A large-tonnage two-span self-propelled overhead moving formwork and its construction method

Abstract

The present invention discloses a large-tonnage two-span self-propelled movable formwork for upper bearing and its construction method. A large-tonnage two-span self-propelled movable formwork for upper bearing includes a main frame, a front auxiliary support leg, a rear auxiliary support leg, a main support leg, a hanging outer rib, an outer formwork system and an inner formwork system. The main frame is composed of two groups of longitudinal beams, several groups of cantilever beams and several groups of connecting systems. Each group of longitudinal beams is composed of a main beam and a guide beam. The main beam is a combined structure with three or more layers. Strain sensors are arranged inside the main beam. A pressure sensing component is arranged inside the rear auxiliary support leg to monitor the pressure condition of the rear auxiliary support leg in real time. An auxiliary support component is arranged below the main beam inside the main support leg to support the main beam under heavy load. By adopting a combined structure with three or more layers for the main frame, the present invention can well meet the stiffness requirements for the construction of large-tonnage bridges, enabling the device to adapt to the construction conditions of large-tonnage bridge erection, and greatly improving both safety and economy.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge erection machines and movable formwork systems, and particularly to a large-tonnage two-span self-propelled movable formwork system on the upper chord. Background Art

[0002] In recent years, with the large-scale implementation of railway, highway, and cross-river and cross-sea bridge construction in China, the movable formwork construction method with the characteristics of safety, high efficiency, and economy has become increasingly common. With the gradual formation of the railway network in the central and eastern regions of China, bridge construction has gradually shifted to mountainous areas in the western and southern regions. Due to the topographical and geological conditions in most mountainous areas, it is difficult to construct bridge piers, so it is necessary to increase the single-span length and single-span weight of bridges. Therefore, bridges are developing towards the direction of large spans and large tonnages. However, since the main girders of conventional movable formwork systems are mostly two-layer structures, when constructing large-tonnage bridges, it is necessary to increase the height of the main girders. This increases the height of the single-layer main girders, and during the transportation of the single-layer main girders, there are problems such as height and weight restrictions, which directly affect the economy of the overall construction and make the existing movable formwork systems unable to adapt to the construction conditions of large-span and large-tonnage bridges.

[0003] Therefore, there is a need for a movable formwork system that can effectively meet the construction requirements of large-tonnage bridges and a construction method applicable to this movable formwork system. Summary of the Invention

[0004] The present invention aims at the problems existing in the prior art and provides a large-tonnage two-span self-propelled movable formwork system on the upper chord.

[0005] The technical solution adopted to achieve the above object is as follows:

[0006] A large-tonnage two-span self-propelled movable formwork system on the upper chord includes a main frame, front auxiliary legs, rear auxiliary legs, main legs, hanging outer ribs, an outer formwork system, and an inner formwork system. The main frame is composed of two groups of longitudinal beams, several groups of cantilever beams, and several groups of connecting systems. Each group of longitudinal beams is composed of a main girder and a guide girder. It is characterized in that the main girder is a combined structure of three layers or more, a strain sensor is provided inside the main girder, a pressure sensing component is provided inside the rear auxiliary leg to monitor the pressure condition of the rear auxiliary leg in real time, and an auxiliary support component is provided below the main girder inside the main leg to provide heavy-load support for the main girder.

[0007] Further, the main girder is a three-layer combined structure, specifically divided into an upper layer, a middle layer, and a lower layer;

[0008] The upper layer is a π-shaped structure, the middle layer of the main girder is a truss and box-shaped rectangular column structure, and the lower layer of the main girder is an inverted π-shaped structure.

[0009] Further, the guide girder is a combination of a rectangular truss mechanism and a box-shaped structure.

[0010] Further, the rear auxiliary outrigger includes a support column, a cross beam, and a traveling mechanism;

[0011] The support column is arranged at the tail of the main frame and is connected to the main frame by bolt flanges. The traveling mechanism is arranged at the bottom of the support column through the cross beam, and the pressure sensing device is arranged inside the traveling mechanism.

[0012] Further, the pressure sensing device is a pressure sensor pin shaft.

[0013] Further, there are two sets of main outriggers, which are respectively arranged at the front end and the rear end of the main beam. Each set of main outriggers includes a shifting trolley, a longitudinal movement mechanism, an upper cross beam, a column steel structure, a column connection frame, a transverse movement strut assembly, a beam surface support seat, and pier top anchorage;

[0014] The upper cross beam is connected to the beam surface support seat through the column steel structure and is supported on the pier. The pier top anchorage is connected to

[0015] The longitudinal movement mechanism is arranged inside the shifting trolley, and the shifting trolley is arranged below the main beam through the longitudinal movement mechanism. The auxiliary support device is arranged inside the shifting trolley and supports below the main beam.

[0016] Further, two shifting trolleys are relatively arranged inside each main outrigger and respectively support below each main beam. The auxiliary support device is a super high pressure oil cylinder, and the output end of the super high pressure oil cylinder supports below the main beam.

[0017] Further, the hanging outer rib includes a left hanging outer rib, a right hanging outer rib, a left rotating oil cylinder, and a right rotating oil cylinder. The left hanging outer rib and the right hanging outer rib are relatively rotatably connected to both sides below the cantilever beam. The vertical sections of the left hanging outer rib and the right hanging outer rib are respectively connected to the lower parts of both ends of the cantilever beam through the left rotating oil cylinder and the right rotating oil cylinder. The left rotating oil cylinder and the right rotating oil cylinder are rotatably connected to the left hanging outer rib, the right hanging outer rib, and the cantilever beam. The bottoms of the left hanging outer rib and the right hanging outer rib are connected by an inclined flange.

[0018] Further, the side of the external formwork system is fixedly supported inside the left hanging outer rib and the right hanging outer rib through a strut, and the bottom of the external formwork system is fixedly supported at the bottoms of the left hanging outer rib and the right hanging outer rib through a longitudinal support.

[0019] The present invention also discloses a construction method for a large-tonnage two-span self-propelled mobile formwork for upper deck, including the following steps:

[0020] Step A: Install and debug the formwork support. Control the jacking of the front and main rear legs to raise the movable formwork to the beam erection elevation. Adjust the position and elevation of the external formwork system, set the camber, fix the external formwork system, install the internal formwork system, and adjust the position and elevation again. Start the concrete pouring from the front and rear piers in sequence towards the center of the box, and perform concrete curing.

[0021] Step B: Demolish the internal formwork system, remove the end formwork, tension the prestressed steel bars, and grout. Control the lowering of the whole machine and let it fall on the sliding seats of the front and rear leg moving trolleys. Remove the connection between the left hanging outer rib and the right hanging outer rib. Control the rotating mechanism to drive the left hanging outer rib and the right hanging outer rib to rotate outwards by 30 degrees to avoid the bridge pier.

[0022] Step C: Adjust the rear auxiliary leg to support it on the beam surface. Monitor the pressure condition of the rear auxiliary leg through the pressure sensing component. Control the jacking of the rear auxiliary leg to make the main rear leg become void, and hook it under the main frame. Control the forward movement of the main rear leg by one span to a position about two meters behind the front main leg and support it on the beam surface of the front pier top.

[0023] Step D: Control the jacking of the front auxiliary leg and the main rear leg to lift the front main leg off the ground and hook the front main leg under the main frame (at this time, the whole machine is in a three-leg support state, which is a statically indeterminate structure, and it is required that the height difference between the three legs should not be too large and the middle leg must be stressed. The elevation of each leg must be measured on site to ensure the above requirements). Control the forward movement of the front main leg by one span to reach the front pier top, that is, move behind the front auxiliary leg and support it at the designated position on the front pier top. Lower the front auxiliary leg and the main rear leg to make the main beam fall on the sliding seats of the front and main rear legs, and perform heavy-duty support through the auxiliary support component. The traveling mechanism of the rear auxiliary leg falls on the traveling track. Support and anchor the front main leg on the front pier top, and retract the front auxiliary leg to make it in a void state.

[0024] Step E: Control the longitudinal movement mechanism of the main rear leg to move the whole machine forward to a new beam erection position, and control the front auxiliary leg to reach the front pier top for support.

[0025] Step F: Release the anchorage of the front auxiliary leg. Control the rotating mechanism to drive the left hanging outer rib and the right hanging outer rib to rotate inwards, and make the left hanging outer rib and the right hanging outer rib close and fix. Control the jacking of the front and main rear legs to raise the movable formwork to the beam erection elevation. Adjust the position and elevation of the external formwork system, set the camber, fix the external formwork system, install the internal formwork system, and adjust the position and elevation again. Start the concrete pouring from the front and rear piers in sequence towards the center of the box, and perform concrete curing.

[0026] Step G: Repeat steps B to F to complete the remaining box girder pouring operations until the overall bridge construction is completed.

[0027] The beneficial effects of the present invention are as follows:

[0028] 1. In the present invention, the main frame is composed of a combined structure with three or more layers. Among the three-layer structures, the upper and lower layers are respectively of π-shaped and inverted π-shaped, and the middle layer is of a truss and box-shaped rectangular column structure. This enables the single-layer main beam to meet the height and weight limits during transportation while ensuring the stiffness requirements for the construction of large-tonnage bridges. Moreover, by adopting the method of cooperating with an auxiliary support device and a pressure sensing device, the auxiliary support device supports the weights of equipment such as the entire main frame, hanging outer ribs, formwork system, as well as structural materials such as steel bars and concrete, so that the device can adapt to the construction conditions of large-tonnage bridge erection and greatly improve the economy of construction.

[0029] 2. In the device of the present invention, the main frame adopts a double-main-beam structure. Compared with the single-main-beam structure, the double-main-beam structure is more stable and has stronger anti-typhoon ability.

[0030] 3. In the device of the present invention, there are also two groups of hanging tracks. A hoisting device is arranged inside the hanging tracks, and the hoisting device is used to install and disassemble other components except the main beam structure in the movable formwork, including materials such as steel bars, inner formwork, corrugated pipes, steel wire pipes during construction, or other small mechanical equipment, which greatly facilitates on-site construction.

[0031] 4. The device of the present invention can realize two-way construction. The guiding beam inside the device is turned around and assembled in front of the main beam in the new construction direction, and at the same time, the auxiliary support legs after hoisting are placed at the tail of the main beam at the construction rear, thus realizing two-way construction.

[0032] 5. The present invention adopts the design of rotating and opening the oil cylinders of the left and right hanging outer rib systems. Compared with the previous method of laterally shifting left and right to avoid bridge piers, this method can achieve the goal in one step, without the need for manual auxiliary pin replacement, has high efficiency, and the overall lateral space occupied is small, without interference with the side roads, greatly improving both safety and economy.

[0033] 6. The present invention adopts a through-type structure, which has low requirements for the form and height of bridge piers, and no additional temporary supports are required for the construction of the first and last spans; that is, there are no requirements for the ground under the bridge, reducing land acquisition and being beneficial to environmental protection.

[0034] 7. In the present invention, the connection part of the left and right hanging outer ribs in the middle of the hanging outer rib system is designed as an inclined flange, which is conducive to the rotation and opening of the hanging outer ribs.

[0035] 8. In the present invention, a plurality of strain sensors are arranged inside the middle layer of the main beam to monitor the stress condition of the equipment in real time, effectively improving the safety during the construction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1Schematic diagram of the structure of the device of the present invention;

[0037] Figure 2 Cross-sectional view of the device of the present invention in the mold-closing and pouring state;

[0038] Figure 3 Cross-sectional view of the device of the present invention in the state of rotating and opening the mold through-hole;

[0039] Figure 4 Schematic diagram of the structure of the main frame in the device of the present invention;

[0040] Figure 5 Schematic diagram of the structure of the front auxiliary support leg in the device of the present invention;

[0041] Figure 6 Schematic diagram of the structure of the rear auxiliary support leg in the device of the present invention;

[0042] Figure 7 Schematic diagram of the structure of the front main support leg in the device of the present invention;

[0043] Figure 8 Schematic diagram of the construction process of the moving formwork construction method of the present invention Figure 1 ;

[0044] Figure 9 For the construction process schematic Figure 1 Schematic diagram of the cross-section at the mid-span in the pouring state in the construction process;

[0045] Figure 10 For the construction process schematic Figure 1 Schematic diagram of the cross-section of the rear main support leg in the construction process;

[0046] Figure 11 For the construction process schematic Figure 1 Schematic diagram of the cross-section of the front main support leg in the construction process;

[0047] Figure 12 Schematic diagram of the construction process of the moving formwork construction method of the present invention Figure 2 ;

[0048] Figure 13 For the construction process schematic Figure 2 Schematic diagram of the cross-section in the through-hole state in the construction process;

[0049] Figure 14 For the construction process schematic Figure 2 Schematic diagram of the cross-section of the rear main support leg in the construction process;

[0050] Figure 15 For the construction process schematic Figure 2 Schematic diagram of the cross-section of the front main support leg in the construction process;

[0051] Figure 16 Schematic diagram of the construction process of the moving formwork construction method of the present invention Figure 3 ;

[0052] Figure 17 Schematic diagram of construction process Figure 3 Schematic diagram of the cross-section of the rear auxiliary outrigger;

[0053] Figure 18 Schematic diagram of construction process Figure 3 Schematic diagram of the cross-section of the front main outrigger;

[0054] Figure 19 Schematic diagram of construction process Figure 3 Schematic diagram of the cross-section of the front auxiliary outrigger;

[0055] Figure 20 Schematic diagram of the construction process of the traveling formwork construction method of the present invention Figure 4 ;

[0056] Figure 21 Schematic diagram of construction process Figure 4 Schematic diagram of the cross-section of the rear auxiliary outrigger;

[0057] Figure 22 Schematic diagram of construction process Figure 4 Schematic diagram of the cross-section of the rear main outrigger;

[0058] Figure 23 Schematic diagram of construction process Figure 4 Schematic diagram of the cross-section of the front auxiliary outrigger;

[0059] Figure 24 Schematic diagram of the construction process of the traveling formwork construction method of the present invention Figure 5 ;

[0060] Figure 25 Schematic diagram of construction process Figure 5 Schematic diagram of the cross-section of the rear auxiliary outrigger;

[0061] Figure 26 Schematic diagram of construction process Figure 5 Schematic diagram of the cross-section of the rear main outrigger;

[0062] Figure 27 Schematic diagram of construction process Figure 5 Schematic diagram of the cross-section of the front main outrigger;

[0063] Figure 28 Schematic diagram of the construction process of the traveling formwork construction method of the present invention Figure 6 ;

[0064] Figure 29 Schematic diagram of construction process Figure 6 Schematic diagram of the cross-section at the mid-span in the pouring state;

[0065] Figure 30 Schematic diagram of construction process Figure 6 Schematic diagram of the cross-section of the rear main outrigger;

[0066] Figure 31 Schematic diagram of the construction process Figure 6 Schematic diagram of the front main outrigger section

[0067] Wherein, 1 - main frame, 101 - longitudinal beam, 102 - cantilever beam, 103 - connecting system, 104 - main beam, 105 - guide beam, 2 - front auxiliary outrigger, 3 - rear auxiliary outrigger, 301 - cross beam, 302 - traveling mechanism, 303 - pressure sensor pin shaft, 4 - front main outrigger, 401 - shifting trolley, 402 - ultra-high pressure oil cylinder, 5 - rear main outrigger, 6 - hanging outer rib, 601 - left hanging outer rib, 602 - right hanging outer rib, 603 - left rotating oil cylinder, 604 - right rotating oil cylinder, 605 - inclined flange, 606 - transverse threaded steel bar tie rod, 607 - vertical threaded steel bar suspension rod, 7 - external formwork system, 701 - strut, 8 - internal formwork system, 9 - hanging track, 10 - hanging lifting device.

[0068] The accompanying drawings are only for illustrative purposes and should not be construed as a limitation of this patent; for a better illustration of this embodiment, some components in the accompanying drawings may be omitted, enlarged or reduced, which do not represent the dimensions of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the accompanying drawings may be omitted. Detailed implementation manners

[0069] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0070] Such as Figure 1-7As shown in the figure, this embodiment discloses a new type of mobile formwork applicable to the erection of large-tonnage bridges, including a main frame 1, a front auxiliary leg 2, a rear auxiliary leg 3, a front main leg 4, a rear main leg 5, a hanging outer rib 6, an outer formwork system 7, and an inner formwork system 8. The main frame 1 is composed of two groups of longitudinal beams 101, several groups of cantilever beams 102, and several groups of connecting systems 103. Among them, the longitudinal beam 101 is a double-beam structure composed of a main beam 104 and a guide beam 105. The front auxiliary leg 2 is arranged at the front end of the guide beam 105 in the main frame 1 and supports on the pier top to realize the longitudinal movement of the formwork through the hole. There are two sets of main legs, namely the front main leg 4 and the rear main leg 5, which are located at the front and rear ends of the main beam 104 respectively. The main legs are the main supporting components. Disassembling the lower columns and frame structures can also meet the standing positions of various construction conditions. The rear auxiliary leg 3 is located at the tail of the main frame 1 and is connected to the main frame 1 through bolt flanges. One left hanging outer rib 601 and one right hanging outer rib 602 form a group. The hanging outer rib 6 is composed of multiple groups of left hanging outer ribs 601 and right hanging outer ribs 602, and is arranged horizontally along the lower part of the main beam. Each group of left hanging outer ribs 601 and right hanging outer ribs 602 is respectively arranged under each group of cantilever beams 102 on the main beam 104. On the outer sides of each group of left hanging outer ribs 601 and right hanging outer ribs 602, there are also a left rotating oil cylinder 603 and a right rotating oil cylinder 604 that act on the opening and closing of the hanging outer rib 6. The left rotating oil cylinder 603 and the right rotating oil cylinder 604 are respectively arranged at both ends of the cantilever beam 102, and the output ends of the left rotating oil cylinder 603 and the right rotating oil cylinder 604 are connected to the vertical sections of the left hanging outer rib 601 and the right hanging outer rib 602. The outer formwork system 7 is supported on the inner side of the hanging outer rib 6 through a support rod 701. An inner formwork system 8 that cooperates with the outer formwork system 7 is also arranged inside the outer formwork system 7 to realize the pouring and forming of concrete.

[0071] As Figure 1-4 shown, the main frame 1 is composed of two groups of longitudinal beams 101, several groups of cantilever beams 102, and several groups of connecting systems 103. Among them, the longitudinal beam 101 is a double-beam structure composed of a main beam 104 and a guide beam 105. The guide beam 105 is in the form of a combination of a rectangular truss structure and a box structure. The main frame 1 acts with heavy load on the main legs. The main frame 1 mainly supports the weights of equipment such as the hanging outer rib 6, the outer formwork system 7, and the inner formwork system 8, as well as the weights of structural materials such as steel bars and concrete. The main beam 104 is a combined structure of three layers or more. In this embodiment, the main beam 104 is a three-layer combined structure. Among them, the upper layer of the main beam 104 is a π-shaped structure, the middle layer of the main beam 104 is a truss and box-shaped rectangular column structure, and the lower layer of the main beam 104 is an inverted π-shaped structure. Being divided into three layers can effectively enable the single-layer main beam to meet the height and weight limits during transportation while ensuring the stiffness requirements for the construction of large-tonnage bridges of the overall main beam, so as to meet the stiffness requirements for the construction of large-tonnage bridges. When applying this three-layer main beam 104 to the construction of large-tonnage bridges, taking the main beam of 50.7 m as an example:

[0072] The maximum mid-span deflection of the main beam after casting is ;

[0073] The maximum mid-span deflection of the main beam before casting is ;

[0074] The maximum deflection of the main beam is ;

[0075] According to the process standard , it can be known that it meets the process requirements.

[0076] Where L is the length of the main beam.

[0077] As Figure 2 shown, there are two sets of transverse hanging rails 9 provided on the connecting system 103 of the main frame 1. Each set of hanging rails 9 is slidably provided with a hanging hoisting device 10. The hanging hoisting device 10 is a 5t electric hoist, which can walk in the hanging rails 9 to facilitate construction and reduce the labor intensity of on-site operators. This hanging system is mainly used to install and disassemble components of the moving formwork other than the main beam structure, including materials such as steel bars, internal formwork, corrugated pipes, and steel strands (each bundle weighing within 5.0t) during construction or other small-scale mechanical equipment.

[0078] As Figure 1-7 shown, there are two main legs in total, which are respectively located at the front end and the rear end of the main beam 104 on the main frame 1. The main legs are the main supporting components. At the same time, by disassembling the lower columns and frame structures of the main legs, it can also meet the standing positions of construction conditions at different construction heights. The two main legs are the front main leg 4 and the rear main leg 5 respectively. Except for the different positions they are in, the rest of the structures are the same.

[0079] As Figure 1-7 shown, taking the front main leg 4 as an example, the front main leg 4 is composed of a shifting trolley 401, a longitudinal movement mechanism, an upper cross beam, a column steel structure, a column connection frame, a transverse movement support rod assembly, a beam surface support seat, and pier top anchorage, etc. The upper cross beam is supported on the pier through the column steel structure. The shifting trolley 401 is arranged above the upper cross beam. The longitudinal movement mechanism is arranged inside the shifting trolley 401, and the shifting trolley 401 is arranged below the main beam 104 through the longitudinal movement mechanism. The auxiliary support device is arranged inside the shifting trolley 401 and supports below the main beam 104. Among them, the upper cross beam is of box structure, and there are ear beam holes and ear seats designed on both sides for installing anchoring threaded steel bars and anchoring support rods. The columns and the frame are connected to the upper cross beam through detachable high-strength bolts. The shifting trolley 401 serves as the main support of the main beam, and there is also a super-high pressure oil cylinder 402 arranged on it, which can effectively support the main beam to meet the construction of large-tonnage bridges.

[0080] As Figure 7As shown in the figure, there are two shifting trolleys 401, which are respectively arranged on both sides of the upper cross beam of the front main leg 4, and are respectively supported under the two main girders 104. Correspondingly, there are also two ultra-high pressure cylinders 402, which are respectively arranged in the two front main legs 4. The output end of the ultra-high pressure cylinder 402 is supported under the main girder 104. In this embodiment, the ultra-high pressure cylinder 402 is an auxiliary support device.

[0081] As Figure 5 shown in the figure, the front auxiliary leg 2 is composed of a hinge seat, an upper support, a column, a connecting frame, a jacking cylinder, a support and an anchor. The upper support of the front auxiliary leg 2 is arranged at the front end of the guide beam 105 through the hinge seat, and is supported on the pier top through the support and the anchor. The main function of the front auxiliary leg 2 is to enable the longitudinal movement of the formwork through the hole. When there is a cast-in-place concrete beam at the end span and in front of the construction site, after removing the column and the connecting frame, it is supported on the cast-in-place concrete beam to realize the longitudinal movement through the hole of the end span, and it can meet the standing positions of various construction conditions.

[0082] As Figure 6 shown in the figure, the rear auxiliary leg 3 is composed of a support column, upper and lower spherical hinges, a cross beam 301, a traveling mechanism 302, a longitudinal movement track and two 200t hydraulic manual jacks. The support column of the rear auxiliary leg 3 is arranged at the tail of the main frame 1 and is connected to the main frame 1 through bolt flanges. The traveling mechanism 302 is arranged at the bottom of the rear auxiliary leg 3. The traveling mechanism 302 is a wheel-rail type driven traveling mechanism. There are two traveling mechanisms 302 in total, and there are several traveling wheels in the traveling mechanism 302. The rear auxiliary leg 3 is arranged above the pier top through the traveling mechanism 302. The two 200t hydraulic manual jacks are respectively arranged on the outer sides of the two traveling mechanisms 302. In this embodiment, the rear auxiliary leg 3 is designed with two states:

[0083] When the whole machine passes through the hole, the rear auxiliary leg 3 travels on the cast-in-place concrete beam;

[0084] When the rear main leg 5 passes through the hole, the rear auxiliary leg 3 is converted to a jack and supported on the beam surface.

[0085] As Figure 6 shown in the figure, a pressure sensor pin 303 is designed in the traveling mechanism 302 of the rear auxiliary leg 3, which can real-time detect the force condition of the rear auxiliary leg, improving the overall safety and reliability of the equipment. In this embodiment, the pressure sensor pin 303 is a pressure sensing device.

[0086] As Figure 1-3As shown in the figure, the hanging outer rib 6 is composed of a plurality of left hanging outer ribs 601 and a plurality of right hanging outer ribs 602. A single left hanging outer rib 601 and a single right hanging outer rib 602 cooperate with each other as a group. Each group of left hanging outer ribs 601 and right hanging outer ribs 602 are respectively arranged below each group of cantilever beams 102 on the main beam 104. On the outer sides of each group of left hanging outer ribs 601 and right hanging outer ribs 602, there are also a left rotary oil cylinder 603 and a right rotary oil cylinder 604 that act on the opening and closing of the hanging outer rib 6. The left rotary oil cylinder 603 and the right rotary oil cylinder 604 are respectively arranged at both ends of the cantilever beam 102, and the output ends of the left rotary oil cylinder 603 and the right rotary oil cylinder 604 are connected to the vertical sections of the left hanging outer rib 601 and the right hanging outer rib 602. When the oil cylinders of the left rotary oil cylinder 603 and the right rotary oil cylinder 604 expand and contract, the opening and closing of the left hanging outer rib 601 and the right hanging outer rib 602 can be realized.

[0087] As Figure 1-3 shown, the middle connection part of the left hanging outer rib 601 and the right hanging outer rib 602 is designed as an inclined flange connection. After the left hanging outer rib 601 and the right hanging outer rib 602 are closed, the upper part of the left hanging outer rib 601 and the right hanging outer rib 602 is locked by the connecting pin shaft with the cantilever beam 102, and the bottom connection part of the left hanging outer rib 601 and the right hanging outer rib 602 is locked by the inclined flange 605, which can avoid the lateral sliding of the left hanging outer rib 601 and the right hanging outer rib 602. At the same time, the setting of the inclined flange 605 is beneficial to the rotary opening of the left hanging outer rib 601 and the right hanging outer rib 602.

[0088] As Figure 1-2 shown, the outer mold system 7 is supported on the inner side of the hanging outer rib 6 through a strut 701. There is a longitudinal support between the bottom of the outer mold system 7 and the hanging outer rib 6, which is used to increase the longitudinal stability of the hanging system. An inner mold system 8 that cooperates with the outer mold system 7 is arranged inside the outer mold system 7. Inside the hanging outer rib 6, there are also a transverse threaded steel bar tie rod 606 and a vertical threaded steel bar hanger 607 that cooperate with the outer mold system 7 and the inner mold system 8. Among them, there are two vertical threaded steel bar hangers 607 in total, and they respectively pass through the outer mold system 7 from the bottom of the hanging outer rib 6 and are arranged below the two main beams 104. The transverse threaded steel bar tie rod 606 passes through the left hanging outer rib 601, the outer mold system 7, and the right hanging outer rib 602 horizontally.

[0089] As Figure 1-31 shown, when the present invention is in use, it includes the following steps:

[0090] Step A: Install and debug the formwork support. Control the jacking of the front main leg 4 and the rear main leg 5 to raise the movable formwork to the beam erection elevation. Adjust the position and elevation of the external formwork system 7, set the camber, fix the external formwork system 7, install the internal formwork system 8, and adjust the position and elevation again. Start pouring concrete from the front and rear piers sequentially towards the center, and perform concrete curing.

[0091] Step B: Demolish the internal formwork system 8, remove the end formwork, tension the prestressed steel bars, and grout. Control the lowering of the whole machine and let it rest on the slide seats of the moving trolleys of the front main leg 4 and the rear main leg 5. Remove the connection of the inclined flange 605 between the left hanging outer rib 601 and the right hanging outer rib 602. Control the left rotation oil cylinder 603 and the right rotation oil cylinder 604 of the rotating mechanism to drive the left hanging outer rib 601 and the right hanging outer rib 602 to rotate outwards by 30 degrees to avoid the bridge pier.

[0092] Step C: Adjust the rear auxiliary leg 3 to make it support on the beam surface. Monitor the pressure condition of the rear auxiliary leg through the pressure sensor pin 303. Control the jacking of the rear auxiliary leg 3 to make the rear main leg 5 lose contact with the ground and hook it under the main frame 1. Control the rear main leg 5 to move forward one span to a position about two meters behind the front main leg 4 and support on the beam surface of the front pier top.

[0093] Step D: Control the jacking of the front auxiliary leg 2 and the rear main leg 5 to lift the front main leg 4 off the ground and hook the front main leg 4 under the main frame 1 (at this time, the whole machine is in a three-leg support state, which is a statically indeterminate structure, and it is required that the height difference between the three legs shall not be greater than 30 mm and the middle leg must be stressed. The elevation of each leg must be measured on site to ensure the above requirements). Control the front main leg 4 to move forward one span to reach the front pier top, that is, to a position 0.75 m behind the front auxiliary leg 2, and support at the designated position on the front pier top. The front auxiliary leg 2 and the rear main leg 5 descend to make the main beam 104 rest on the slide seats of the moving trolleys of the front main leg 4 and the rear main leg 5, and perform heavy-duty support through the ultra-high pressure oil cylinder 402 in the moving trolley 401. The traveling mechanism 302 of the rear auxiliary leg 3 is placed on the traveling track, support and anchor the front main leg 4 on the front pier top, and retract the front auxiliary leg 2 to make it in a state of being off the ground.

[0094] Step E: Control the longitudinal movement mechanism of the rear main leg 5 to move the whole machine forward to a new beam erection position, and control the front auxiliary leg 2 to reach the front pier top for support.

[0095] Step F: Release the anchorage of the front auxiliary outriggers 2, control the left rotation cylinder 603 and the right rotation cylinder 604 of the rotating mechanism to drive the left suspension outer rib 601 and the right suspension outer rib 602 to rotate inward, and make the left suspension outer rib 601 and the right suspension outer rib 602 close and fix. Control the front main outriggers 4 and the rear main outriggers 5 to lift, so that the mobile formwork is lifted to the beam-making elevation, adjust the position and elevation of the external formwork system 7, and set the camber. Fix the external formwork system 7, install the internal formwork system 8, and adjust the position and elevation again. Start pouring concrete from the front and rear piers in sequence towards the center, and perform concrete curing;

[0096] Step G: Repeat Step B to Step F to complete the remaining box girder pouring operations until the overall bridge construction is completed.

[0097] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the protection scope of the present invention.

[0098] If terms such as "first" and "second" are used in this article to limit components, those skilled in the art should be aware that the use of "first" and "second" is only for the convenience of describing the present invention and simplifying the description. Without additional declaration, the above terms have no special meaning.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. Construction method of a large-tonnage two-span self-propelled overhead mobile formwork, characterized in that The large-tonnage two-span self-propelled overhead mobile formwork includes a main frame, front auxiliary legs, rear auxiliary legs, main legs, hanging outer ribs, outer formwork system and inner formwork system. The main frame is composed of two groups of longitudinal beams, several groups of cantilever beams and several groups of connecting systems. Each group of longitudinal beams is composed of a main beam and a guide beam. The main beam is a combined structure with three or more layers. Strain sensors are provided inside the main beam. A pressure sensing component is provided inside the rear auxiliary leg to monitor the pressure condition of the rear auxiliary leg in real time. An auxiliary support component is provided below the main beam inside the main leg to provide heavy-load support for the main beam. The construction method includes the following steps: Step A: Install and debug the formwork, control the jacking of the front and main legs so that the mobile formwork reaches the beam-making elevation position, adjust the position and elevation of the outer formwork system, set the camber, fix the outer formwork system, install the inner formwork system, and adjust the position and elevation again. Start pouring concrete from the front and rear piers in sequence to the center of the box, and perform concrete curing. Step B: Remove the inner formwork system, remove the end formwork, tension the prestressed steel bars, and grout. Control the whole machine to drop and land on the sliding seats of the front and rear leg moving trolleys. Remove the connection between the left and right hanging outer ribs. Control the rotating mechanism to drive the left and right hanging outer ribs to rotate outward by 30 degrees to avoid the bridge pier. Step C: Adjust the rear auxiliary leg so that the rear auxiliary leg supports on the beam surface, and monitor the pressure condition of the rear auxiliary leg through the pressure sensing component. Control the rear auxiliary leg to jack up so that the main rear leg is off the ground and hook it under the main frame. Control the main rear leg to move forward one span and reach two meters behind the front main leg, and support on the beam surface of the front pier top. Step D: Control the jacking of the front auxiliary leg and the main rear leg, and then lift the front main leg off the ground and hook the front main leg under the main frame. At this time, the whole machine is in a three-leg support state, which is a statically indeterminate structure, and it is required that the height difference between the three legs should not be too large and the middle leg must be stressed. The elevation of each leg must be measured on site to ensure the above requirements. Control the front main leg to move forward one span and reach the front pier top, that is, move behind the front auxiliary leg, and support at the designated position on the front pier top. The front auxiliary leg and the main rear leg drop, so that the main beam lands on the sliding seats of the front and main rear legs, and heavy-load support is provided through the auxiliary support component. The traveling mechanism of the rear auxiliary leg lands on the traveling track, support and anchor the front main leg on the front pier top, and retract the front auxiliary leg to make it in a state of being off the ground. Step E: Control the longitudinal movement mechanism of the main rear leg so that the whole machine moves forward to a new beam-making position, and control the front auxiliary leg to reach the front pier top for support. Step F: Release the anchorage of the front auxiliary outriggers, control the rotation mechanism to drive the left and right hanging outer ribs to rotate inward, and make the left and right hanging outer ribs close and fix together. Control the front and main outriggers to lift, so that the movable formwork is raised to the beam-making elevation, adjust the position and elevation of the external formwork system, set the camber, fix the external formwork system, install the internal formwork system, and adjust the position and elevation again. Start pouring concrete from the front and rear piers in sequence to the center of the box, and perform concrete curing; Step G: Repeat Steps B to F to complete the remaining box girder pouring operations until the overall bridge construction is completed.

2. The construction method of a large-tonnage two-span self-propelled movable formwork for the upper chord according to claim 1, characterized in that, The main beam is a three-layer composite structure, specifically divided into an upper layer, a middle layer, and a lower layer; The upper layer is a π-shaped structure, the middle layer of the main beam is a truss and box-shaped rectangular column structure, and the lower layer of the main beam is an inverted π-shaped structure.

3. The construction method of a large-tonnage two-span self-propelled movable formwork for overpass according to claim 1, characterized in that The guide beam is a combination of a rectangular truss mechanism and a box-shaped structure.

4. The construction method of a large-tonnage two-span self-propelled movable formwork for upper bearing according to claim 1, characterized in that, The rear auxiliary outrigger includes a support column, a cross beam, and a traveling mechanism; The support column is arranged at the tail of the main frame and is connected to the main frame by bolt flanges. The traveling mechanism is arranged at the bottom of the support column through the cross beam, and the pressure sensing component is arranged inside the traveling mechanism.

5. The construction method of a large-tonnage two-span self-propelled movable formwork for upper bearing according to claim 4, characterized in that, The pressure sensing component is a pressure sensor pin shaft.

6. The construction method of a large-tonnage two-span self-propelled movable formwork for upper bearing according to claim 1, characterized in that, There are two sets of main outriggers in total, which are respectively arranged at the front end and the rear end of the main beam. Each set of main outriggers includes a shifting trolley, a longitudinal movement mechanism, an upper cross beam, a column steel structure, a column connection frame, a transverse movement strut assembly, a beam surface support seat, and pier top anchorage; The upper cross beam is connected to the beam surface support seat through the column steel structure and is supported on the pier. The pier top anchorage is connected to The longitudinal movement mechanism is arranged inside the shifting trolley, and the shifting trolley is arranged under the main beam through the longitudinal movement mechanism. The auxiliary support component is arranged inside the shifting trolley and supports under the main beam.

7. The construction method of a large-tonnage two-span self-propelled movable formwork for upper bearing according to claim 6, characterized in that, Two shifting trolleys are relatively arranged inside each main outrigger and respectively support under each main beam. The auxiliary support component is a super high-pressure oil cylinder, and the output end of the super high-pressure oil cylinder supports under the main beam.

8. The construction method of a large-tonnage two-span self-propelled movable formwork for overhead bridges according to claim 1, characterized in that, The hanging outer ribs include a left hanging outer rib, a right hanging outer rib, a left rotating oil cylinder, and a right rotating oil cylinder. The left and right hanging outer ribs are relatively rotatably connected to both sides under the cantilever beam. The vertical sections of the left and right hanging outer ribs are respectively connected to the lower parts of both ends of the cantilever beam through the left and right rotating oil cylinders. The left and right rotating oil cylinders are rotatably connected to the left and right hanging outer ribs and the cantilever beam. The bottoms of the left and right hanging outer ribs are connected by an inclined flange.

9. The construction method of a large-tonnage two-span self-propelled movable formwork for the upper chord according to claim 1, characterized in that, The side of the external formwork system is fixedly supported inside the left and right hanging outer ribs through a strut, and the bottom of the external formwork system is fixed to the bottoms of the left and right hanging outer ribs through a longitudinal support.

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