Cast-in-place box girder construction method based on movable formwork bridge fabrication machine

Abstract

The invention discloses a cast-in-place box girder construction method based on a movable formwork bridge fabrication machine, and relates to the technical field of bridge construction.The cast-in-place box girder construction method based on the movable formwork bridge fabrication machine comprises the steps that the movable formwork bridge fabrication machine is installed on a pier; the template structure is matched with the size and the shape of the to-be-cast-in-place box girder; binding bottom plate reinforcing steel bars of the to-be-cast-in-place box girder, and installing a prestressed pipeline; web plates and flange plates of the to-be-cast-in-place box girder are installed; pouring bottom plate concrete of the to-be-cast-in-place box girder; concrete of the web plates and the flange plates is poured; and prestress tensioning is conducted on the box girder to be cast in place, pipeline grouting is conducted, and the cast-in-place box girder is formed. The movable formwork bridge fabrication machine is mounted on the bridge pier, so that the construction space and the material consumption are saved, and the construction efficiency is improved. And meanwhile, the template structure of the movable formwork bridge fabrication machine is adjusted to be matched with the size and the shape of the to-be-cast-in-situ box girder, so that the forming quality of the cast-in-situ box girder is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction, and in particular to a cast-in-place box girder construction method based on a mobile formwork bridge-building machine. Background Art

[0002] With the continuous development of bridge engineering, cast-in-place box girders have become an indispensable structural form in bridge construction due to their excellent mechanical properties and wide applicability. Cast-in-place box girders have the advantages of large span, good rigidity, and reasonable force, and have been widely used in the construction of large-span bridges.

[0003] At present, the construction of cast-in-place box girders mainly adopts two traditional construction methods: the scaffolding method and the bracket method. The scaffolding method requires the erection of a full-height scaffold under the bridge, which occupies the space under the bridge, has complex construction procedures, a long cycle, and high material consumption. The bracket method requires the installation of brackets on the piers. Although the construction efficiency is improved compared to the scaffolding method, it still requires a lot of manual work to erect and dismantle the formwork, and the construction efficiency and safety need to be improved. In addition, in traditional construction methods, the adjustment and installation accuracy of the formwork is difficult to guarantee, which can easily lead to dimensional deviations and appearance quality problems of cast-in-place box girders. During the concrete pouring process, quality defects such as segregation and honeycomb are also prone to occur, affecting the strength and durability of the cast-in-place box girder.

[0004] Therefore, with the increasing scale and complexity of bridge construction, the traditional cast-in-place box girder construction method has been unable to meet the growing construction requirements. The scaffolding method and bracket method have problems such as low construction efficiency, difficulty in quality control, high safety risks and high construction costs, which restrict the promotion and application of cast-in-place box girders. Summary of the invention

[0005] The main purpose of the present invention is to propose a cast-in-place box girder construction method based on a mobile formwork bridge-building machine, aiming to solve the technical problems of low construction efficiency, great difficulty in quality control, high safety risks and high construction costs existing in traditional construction methods.

[0006] To achieve the above-mentioned purpose, the present invention proposes a cast-in-place box girder construction method based on a mobile formwork bridge-building machine, and the cast-in-place box girder construction method based on a mobile formwork bridge-building machine comprises:

[0007] Installing the mobile formwork bridge-building machine on the bridge pier;

[0008] Adjusting the formwork structure of the mobile formwork bridge-building machine so that the formwork structure matches the size and shape of the box girder to be cast in situ;

[0009] Binding the bottom plate steel bars of the box girder to be cast in situ and installing the prestressed pipes;

[0010] Install the web plate and flange plate of the box girder to be cast in situ;

[0011] Pour the bottom plate concrete of the box girder to be cast-in-place.

[0012] After the bottom plate concrete reaches the preset strength, pour the concrete of the web and the flange plate.

[0013] After the concrete pouring is completed, carry out curing until the concrete reaches the design strength.

[0014] Carry out the prestress tensioning of the box girder to be cast-in-place and carry out duct grouting to form the cast-in-place box girder.

[0015] In an embodiment, the movable scaffolding bridge erector includes a load-bearing main girder, a formwork, a formwork structure and longitudinal movement auxiliary legs. The load-bearing main girder extends along the longitudinal bridge direction. Two main legs are respectively arranged at both ends of the load-bearing main girder along its extension direction. The two main legs are respectively connected to the top of the bridge pier through support cylinders. The formwork is arranged on the load-bearing main girder. The formwork structure is suspended on the load-bearing main girder through the formwork. The longitudinal movement auxiliary legs are installed on the load-bearing main girder and are arranged between the two main legs. The longitudinal movement auxiliary legs are connected with longitudinal movement cylinders. The longitudinal movement cylinders are used to push the load-bearing main girder and the formwork to drive the formwork structure to move along the longitudinal bridge direction.

[0016] The steps of adjusting the formwork structure of the movable scaffolding bridge erector to make the formwork structure match the size and shape of the box girder to be cast-in-place include:

[0017] Lift and install the inner formwork and outer formwork of the box girder to be cast-in-place onto the formwork and connect them to the formwork through anchor fittings.

[0018] Adjust the width and inclination angle of the formwork to make the formwork structure match the size and shape of the box girder to be cast-in-place.

[0019] In an embodiment, the formwork structure includes a bottom formwork assembly, a side formwork assembly and an inner formwork assembly.

[0020] The steps of adjusting the width and inclination angle of the formwork to make the formwork structure match the size and shape of the box girder to be cast-in-place include:

[0021] Splice a plurality of the bottom formwork assemblies and connect the side formwork assemblies to the bottom formwork assemblies through adjustable connecting pieces.

[0022] According to the width and cross-sectional shape of the box girder to be cast-in-place, adjust the length or angle of the adjustable connecting pieces to make the side formwork assembly and the bottom formwork assembly match the size and shape of the box girder to be cast-in-place.

[0023] Lay the inner formwork assembly on the inner sides of the bottom formwork assembly and the side formwork assembly and carry out fixation and support.

[0024] In one embodiment, the adjustable connecting member includes a connecting plate, a connecting screw, a locking nut, a slide rail, and two limiting blocks. The connecting plate is fixed to the edge of the bottom die assembly. The connecting screw is threadedly connected to the connecting plate and is used to adjust the distance between the side die assembly and the bottom die assembly through the connecting plate. The locking nut is threadedly connected to the connecting screw. The slide rail is installed on the connecting plate. The side die assembly is slidably installed on the slide rail. There is a gap between the two limiting blocks. The two limiting blocks are connected to the slide rail, and the side die assembly is disposed between the two limiting blocks.

[0025] The steps of splicing a plurality of the bottom die assemblies and connecting the side die assembly to the bottom die assembly through the adjustable connecting member include:

[0026] Splicing a plurality of the bottom die assemblies using a splicing plate;

[0027] Rotating the connecting screw to adjust the position of the side die assembly;

[0028] Tightening the locking nut to fix the side die assembly and connect the side die assembly to the bottom die assembly.

[0029] In one embodiment, the die carrier includes a cantilever beam and a suspension arm. The cantilever beam is connected to the suspension arm through a pin shaft, and the suspension arm is installed on the load-bearing main beam.

[0030] The steps of hoisting the inner die and the outer die of the precast box girder to be cast-in-place onto the die carrier and connecting them to the die carrier through anchor fittings include:

[0031] Hinging one end of the cantilever beam to the suspension arm and fixedly connecting the other end of the cantilever beam to the bottom die assembly;

[0032] Connecting the suspension arm to the load-bearing main beam;

[0033] Hoisting the inner die and the outer die of the precast box girder to be cast-in-place onto the cantilever beam;

[0034] Adjusting the position of the inner die and the outer die of the precast box girder to be cast-in-place by adjusting the hinge angle between the cantilever beam and the suspension arm and the connection position of the suspension arm on the load-bearing main beam, and connecting them to the cantilever beam through anchor fittings.

[0035] In one embodiment, the cantilever beam is a triangular truss structure, and both sides of the load-bearing main beam are connected to the cantilever beam. The suspension arm is a truss structure, and the suspension arm is connected to the load-bearing main beam through an adjustable strut.

[0036] In one embodiment, the steps of installing the movable scaffolding bridge erector on the pier include:

[0037] Install the load-bearing main girder on the pier;

[0038] Connect the two main legs to the top of the pier respectively through the support cylinders;

[0039] Use the control system to control the support cylinders to drive the main legs to drive the load-bearing main girder to move vertically, and control the longitudinal movement cylinders to drive the longitudinal movement auxiliary legs to drive the load-bearing main girder to move longitudinally to the construction position;

[0040] Suspend the formwork structure with the formwork to complete the installation of the movable scaffolding bridge erector.

[0041] In one embodiment, the steps of tying the bottom steel bars of the box girder to be cast-in-place and installing the prestressed ducts include:

[0042] Layout and tie the main steel bars and distribution steel bars of the box girder to be cast-in-place, and install the prestressed ducts;

[0043] Install spacers and stools to ensure the thickness of the steel bar protection layer.

[0044] In one embodiment, the steps of pouring the bottom concrete of the box girder to be cast-in-place include:

[0045] Use pumped concrete and adopt the layered pouring method to pour the bottom concrete of the box girder to be cast-in-place, and control the slump of the bottom concrete between 160 mm and 200 mm.

[0046] In one embodiment, the steps of performing the prestress tensioning of the box girder to be cast-in-place and performing duct grouting to form the cast-in-place box girder include:

[0047] Use a jack and a pressure gauge to perform the prestress tensioning of the box girder to be cast-in-place, and perform duct grouting to form the cast-in-place box girder.

[0048] The technical solution of the present invention installs a movable formwork bridge erector on the pier. By utilizing its flexible movement and positioning characteristics, it avoids the problems of erecting full hall scaffolds or installing fixed brackets in traditional construction methods, saves construction space and material consumption, and improves construction efficiency. At the same time, by adjusting the formwork structure of the movable formwork bridge erector to match the size and shape of the cast-in-place box girder to be constructed, it ensures the dimensional accuracy and appearance quality of the cast-in-place box girder, overcoming the problem that it is difficult to ensure the installation accuracy of the formwork in traditional construction methods. In addition, steps such as steel bar binding, prestressed duct installation, and web and flange plate installation are carried out on the movable formwork bridge erector, eliminating the need for additional working platforms, improving construction safety and convenience. By adopting the method of layered pouring, first pouring the bottom slab concrete and then pouring the concrete of the web and flange plates after it reaches the preset strength, it effectively controls quality defects such as concrete segregation and honeycombing, ensuring the strength and durability of the cast-in-place box girder. After the concrete pouring is completed, the movable formwork bridge erector can provide good environmental conditions for concrete curing, ensuring the curing quality. Finally, prestress tensioning is used to improve the overall stiffness and bearing capacity of the cast-in-place box girder, and duct grouting is carried out to protect the prestressed steel bars, extending the service life of the cast-in-place box girder. Description of the Drawings

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0050] Figure 1 It is a schematic flow chart of an embodiment of the cast-in-place box girder construction method based on a movable formwork bridge erector provided by the present invention;

[0051] Figure 2 It is a schematic structural diagram of an embodiment of the cast-in-place box girder construction method based on a movable formwork bridge erector provided by the present invention;

[0052] Figure 3 It is a schematic structural diagram of another embodiment of the cast-in-place box girder construction method based on a movable formwork bridge erector provided by the present invention.

[0053] Explanation of the Reference Numerals in the Drawings:

[0054] 100, load-bearing main girder; 200, main support leg; 300, formwork; 400, formwork structure; 500, longitudinal movement auxiliary support leg; 600, longitudinal movement oil cylinder; 700, support oil cylinder; 310, cantilever beam; 320, lifting arm; 410, bottom formwork assembly; 420, side formwork assembly.

[0055] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0058] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0059] At present, the construction of cast-in-place box girders mainly adopts two traditional construction methods: the scaffolding method and the bracket method. The scaffolding method requires the erection of a full-height scaffold under the bridge, which occupies the space under the bridge, has complex construction procedures, a long cycle, and high material consumption. The bracket method requires the installation of brackets on the piers. Although the construction efficiency is improved compared to the scaffolding method, it still requires a lot of manual work to erect and dismantle the formwork, and the construction efficiency and safety need to be improved. In addition, in traditional construction methods, the adjustment and installation accuracy of the formwork is difficult to guarantee, which can easily lead to dimensional deviations and appearance quality problems of cast-in-place box girders. During the concrete pouring process, quality defects such as segregation and honeycomb are also prone to occur, affecting the strength and durability of the cast-in-place box girder.

[0060] Therefore, with the continuous increase in the scale and complexity of bridge engineering construction, the traditional cast-in-place box girder construction method has been difficult to meet the growing construction requirements. The support method and bracket method have problems such as low construction efficiency, high difficulty in quality control, high safety risks, and high construction costs, which restrict the popularization and application of cast-in-place box girders.

[0061] To solve this technical problem, the present invention proposes a cast-in-place box girder construction method based on a movable scaffolding bridge erector.

[0062] Please refer to Figures 1 to 3 , in an embodiment of the present invention, the cast-in-place box girder construction method based on a movable scaffolding bridge erector includes:

[0063] Step S10: Install the movable scaffolding bridge erector on the pier;

[0064] Step S20: Adjust the formwork structure 400 of the movable scaffolding bridge erector to make the formwork structure 400 match the size and shape of the box girder to be cast-in-place;

[0065] Step S30: Bind the bottom steel bars of the box girder to be cast-in-place and install prestressed ducts;

[0066] Step S40: Install the webs and flange plates of the box girder to be cast-in-place;

[0067] Step S50: Pour the bottom concrete of the box girder to be cast-in-place;

[0068] Step S60: After the bottom concrete reaches the preset strength, pour the concrete of the webs and flange plates;

[0069] Step S70: After the concrete pouring is completed, carry out curing until the concrete reaches the design strength;

[0070] Step S80: Carry out prestress tensioning of the box girder to be cast-in-place and conduct duct grouting to form the cast-in-place box girder.

[0071] Specifically, in step S10, first install the movable scaffolding bridge erector on the pier. The movable scaffolding bridge erector can move and position flexibly on the pier, avoiding the problems of setting up full hall supports or installing fixed brackets in the traditional construction method, saving construction space and material consumption, and improving construction efficiency.

[0072] Then, in step S20, adjust the formwork structure 400 of the movable scaffolding bridge erector to make it match the size and shape of the box girder to be cast-in-place. Through the precise adjustment of the formwork structure 400, the dimensional accuracy and appearance quality of the cast-in-place box girder can be ensured, avoiding the problem that it is difficult to guarantee the installation accuracy of the formwork in the traditional construction method.

[0073] In steps S30 and S40, the bottom steel bars of the box girder to be cast-in-place are respectively tied and the prestressed ducts are installed, and the webs and flange plates are installed. These steps can be carried out on the movable scaffolding formwork bridge machine without additional erection of a working platform, improving the construction safety and convenience.

[0074] Subsequently, in steps S50 and S60, the bottom concrete of the box girder to be cast-in-place is first poured, and after the bottom concrete reaches the preset strength, the concrete of the webs and flange plates is poured. By adopting the layered pouring method, quality defects such as segregation and honeycombing of the concrete can be effectively controlled, ensuring the strength and durability of the cast-in-place box girder.

[0075] In step S70, after the concrete pouring is completed, curing is carried out until the concrete reaches the design strength. The movable scaffolding formwork bridge machine can provide good environmental conditions for the concrete curing, ensuring the curing quality.

[0076] Finally, in step S80, the prestress tensioning of the box girder to be cast-in-place is carried out, and duct grouting is carried out to form the final cast-in-place box girder. The prestress tensioning can improve the overall stiffness and bearing capacity of the cast-in-place box girder, while the duct grouting can protect the prestressed steel bars and extend the service life of the cast-in-place box girder.

[0077] In the technical solution provided by the present invention, by installing a movable scaffolding formwork bridge machine on the pier and utilizing its flexible movement and positioning characteristics, the problems of erecting a full hall scaffold or installing a fixed bracket in the traditional construction method are avoided, saving construction space and material consumption and improving construction efficiency. At the same time, by adjusting the formwork structure 400 of the movable scaffolding formwork bridge machine to match the size and shape of the box girder to be cast-in-place, the dimensional accuracy and appearance quality of the cast-in-place box girder are ensured, overcoming the problem that it is difficult to guarantee the installation accuracy of the formwork in the traditional construction method. In addition, steps such as steel bar tying, prestressed duct installation, and web and flange plate installation are carried out on the movable scaffolding formwork bridge machine without additional erection of a working platform, improving the construction safety and convenience. By adopting the layered pouring method, first pouring the bottom concrete and then pouring the concrete of the webs and flange plates after it reaches the preset strength, quality defects such as segregation and honeycombing of the concrete are effectively controlled, ensuring the strength and durability of the cast-in-place box girder. After the concrete pouring is completed, the movable scaffolding formwork bridge machine can provide good environmental conditions for the concrete curing, ensuring the curing quality. Finally, the overall stiffness and bearing capacity of the cast-in-place box girder are improved through prestress tensioning, and duct grouting is carried out to protect the prestressed steel bars, extending the service life of the cast-in-place box girder.

[0078] In an embodiment of the present invention, the movable scaffolding bridge erector includes a load-bearing main girder 100, a formwork 300, a formwork structure 400, and longitudinal movement auxiliary legs 500. The load-bearing main girder 100 extends along the longitudinal bridge direction. Two main legs 200 are respectively arranged at both ends of the load-bearing main girder 100 along its extension direction. The two main legs 200 are respectively connected to the top of the bridge pier through support cylinders 700. The formwork 300 is arranged on the load-bearing main girder 100. The formwork structure 400 is suspended from the load-bearing main girder 100 through the formwork 300. The longitudinal movement auxiliary legs 500 are installed on the load-bearing main girder 100, and the longitudinal movement auxiliary legs 500 are arranged between the two main legs 200. The longitudinal movement auxiliary legs 500 are connected with longitudinal movement cylinders 600. The longitudinal movement cylinders 600 are used to push the load-bearing main girder 100 and the formwork 300 to drive the formwork structure 400 to move along the longitudinal bridge direction.

[0079] The steps of adjusting the formwork structure 400 of the movable scaffolding bridge erector to make the formwork structure 400 match the size and shape of the box girder to be cast-in-place include:

[0080] Step S21: Hoist the inner formwork and outer formwork of the box girder to be cast-in-place onto the formwork 300 and connect them to the formwork 300 through anchor fittings.

[0081] Step S22: Adjust the width and inclination angle of the formwork 300 to make the formwork structure 400 match the size and shape of the box girder to be cast-in-place.

[0082] It should be noted that the longitudinal bridge direction and the transverse bridge direction in this application are in the same horizontal plane. The longitudinal bridge direction, the transverse bridge direction, and the vertical direction are equivalent to the X direction, the Y direction, and the Z direction in the well-known coordinate system.

[0083] Specifically, the movable scaffolding bridge erector includes a load-bearing main girder 100, a formwork 300, a formwork structure 400, and longitudinal movement auxiliary legs 500. The load-bearing main girder 100 extends along the longitudinal bridge direction. One main leg 200 is arranged at each end thereof. The main legs 200 are connected to the top of the bridge pier through support cylinders 700. This ensures the stability and adjustability of the entire structure, enabling the formwork 300 to adjust its position according to specific construction requirements.

[0084] The formwork support 300 is installed on the load-bearing main beam 100, and the formwork structure 400 is suspended from the load-bearing main beam 100 through the formwork support 300. This setting allows the formwork structure 400 to move longitudinally along the bridge as needed, thus adapting to the construction requirements of different sections. The longitudinal movement auxiliary support legs 500 are installed on the load-bearing main beam 100 and are located between the two main support legs 200, and are equipped with longitudinal movement oil cylinders 600 to push the load-bearing main beam 100 and the formwork support 300, driving the formwork structure 400 to move along the longitudinal direction of the bridge. This mobility greatly improves the construction flexibility and efficiency, while reducing the manpower requirements and construction time.

[0085] More specifically, in step S21, the inner formwork and the outer formwork of the precast box girder to be cast-in-place are hoisted onto the formwork support 300 and connected to the formwork support 300 through anchor fittings. This step ensures the stable installation and precise positioning of the formwork.

[0086] In step S22, the width and inclination angle of the formwork support 300 are adjusted. Through this adjustment, the formwork structure 400 can precisely match the size and shape of the box girder to be cast-in-place, ensuring the construction quality and the integrity of the structure.

[0087] In an embodiment of the present invention, the formwork structure 400 includes a bottom formwork assembly 410, a side formwork assembly 420, and an inner formwork assembly;

[0088] The steps of adjusting the width and inclination angle of the formwork support 300 to make the formwork structure 400 match the size and shape of the box girder to be cast-in-place include:

[0089] In step S221, a plurality of the bottom formwork assemblies 410 are spliced, and the side formwork assembly 420 is connected to the bottom formwork assembly 410 through adjustable connecting pieces;

[0090] In step S222, according to the width and cross-sectional shape of the box girder to be cast-in-place, the length or angle of the adjustable connecting piece is adjusted so that the side formwork assembly 420, the bottom formwork assembly 410 match the size and shape of the box girder to be cast-in-place;

[0091] In step S223, the inner formwork assembly is laid on the inner sides of the bottom formwork assembly 410 and the side formwork assembly 420, and is fixed and supported.

[0092] Specifically, in order to adjust the width and inclination angle of the formwork support 300 to make the formwork structure 400 match the size and shape of the box girder to be cast-in-place, the present invention adopts the following steps:

[0093] In step S221, first, a plurality of bottom die components 410 are spliced to form a complete bottom die. Then, the side die component 420 is connected to the bottom die component 410 through adjustable connecting pieces. The setting of the adjustable connecting pieces enables the side die component 420 to be flexibly adjusted relative to the bottom die component 410 to adapt to different cross-sectional shapes of the cast-in-place box girders.

[0094] In step S222, according to the specific width and cross-sectional shape of the cast-in-place box girder to be constructed, the length or angle of the adjustable connecting piece is adjusted. Through this precise adjustment, the side die component 420 and the bottom die component 410 can accurately match the size and shape of the cast-in-place box girder to be constructed, ensuring the construction quality and dimensional accuracy of the cast-in-place box girder.

[0095] In step S223, the inner die component is laid on the inner sides of the bottom die component 410 and the side die component 420 and is fixed and supported. The setting of the inner die component can form the internal space of the cast-in-place box girder and at the same time provide necessary support to ensure the stability of the formwork structure 400 during the concrete pouring process.

[0096] In an embodiment of the present invention, the adjustable connecting piece includes a connecting plate, a connecting screw, a locking nut, a slide rail, and two limiting blocks. The connecting plate is fixed to the edge of the bottom die component 410. The connecting screw is threadedly connected to the connecting plate and is used to adjust the distance between the side die component 420 and the bottom die component 410 through the connecting plate. The locking nut is threadedly connected to the connecting screw. The slide rail is installed on the connecting plate. The side die component 420 is slidably installed on the slide rail. There is a gap between the two limiting blocks. The two limiting blocks are connected to the slide rail, and the side die component 420 is arranged between the two limiting blocks.

[0097] The steps of splicing the plurality of bottom die components 410 and connecting the side die component 420 to the bottom die component 410 through the adjustable connecting piece include:

[0098] Step S2211: Splice the plurality of bottom die components 410 using a splicing plate;

[0099] Step S2212: Rotate the connecting screw to adjust the position of the side die component 420;

[0100] Step S2213: Tighten the locking nut to fix the side die component 420 and connect the side die component 420 to the bottom die component 410.

[0101] Specifically, the slide rail is installed on the connecting plate, and the side mold assembly 420 is slidably installed on the slide rail. Two limit blocks are connected to the slide rail, and a gap is formed between the two limit blocks. The side mold assembly 420 is arranged in this gap. Enabling the side mold assembly 420 to slide along the slide rail within a certain range improves the flexibility of position adjustment of the side mold assembly 420.

[0102] In the step of splicing multiple bottom mold assemblies 410 and connecting the side mold assembly 420 to the bottom mold assembly 410 through adjustable connecting pieces, first, splice multiple bottom mold assemblies 410 using splicing plates (step S2211) to form a complete bottom mold. Then, adjust the position of the side mold assembly 420 by rotating the connecting screw (step S2212) to make its position match that of the bottom mold assembly 410. Finally, tighten the locking nut to fix the position of the side mold assembly 420, so that the side mold assembly 420 is reliably connected to the bottom mold assembly 410 (step S2213).

[0103] The adjustable connecting piece effectively solves the problem that the traditional fixed connection method is difficult to meet the requirements of different cross-sectional shapes of cast-in-place box girders. Through the rotational adjustment of the connecting screw and the sliding cooperation of the slide rail, the position of the side mold assembly 420 can be flexibly and precisely adjusted to form the required cross-sectional shape with the bottom mold assembly 410. At the same time, the setting of the locking nut ensures the stability of the adjusted position and avoids position deviation during construction.

[0104] In an embodiment of the present invention, the formwork 300 includes a cantilever beam 310 and a lifting arm 320. The cantilever beam 310 is connected to the lifting arm 320 through a pin shaft, and the lifting arm 320 is installed on the load-bearing main beam 100;

[0105] The step of hoisting the inner mold and the outer mold of the precast box girder to be cast-in-place onto the formwork 300 and connecting them to the formwork 300 through anchor fittings includes:

[0106] Step S211: Hinge one end of the cantilever beam 310 to the lifting arm 320, and fixedly connect the other end of the cantilever beam 310 to the bottom mold assembly 410;

[0107] Step S212: Connect the lifting arm 320 to the load-bearing main beam 100;

[0108] Step S213: Hoist the inner mold and the outer mold of the precast box girder to be cast-in-place onto the cantilever beam 310;

[0109] Step S214: Adjust the position of the inner mold and the outer mold of the precast box girder to be cast-in-place by adjusting the hinge angle between the cantilever beam 310 and the lifting arm 320 and the connection position of the lifting arm 320 on the load-bearing main beam 100, and connect them to the cantilever beam 310 through anchor fittings.

[0110] Specifically, in order to hoist the inner formwork and outer formwork of the precast box girder to be cast-in-place onto the formwork support 300 and connect them to the formwork support 300 through anchor fittings, the present invention adopts the following steps:

[0111] In step S211, one end of the cantilever beam 310 is hinged to the boom 320, and at the same time, the other end of the cantilever beam 310 is fixedly connected to the bottom formwork assembly 410. The hinged and fixed connections can ensure the stability and adjustability between the cantilever beam 310, the boom 320, and the bottom formwork assembly 410.

[0112] In step S212, the boom 320 is connected to the load-bearing main beam 100. Through this connection method, the boom 320 can adjust its position on the load-bearing main beam 100, thereby indirectly adjusting the positions of the cantilever beam 310 and the bottom formwork assembly 410.

[0113] In step S213, the inner formwork and outer formwork of the precast box girder to be cast-in-place are hoisted onto the cantilever beam 310. Utilizing the load-bearing capacity of the cantilever beam 310, the stable installation of the inner formwork and outer formwork is achieved.

[0114] In step S214, by adjusting the hinge angle between the cantilever beam 310 and the boom 320 and the connection position of the boom 320 on the load-bearing main beam 100, the positions of the inner formwork and outer formwork of the precast box girder to be cast-in-place can be accurately adjusted. After the adjustment is completed, the inner formwork and outer formwork are connected to the cantilever beam 310 through anchor fittings to ensure the stability of their positions.

[0115] In an embodiment of the present invention, the cantilever beam 310 is a triangular truss structure, and both sides of the load-bearing main beam 100 are respectively connected to the cantilever beam 310; the boom 320 is a truss structure, and the boom 320 is connected to the load-bearing main beam 100 through an adjustable strut.

[0116] Specifically, the cantilever beam 310 adopts a triangular truss structure, and both sides of the load-bearing main beam 100 are respectively connected to the cantilever beam 310. This structural design can effectively improve the load-bearing capacity and stability of the cantilever beam 310, ensuring that the inner formwork and outer formwork of the precast box girder to be cast-in-place can be safely and stably hoisted onto the cantilever beam 310. At the same time, the boom 320 adopts a truss structure and is connected to the load-bearing main beam 100 through an adjustable strut. The application of the truss structure improves the strength and stiffness of the boom 320, enabling it to reliably support and adjust the position of the cantilever beam 310. The setting of the adjustable strut further enhances the flexibility of the connection between the boom 320 and the load-bearing main beam 100, facilitating the adjustment of the position of the boom 320 according to actual construction requirements.

[0117] The cantilever beam 310 and the jib 320 effectively solve the problems of insufficient load-bearing capacity, poor stability, and inconvenient adjustment of the formwork 300 in the traditional construction method. The cantilever beam 310 with a triangular truss structure has excellent mechanical properties and can safely and stably carry the precast inner formwork and outer formwork. The jib 320 with a truss structure provides reliable support and adjustment capabilities to ensure that the cantilever beam 310 can be accurately positioned according to the construction requirements.

[0118] In an embodiment of the present invention, the step of installing the movable formwork bridge building machine on the pier includes:

[0119] Step S11: Install the load-bearing main beam 100 on the pier;

[0120] Step S12: Connect the two main legs 200 to the top of the pier through the support cylinders 700 respectively;

[0121] Step S13: Use the control system to control the support cylinders 700 to drive the main legs 200 to drive the load-bearing main beam 100 to move vertically, and control the longitudinal movement cylinders 600 to drive the longitudinal movement auxiliary legs 500 to drive the load-bearing main beam 100 to move longitudinally along the bridge to the construction position;

[0122] Step S14: Hang the formwork structure 400 by using the formwork 300 to complete the installation of the movable formwork bridge building machine.

[0123] Specifically, step S11 involves installing the load-bearing main beam 100 on the pier. The load-bearing main beam 100, as the support structure of the entire movable formwork bridge building machine, its correct installation is the key to ensuring the safety and reliability of subsequent operations.

[0124] In step S12, the two main legs 200 are respectively connected to the top of the pier through the support cylinders 700. This not only further stabilizes the position of the load-bearing main beam 100 but also improves the flexibility of the overall structure and the ability to adapt to different construction environments by using the adjustability of the cylinders.

[0125] Step S13 uses the control system to control the support cylinders 700 to drive the main legs 200 to drive the load-bearing main beam 100 to move vertically, and drives the longitudinal movement auxiliary legs 500 to drive the load-bearing main beam 100 to move longitudinally along the bridge to the construction position through the longitudinal movement cylinders 600. Ensure that the load-bearing main beam 100 can be accurately moved to the predetermined construction position.

[0126] Step S14 involves the process of hanging the formwork structure 400 by using the formwork 300.

[0127] In an embodiment of the present invention, the step of tying the bottom steel bars of the box girder to be cast in situ and installing the prestressed ducts includes:

[0128] Step S31: Arrange and tie the main reinforcement and distribution reinforcement of the box girder to be cast-in-place, and install the prestressed ducts.

[0129] Step S32: Install spacers and stools to ensure the thickness of the steel bar protection layer.

[0130] Specifically, Step S31 involves arranging and tying the main reinforcement and distribution reinforcement of the box girder to be cast-in-place, and installing the prestressed ducts at the same time. The main reinforcement and distribution reinforcement form the steel bar framework. The installation of the prestressed ducts prepares for the subsequent prestress tensioning, ensuring that the prestress can effectively act on the concrete structure.

[0131] In Step S32, the thickness of the steel bar protection layer is ensured by installing spacers and stools. The use of spacers and stools can control the thickness of the protection layer, avoiding quality problems such as steel bar corrosion caused by too thin a protection layer or concrete cracks caused by too thick a protection layer. In the embodiments of the present invention, the steps of pouring the bottom plate concrete of the box girder to be cast-in-place include:

[0132] Step S51: Use pumped concrete and adopt a layered pouring method to pour the bottom plate concrete of the box girder to be cast-in-place, and control the slump of the bottom plate concrete between 160 mm and 200 mm.

[0133] Specifically, in Step S51, the use of pumped concrete is to ensure that the concrete can be evenly distributed in the formwork and can effectively control the fluidity of the concrete to adapt to the complex shape of the bottom plate of the cast-in-place box girder.

[0134] The adoption of the layered pouring method is to prevent the segregation of the concrete during the pouring process. This method ensures good bonding between the layers of concrete by adding and compacting the concrete layer by layer, thereby increasing the overall consistency and strength of the structure.

[0135] Controlling the slump of the bottom plate concrete between 160 mm and 200 mm is to ensure that the concrete has appropriate plasticity. This not only helps the construction operation of the concrete but also ensures the density and strength of the concrete during the hardening process.

[0136] In the embodiments of the present invention, the steps of performing the prestress tensioning of the box girder to be cast-in-place and performing duct grouting to form the cast-in-place box girder include:

[0137] Step S81: Use a jack and a pressure gauge to perform the prestress tensioning of the box girder to be cast-in-place and perform duct grouting to form the cast-in-place box girder.

[0138] Specifically, in step S81, a jack and a pressure gauge are used for the prestress tensioning of the box girder to be cast-in-place. Prestress tensioning is to introduce prestress in the concrete structure so that it maintains a compressive stress state under external loads, thereby improving the tensile strength and stiffness of the structure. The jack is used to apply prestress, while the pressure gauge is used to monitor and control the magnitude of prestress to ensure the precise application of prestress.

[0139] Meanwhile, step S81 also includes duct grouting. Duct grouting is to inject cement slurry into the prestress ducts after the prestress tensioning is completed, so that the prestressed tendons and the concrete structure form a reliable bond. Grouting can not only protect the prestressed tendons from corrosion, but also improve the stress transfer efficiency between the prestressed tendons and the concrete, further enhancing the overall performance of the structure.

[0140] Through the implementation of prestress tensioning and duct grouting, the box girder to be cast-in-place finally becomes a cast-in-place box girder with high load-bearing capacity and durability. It effectively solves the problems existing in the construction of traditional cast-in-place box girders, such as concrete cracking, prestress loss and insufficient durability.

[0141] The above description is only an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformation made under the technical concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A cast-in-place box girder construction method based on a mobile formwork bridge-building machine, characterized in that: The cast-in-place box girder construction method based on the mobile formwork bridge-building machine comprises: Installing the mobile formwork bridge-building machine on the bridge pier; Adjusting the formwork structure of the mobile formwork bridge-building machine so that the formwork structure matches the size and shape of the box girder to be cast in situ; Binding the bottom plate steel bars of the box girder to be cast in situ and installing the prestressed pipes; Install the web plate and flange plate of the box girder to be cast in situ; pouring the bottom slab concrete of the box girder to be cast in situ; After the bottom plate concrete reaches a preset strength, pouring the concrete of the web plate and the flange plate; After the concrete is poured, curing is performed until the concrete reaches the designed strength; The prestressed box girder to be cast in situ is tensioned, and pipeline grouting is performed to form the cast-in-situ box girder.

2. The cast-in-place box girder construction method based on a mobile formwork bridge-building machine according to claim 1, characterized in that: The mobile formwork bridge-building machine comprises a load-bearing main beam, a formwork, a formwork structure and a longitudinal shift auxiliary leg. The load-bearing main beam extends in the longitudinal direction of the bridge. Two main legs are respectively arranged at the two ends of the load-bearing main beam in the direction of its extension. The two main legs are respectively connected to the top of the pier through supporting cylinders. The formwork is arranged on the load-bearing main beam. The formwork structure is suspended on the load-bearing main beam through the formwork. The longitudinal shift auxiliary leg is installed on the load-bearing main beam, and the longitudinal shift auxiliary leg is arranged between the two main legs. The longitudinal shift auxiliary leg is connected to a longitudinal shift cylinder, and the longitudinal shift cylinder is used to push the load-bearing main beam and the formwork to drive the formwork structure to move in the longitudinal direction of the bridge. The step of adjusting the template structure of the mobile formwork bridge-building machine so that the template structure matches the size and shape of the cast-in-place box girder comprises: The inner and outer molds of the prefabricated box beam to be cast in situ are hoisted onto the mold frame and connected to the mold frame via anchors; The width and inclination angle of the formwork are adjusted to match the size and shape of the box girder to be cast in situ.

3. The cast-in-place box girder construction method based on a mobile formwork bridge-building machine as claimed in claim 2, characterized in that: The template structure includes a bottom mold assembly, a side mold assembly and an inner mold assembly; The step of adjusting the width and inclination angle of the formwork to match the size and shape of the formwork structure with the box girder to be cast in situ comprises: Splicing a plurality of the bottom mold assemblies, and connecting the side mold assembly to the bottom mold assembly via an adjustable connector; According to the width and cross-sectional shape of the box girder to be cast in situ, the length or angle of the adjustable connector is adjusted so that the side formwork assembly and the bottom formwork assembly match the size and shape of the box girder to be cast in situ; The inner mold assembly is laid on the inner side of the bottom mold assembly and the side mold assembly, and is fixed and supported.

4. The cast-in-place box girder construction method based on a mobile formwork bridge-building machine as claimed in claim 3 is characterized in that: The adjustable connecting member comprises a connecting plate, a connecting screw, a locking nut, a slide rail and two limit blocks, wherein the connecting plate is fixed to the edge of the bottom mold assembly, the connecting screw is threadedly connected to the connecting plate, and is used to adjust the distance between the side mold assembly and the bottom mold assembly through the connecting plate; the locking nut is threadedly connected to the connecting screw; the slide rail is mounted on the connecting plate, the side mold assembly can be slidably mounted on the slide rail, there is a gap between the two limit blocks, the two limit blocks are connected to the slide rail, and the side mold assembly is arranged between the two limit blocks; The step of splicing a plurality of the bottom mold assemblies and connecting the side mold assembly to the bottom mold assembly via an adjustable connector comprises: Using a splicing plate to splice a plurality of the bottom mold assemblies; Rotating the connecting screw to adjust the position of the side mold assembly; Tighten the locking nut to fix the side mold assembly, so that the side mold assembly is connected to the bottom mold assembly.

5. The cast-in-place box girder construction method based on a mobile formwork bridge-building machine as claimed in claim 3, characterized in that: The formwork comprises a cantilever beam and a suspension arm, the cantilever beam is connected to the suspension arm through a pin shaft, and the suspension arm is installed on the load-bearing main beam; The step of hoisting the prefabricated inner and outer molds of the cast-in-place box beam onto the mold frame and connecting them to the mold frame through anchors comprises: One end of the cantilever beam is hinged to the boom, and the other end of the cantilever beam is fixedly connected to the bottom mold assembly; Connecting the boom to the load-bearing main beam; Hanging the prefabricated inner and outer forms of the cast-in-place box beam on the cantilever beam; By adjusting the hinge angle between the cantilever beam and the boom and the connection position of the boom on the load-bearing main beam, the positions of the inner and outer molds of the prefabricated box beam to be cast-in-place are adjusted, and the box beam is connected to the cantilever beam through anchors.

6. The cast-in-place box girder construction method based on a mobile formwork bridge-building machine as claimed in claim 5, characterized in that: The cantilever beam is a triangular truss structure, and the two sides of the load-bearing main beam are respectively connected to the cantilever beam; the boom is a truss structure, and the boom is connected to the load-bearing main beam through an adjustable strut.

7. The cast-in-place box girder construction method based on a mobile formwork bridge-building machine as claimed in claim 2, characterized in that: The step of installing the mobile formwork bridge-building machine on the bridge pier comprises: Installing the load-bearing main beam on the bridge pier; The two main legs are respectively connected to the top of the pier through the supporting oil cylinder; The control system is used to control the supporting oil cylinder to drive the main supporting leg to drive the load-bearing main beam to move vertically, and the longitudinal movement oil cylinder is controlled to drive the longitudinal movement auxiliary supporting leg to drive the load-bearing main beam to move along the longitudinal bridge direction to the construction position; The formwork structure is suspended by using the formwork to complete the installation of the mobile formwork bridge-building machine.

8. The cast-in-place box girder construction method based on a mobile formwork bridge-building machine according to any one of claims 1 to 7, characterized in that: The steps of tying the bottom plate steel bars of the cast-in-place box beam and installing the prestressed pipes include: Arrange and tie the main reinforcement and distribution reinforcement of the box girder to be cast in situ, and install the prestressed pipe; Install spacers and saddles to ensure the thickness of the steel bar cover.

9. The cast-in-place box girder construction method based on a mobile formwork bridge-building machine according to any one of claims 1 to 7, characterized in that: The step of pouring the bottom slab concrete of the cast-in-place box beam comprises: The bottom slab concrete of the to-be-cast-in-place box girder is cast by using pumped concrete and a layered casting method, and the slump of the bottom slab concrete is controlled between 160 mm and 200 mm.

10. The cast-in-place box girder construction method based on a mobile formwork bridge-building machine according to any one of claims 1 to 7, characterized in that: The steps of prestressing the cast-in-place box girder and performing pipeline grouting to form the cast-in-place box girder include: The prestressing of the cast-in-place box girder is performed by using a jack and a pressure gauge, and pipeline grouting is performed to form the cast-in-place box girder.

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