reinforcement framework.

[0074] In this way, the modular bridge bent cap reinforcement framework can be made by welding, binding and sleeve 71 connection among the inclined bottom plate 31, the flat bottom plate 32 and the U-shaped positioning frame 4.

[0075] The I-beam 2 is a type of steel, and the plurality of I-beams 2 are laid transversely between the ground 1 and the inclined bottom plate 31 and the flat bottom plate 32, each I-beam 2 is laid at a certain distance, and the two vertical rods 41 of the U-shaped positioning frame 4 are respectively welded firmly with the I-beam 2 by two inclined rods.

[0076] The inclined bottom plate 31 and the flat bottom plate 32 are both steel plates, and are welded in the middle of the plurality of I-beams 2 as the bottom plate of the modular bridge bent cap reinforcement framework, the upper surface of the inclined bottom plate 31 and the flat bottom plate 32 is marked with grid lines according to the number and spacing of the longitudinal reinforcement 61 and the stirrup I or the stirrup II of the bridge bent cap reinforcement framework, as the position pattern of the above-mentioned reinforcement; the slope of the inclined bottom plate 31 is the same as the slope of the inclined reinforcement 611 of the cantilever section 6.

[0077] The U-shaped positioning frame 4 is used as a support for positioning the longitudinal steel bars 61, the inclined steel bars 611, the horizontal steel bars 62, the stirrup I and the stirrup II, the two vertical rods of each U-shaped positioning frame 4 are clamped at the two sides of the inclined bottom plate and the flat bottom plate and are welded on the top surface of the I-shaped steel, and the top of the two vertical rods 41 of each U-shaped positioning frame is electrically welded by the longitudinal crosspiece 5.

[0078] The vertical rod 41 is a closed square shape welded by two angle steels, a row of square holes is opened on the vertical rod 41 along the height, the number, the interval and the height of the square holes are consistent with the vertical arrangement of the longitudinal steel bars 61, and the square hole opened by one of the vertical rods 41 is a through hole, that is, it penetrates through the two angle steels of the closed square shape, and the square hole opened by the other vertical rod 41 is a non-through hole which only penetrates through one angle steel; the horizontal rod 43 is a square steel, the upper surface of the square steel is engraved with a number of grooves equal to the number of the longitudinal steel bars 61 in each row to position the longitudinal steel bars, the number of the horizontal rods 43 in each U-shaped positioning frame 4 is equal to the number of the square holes in one row, the square steel is inserted into the through square hole of one vertical rod 41 and then is inserted into the square hole of the non-through vertical rod, the total length of each square steel is 5cm-10cm larger than the middle width of the U-shaped positioning frame 4, and after the bridge cap beam reinforcement framework is completed, the square steel is extracted to hoist the bridge cap beam reinforcement framework and then is stacked in a predetermined site.

[0079] The longitudinal steel bars 61, the inclined steel bars 611, the horizontal steel bars 62, the stirrup I and the stirrup II are the constituent steel bars of the cap beam reinforcement framework, the longitudinal steel bars 61 of the column top section 8 and the cantilever section 6 are distributed in multiple layers, the longitudinal steel bars 61 in each layer have the same diameter, and the number of the longitudinal steel bars 61 in each layer is determined according to the stress condition of the structure.

[0080] The longitudinal steel bars 61 in the lowest row of the cantilever section 6 are the inclined steel bars 611, the longitudinal steel bars 61 of the column top section 8 extend along the cantilever section 6 due to the inclination of the cantilever section, and the number of layers of the longitudinal steel bars 61 is gradually reduced at certain intervals; in the connecting section 7 between the column top section 8 and the cantilever section 6, the longitudinal steel bars in one layer are alternately and staggered in length, the upper and lower layers are also alternately and staggered in length, the staggered length is 50cm-100cm, and the staggered sections are connected by the sleeves 71; the horizontal steel bars 62 are transversely connected to the longitudinal steel bars 61 at certain intervals.

[0081] The stirrup I 63 and the stirrup II 64 are respectively used in the cantilever section 6 and the column top section 8, have a square shape, wrap the bottom layer, the top layer and the left and right sides of the longitudinal steel bars 61, and wrap the outer edges of all the longitudinal steel bars 61 as a single closed square double-leg stirrup, the same section with a larger width uses two closed stirrups and four steel bars staggered in the width direction as a four-leg stirrup; the stirrup I 63 has different heights at different sections due to the inclination of the cantilever section 6.

[0082] The sleeve 71 is made of Q235 or Q345 steel pipe with internal threads, and the corresponding long and short longitudinal steel bars 61 are also made with external threads, and the cantilever section 6 and the column top section 8 are engaged with each other at the corresponding longitudinal steel bars 61 of the connecting section 7.

[0083] The modular bridge bent cap steel reinforcement framework is composed of two modular cantilever section steel reinforcement frameworks and one modular column top section steel reinforcement framework. When the two modular cantilever section steel reinforcement frameworks and one modular column top section steel reinforcement framework are connected by welding, binding and the sleeve 71 in the inclined bottom plate 31, the flat bottom plate 32 and the U-shaped positioning frame 4, the sleeve 71 is used to connect the connecting section, and all the sleeves 71 are rotated and reserved on one side of the cantilever section 6 steel reinforcement framework or the column top section 8 steel reinforcement framework to play a role in separating the two sections. The cantilever section steel reinforcement framework and the column top section steel reinforcement framework are hoisted and placed in the yard for use. The cantilever section steel reinforcement framework needs to be provided with a support at the cantilever A to maintain the shape size of the cantilever section steel reinforcement framework and reduce deformation.

[0084] When the cantilever section steel reinforcement framework is provided with a support 44 at the cantilever A, it is considered as a simply supported variable cross-section beam. During stacking, the deflection deformation curve of the lowermost inclined steel bar 611 of the cantilever section steel reinforcement framework is , and the maximum relaxation deformation amount ; when the cantilever section steel reinforcement framework is hoisted into the bent cap formwork and spliced with the column top section steel reinforcement framework, the cantilever section steel reinforcement framework and the column top section steel reinforcement framework are connected at the connecting section by the sleeve 71, and the o end is the fixed end of the cantilever beam. At this time, the deflection of the cantilever beam in the span is , and the requirement , that is, the maximum relaxation deformation amount of the cantilever section steel reinforcement framework during stacking is approximately , and the deflection of the cantilever section steel reinforcement framework and the column top section steel reinforcement framework after splicing by the sleeve 71 should meet the splicing standard error requirement , or , that is, the maximum deflection of the cantilever end after the cantilever section steel reinforcement framework and the column top section steel reinforcement framework are spliced by the sleeve 71 should meet the splicing standard error requirement .

[0085] Formula one, calculation of characteristic parameters of cantilever section steel reinforcement framework

[0086] The longitudinal steel bars 61, inclined steel bars 611, transverse steel bars 62, stirrups I 63 and stirrups II 64 of the cantilever section steel reinforcement framework are welded into a non-deformable framework. The cantilever section steel reinforcement framework is considered as a truss, and its main characteristic parameters are represented in the form of equivalent. The equivalent bulk density , the equivalent elastic modulus E , the equivalent self-weight load and the moment of inertia are calculated by the following formulas:

[0087] Formula 2: Relaxation Deformation of Cantilever Beam The cantilever end deflection after the modular cantilever section reinforcement cage is spliced ​​with the column top section reinforcement cage using sleeves. calculate

[0088] 1. Relaxation deformation of cantilever beam calculate

[0089] During the stacking period after the cantilever section steel reinforcement cage is fabricated, it is regarded as a simply supported variable cross-section beam;

[0090] Obtained by numerical calculation;

[0091] 2. The downward deflection of the cantilever end after the modular cantilever section reinforcement cage is spliced ​​with the column top section reinforcement cage using sleeves. calculate

[0092] The modular cantilever section steel cage and the column top section steel cage are spliced ​​together with sleeves and regarded as a cantilever beam.

[0093] Obtained by numerical calculation;

[0094] Formula 3: Quality Control Standards for the Installation of Reinforcing Steel Cages in Modular Bridge Cap Beams

[0095] The symbols in Formula 1, Formula 2, and Formula 3 are defined as follows:

[0096] —These represent the width of the steel reinforcement frame module, the length of the cantilever segment 6, and the lengths of the connecting segment 7 and the column top segment 8, respectively. ;

[0097] —These are the unit weight of the reinforcing bars and the unit weight of the reinforcing bar cage in the cantilever section, which are considered as equivalent to the unit weight of the truss structure. ;

[0098] —These are the elastic modulus of the reinforcing bars and the elastic modulus of the reinforcing bar cage in the cantilever section, which are considered equivalent to the elastic modulus of the truss structure. ;

[0099] —The relaxation deformation coefficient of the steel reinforcement cage of the cantilever section is regarded as the equivalent elastic modulus of the truss structure. It is determined by field tests or past engineering construction experience and is dimensionless.

[0100] —These are the steel reinforcement cages for the cantilever sections. The total area of ​​longitudinal reinforcement 61 at the cross-section, ;

[0101] — the cantilever segment reinforcement cage the distance between the center of the longitudinal reinforcement 61 of the highest layer of the truss at the cross section and the center of the longitudinal reinforcement of the lowest layer, ;

[0102] — the slope of the inclined bottom plate 31 and the inclined reinforcement of the cantilever segment, ;

[0103] — the cantilever segment reinforcement cage truss the diameter of the longitudinal reinforcement 61 of the first layer at the cross section, ;

[0104] — the cantilever segment reinforcement cage truss the moment of inertia of the longitudinal reinforcement 61 of the first layer at the cross section, the total cross-sectional area of the longitudinal reinforcement 61, the height from the center of the bottom longitudinal reinforcement to the neutral axis , ;

[0105] — the cantilever segment reinforcement cage truss the moment of inertia of the longitudinal reinforcement 61 of the first layer at the cross section, the total moment of inertia considering the transverse reinforcement 62 and the total moment of inertia increase coefficient considering the stirrup I or the stirrup II, determined by field tests or by previous construction experience, , , dimensionless;

[0106] — the bending moment at the cross section when the cantilever segment reinforcement cage is considered as a simply supported variable cross-section beam during the stacking period after the completion of the cantilever segment reinforcement cage, the bending moment at the cross section when the modular cantilever segment reinforcement cage is considered as a cantilever beam after the splicing of the sleeve 71 of the cantilever segment reinforcement cage and the column top segment reinforcement cage, the bending moment at the cross section, ;

[0107] — the deflection curve at the cross section when the cantilever segment reinforcement cage is considered as a simply supported variable cross-section beam during the stacking period after the completion of the cantilever segment reinforcement cage, the deflection curve at the cross section when the cantilever segment reinforcement cage is considered as a simply supported variable cross-section beam during the stacking period after the completion of the cantilever segment reinforcement cage, the amount of relaxation deformation at the cross section, ;

[0108] The sleeve 71 is spliced for the modular cantilever segment steel framework and the column top segment steel framework, and is regarded as a cantilever beam The sag deformation curve at the cross section, The sag deformation at the cross section, the maximum deformation of the cantilever segment 6,

[0109] The allowable splicing error standard amount of the modular bridge bent cap steel framework installation,

[0110] The installation method of the modular bridge bent cap steel framework mainly comprises the following steps:

[0111] 1. The initial modular bridge bent cap steel framework production mold frame size is determined according to the construction drawing;

[0112] 2. The formula one, the formula two and the formula three are used to calculate the sag deformation at the cross section when the cantilever segment steel framework is regarded as a simply supported variable cross-section beam during the stacking period after the production is completed The relaxation deformation at the cross section , and the cantilever beam when the sleeve is spliced for the modular cantilever segment steel framework and the column top segment steel framework The sag deformation at the cross section , the maximum deformation of the cantilever end ;

[0113] 3. The inclination angle of the inclined steel bars and the inclined bottom plates is adjusted, so that the modular bridge bent cap steel framework installation splicing error satisfies , and simultaneously satisfies ;

[0114] 4. The initial size is adjusted, the modular bridge bent cap steel framework production mold frame is designed, the raw materials for producing the steel processing platform are selected, the I-shaped steel 2, the inclined bottom plate 31, the flat bottom plate 32, the U-shaped positioning frame 4, the vertical rod 41, the inclined support 42, the horizontal rod 43, the support 44 and the crosspiece 5 are produced;

[0115] 5. The steel base is installed, is arranged transversely along the length direction of the bent cap, and the length of the base is reserved to a certain length according to the construction requirement;

[0116] 6. The modular bridge bent cap steel framework production mold frame is assembled, and the sizes of the parts are detected to satisfy the design requirement;

[0117] 7. The positions of various steel bars are marked on the platform according to the steel framework design drawing;

[0118] Step two, the production of the bent cap steel framework

[0119] 1. The longitudinal steel bars 61, the inclined steel bars 611, the horizontal steel bars 62, the stirrups I 63 and the stirrups II 64 are cut, and the required quantity, specification and size are accurate;​​​

[0120] ②The longitudinal steel bars 61 of the cantilever section 6 and the column top section 8 are connected into a whole by sleeves 71 at the truncated positions of the longitudinal steel bars 61;

[0121] ③The cross bars 43 are inserted into the reserved holes of the vertical bars 41 of the U-shaped positioning frame 4, and the prepared hoop I and hoop II are stood up on the inclined floor 31 and the flat floor 32 and temporarily fixed with the cross bars 43 by binding wires;

[0122] ④The longitudinal steel bars 61 corresponding to each layer are pulled from one cantilever end 6 to the other cantilever end by steel guide ropes from bottom to top;

[0123] ⑤The horizontal steel bars 62 of each layer are placed;

[0124] ⑥The intersection points of the longitudinal steel bars 61, the inclined steel bars 611, the horizontal steel bars 62, the hoop I 63 and the hoop II 64 are fixed with binding wires or spot welding, and the protective layer cushion is installed;

[0125] ⑦The temporary fixing binding wires of the hoop I, the hoop II and the cross bars are removed;

[0126] ⑧The sleeves 71 connecting the longitudinal steel bars 61 of the cantilever section 6 and the column top section 8 are rotated to any single side of the longitudinal steel bars 61, so that the modular cover beam steel framework of the cantilever section 6 and the column top section 8 is separated;

[0127] ⑨The all cross bars 43 are pulled out by a crane with a small amount of lifting upward;

[0128] ⑩The cantilever section 6 and the column top section 8 are respectively transported and orderly stacked on the site, and the supports 44 are placed at the small cross-section positions of the cantilever section;

[0129] Step three, cover beam steel framework installation

[0130] ①The cover beam formwork is laid on the column top support which has been constructed, and the cover beam construction working platform is set;

[0131] ②The column top section module steel framework is hoisted and placed accurately, and then the cantilever section module steel frameworks on both sides are hoisted and placed, and the positions of the column top section 8 and the cantilever sections 6 on both sides are adjusted accurately;

[0132] ③The longitudinal steel sleeves of the cantilever section 6 and the column top section 8 are rotated to connect the steel framework into a whole;

[0133] ④The prestressed tendon corrugated pipe is installed according to the design requirements to ensure smooth line type;

[0134] ⑤The position of the concrete protective layer cushion is adjusted, and the error between the cover beam steel framework and the cover beam concrete formwork is detected to meet the standard design requirements;

[0135] ⑥The cover beam cement concrete is poured and cured qualified.

[0136] The embodiments of the present application are merely used for illustrating the present application but not for limiting the scope of the present application. In addition, it should be understood that after reading the present application, various modifications or changes can be made by those skilled in the art, and these equivalent forms should also fall within the scope of the appended claims of the present application.

Claims

1. A modular bridge bent reinforcement cage comprising laying a plurality of I-beams (2) equidistantly on a flat and solid cement concrete ground surface (1), characterized in that The multiple I-shaped steel (2) is respectively laid with flat bottom plates (32) for making the connecting section steel reinforcement framework module width and the column top section steel reinforcement framework module width, and with inclined bottom plates (31) for making the cantilever section steel reinforcement framework module width at one side outer end of the flat bottom plate, and then a plurality of U-shaped positioning frames (4) for erecting the flat bottom plate (32) side steel reinforcement framework and the inclined bottom plate (31) side steel reinforcement framework are welded on both sides of the multiple I-shaped steel (2); the top of the vertical rod (41) on both sides of the multiple U-shaped positioning frames (4) is fixedly connected by the transverse rod (5) through lengthwise welding, the vertical rod (41) on both sides of the multiple U-shaped positioning frames (4) is respectively welded with a plurality of inclined braces (42) on both sides of the I-shaped steel (2), and a plurality of transverse rods (43) for supporting the longitudinal steel reinforcement of the steel reinforcement framework are arranged on the vertical rod (41) on both sides of the multiple U-shaped positioning frames (4); the modular bridge cap beam steel reinforcement framework comprises two modular cantilever section steel reinforcement frameworks and one modular column top section steel reinforcement framework which are made by welding, binding and sleeve (71) connection among the inclined bottom plate (31), the flat bottom plate (32) and the U-shaped positioning frame (4), the cantilever section steel reinforcement framework and the column top section steel reinforcement framework are hoisted and placed in the stockyard for standby, wherein the cantilever section steel reinforcement framework needs to be provided with a support at the cantilever A to maintain the shape size of the cantilever section steel reinforcement framework and reduce deformation; the inclined bottom plate (31) and the flat bottom plate (32) are both steel plates and are welded as the bottom plates of the modular bridge cap beam steel reinforcement framework in the middle of the multiple I-shaped steel (2), the upper surfaces of the inclined bottom plate (31) and the flat bottom plate (32) are marked with grid lines according to the number and spacing of the longitudinal steel reinforcement (61) and the stirrup I (63) or the stirrup II (64) of the bridge cap beam steel reinforcement framework, as the position drawing of the above-mentioned steel reinforcement; the slope of the inclined bottom plate (31) is the same as the slope of the inclined steel reinforcement (611) of the cantilever section (6).

2. The modular bridge deck girder reinforcement cage of claim 1, wherein When the cantilever section steel reinforcement cage is supported at cantilever A (44), it is considered as a simply supported variable cross-section beam. During stacking, the sagging deformation curve of the bottommost inclined steel bar (611) of the cantilever section steel reinforcement cage is as follows: Its maximum relaxation deformation When the cantilever section of the reinforcing steel cage is hoisted into the cap beam formwork and spliced ​​with the column top section of the reinforcing steel cage, the cantilever section of the reinforcing steel cage and the column top section of the reinforcing steel cage are connected at the connection section using a sleeve (71). o The end is the fixed end of the cantilever beam, and the sag deflection at mid-span of the cantilever beam is... ,Require That is, the maximum relaxation deformation during the stacking of the cantilever section steel reinforcement cage is approximately... The sag deflection after splicing with the cantilever section reinforcement cage and the column top section reinforcement cage using sleeves (71) The sum must meet the splicing standard error requirements. ,or That is, the maximum downward deflection of the cantilever end after the cantilever section steel reinforcement cage and the column top section steel reinforcement cage are spliced ​​together with sleeves (71). The splicing standard error requirements must be met. ; Formula one, cantilever section steel reinforcement framework characteristic parameter calculation The longitudinal steel bars (61), the inclined steel bars (611), the horizontal steel bars (62), the stirrup I (63) and the stirrup II (64) of the cantilever segment steel framework are welded by electric welding to form a framework which is not easy to deform, the cantilever segment steel framework is regarded as a truss structure, and the main characteristic parameters of the truss structure are expressed in the equivalent form, and the equivalent bulk density , the equivalent elastic modulus E , the equivalent dead load and the moment of inertia are calculated by the following formulas: Equation two, cantilever beam relaxation deformation And the cantilever end deflection after splicing the sleeve of the modular cantilever segment reinforcement cage and the column top segment reinforcement cage Calculation 1. Amount of cantilever beam relaxation deformation Calculation The cantilever section steel reinforcement framework is regarded as a simply supported variable cross-section beam during the stacking period after the completion of the cantilever section steel reinforcement framework; Calculated from numerical data; 2. Cantilever end deflection of modularized sleeve jointing between cantilever segment reinforcement cage and column top segment reinforcement cage Computing The modular cantilever section steel reinforcement framework and the column top section steel reinforcement framework are regarded as a cantilever beam after splicing by the sleeve; Calculated from numerical data; Formula three, modular bridge cap beam steel reinforcement framework installation quality control standard The symbols in formula one, formula two and formula three are defined as follows: - width of the reinforcement cage module, length of the cantilever segment (6), length of the connecting segment (7) and column top segment (8), respectively, ; - the unit weight of the reinforcement, respectively the equivalent unit weight of the reinforcement skeleton of the cantilever section considered as a truss, ; - the elastic modulus of the steel bars, respectively, the equivalent elastic modulus of the steel bar framework of the cantilever segment considered as a truss, ; - the relaxation deformation coefficient of the cantilever segment reinforcement skeleton, considered as a substitute for the elastic modulus of the truss, is determined by field tests or by construction experience from previous projects, dimensionless; - the cantilever segment steel reinforcement framework respectively the total area of the longitudinal reinforcement (61) at the section, ; - cantilever segment reinforcement cage the distance between the center of the longitudinal reinforcement (61) of the highest layer of truss and the center of the longitudinal reinforcement of the lowest layer of truss at the section, ; - slope of the inclined soffit (31) and of the cantilever segment inclined reinforcement, ; - cantilever segment reinforced skeleton truss sectional first diameter of the layer of longitudinal reinforcement (61), ; —These are cantilevered steel frame trusses. The first section layer The total cross-sectional area of ​​the longitudinal reinforcement (61), the distance from the center of the bottom longitudinal reinforcement to the neutral axis height, ;total — cantilever segment reinforced skeleton truss sectional number of longitudinal reinforcement of the layer; - cantilever segment reinforced skeleton truss inertia moment at the section inertia moment of the layer longitudinal reinforcement (61) to itself, inertia moment at the section, total inertia moment increase factor taking into account the transverse reinforcement (62) and stirrup I (63) or stirrup II (64), determined from field tests or from previous construction experience, , , dimensionless; - the bending moment at the section, when the cantilever segment reinforcement cage is considered as a simply supported variable cross-section beam during the storage period - the bending moment at the section, when the cantilever segment reinforcement cage is considered as a cantilever beam after the splicing of the modular cantilever segment reinforcement cage and the column top segment reinforcement cage with the sleeve (71) - the bending moment at the section, ; - the cantilever segment reinforcement skeleton is considered as a simply supported variable cross-section beam during the stacking period respectively - the sagging deformation curve at the cross-section, - the relaxation deformation at the cross-section, ; - the sleeve (71) for splicing the modular cantilever segment reinforcement cage and the column top segment reinforcement cage respectively, when considered as a cantilever beam - the deflection curve at the section, - the deflection at the section, the maximum deflection of the cantilever segment (6), ; - Modular bridge deck reinforcement skeleton installation tolerance standard, ; - vertical reaction forces of a simply supported beam with variable cross section, ;​ the letter in subscript represents a simply supported state of the variable cross-section beam.

3. A modular bridge deck girder reinforcement cage according to claim 2, characterised in that The U-shaped positioning frame (4) is used as a support for positioning the longitudinal steel bars (61), the inclined steel bars (611), the horizontal steel bars (62), the stirrup I (63) and the stirrup II (64), the bottom of the two vertical rods (41) in each U-shaped positioning frame (4) is clamped on the two sides of the inclined bottom plate (31) and the flat bottom plate (32) and is welded on the top surface of the I-shaped steel (2), the top of the two vertical rods (41) in each U-shaped positioning frame (4) is electrically welded by the longitudinal crosspiece (5), the vertical rod (41) is a closed mouth-shaped character formed by welding two angle steels, a row of square holes is opened along the height of the vertical rod (41), the number, the interval and the height of the square holes are consistent with the vertical arrangement of the longitudinal steel bars (61), the square hole opened in one of the vertical rods is a through hole, that is, the through closed mouth-shaped character of the two angle steels, and the square hole opened in the other vertical rod is a non-through hole which only opens one angle steel, the horizontal rod (43) is a square steel, the upper surface of the square steel is engraved with grooves with the same number as each row of the longitudinal steel bars (61) to position the longitudinal steel bars, the number of the horizontal rod (43) in each U-shaped positioning frame is the same as the number of the square holes in one row, the square steel is inserted into the through square hole of one vertical rod (41) to the square hole of the non-through vertical rod, the total length of each square steel is 5cm-10cm larger than the middle width of the U-shaped positioning frame (4), and after the bridge bent cap steel reinforcement framework is completed, the square steel is extracted to hoist the bridge bent cap steel reinforcement framework and stack it in the preset site.

4. The modular bridge deck girder reinforcement cage of claim 2, wherein The longitudinal steel bars (61), the inclined steel bars (611), the horizontal steel bars (62), the stirrup I (63) and the stirrup II (64) are the constituent steel bars of the bent cap steel reinforcement framework, the longitudinal steel bars (61) of the column top section (8) and the cantilever section (6) are distributed in multiple layers, the longitudinal steel bars (61) in each layer have the same diameter, and the number of the longitudinal steel bars (61) in each layer is determined according to the stress condition of the structure by design, the longitudinal steel bars (61) in the lowest layer of the cantilever section (6) are the inclined steel bars (611), due to the inclination of the cantilever section, the longitudinal steel bars (61) of the column top section (8) are extended along the cantilever section (6) and gradually reduce the number of layers of the longitudinal steel bars (61) at certain intervals, in the connecting section (7) between the column top section (8) and the cantilever section (6), the longitudinal steel bars in one layer are alternately staggered and cut, the upper and lower layers are also staggered and cut in a plum blossom shape, the cut parts are connected to each other by sleeves (71), and the staggered length is 50cm-100cm, the horizontal steel bars (62) are transversely connected to the longitudinal steel bars (61) at certain intervals, the stirrup I (63) and the stirrup II (64) are respectively used in the cantilever section (6) and the column top section (8), have the shape of a mouth-shaped character, wrap the bottom layer, the top layer and the left and right sides of the longitudinal steel bars (61) and wrap the outer edges of all the longitudinal steel bars (61) into a single closed mouth-shaped character double-leg stirrup, the same cross section with a relatively wide width adopts two closed stirrups and four steel bars staggered in the width direction as a four-leg stirrup, the stirrup I (63) in the cantilever section (6) has different heights in different cross sections due to the inclination.

5. The modular bridge deck girder reinforcement cage of claim 2, wherein The sleeve (71) is internally threaded by Q235 or Q345 steel pipe, and the corresponding each longitudinal steel bar (61) is externally threaded at the staggered long and short positions, and the cantilever section (6) and the column top section (8) are engaged with each other at the corresponding longitudinal steel bars (61) of the connecting section (7).

6. The modular bridge deck girder reinforcement cage of claim 2, wherein The I-beams (2) are profile steels, and a plurality of I-beams are transversely laid between the ground (1) and the inclined bottom plate (31) and the flat bottom plate (32), each I-beam (2) is laid at a certain distance, and the two vertical rods (41) of the U-shaped positioning frame (4) are respectively welded with the I-beams (2) by two inclined rods.

7. A method of installing a modular bridge deck girder reinforcement cage according to claim 2, characterised in that The installation method comprises the following steps: Step one, modular bridge bent cap steel bar framework production mold frame assembly 1. Determine the initial size of the modular bridge bent cap steel bar framework production mold frame according to the construction drawing; ② By formula one, formula two and formula three to calculate the cantilever segment reinforcement framework production after the period of stacking as a simply supported variable cross-section beam Relaxation deformation at the cross-section , and the modular cantilever segment reinforcement framework and the column top segment reinforcement framework are spliced with sleeves and regarded as a cantilever beam Relaxation deformation at the cross-section Sag deformation , maximum deformation at the cantilever end ; ③Adjust the inclination angle of the inclined steel bars and inclined bottom plates to make the installation and splicing error of the modular bridge bent cap steel reinforcement framework meet , and meet ; 4. Adjust the initial size, design the modular bridge bent cap steel bar framework production mold frame, select the raw materials for manufacturing the steel bar processing platform, and manufacture the I-beams (2), the inclined bottom plate (31), the flat bottom plate (32), the U-shaped positioning frame (4), the vertical rod (41), the inclined brace (42), the cross rod (43), the support (44), and the crosspiece (5); 5. Install the profile steel base, which is arranged transversely along the length direction of the bent cap, and the length of the base is reserved according to the construction requirement; 6. Assemble the modular bridge bent cap steel bar framework production mold frame, and detect the sizes of each part to meet the design requirement; 7. Mark the positions of various steel bars on the platform according to the steel bar design drawing; Step two, bent cap steel bar framework production 1. Cut the longitudinal steel bars (61), the inclined steel bars (611), the transverse steel bars (62), the stirrups I (63), and the stirrups II (64) for standby, and the required quantity, specification, and size are accurate; 2. The longitudinal steel bars (61) of the cantilever section (6) and the column top section (8) are connected into a whole by the sleeve (71) at the cut-off position; 3. Insert the cross rod (43) into the reserved holes of each layer of the vertical rod (41) of the U-shaped positioning frame (4), and stand up each row of the stirrups I (63) and the stirrups II (64) on the inclined bottom plate (31) and the flat bottom plate (32), and temporarily fix the cross rod (43) by using the wire; 4. Use the steel bar guide cable to pull the corresponding longitudinal steel bars (61) of each layer from one cantilever end to the other cantilever end from bottom to top; 5. Place each layer of the transverse steel bars (62); 6. Use the wire or spot welding to fix the intersection points of the longitudinal steel bars (61), the inclined steel bars (611), the transverse steel bars (62), the stirrups I (63), and the stirrups II (64), and install the protective layer cushion block; 7. Remove the temporary fixing wire of the stirrups I (63), the stirrups II (64), and the cross rod (43); 8. Rotate the sleeve (71) connecting the longitudinal steel bars (61) of the cantilever section (6) and the column top section (8) to any single side of the longitudinal steel bars (61), so that the modular bent cap steel bar framework of the cantilever section (6) and the column top section (8) is separated; 9. Use the crane to slightly lift upward, and pull out all the cross rods (43); 10. Transport the cantilever section (6) and the column top section (8) to the site respectively, and orderly stack them, and pad the small section of the cantilever section with the support; Step three, bent cap steel bar framework installation 1. Lay the bent cap formwork on the completed column top support, and set the bent cap construction working platform; ②Hoist column top section module reinforcement skeleton, hoist position accurate, hoist two side cantilever section module reinforcement skeleton again, adjust column top section (8), two side cantilever section (6) position accurate; ③Rotate cantilever section (6), column top section (8) longitudinal reinforcement (61) sleeve (71), connect reinforcement skeleton into a whole; ④According to design requirement, install prestressed tendon corrugated pipe, ensure linear flow smooth; ⑤Adjust concrete cover block position, detect cover beam reinforcement skeleton and cover beam concrete formwork between error meet standard design requirement; ⑥Pour cover beam cement concrete and maintain qualified.

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