Self-propelled movable formwork span-crossing cast-in-place box girder and construction method thereof

Abstract

The invention relates to a self-propelled movable formwork span-crossing cast-in-place box girder and a construction method thereof. The construction method comprises the main construction steps that construction preparation is conducted; mounting a shear-resistant beam box; assembling a main beam; the single-side cross beam is connected with the main beam; integrally lifting a single-side cross beam-main beam integrated structure; mounting a bracket platform structure; mounting a moving trolley; lowering the single-side cross beam-main beam integrated structure to a bracket; the left cross beam and the right cross beam are folded and spliced; mounting a template structure; pouring the box girder; demolding is conducted; and the main beam moves to the next section. The quality safety of a bracket support on a pier column is improved, crushing and pier column concrete shearing are reduced, loosening of the bracket is reduced, the bracket and the pier column are tightly held, meanwhile, the influence of the dead weight of a main beam of a movable formwork and wind power on the main beam is relieved, and the connecting and installing convenience of the main beam and a cross beam is improved; and the mounting and dismounting efficiency of the template supporting structure of the movable formwork is improved.

Description

Technical Field

[0001] The invention relates to a self-propelled mobile formwork cross-span cast-in-place box girder and a construction method thereof, and is mainly suitable for cast-in-place box girder formwork where the ground conditions are complicated, such as cliffs, seaside, across rivers, across lakes, across existing lines, etc. and where full-length supports cannot be set up. Background Art

[0002] With the continuous development of bridge construction technology in my country, self-propelled mobile formwork is increasingly widely used in cast-in-place box girder construction due to its advantages of not being restricted by foundation conditions, not being affected by crossing rivers and valleys, and being easy to move. The mobile formwork uses the bridge piers as support and forms an integral part with the bridge piers to withstand various loads during cast-in-place box girder construction. The main components of the self-propelled formwork can be divided into a load-bearing system, a guide system, a support system, a propulsion system, a transverse connection system, a template system, a guide beam system, a corbel reverse system, and an auxiliary system.

[0003] The following are the main problems in the current installation and construction of mobile formwork for cast-in-place box girders: (1) The mobile formwork system is supported on the pier column by corbels. The lower part of the corbels mainly exerts pressure and shear force on the pier column, while the upper part mainly exerts tension. The pressure and shear force at the lower part of the corbels are relatively large. Due to the stress concentration effect, it is easy to crush or shear the local concrete of the pier column, causing quality and safety hazards to the pier column; (2) During the longitudinal movement of the mobile formwork system, under the action of the longitudinal impact force, the corbel bracket is not firmly fixed and is easy to loosen and deviate, which has certain safety risks. (3) The main beam of the mobile formwork is large in size, heavy in weight, and heavy in load. It is greatly affected by wind when it is on a high pier; (4) The main beam of the mobile formwork is difficult to connect with the cross beam, and the installation and disassembly operations are inconvenient. Workers cannot directly enter the cross beam from the main beam to perform installation and disassembly operations; (5) The mobile formwork support structure adopts hybrid rod support. After pouring a section of the box beam, when the main beam moves longitudinally through the hole, the hybrid support needs to be completely dismantled. When it reaches the next section of the box beam to be poured, the formwork support structure needs to be re-installed, which is time-consuming and labor-intensive.

[0004] In view of the above problems, it is urgent to invent a simple and effective self-propelled mobile formwork for spanning cast-in-place box girders and a construction method thereof, so as to improve the quality and safety of the corbel support on the pier column, reduce the crushing and shearing of the pier column concrete, reduce the looseness of the corbel, make the corbel and the pier column "hold tightly", and at the same time, reduce the deadweight of the main beam of the mobile formwork and the influence of wind on the main beam, improve the convenience of connection and installation between the main beam and the cross beam, and improve the installation and removal efficiency of the mobile formwork template support structure when supporting the formwork of the cast-in-place box girder and the main beam moving longitudinally through the hole. Summary of the invention

[0005] The purpose of this application is to provide a kind of X to address the above-mentioned problems existing in the prior art.

[0006] In order to achieve the above application purpose, this application adopts the following technical solution: a self-propelled mobile formwork cross-span cast-in-place box girder construction method, including the following operation steps:

[0007] S00, Construction Preparation:

[0008] The pier column is constructed according to the design requirements. During the binding process of the main reinforcement of the pier column, multiple pre-buried rake reinforcements are welded according to the designed positions, and multiple high-strength connecting reinforcements are welded on the pre-buried rake reinforcements;

[0009] Set up a self-propelled mobile formwork assembly platform on the ground, produce, cut and weld the main beam, left beam and right beam components in the factory in advance, and transport the components to the construction site;

[0010] Prepare the corbel components including the enlarged end of the corbel bottom, L-shaped pier rib, corbel tripod, corbel top beam, corbel tension anchor end, corbel platform steel plate, tension bearing beam, vertical bearing plate, and horizontal structural plate in advance, and assemble the components into one;

[0011] S10. Install shear beam box:

[0012] The shear beam box manufactured in advance is welded to multiple high-strength connecting bars on the pier column, and each shear beam box is connected to multiple embedded rake bars;

[0013] S20, assembling the main beam:

[0014] On the ground assembly platform, crawler cranes are used to lift various components to assemble the main beam. Flange seats are welded in advance on the web of the main beam. Pullies are installed under the bottom plate of the main beam and coated with butter. After the first section of the main beam is in place, the second section of the main beam is installed. The two sections of the main beam are assembled together. The upper and lower connecting plates are installed first, and then the side connecting plates are installed. The multiple sections of the main beam are connected and installed at the end of the front section of the main beam. The nose bridge adopts a steel truss structure;

[0015] S30, single-side cross beam connected to main beam:

[0016] First, assemble the left and right beams, weld flanges at the ends of the left and right beams, butt-joint the left and right beams with the main beams, install spiral tops on the top of each beam, and weld cross braces between two adjacent beams;

[0017] S40, overall improvement of the single-side crossbeam-main beam integrated structure:

[0018] The formwork integral hydraulic lifting system is installed on the top of the pier column, and the integral synchronous lifting is controlled by computer to lift the integral structure of the left main beam and the left cross beam to the designed height, and the integral structure of the right main beam and the right cross beam is also lifted to the designed height;

[0019] S50, install the bracket platform structure:

[0020] After the crane lifts the corbel assembly structure, align the enlarged end of the corbel bottom with the enlarged section of the shear beam box, and the horizontal structural plate with the standard section of the shear beam box, and then insert it. Adjust the angle of the corbel so that the L-shaped pier-holding rib plate holds the pier column tightly. Use the wire rope and hand hoist to hang the cantilever end of the corbel to temporarily fix it.

[0021] Install the tripod brackets on the other side. When the tripod brackets on both sides of the pier are temporarily fixed, install high-strength precision-rolled threaded bars between the tensioned anchoring ends of the two opposite brackets. Tighten and tension the high-strength precision-rolled threaded bars according to the design requirements, so that the two opposite bracket structures hold the pier tightly. After tightening the high-strength precision-rolled threaded bars, release the temporary fixation of the wire rope and the hand winch.

[0022] S60, install the mobile car:

[0023] Pour a certain amount of lubricating oil into the ball groove on the steel plate of the corbel platform, insert a certain amount of steel balls into the ball groove, weld a transverse horizontal hydraulic jack on the jack reaction plate, place the sliding trolley on the steel plate of the corbel platform, and connect the side of the sliding trolley with the transverse horizontal hydraulic jack;

[0024] Weld multiple vertical hydraulic jacks on the upper part of the sliding trolley, place the high-strength steel plate with slide groove on the top of the vertical hydraulic jacks, and fix them;

[0025] S70, lower the single-side crossbeam-main beam integrated structure to the corbel:

[0026] The hydraulic lifting system at the top of the pier column lowers the integral structure of the left main beam and the left cross beam onto the high-strength steel plate with a slide groove, and the pulley of the main beam is embedded in the slide groove of the high-strength steel plate with a slide groove. Similarly, the integral structure of the right main beam and the right cross beam is also placed on the high-strength steel plate with a slide groove;

[0027] S80, left and right beams are joined together:

[0028] The main beams on both sides of the pier are pushed by the external hydraulic jacking system along the longitudinal bridge direction of the slide groove on the high-strength steel plate with slide groove to the position of the casting state, and the horizontal and transverse position of the sliding trolley is adjusted to make the main beams on both sides move horizontally to the center line of the pier;

[0029] After the flanges at the ends of the left and right beams are aligned, the left and right beams are fastened with bolts. At this time, the main beams and beams on both sides of the pier form a stable frame system.

[0030] S90, installation template structure:

[0031] Hinge the combined horizontal beam and the back rib in advance, fix the combined horizontal beam on the spiral top, install the telescopic support rod at the bottom of the back rib, lay the bottom formwork on the combined horizontal beam, lay the side formwork on the back rib, adjust the spiral top to keep the combined horizontal beam horizontal, adjust the angle of the multi-segment back rib, and make the side formwork meet the design requirements;

[0032] S100, casting box beam:

[0033] Tie the steel cage of the cast-in-place box girder on the bottom form and side form according to the design requirements, install the inner form, pour concrete, and perform maintenance;

[0034] S110, demoulding:

[0035] When the concrete strength of the cast-in-place box girder reaches the design requirements, loosen the telescopic support rod and adjust the screw top to separate the formwork from the concrete;

[0036] Adjust the vertical hydraulic jack on the sliding trolley to lower the main beam to a suitable distance, remove the bolts on the flange between the left and right beams, adjust the horizontal position of the sliding trolley, move the sliding trolley to both sides of the center line of the pier, and completely separate the left and right beams into two independent structures;

[0037] At the same time, the combined horizontal beam is also separated into two parts, so that the bottom formwork and the side formwork are completely separated from the concrete, and the bottom formwork and the side formwork are removed;

[0038] S120, main beam moves to the next section:

[0039] When the left and right beams are completely separated and moved to both sides of the pier, when the flanges at the ends of the left and right beams are at a suitable distance from the edge of the pier, start the external hydraulic jacking system to push the main beam longitudinally along the slide groove on the high-strength steel plate with slide grooves and move along the bridge direction, so that the nose beam at the end of the front section of the main beam overlaps the bracket support system installed on the pier in advance, completing the self-propelled mobile formwork system through-hole;

[0040] After passing the hole, the left and right beams are closed and spliced, the formwork is laid, the box beam is cast, and the formwork is removed. The steps S80-S110 are repeated until the casting construction of the cast-in-place box beams of all sections is completed.

[0041] Furthermore, the enlarged end of the bottom of the corbel is inserted into the shear beam box, horizontal structural plates are arranged on both sides of the enlarged end of the bottom of the corbel to connect the L-shaped pier ribs, a corbel tripod is arranged between the horizontal structural plate and the top beam of the corbel, a tensioning load-bearing beam is arranged at the end of the top beam of the corbel, a corbel tensioning anchoring end is arranged at the end of the tensioning load-bearing beam, and a vertical load-bearing plate is arranged between the tensioning load-bearing beam and the horizontal structural plate.

[0042] Furthermore, a corbel platform steel plate is welded to the top of the cross beam at the top of the corbel, and two ball grooves are arranged on the upper surface of the corbel platform steel plate; two slide grooves are arranged on the upper part of the high-strength steel plate with slide grooves, and two rows of pulleys are arranged at the lower part of the main beam.

[0043] Furthermore, a plurality of movable door panels are arranged on the web of the main beam, and the movable door panels can move horizontally, and holes are formed in the web of the main beam after the movable door panels move.

[0044] Furthermore, the embedded rake reinforcement is a nail rake structure, and the embedded rake reinforcement is welded to the main reinforcement of the pier column; the shear beam box is mainly composed of two parts, the beam box expansion section and the beam box standard section, and the shear beam box is connected by at least three embedded rake reinforcements, and multiple high-strength connecting bars are welded between each embedded rake reinforcement and the shear beam box.

[0045] Furthermore, the base of the transverse horizontal hydraulic jack is fixed on the jack reaction plate, and the jack reaction plate is welded to the edge of the steel plate of the corbel platform; the pulley is a steel wheel with a diameter of 5 cm, which is evenly arranged along the longitudinal direction of the main beam, and the distance between the centers of adjacent pulleys is 20 cm.

[0046] Furthermore, the back rib is composed of multiple sections, each section is hingedly connected, the angle of the template can be adjusted according to needs, and the telescopic support rod can be freely extended and retracted to ensure the firmness of the support.

[0047] Furthermore, during the casting process of the cast-in-place box girder, the left crossbeam and the right crossbeam are merged into one, and the left and right combined horizontal crossbeams are automatically spliced ​​into one.

[0048] The self-propelled movable formwork over-span cast-in-place box girder is constructed by the above-mentioned self-propelled movable formwork over-span cast-in-place box girder construction method.

[0049] The present invention has the following characteristics and beneficial effects:

[0050] 1) The present invention has developed a shear beam box with good compression and shear resistance. The lower part of the corbel bracket is inserted into the shear beam box. The corbel bracket support system is supported by the shear beam box, which can effectively reduce the stress concentration effect of crushing or shearing the local concrete of the pier column, ensure the integrity of the pier column, and improve the quality and safety.

[0051] 2) The lower part of the corbel bracket of the present invention is clamped to the pier column by an L-shaped pier-holding rib, and the upper part is fixed by tensioning by high-strength precision-rolled threaded bars, which effectively ensures that the corbel bracket does not loosen or deviate during the longitudinal movement of the mobile formwork system, thereby improving the firmness of the bracket.

[0052] 3) The present invention arranges a grooved platform steel plate on the upper part of the corbel bracket, and steel balls are arranged in the grooves. The mobile trolley moves horizontally on the platform steel plate under the action of the jack, and the action of the steel balls is used to reduce the resistance, thereby realizing the horizontal and lateral automated movement of the main beam of the mobile formwork system, and improving the construction efficiency of the mobile formwork system in hole passing, formwork support, and formwork removal.

[0053] 4) The present invention can not only reduce the deadweight of the main beam by arranging a movable door panel on the main beam, but also achieve ventilation effect by forming a door opening through the movable door panel, thereby reducing the influence of wind on the main beam.

[0054] 5) The main beam and the cross beam of the present invention are connected by flanges, and the left cross beam and the right cross beam are also spliced ​​into one by flanges. Workers can enter the cross beam through the main beam web door opening for installation and removal, thereby improving the installation efficiency and convenience of the main beam and the cross beam.

[0055] 6) When the main beam of the present invention moves toward the center line of the pier, it drives the left and right cross beams to move together. After the left and right cross beams are assembled into one, the combined horizontal cross beam is also combined into one, so that the back ribs, telescopic support rods and formwork can be installed quickly. After the cast-in-place box beam is poured, before the main beam slides longitudinally, the elevation of the main beam is lowered, and the main beam is moved laterally to both sides of the pier, the left and right cross beams are separated, and the combined horizontal cross beam is disengaged into two parts. After the formwork is disengaged from the concrete, only the formwork needs to be removed, and there is no need to remove the back ribs and telescopic support rods, which can save a lot of time for installing and dismantling the box beam formwork support system. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is a structural diagram of the self-propelled movable formwork cross-span cast-in-place box girder bracket support system of the present invention;

[0057] Figure 2 This is a structural diagram of the corbel bracket of the present invention;

[0058] Figure 3 This is a cross-sectional view of the support system of the self-propelled mobile formwork over the cast-in-place box beam bracket of the present invention ( Figure 1 Middle AA section view);

[0059] Figure 4 It is a plan view of the sliding trolley of the present invention sliding transversely on the steel plate of the corbel platform;

[0060] Figure 5 This is a structural diagram of the connection between the embedded rake reinforcement and the main reinforcement of the pier column of the present invention;

[0061] Figure 6 It is a connection reinforcement diagram of the embedded rake reinforcement and the shear beam box of the present invention;

[0062] Figure 7This is a structural diagram of the connection between the main beam and the left and right cross beams of the self-propelled mobile formwork system of the cast-in-place box beam of the present invention (the left and right cross beams are separate independent structures);

[0063] Figure 8 This is a structural diagram of the connection between the main beam and the left and right cross beams of the self-propelled mobile formwork system of the cast-in-place box beam of the present invention (the left and right cross beams are combined into one);

[0064] Fig. 9 It is a detailed diagram of the main beam structure of the self-propelled mobile formwork system of the cast-in-place box beam of the present invention;

[0065] Fig.10 It is a schematic diagram of the separation and splicing of the left and right beams of the self-propelled mobile formwork system of the cast-in-place box beam of the present invention;

[0066] Fig.11 This is a structural diagram of a self-propelled mobile formwork system for cast-in-place box beams of the present invention, in which a cross brace reinforcement is arranged between two adjacent cross beams;

[0067] Fig.12 This is a structural diagram of a self-propelled mobile formwork system for supporting formwork for a cast-in-place box beam according to the present invention;

[0068] Fig.13 This is a structural diagram of the self-propelled mobile formwork system when the main beam moves longitudinally in the present invention;

[0069] Fig.14 It is a schematic diagram of the longitudinal movement of the main beam-nose beam integrated structure of the self-propelled mobile formwork system of the cast-in-place box beam of the present invention through the span (hole).

[0070] In the figure, 1, pier column; 2, embedded rake reinforcement; 3, shear beam box; 3-1, beam box expansion section; 3-2, beam box standard section; 4, corbel bottom expansion end; 5, L-shaped pier rib plate; 6, corbel tripod; 7, corbel top crossbeam; 8, corbel tension anchor end; 9, high-strength precision-rolled threaded reinforcement; 10, corbel platform steel plate; 11, steel ball; 12, sliding trolley; 13, horizontal hydraulic jack; 14, jack reaction plate; 15, vertical hydraulic jack; 16, high-strength steel plate with slide; 17, slide; 18, pulley; 19, main beam ; 20. Tensioned load-bearing beam; 21. Vertical load-bearing plate; 22. Horizontal structural plate; 23. Ball groove; 24. Pier column main reinforcement; 25. High-strength connecting reinforcement; 26. Flange seat; 27. Flange plate; 28. Left crossbeam; 29. ​​Right crossbeam; 30. Bolts; 31. Main beam web; 32. Movable door panel; 33. Screw top; 34. Cross brace; 35. Combined horizontal crossbeam; 36. Bottom form; 37. Inner form; 38. Cast-in-place box beam; 39. Side form; 40. Back rib; 41. Telescopic support rod; 42. Corbel support system; 43. Nose bridge. DETAILED DESCRIPTION

[0071] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0072] Those skilled in the art should understand that, in the disclosure of the present application, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be understood as limiting the present application.

[0073] The working principle of the external force hydraulic jacking system for the longitudinal movement of the main beam, the embedded rake reinforcement structure and the embedded requirements, the shape, size and material requirements of the shear beam box, the technical requirements for the welding of high-strength connecting reinforcement, the composition and assembly technical requirements of the various components of the corbel, the tensile strength and technical requirements of the high-strength precision-rolled threaded reinforcement, the bearing capacity detection of the corbel tripod, the sliding working principle of the sliding trolley, the jack fixing method, the slide groove size, the pulley installation technical requirements, the production requirements and plate material of the high-strength steel plate with slide groove, the horizontal, transverse and vertical movement principle of the main beam, the flange seat and flange plate connection structure, the movable door plate structure on the web of the main beam, the spiral top structure and working principle, the template size, the template and the back rib connection, the back rib and the telescopic support rod connection method, the concrete pouring process, the nose bridge and the main beam connection structure, the working principle of the nose bridge auxiliary main beam longitudinal movement hole, various types of bolt structures, steel plate welding technology, etc., the present invention will not be repeated, and the implementation method of the present invention will be emphasized.

[0074] Example 1

[0075] This embodiment provides a construction structure for a self-propelled mobile formwork over-span cast-in-place box girder, including:

[0076] like Figure 5-6 The diagram of the connection reinforcement of the embedded rake reinforcement and the shear beam box shown includes a pier 1, embedded rake reinforcement 2, a shear beam box 3, an expanded beam box section 3-1, a standard beam box section 3-2, a pier main reinforcement 24, a high-strength connecting reinforcement 25, etc. The embedded rake reinforcement 2 is embedded in the pier 1, and the embedded rake reinforcement 2 is a nail rake structure. The embedded rake reinforcement 2 is welded to the pier main reinforcement 24. The shear beam box 3 is mainly composed of two parts: the expanded beam box section 3-1 and the standard beam box section 3-2. The shear beam box 3 is connected by at least three embedded rake reinforcements 2, and a plurality of high-strength connecting reinforcements 25 are welded between each embedded rake reinforcement 2 and the shear beam box 3.

[0077] like Figure 2 ,6 The structure diagram of the corbel bracket shown in the figure includes a shear beam box 3, an enlarged beam box section 3-1, a standard beam box section 3-2, an enlarged end of the corbel bottom 4, an L-shaped pier rib plate 5, a corbel tripod 6, a corbel top cross beam 7, a tension bearing beam 20, a vertical bearing plate 21, a horizontal structural plate 22, etc. The enlarged end of the corbel bottom 4 is inserted into the enlarged beam box section 3-1, and horizontal structural plates 22 are arranged on both sides of the enlarged end of the corbel bottom 4 to connect the L-shaped pier rib plate 5. The horizontal structural plate 22 is inserted into the standard beam box section 3-2, and the lower part of the corbel bracket support system is supported by the shear beam box 3. A corbel tripod 6 is arranged between the horizontal structural plate 22 and the top cross beam 7 of the corbel, a tension bearing beam 20 is arranged at the end of the top cross beam 7 of the corbel, a corbel tension anchoring end 8 is arranged at the end of the tension bearing beam 20, and a vertical bearing plate 21 is arranged between the tension bearing beam 20 and the horizontal structural plate 22.

[0078] like Figure 1 , 3 The structure diagram of the self-propelled mobile formwork cross-span cast-in-place box girder bracket support system shown in the figure includes a pier column 1, an L-shaped pier holding rib plate 5, a bracket tensioning anchor end 8, a high-strength precision-rolled threaded bar 9, etc. The L-shaped pier holding rib plate 5 holds the pier column 1 tightly, and high-strength precision-rolled threaded bar 9 is arranged between the bracket tensioning anchor ends 8 on two opposite sides of the pier column 1 for tensioning.

[0079] like Figure 1 , 4 The shown sliding trolley slides horizontally on the corbel platform steel plate in a plan view, comprising a corbel top crossbeam 7, a corbel platform steel plate 10, steel balls 11, a sliding trolley 12, a transverse horizontal hydraulic jack 13, a jack reaction plate 14, etc. The corbel platform steel plate 10 is welded to the top of the corbel top crossbeam 7, two ball grooves 23 are arranged on the upper surface of the corbel platform steel plate 10, and a plurality of steel balls 11 are arranged in the ball grooves 23. The sliding trolley 12 is placed on the corbel platform steel plate 10, and two transverse horizontal hydraulic jacks 13 are arranged on the side of the sliding trolley 12. The base of the transverse horizontal hydraulic jack 13 is fixed on the jack reaction plate 14, and the jack reaction plate 14 is welded to the edge of the corbel platform steel plate 10. The sliding trolley 12 can be pushed by the transverse horizontal hydraulic jack 13 to move horizontally.

[0080] like Figure 1 The structural diagram of the self-propelled mobile formwork cross-span cast-in-place box girder corbel support system shown in the figure includes a sliding trolley 12, a vertical hydraulic jack 15, a high-strength steel plate with a slide groove 16, a slide groove 17, a pulley 18, a main beam 19, a ball groove 23, etc. Three vertical hydraulic jacks 15 are fixed on the upper part of the sliding trolley 12, the top of the vertical hydraulic jack 15 is connected to the high-strength steel plate with a slide groove 16, the bottom of the vertical hydraulic jack 15 is welded and fixed to the sliding trolley 12 as a whole, and the top is welded to the high-strength steel plate with a slide groove 16, and the height of the high-strength steel plate with a slide groove 16 can be adjusted by the vertical hydraulic jack 15.

[0081] Furthermore, two slide grooves 17 are arranged on the upper part of the high-strength steel plate with slide grooves 16, and two rows of pulleys 18 are arranged on the lower part of the main beam 19. The pulleys 18 are steel wheels with a diameter of 5 cm, and are evenly spaced along the longitudinal direction of the main beam 19. The distance between the centers of adjacent pulleys 18 is 20 cm. The pulleys 18 are embedded in the slide grooves 17, and the main beam 19 can move longitudinally along the slide grooves 17 through the pulleys 18 under the push of external force.

[0082] like Figure 7-9 The structure diagram of the connection between the main beam and the left and right cross beams of the self-propelled mobile formwork system of the cast-in-place box beam shown in the figure includes a high-strength steel plate with a slide groove 16, a slide groove 17, a pulley 18, a main beam 19, a flange seat 26, a main beam web 31, a movable door panel 32, etc. Two rows of pulleys 18 are arranged at the lower part of the main beam 19, and the pulley 18 can slide along the slide groove 17 at the upper part of the high-strength steel plate with a slide groove 16. A plurality of movable door panels 32 are arranged on the main beam web 31, and the movable door panels 32 can move horizontally. The horizontal movement structure of the movable door panels 32 is similar to the translation structure of the glass window. After the movable door panels 32 move, holes are formed on the main beam web 31, and flange seats 26 are arranged on the main beam web 31 at uniform intervals.

[0083] like Figure 7 , 10 -11 shows a schematic diagram of the separation and splicing of the left and right beams of the self-propelled mobile formwork system of the cast-in-place box beam, including the main beam 19, flange seat 26, flange plate 27, left beam 28, right beam 29, bolts 30, screw top 33, cross brace 34, etc., flange plates 27 are set at the ends of the left beam 28 and the right beam 29, and the left beam 28 and the right beam 29 are connected to the flange seat 26 of the main beam 19 through the flange plate 27, and the flange plate 27 is connected to the flange seat 26 through bolts 30. Multiple screw tops 33 are set on the upper part of the left beam 28 and the right beam 29, and cross braces 34 are set between the two adjacent left beams 28 for strengthening the connection. Similarly, cross braces 34 are also set between the two adjacent right beams 29 for strengthening the connection.

[0084] like Fig.12The structure diagram of the self-propelled mobile formwork system for supporting the formwork of the cast-in-place box beam shown in the figure includes a main beam 19, a left cross beam 28, a right cross beam 29, a spiral top 33, a combined horizontal cross beam 35, a bottom form 36, an inner form 37, a cast-in-place box beam 38, a side form 39, a back rib 40, a telescopic support rod 41, etc. After the main beam 19 slides longitudinally onto the next section of the pier column 1, the main beam 19 moves horizontally toward the center line of the pier, driving the left cross beam 28 and the right cross beam 29 to move horizontally toward the center line of the pier, and the flange 27 of the left cross beam 28 and the flange 27 of the right cross beam 29 are docked, and the flanges 27 of the two are connected into one by bolts 30. The combined horizontal cross beam 35 is fixed on the upper part of the spiral top 33, and the combined horizontal cross beam 35 is assembled in two left and right sections, and is separated and merged along with the separation of the left cross beam 28 and the right cross beam 29. During the casting process of the cast-in-place box girder 38, the left crossbeam 28 and the right crossbeam 29 are merged into one, and the left and right sections of the combined horizontal crossbeams 35 are automatically spliced ​​into one. The ends of the combined horizontal crossbeams 35 are connected to the back ribs 40 by hinged means. The back ribs 40 are composed of multiple sections, and each section is hingedly connected. The angle of the template can be adjusted as needed. The back ribs 40 are supported on the top of the main beam 19 by telescopic support rods 41. The telescopic support rods 41 can be freely extended and retracted to ensure the firmness of the support; the bottom mold 36 is laid on the upper part of the combined horizontal crossbeam 35, and the side mold 39 is laid on the upper part of the back ribs 40.

[0085] like Fig.13 The structural diagram of the self-propelled mobile formwork system when the main beam moves longitudinally is shown, including the main beam 19, the left crossbeam 28, the right crossbeam 29, the combined horizontal crossbeam 35, etc. When the main beam 19 slides longitudinally through the hole, the left crossbeam 28 and the right crossbeam 29 are separated into independent structures, and the combined horizontal crossbeam 35 is disengaged into a two-part structure.

[0086] like Fig.14 The schematic diagram of the longitudinal movement of the main beam-nose bridge integrated structure of the self-propelled mobile formwork system of the cast-in-place box girder shown in the figure includes a pier 1, a main beam 19, a corbel support system 42, a nose bridge 43, etc., a nose bridge 43 is arranged at the end of the front main beam 19, and the main beam 19 is supported on the corbel support system 42 on the pier 1. The main beam 19 drives the entire formwork system to slide forward along the longitudinal direction of the line under the pushing action of the external hydraulic jacking system, and the longitudinal movement through the hole is assisted by the nose bridge 43. The working principle of the nose bridge 43 assisting the longitudinal movement through the hole is similar to the structure of the guide beam set when the steel box girder is jacked over the span.

[0087] Example 2

[0088] Based on the same concept, the present invention also provides a self-propelled mobile formwork cross-span cast-in-place box girder and a construction method thereof, which is characterized by comprising the following steps:

[0089] S00, Construction preparation: Carry out the construction of the pier column 1 according to the design requirements. During the binding process of the main reinforcement 24 of the pier column, weld multiple embedded rake reinforcements 2 according to the designed position, weld multiple high-strength connecting reinforcements 25 on the embedded rake reinforcements 2, set up an assembly platform of a self-propelled mobile formwork on the ground, produce the blanking, cutting, and welding of the main beam 19, the left crossbeam 28, and the right crossbeam 29 in the factory in advance, and transport the components to the construction site. Make the corbel bottom enlarged end 4, L-shaped pier rib plate 5, corbel tripod 6, corbel top crossbeam 7, corbel tension anchor end 8, corbel platform steel plate 10, tension bearing beam 20, vertical bearing plate 21, horizontal structural plate 22 and other corbel components in advance, and assemble the components into one.

[0090] S10, installing the shear beam box: welding the pre-produced shear beam box 3 to the multiple high-strength connecting bars 25 on the pier column 1, and each shear beam box 3 is connected to multiple embedded rake bars 2.

[0091] S20, assembling the main beam: on the ground assembly platform, use a crawler crane to lift various components to assemble the main beam 19, weld the flange seat 26 on the web 31 of the main beam in advance, install the pulley 18 under the bottom plate of the main beam 19, and apply butter to the pulley 18. After the first section of the main beam 19 is in place, install the second section of the main beam 19, and put the two sections of the main beam 19 together. First install the upper and lower connecting plates, then install the side connecting plates, tighten the bolts, connect the multiple sections of the main beam 19 into a whole, and connect and install the nose bridge 43 at the end of the front section of the main beam 19. The nose bridge 43 adopts a steel truss structure.

[0092] S30, connecting the single-sided cross beam to the main beam: first assemble the left cross beam 28 and the right cross beam 29, weld the flanges 27 to the ends of the left and right cross beams, respectively butt-jointly install the left cross beam 28 and the right cross beam 29 to the main beam 19, install a spiral top 33 on the top of each cross beam, and weld a cross brace 34 between two adjacent cross beams.

[0093] S40, overall lifting of the single-sided crossbeam-main beam integrated structure: Install the formwork integral hydraulic lifting system on the top of the pier 1, and use computer-controlled overall synchronous lifting technology to lift the left main beam 19-left crossbeam 28 integral structure to the designed height. Similarly, lift the right main beam 19-right crossbeam 29 integral structure to the designed height.

[0094] S50. Install the corbel platform structure: after the crane lifts the corbel assembly structure, align the enlarged end 4 of the corbel bottom with the enlarged section 3-1 of the shear beam box, align the horizontal structural plate 22 with the standard section 3-2 of the shear beam box, and then insert it. Adjust the angle of the corbel so that the L-shaped pier-holding rib 5 holds the pier column 1 tightly. Use wire rope and hand winch to temporarily fix the cantilever end of the corbel. Install the corbel tripod on the other side. When the corbel tripods on both sides of the pier column 1 are temporarily fixed, install high-strength precision-rolled threaded bars 9 between the two opposite corbel tensioning anchor ends 8. Tighten and tension the high-strength precision-rolled threaded bars 9 according to the design requirements, so that the two opposite corbel structures hold the pier column 1 tightly. After tightening the high-strength precision-rolled threaded bars 9, release the temporary fixation of the wire rope and hand winch.

[0095] S60, install the mobile trolley: pour a certain amount of lubricating oil into the ball groove 23 on the corbel platform steel plate 10, insert a certain amount of steel balls 11 into the ball groove 23, weld the horizontal hydraulic jack 13 on the jack reaction plate 14, place the sliding trolley 12 on the corbel platform steel plate 10, connect the side of the sliding trolley 12 with the horizontal hydraulic jack 13, and test whether the horizontal hydraulic jack 13 can freely push the sliding trolley 12 to slide freely on the corbel platform steel plate 10. Weld a plurality of vertical hydraulic jacks 15 on the upper part of the sliding trolley 12, place the high-strength steel plate 16 with slide grooves on the top of the vertical hydraulic jack 15, and fix it.

[0096] S70. Lower the single-sided crossbeam-main beam integrated structure to the corbel: the hydraulic lifting system on the top of the pier 1 lowers the left main beam 19-left crossbeam 28 integrated structure to the high-strength steel plate 16 with the slide groove, and the pulley 18 of the main beam 19 is embedded in the slide groove 17 of the high-strength steel plate 16 with the slide groove. Similarly, the right main beam 19-right crossbeam 29 integrated structure is also placed on the high-strength steel plate 16 with the slide groove.

[0097] S80, the left and right cross beams are closed and spliced: the main beams 19 on both sides of the pier 1 are pushed by the external hydraulic jacking system, and the slide grooves 17 on the high-strength steel plates 16 with slide grooves are moved longitudinally to the casting state. By adjusting the horizontal and transverse positions of the sliding trolley 12, the main beams 19 on both sides are moved transversely to the center line of the pier 1. After the flanges 27 at the ends of the left cross beam 28 and the right cross beam 29 are aligned, the left cross beam 28 and the right cross beam 29 are fastened by bolts 30. At this time, the main beams and cross beams on both sides of the pier 1 form a stable frame system.

[0098] S90. Install the formwork structure: hinge the combined horizontal beam 35 and the back rib 40 in advance, fix the combined horizontal beam 35 on the spiral top 33, install the telescopic support rod 41 at the lower part of the back rib 40, lay the bottom form 36 on the combined horizontal beam 35, lay the side form 39 on the back rib 40, adjust the spiral top 33 to keep the combined horizontal beam 35 horizontal, adjust the angle of the multi-segment back rib 40, so that the side form 39 meets the design requirements.

[0099] S100, casting box girder: tie the steel cage of the cast-in-place box girder 38 on the bottom form 36 and the side form 39 according to the design requirements, install the inner form 37, cast concrete, and perform curing.

[0100] S110, demoulding: when the concrete strength of the cast-in-place box beam 38 reaches the design requirement, loosen the telescopic support rod 41, adjust the screw top 33 to separate the formwork from the concrete, adjust the vertical hydraulic jack 15 on the sliding trolley 12 to lower the elevation of the main beam 19 by 30 cm, remove the bolts 30 on the flange 27 between the left beam 28 and the right beam 29, adjust the lateral horizontal position of the sliding trolley 12, move the sliding trolley 12 to both sides of the center line of the pier 1, so that the left beam 28 and the right beam 29 are completely separated into two independent structures, and at the same time, the combined horizontal beam 35 is also separated into two parts, so that the bottom form 36 and the side form 39 are completely separated from the concrete, and the bottom form 36 and the side form 39 are removed.

[0101] S120, main beam moves to the next section: when the left cross beam 28 and the right cross beam 29 are completely separated and moved to both sides of the pier 1, when the flange 27 at the end of the left cross beam 28 and the right cross beam 29 is about 8-10cm away from the edge of the pier 1, start the external force hydraulic jacking system to push the main beam 19 longitudinally along the slide groove 17 on the high-strength steel plate 16 with slide groove along the bridge direction, so that the nose beam 43 at the end of the front section of the main beam 19 is overlapped on the corbel support system 42 that has been installed on the pier 1 in advance, and the self-propelled mobile formwork system is passed through the hole. After passing through the hole, the left and right cross beams are closed and spliced ​​→ the formwork is laid → the box beam is cast → the mold is demolded, and the operations of steps S80-S110 are repeated until the casting construction of the cast-in-place box beam 38 of all sections is completed.

[0102] The parts not described in detail in this application are prior art, so this application does not describe them in detail.

[0103] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0104] Although this article uses more professional terms, it does not exclude the possibility of using other terms. These terms are used only to more conveniently describe and explain the essence of this application; interpreting them as any additional restrictions is contrary to the spirit of this application.

[0105] The present application is not limited to the above-mentioned optimal implementation mode. Anyone can derive other forms of products under the inspiration of this application. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present application.

Claims

1. A self-propelled mobile formwork cross-span cast-in-place box girder construction method, characterized in that: The steps include: S00, Construction Preparation: The pier column (1) is constructed according to the design requirements. During the binding process of the main reinforcement (24) of the pier column, a plurality of pre-embedded rake reinforcements (2) are welded according to the designed positions, and a plurality of high-strength connecting reinforcements (25) are welded on the pre-embedded rake reinforcements (2); An assembly platform of a self-propelled mobile formwork is set up on the ground, and various components of the main beam (19), the left cross beam (28), and the right cross beam (29) are produced, cut, and welded in advance in the factory, and the various components are transported to the construction site; The bracket components including the enlarged end of the bottom of the bracket (4), the L-shaped pier rib plate (5), the bracket tripod (6), the top crossbeam of the bracket (7), the tension anchor end of the bracket (8), the bracket platform steel plate (10), the tension bearing beam (20), the vertical bearing plate (21), and the horizontal structural plate (22) are manufactured in advance, and the components are assembled into one; S10. Install shear beam box: The shear beam box (3) manufactured in advance is welded to a plurality of high-strength connecting bars (25) on the pier column (1), and each shear beam box (3) is connected to a plurality of pre-embedded rake bars (2); S20, assembling the main beam: On the ground assembly platform, a crawler crane is used to lift various components to assemble the main beam (19), a flange seat (26) is welded in advance on the web plate (31) of the main beam, a pulley (18) is installed under the bottom plate of the main beam (19), and the pulley (18) is coated with butter. After the first section of the main beam (19) is in place, the second section of the main beam (19) is installed, and the two sections of the main beam (19) are assembled together, and the upper and lower connecting plates are installed first, and then the side connecting plates are installed, and the multiple sections of the main beam (19) are connected to form a whole, and a nose bridge (43) is connected and installed at the end of the front section of the main beam (19), and the nose bridge (43) adopts a steel truss structure; S30, single-side cross beam connected to main beam: First, assemble the left cross beam (28) and the right cross beam (29), weld the flanges (27) at the ends of the left and right cross beams, butt-jointly install the left cross beam (28) and the right cross beam (29) with the main beam (19), install a spiral top (33) on the top of each cross beam, and weld a cross brace (34) between two adjacent cross beams; S40, overall improvement of the single-side crossbeam-main beam integrated structure: An integral hydraulic lifting system for the formwork is installed on the top of the pier column (1), and the integral synchronous lifting is controlled by a computer to lift the integral structure of the left main beam (19) and the left cross beam (28) to a designed height, and the integral structure of the right main beam (19) and the right cross beam (29) is also lifted to a designed height; S50, install the bracket platform structure: After the crane lifts the bracket assembly structure, the bracket bottom enlarged end (4) is aligned with the shear beam box enlarged section (3-1), and the horizontal structural plate (22) is aligned with the shear beam box standard section (3-2) and then inserted, and the angle of the bracket is adjusted so that the L-shaped pier holding rib plate (5) holds the pier column (1) tightly, and the cantilever end of the bracket is hung and temporarily fixed by using a wire rope and a hand winch; Install the other side of the bracket tripod (6). When the bracket tripods (6) on both sides of the pier column (1) are temporarily fixed, install the high-strength precision-rolled threaded reinforcement (9) between the tensioning anchoring ends (8) of the two opposite brackets. Tighten and tension the high-strength precision-rolled threaded reinforcement (9) according to the design requirements, so that the two opposite bracket structures hold the pier column (1). After tightening the high-strength precision-rolled threaded reinforcement (9), release the temporary fixation of the wire rope and the hand chain hoist. S60, install the mobile car: A certain amount of lubricating oil is poured into the ball groove (23) on the corbel platform steel plate (10), a certain amount of steel balls (11) are inserted into the ball groove (23), a transverse horizontal hydraulic jack (13) is welded on the jack reaction plate (14), a sliding trolley (12) is placed on the corbel platform steel plate (10), and the side of the sliding trolley (12) is connected to the transverse horizontal hydraulic jack (13); A plurality of vertical hydraulic jacks (15) are welded on the upper part of the sliding carriage (12), and a high-strength steel plate (16) with a slide groove is placed on the top of the vertical hydraulic jacks (15) and fixed; S70, lower the single-side crossbeam-main beam integrated structure to the corbel: The hydraulic lifting system at the top of the pier (1) lowers the overall structure of the left main beam (19) and the left cross beam (28) onto the high-strength steel plate (16) with a slide groove, and the pulley (18) of the main beam (19) is embedded in the slide groove (17) of the high-strength steel plate (16) with a slide groove. Similarly, the overall structure of the right main beam (19) and the right cross beam (29) is also placed on the high-strength steel plate (16) with a slide groove; S80, left and right beams are joined together: The main beams (19) on both sides of the pier column (1) are pushed by an external hydraulic jacking system to move along the slide groove (17) on the high-strength steel plate (16) with a slide groove in the longitudinal direction of the bridge to the position of the casting state, and the horizontal and transverse position of the sliding trolley (12) is adjusted to make the main beams (19) on both sides move transversely to the center line of the pier column (1); After the flanges (27) at the ends of the left cross beam (28) and the right cross beam (29) are aligned, the left cross beam (28) and the right cross beam (29) are fastened by bolts (30), and at this time, the main beams and cross beams on both sides of the pier column (1) form a stable frame system; S90, installation template structure: The combined horizontal beam (35) and the back rib (40) are hingedly connected in advance, the combined horizontal beam (35) is fixed on the spiral top (33), a telescopic support rod (41) is installed at the lower part of the back rib (40), a bottom mold (36) is laid on the combined horizontal beam (35), a side mold (39) is laid on the back rib (40), the spiral top (33) is adjusted to keep the combined horizontal beam (35) horizontal, and the angle of the multi-segment back rib (40) is adjusted to make the side mold (39) meet the design requirements; S100, casting box beam: The steel cage of the cast-in-place box beam (38) is tied on the bottom form (36) and the side form (39) according to the design requirements, the inner form (37) is installed, the concrete is poured, and the concrete is maintained; S110, demoulding: When the concrete strength of the cast-in-place box beam (38) reaches the design requirement, the telescopic support rod (41) is loosened and the screw top (33) is adjusted to separate the formwork from the concrete; The vertical hydraulic jack (15) on the sliding trolley (12) is adjusted to lower the elevation of the main beam (19) by an appropriate distance, the bolts (30) on the flange (27) between the left crossbeam (28) and the right crossbeam (29) are removed, and the horizontal position of the sliding trolley (12) is adjusted to move the sliding trolley (12) to both sides of the center line of the pier (1), so that the left crossbeam (28) and the right crossbeam (29) are completely separated into two independent structures; At the same time, the combined horizontal beam (35) is also separated into two parts, so that the bottom form (36) and the side form (39) are completely separated from the concrete, and the bottom form (36) and the side form (39) are removed; S120, main beam moves to the next section: When the left crossbeam (28) and the right crossbeam (29) are completely separated and moved to both sides of the pier (1), when the flanges (27) at the ends of the left crossbeam (28) and the right crossbeam (29) are at a suitable distance from the edge of the pier (1), the external hydraulic jacking system is started to push the main beam (19) longitudinally along the slide groove (17) on the high-strength steel plate with slide groove (16) along the bridge direction, so that the nose bridge (43) at the end of the front section of the main beam (19) is overlapped on the bracket support system (42) installed in advance on the pier (1), completing the self-propelled mobile formwork system through-hole; After the holes are passed, the left and right beams are closed and spliced, the template is laid, the box beam is cast, and the mold is removed. The operations of steps S80-S110 are repeated until the casting construction of the cast-in-place box beam (38) of all sections is completed.

2. The self-propelled mobile formwork cross-span cast-in-place box girder construction method according to claim 1 is characterized in that: The enlarged end (4) of the corbel is inserted into the shear beam box (3), and horizontal structural plates (22) are arranged on both sides of the enlarged end (4) of the corbel to connect the L-shaped pier ribs (5). A corbel tripod (6) is arranged between the horizontal structural plate (22) and the top cross beam (7) of the corbel, and a tensioning load-bearing beam (20) is arranged at the end of the top cross beam (7) of the corbel. A corbel tensioning anchoring end (8) is arranged at the end of the tensioning load-bearing beam (20), and a vertical load-bearing plate (21) is arranged between the tensioning load-bearing beam (20) and the horizontal structural plate (22).

3. The self-propelled mobile formwork cross-span cast-in-place box girder construction method according to claim 1 is characterized in that: A corbel platform steel plate (10) is welded to the top of the corbel top cross beam (7), and two ball grooves (23) are arranged on the upper surface of the corbel platform steel plate (10); two slide grooves (17) are arranged on the upper part of the high-strength steel plate with slide grooves (16), and two rows of pulleys (18) are arranged on the lower part of the main beam (19).

4. The self-propelled mobile formwork cross-span cast-in-place box girder construction method according to claim 1 is characterized in that: A plurality of movable door panels (32) are arranged on the main beam web (31), and the movable door panels (32) can move horizontally. After the movable door panels (32) move, holes are formed in the main beam web (31).

5. The self-propelled mobile formwork cross-span cast-in-place box girder construction method according to claim 1 is characterized in that: The embedded rake reinforcement (2) is a nail rake structure, and the embedded rake reinforcement (2) is welded to the pier column main reinforcement (24); the shear beam box (3) mainly consists of two parts: a beam box expansion section (3-1) and a beam box standard section (3-2); the shear beam box (3) is connected by at least three embedded rake reinforcements (2), and a plurality of high-strength connecting reinforcements (25) are welded between each embedded rake reinforcement (2) and the shear beam box (3).

6. The self-propelled mobile formwork cross-span cast-in-place box girder construction method according to claim 1 is characterized in that: The base of the transverse horizontal hydraulic jack (13) is fixed on the jack reaction plate (14), and the jack reaction plate (14) is welded to the edge of the corbel platform steel plate (10); the pulley (18) is a steel wheel with a diameter of 5 cm, which is evenly spaced along the longitudinal direction of the main beam (19), and the distance between the centers of adjacent pulleys (18) is 20 cm.

7. The self-propelled mobile formwork cross-span cast-in-place box girder construction method according to claim 1 is characterized in that: The back rib (40) is composed of multiple sections, each section is hingedly connected, and the angle of the template can be adjusted according to needs. The telescopic support rod (41) can be freely extended and shortened to ensure the firmness of the support.

8. The self-propelled mobile formwork cross-span cast-in-place box girder construction method according to any one of claims 1 to 7, characterized in that: During the casting process of the cast-in-place box beam (38), the left crossbeam (28) and the right crossbeam (29) are combined into one, and the left and right combined horizontal crossbeams (35) are automatically spliced ​​into one.

9. Self-propelled mobile formwork cross-span cast-in-place box girder, characterized in that: The self-propelled mobile formwork cross-span cast-in-place box girder is constructed by the construction method according to any one of claims 1 to 8.

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