A method for erecting a long-span steel beam

Abstract

The application relates to a large-span steel beam erecting construction method, which comprises the following steps: fixing front support legs, middle support legs and a bridge floor, moving a sky crane to a first position to make counterweight, driving a main truss to move forward to complete the first hole passing; moving the sky crane to a second position to make counterweight in the direction of the tail support legs, releasing the fixation of the middle support legs, driving the middle support legs to move a first preset distance towards the front support legs and fixing the middle support legs with the bridge floor, driving the main truss to move forward to complete the second hole passing; and the like, until the front temporary support legs on the main truss reach the position of the cap beam; releasing the fixation of the middle support legs and driving the middle support legs to move close to the front support legs; releasing the fixation of the front support legs and driving the front support legs to move towards the front temporary support legs and bear on the cap beam; and erecting the steel beam by using the sky crane. The utilization rate of the main truss is improved when the steel beam is erected by twice hole passing, the erecting span is larger, and the construction efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of bridge construction, and in particular to a method for erecting large-span steel beams. Background Technology

[0002] With the rapid development of my country's steel industry and steel structure technology, the number of steel structure bridges is also increasing. The characteristics of steel box girder structure, such as large span, long service life, large torsional stiffness of box section, small section height and good integrity, have made steel box girder structure widely used in the design and construction of municipal and highway bridges, and it has now become the first choice for large span main beam form.

[0003] Due to the development of bridge technology, the span of steel box girders is also constantly increasing and showing a significant growth trend. At the same time, the complexity of the construction environment, the diversity of functional requirements, and the large span of highway steel box girders have brought many technical challenges to the fabrication and installation of steel box girders.

[0004] When erecting existing large-span steel beams, as the current outrigger moves to the next pier, the main truss needs to continue moving forward a certain distance because it needs to use the front end of the main truss as a counterweight to keep both ends of the main truss horizontal. The part of the main truss used as a counterweight cannot participate in the steel beam erection. This erection method will affect the efficiency of construction. Summary of the Invention

[0005] This application provides a method for erecting large-span steel beams to solve the problem in related technologies where the main truss, used as a counterweight, cannot participate in the erection of the steel beams, which affects construction efficiency.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for constructing a large-span steel beam, comprising the following steps: fixing the front support leg and the middle support leg to the bridge deck; moving the overhead crane to a first position as a counterweight to drive the main truss forward and complete the first passage through the span; moving the overhead crane towards the direction of the rear support leg to a second position as a counterweight; releasing the middle support leg from its fixation and driving it to move a first preset distance toward the front support leg and fix it to the bridge deck; driving the main truss forward and completing the second passage through the span; and so on, until the front temporary support leg on the main truss reaches the cap beam position; releasing the middle support leg from its fixation and driving it to move closer to the front support leg; releasing the front support leg from its fixation and driving it to move toward the front temporary support leg and support it on the cap beam; and using the overhead crane to erect the steel beam.

[0007] In some embodiments, before fixing the front outriggers and middle outriggers to the bridge deck, the method further includes the following steps: moving the crane to a second position to apply counterweight; activating the hydraulic systems of the front and rear outriggers to adjust the height of the main truss.

[0008] In some embodiments, before driving the middle outrigger to move a first preset distance toward the front outrigger, the method further includes the step of: reactivating the hydraulic systems of the front and rear outriggers to adjust the height of the main truss.

[0009] In some embodiments, after the front temporary outrigger on the main truss reaches the cap beam position and before releasing the middle outrigger from its fixation, the method further includes the following steps: fixing the tail outrigger to the bridge deck and activating the tail outrigger hydraulic system to adjust the height of the main truss.

[0010] In some embodiments, after the front outrigger is released from its fixed position and driven to move forward to a temporary outrigger and is supported on the cap beam, before the steel beam is erected using a crane, the method further includes the following steps: adjusting the height and level of the main truss; fixing the middle outrigger and the tail outrigger to the bridge deck.

[0011] In some embodiments, a crane is used to erect the steel beam. The specific steps include: using the crane to lift the steel beam and move it above the cap beam; and using the crane to lower the steel beam so that it rests on the cap beam.

[0012] In some embodiments, after the overhead crane lifts the steel beam and before moving the steel beam above the cap beam, the method further includes the steps of: adjusting the height of the steel beam by the overhead crane and keeping the steel beam horizontal.

[0013] In some embodiments, after the steel beam is moved above the cap beam and before the overhead crane lowers the steel beam, the method further includes the following steps: fixing the front and middle outriggers to the bridge deck; and detaching the rear outrigger from the bridge deck.

[0014] In some embodiments, the overhead crane lowers the steel beam, and the specific steps include: lowering the steel beam to a preset distance and stopping the steel beam from falling; adjusting the position of the steel beam; and lowering the steel beam again.

[0015] In some embodiments, after the steel beams are erected using a crane, the method further includes the step of grouting between the steel beams and the cap beam.

[0016] The beneficial effects of the technical solution provided in this application include:

[0017] This application provides a method for constructing a large-span steel beam. By passing through the hole twice, the main truss is kept balanced before the steel beam is erected using a crane. After the current leg moves forward to the temporary leg and is supported on the cap beam, the main truss does not need to continue to move forward for counterweight. Therefore, the utilization rate of the main truss is improved when erecting the steel beam, the erection span is larger, and the construction efficiency is improved. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic flowchart illustrating the construction method for erecting large-span steel beams provided in this application embodiment;

[0020] Figure 2 A schematic diagram of the overall structure (first state) provided for an embodiment of this application;

[0021] Figure 3 A schematic diagram of the overall structure (second state) provided for an embodiment of this application;

[0022] Figure 4 A schematic diagram of the overall structure (third state) provided for an embodiment of this application;

[0023] Figure 5 A schematic diagram of the overall structure (fourth state) provided for an embodiment of this application;

[0024] Figure 6 A schematic diagram of the overall structure (fifth state) provided for an embodiment of this application;

[0025] Figure 7 A schematic diagram of the overall structure (sixth state) provided for an embodiment of this application.

[0026] In the diagram: 1. Main truss; 2. Front support leg; 3. Middle support leg; 4. Tail support leg; 5. Crane; 6. Front temporary support leg; 7. Cap beam. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] See Figures 1 to 7 This application provides a method for erecting large-span steel beams, which solves the problem in related technologies where the main truss used as counterweight cannot participate in the erection of steel beams, thus affecting construction efficiency.

[0029] In the existing technology, the length of the main truss 1 is more than twice the span. The excessive pressure on the main truss 1 during the bridge erection process of large-span steel beams usually limits the construction span. In this application, the main truss 1 is 1.6-1.8 times the span. For example, for a 60-meter span steel beam, if the length of the main truss 1 is 1.8 times the span, then the maximum length of the main truss 1 is 108 meters. In the prior art, the length of the main truss 1 is at least 120 meters, which increases the length of the main truss 1 by at least 12 meters. Its weight will have a significant impact on the erection of large-span steel beams. It will increase the pressure on the front leg 2, middle leg 3, and tail leg 4 of the bridge erecting machine, as well as the pressure on the bridge deck. Therefore, in the existing large-span steel beam erection, when the front leg 2 moves to the next pier position, the main truss 1 needs to continue to move forward a certain distance because the front end of the main truss 1 needs to be used for counterweight to keep both ends of the main truss 1 horizontal. The part of the main truss 1 used as counterweight cannot participate in the steel beam erection. This erection method will affect the construction efficiency.

[0030] This application provides a method for erecting large-span steel beams, aiming to solve the problem in the prior art where the main truss 1, used as a counterweight, cannot participate in the erection of the steel beams, which affects the efficiency of construction.

[0031] Before steel beam erection, the bridge erecting machine needs to be assembled. In this application, the length of the main truss 1 is 108 meters as an example. The bridge erecting machine is assembled on the leveled roadbed. First, the front support leg 2 and the middle support leg 3 of the bridge erecting machine are assembled. Then, the first 60m of the main truss 1 is assembled on the ground. The main truss 1 is composed of multiple 12m long unit truss segments. Then, the 60m main truss 1 is hoisted onto the front support leg 2 and the middle support leg 3. After that, the remaining 48m of the main truss 1 is assembled on the ground. Then, the last 48m segment of the main truss 1 is hoisted and connected to the first 60m segment of the main truss 1. After the main truss 1 is assembled as a whole, the front temporary support leg 6 and the tail support leg 4 are assembled. The overhead crane 5 is assembled on the ground and hoisted onto the main truss 1 using hoisting equipment. Finally, the electrical system, hydraulic system and other auxiliary structures are installed. The bridge erecting machine is debugged. After the debugging is completed, a static load test is carried out. Only after the test is passed can it be put into construction.

[0032] After the bridge erecting machine is assembled, the steel beams are erected.

[0033] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0034] Please refer to Figure 1 , Figure 1 This is a schematic flowchart illustrating a method for constructing a large-span steel beam, as provided in an embodiment of this application.

[0035] like Figure 1As shown, the method includes steps S1 to S6.

[0036] S1: Fix the front support leg 2 and the middle support leg 3 to the bridge deck, move the overhead crane 5 to the first position as a counterweight, drive the main truss 1 forward, and complete the first passage through the hole.

[0037] Before fixing the front outrigger 2 and the middle outrigger 3 to the bridge deck, the overhead crane 5 needs to be moved to the second position for counterweighting. The second position here refers to the position on the main truss 1 near the tail outrigger 4. Then, the hydraulic system of the front outrigger 2 and the tail outrigger 4 is activated to adjust the height of the main truss 1. Next, the front outrigger 2 and the middle outrigger 3 are fixed to the bridge deck, and the rocking and rolling mechanism of the front outrigger 2 and the middle outrigger 3 is released from the main truss 1. The overhead crane 5 is then moved to the first position for counterweighting, where the first position is the front middle part of the main truss 1.

[0038] When the main truss 1 is in an uphill position when passing through the hole, the tail leg 4 needs to be retracted to prevent the tail leg 4 from colliding with the bridge deck during the passage through the hole.

[0039] Regardless of whether the main truss 1 is in an uphill or downhill position, the main truss 1 must remain horizontal when moving forward.

[0040] S2: Move the overhead crane 5 to the second position in the direction of the tail support leg 4 to act as a counterweight, release the fixation of the middle support leg 3, and drive the middle support leg 3 to move the front support leg 2 a first preset distance and fix it to the bridge deck, drive the main truss 1 forward, and complete the second passage through the hole.

[0041] Specifically, the overhead crane 5 is moved towards the rear outrigger 4 and counterweight is applied. Then, the hydraulic systems of the front outrigger 2 and the rear outrigger 4 are restarted to adjust the height of the main truss 1, causing the middle outrigger 3 to detach from the bridge deck. During uphill construction, it is ensured that the middle outrigger 3 will not collide with the bridge deck during its forward movement. The main truss 1 forms an uphill slope of 0-3.5%, meaning that the position of the main truss 1 near the front temporary outrigger 6 is higher than the position of the main truss 1 near the rear outrigger 4. The middle outrigger 3 is then started to roll horizontally, driving it towards the front outrigger. 2. Move the middle support leg 3 a first preset distance, which is 21m-25m. Then stop the horizontal rolling of the middle support leg 3 to fix the middle support leg 3 to the bridge deck. Then retract the tail support leg 4 and the front support leg 2 to support the main truss 1 with the middle support leg 3. After the middle support leg 3 supports the main truss 1, move the overhead crane 5 to the vicinity of the middle support leg 3. Continue to retract the tail support leg 4 to remove the tail support leg 4 from the bridge deck. Finally, start the horizontal rolling of the middle support leg 3 and the front support leg 2 to drive the main truss 1 forward and complete the second crossing.

[0042] S3: Continue in this manner until the front temporary support leg 6 on the main truss 1 reaches the position of the cap beam 7.

[0043] When the front temporary outrigger 6 reaches the position of the cap beam 7, it does not contact the cap beam 7. Then, the tail outrigger 4 is fixed to the bridge deck, and the hydraulic system of the tail outrigger 4 is activated to adjust the height of the main truss 1, so that the middle outrigger 3 is separated from the bridge deck. During the process of adjusting the height of the main truss 1, the front temporary outrigger 6 is also adjusted so that it does not contact the cap beam 7 to bear the force.

[0044] S4: Release the fixation of the middle support leg 3 and drive the middle support leg 3 to move closer to the front support leg 2.

[0045] After releasing the fixing of the middle support leg 3, start the middle support leg 3 to roll horizontally. After the middle support leg 3 moves forward to a position 1m-5m away from the end of the erected beam, it supports the main truss 1. When constructing on a downhill slope, sleepers can be used to support the middle support leg 3.

[0046] S5: Release the fixation of the front outrigger 2 and drive the front outrigger 2 to move towards the front temporary outrigger 6 and bear the load on the cap beam 7.

[0047] Specifically, release the fixation of the front outrigger 2 to the bridge deck, and then retract the front outrigger 2. At this time, the front temporary outrigger 6 cannot touch the ground before the middle outrigger has completed bearing the load. When it is found that the front temporary outrigger 6 is about to touch the ground, the tail outrigger 4 can be retracted slightly. At this time, the tail outrigger 4 always remains under load, while the front outrigger 2 is no longer under load and the front temporary outrigger 6 is in a suspended state. During this process, the height of the tail outrigger 4 and the middle outrigger 3 are adjusted so that the total height of the front temporary outrigger 6 is higher than the height of the front outrigger 2. This ensures that the front outrigger 2 can smoothly enter the position of the cap beam 7. Finally, start the front outrigger 2 to roll horizontally, driving the front outrigger 2 towards the front temporary outrigger 6. When the front outrigger 2 reaches the position of the cap beam 7, fix part of the cross rail of the front outrigger 2 to the cap beam 7, so that the front outrigger 2 supports the main truss 1, while ensuring that the front temporary outrigger 6 is in a suspended state.

[0048] Finally, start the hydraulic system of the front outrigger 2 and the rear outrigger 4, adjust the height and level of the main truss 1. If there are sleepers under the cross rail of the middle outrigger 3, the sleepers must be removed to ensure that the cross rail of the middle outrigger 3 is firmly installed on the bridge deck. Then, insert the safety pins of the front outrigger 2 and the rear outrigger 4 on the bridge deck, and use the cross rail lifting tool to lift the remaining cross rails of the front outrigger 2 onto the cap beam 7 and fix them flat.

[0049] S6: Use crane 5 to erect steel beams.

[0050] The steel beam is erected using the overhead crane 5. The specific steps include: lifting the steel beam with the overhead crane 5 and moving the steel beam above the cap beam 7; lowering the steel beam with the overhead crane 5 so that the steel beam rests on the cap beam 7.

[0051] Specifically, before the steel beams are erected, two beam transport vehicles transport the steel beams to the bridge site. There are two overhead cranes 5. The front overhead crane's lifting device is connected to the front lifting lug of the steel beam, lifting the front end of the beam so that the steel beam is separated from the front of the beam transport vehicle. Then, the front overhead crane and the rear of the beam transport vehicle continue to move the steel beam forward until the rear overhead crane can connect to the rear lifting lug of the steel beam. At this time, the front overhead crane and the rear of the beam transport vehicle stop moving forward, and the rear overhead crane's lifting device is connected to the rear lifting lug of the steel beam. The rear overhead crane lifts the steel beam until it is separated from the rear of the beam transport vehicle. The two overhead cranes 5 adjust the height of the steel beam and keep it horizontal to ensure that the steel beam does not contact or collide with the beam transport vehicle and the main truss 1 when it moves forward. Then, the front and rear overhead cranes lift the steel beam and move it forward at a uniform speed and synchronously until it is above the beam to be covered 7.

[0052] After the steel beam is moved above the cap beam 7, before the overhead crane 5 lowers the steel beam, the tail support leg 4 is retracted, and the front support leg 2 and the middle support leg 3 are supported and stressed, so that the rear end of the main truss 1 is cantilevered. The position of the steel beam is adjusted by the lateral movement system of the middle support leg 3 and the front support leg 2, and the steel beam is moved to the position directly above the installation position so that the connection position of the steel beam support is aligned with the temporary support position of the cap beam 7.

[0053] After alignment, the overhead crane 5 lowers the steel beam. During the descent, the position of the steel beam needs to be adjusted in real time. When the bottom of the steel beam is 5cm-10cm away from the temporary support, stop the descent and adjust the position of the steel beam again so that the orthographic projection of the cross center line of the steel beam support completely coincides with the cross center line of the temporary support of the cap beam 7. Then, the overhead crane 5 continues to lower the steel beam onto the temporary support.

[0054] The temporary supports use 100t specially made jacks with a diameter of less than 15cm and a height of about 20cm. After the steel beam is lowered to the temporary supports, the bridge erecting machine slowly unloads the load, but does not disconnect the bridge erecting machine from the steel beam. Simultaneously, the jacks at the four corners of the bottom of the steel beam are started to ensure that the steel beam is evenly stressed and to adjust the elevation of the steel beam to the design elevation. The permanent supports are then grouted in a timely manner.

[0055] As the steel beam is slowly lowered onto the temporary support, the jacks are activated. At this time, it may be necessary to adjust the height of the steel beam. The suspension points between the bridge erecting machine and the steel beam are not disconnected to ensure that if any corner of the jack malfunctions when adjusting the height of the steel beam, the steel beam can be prevented from overturning or other dangers.

[0056] In this application, by passing through the hole twice, the main truss 1 is kept in balance before the steel beam is erected using the overhead crane 5. After the current leg 2 moves forward to the temporary leg 6 and is supported on the cap beam 7, the main truss 1 does not need to continue to move forward a distance for counterweight. Therefore, the utilization rate of the main truss 1 is improved when erecting the steel beam, the erection span is larger, and thus the construction efficiency is improved.

[0057] After one steel beam is erected, follow the above construction steps to complete the erection of the remaining steel beams in the same span. Then, use a bridge erecting machine or truck crane to install the crossbeams between the steel beams in the same span. Before installing the crossbeams, a safe operating platform needs to be erected on the lower flange of the steel beam using the bridge erecting machine. The contact area between the operating platform and the steel beam needs to be wrapped with anti-slip materials such as rubber to prevent damage to the surface coating of the steel beam. Only after the crossbeams between the two sets of steel beams in the same span are installed can the steel-concrete composite beam be transported on the beam surface of this span.

[0058] During the steel beam erection, monitoring points are arranged at the main stress points of the bridge erecting machine. These monitoring points are integrated with the bridge erecting machine's BIM model. By clicking on the corresponding location in the BIM model, the real-time data collected by the sensors at that location can be viewed. At the same time, alarm threshold ranges are set according to the status of each sensor. When the real-time data collected by the sensor exceeds the threshold range, an alarm will be triggered to ensure the safe operation of the bridge erecting machine under various working conditions.

[0059] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0060] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0061] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for erecting large-span steel beams, characterized in that, It includes the following steps: Fix the front support leg (2) and the middle support leg (3) to the bridge deck, move the overhead crane (5) to the first position as a counterweight, drive the main truss (1) forward, and complete the first passage through the hole; Move the overhead crane (5) to the second position in the direction of the tail support leg (4) to act as a counterweight, release the fixation of the middle support leg (3), and drive the middle support leg (3) to move the front support leg (2) a first preset distance and fix it to the bridge deck, drive the main truss (1) forward, and complete the second passage through the hole. This continues until the front temporary support leg (6) on the main truss (1) reaches the position of the cap beam (7); Release the fixation of the middle support leg (3) and drive the middle support leg (3) to move closer to the front support leg (2); Release the fixation of the front outrigger (2) and drive the front outrigger (2) to move towards the front temporary outrigger (6) and bear the load on the cap beam (7); Using an overhead crane (5), steel beams are erected; Before fixing the front outrigger (2) and the middle outrigger (3) to the bridge deck, the method further includes the following steps: Move the overhead crane (5) to the second position as a counterweight; Start the hydraulic system of the front outrigger (2) and the rear outrigger (4) to adjust the height of the main truss (1); Before driving the middle support leg (3) to move a first preset distance toward the front support leg (2), the method further includes the following steps: Restart the hydraulic systems of the front outrigger (2) and the tail outrigger (4) to adjust the height of the main truss (1); After the front temporary support leg (6) on the main truss (1) reaches the position of the cap beam (7), and before releasing the fixation of the middle support leg (3), the method further includes the following steps: Fix the tail support leg (4) to the bridge deck and start the hydraulic system of the tail support leg (4) to adjust the height of the main truss (1); After releasing the fixing of the front outrigger (2) and driving the front outrigger (2) to move towards the front temporary outrigger (6) and supporting it on the cap beam (7), before using the overhead crane (5) to erect the steel beam, the method further includes the following steps: Adjust the height and level of the main truss (1); Fix the middle support leg (3) and the tail support leg (4) to the bridge deck.

2. The method for erecting large-span steel beams as described in claim 1, characterized in that, Using an overhead crane (5), the steel beams are erected, and the specific steps include: The overhead crane (5) lifts the steel beam and moves it above the cap beam (7); The overhead crane (5) lowers the steel beam so that it rests on the cap beam (7).

3. The method for erecting large-span steel beams as described in claim 2, characterized in that, After the overhead crane (5) lifts the steel beam and before moving it above the cap beam (7), the method further includes the following steps: Adjust the height of the steel beam using the overhead crane (5) and keep the steel beam horizontal.

4. The method for erecting large-span steel beams as described in claim 3, characterized in that, After the steel beam is moved above the cap beam (7) and before the overhead crane (5) lowers the steel beam, the method further includes the following steps: Fix the front outrigger (2) and the middle outrigger (3) to the bridge deck; Make the tail support leg (4) detach from the bridge surface.

5. The method for erecting large-span steel beams as described in claim 1, characterized in that, The overhead crane (5) lowers the steel beam, and the specific steps include: The steel beam stops falling when it reaches the preset distance. Adjust the position of the steel beams; The steel beams were lowered again.

6. The method for erecting large-span steel beams as described in claim 1, characterized in that, After the steel beams are erected using a crane (5), the method further includes the following steps: Grouting is performed between the steel beam and the cap beam (7).

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