A Method for Erection of Steel Girder in Side Span of Continuous Rigid Frame Bridge

Abstract

The invention discloses a method for erecting a steel beam in the side span of a continuous rigid frame. First, a stress conversion frame is installed on the concrete beam segment, and a first adjusting jack and a hoist are installed on the stress conversion frame. The first adjusting jack is connected with a sling. Then, a second adjusting jack is installed on the pier of the side span. After that, a lifting lug is welded at one end of the steel beam, and the whole steel beam is hoisted to the installation position by a floating crane, and one end of the steel beam is supported on the second adjusting jack. Then, the sling is used to connect the lifting lug, and the stress conversion is completed by the first adjusting jack. After that, the position of the steel beam is adjusted by the hoist, the first adjusting jack and the second adjusting jack, and then the steel joint between the steel beam and the concrete beam segment is welded, and then concrete is poured between the steel beam and the concrete beam segment. Finally, the second adjusting jack and the stress conversion frame are removed. This application has the effects of facilitating the hoisting and positioning of the steel beam and improving the hoisting speed of the steel beam.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge construction, and in particular to a method for erecting a steel girder in the side span of a continuous rigid frame bridge. Background Art

[0002] Concrete continuous rigid frames are widely used in highways and railways due to their large spanning capacity, mature construction technology, large structural stiffness, smooth driving, good durability, and low cost. However, due to the large load of railway bridges, when the span is large, it is necessary to reduce the self-weight of the concrete continuous rigid frame. The commonly used method to reduce the weight of the concrete continuous rigid frame is to use a section of steel girder to replace a section of the concrete main girder. However, due to the large overall mass of the replaced steel girder, it is difficult to position during the hoisting process, and the hoisting construction efficiency is low. Summary of the Invention

[0003] In order to facilitate the hoisting and positioning of the steel girder and improve the hoisting speed of the steel girder, the present application provides a method for erecting a steel girder in the side span of a continuous rigid frame.

[0004] A method for erecting a steel girder in the side span of a continuous rigid frame provided by the present application adopts the following technical solutions:

[0005] A method for erecting a steel girder in the side span of a continuous rigid frame includes the following steps:

[0006] Install a stress conversion frame on the concrete beam segment. Install a first adjusting jack and a hoist on the stress conversion frame. The hoist is arranged on the side of the first adjusting jack facing the concrete beam segment, and the first adjusting jack is connected with a suspension cable;

[0007] Install a second adjusting jack on the pier of the side span;

[0008] A lifting lug is welded to one end of the steel girder. The whole steel girder is hoisted to the installation position by a floating crane. The end of the steel girder with the lifting lug is hoisted below the suspension cable, and the other end of the steel girder is supported on the second adjusting jack;

[0009] Connect the lifting lug with the suspension cable, connect the hoist with the steel girder, apply an upward acting force to the suspension cable through the first adjusting jack, and the acting forces of the suspension cable and the second adjusting jack on the steel girder replace the acting force of the floating crane on the steel girder;

[0010] Adjust the position of the steel girder through the first adjusting jack, the second adjusting jack and the hoist, then weld the steel joint between the steel girder and the concrete beam segment, and then pour concrete between the steel girder and the concrete beam segment;

[0011] After the strength of the concrete between the steel beam and the concrete beam section reaches the requirement, a reaction beam is installed between the pier of the side span and the steel beam, and then the second adjustment jack is removed, and then the connection between the sling and the lug is released, and the stress conversion frame is removed.

[0012] By adopting the above technical scheme, it is difficult to accurately position the steel beam by the floating crane due to the large mass of the steel beam and the fact that the floating crane is easily affected by the water flow; after the steel beam is hoisted to the installation position by the floating crane, one end of the steel beam is supported by the second adjusting jack, and the other end of the steel beam is hoisted by the stress conversion frame, the first adjusting jack and the sling to complete the hoisting force conversion of the steel beam; then the position of the steel beam is adjusted by the hoist, the first adjusting jack and the second adjusting jack. Since the hoist, the first adjusting jack and the second adjusting jack are less affected by external factors, it is convenient to accurately position the steel beam and improve the hoisting efficiency of the steel beam.

[0013] Preferably, the stress conversion frame is modified by the walking mechanism, cantilever mechanism and rear anchor mechanism of the hanging basket, and the installation and use method of the stress conversion frame is the same as the installation and use method of the hanging basket.

[0014] By adopting the above technical solution, the conversion frame can be transformed into a hanging basket to save construction time and cost. The technology is mature and it is convenient to calculate the stress conditions of the concrete beam section.

[0015] Preferably, the concrete beam section is constructed by the hanging basket suspended casting method. After the strength of the concrete beam section connected to the steel beam reaches the requirement, the bearing mechanism and the formwork mechanism of the hanging basket are removed, and the walking mechanism, cantilever mechanism and rear anchor mechanism of the hanging basket are retained. Thereafter, several first adjusting jacks are installed on the cantilever of the cantilever mechanism, and then the walking mechanism and the cantilever mechanism are moved forward, and the cantilever of the cantilever mechanism is extended to the outside of the concrete beam section, thereby completing the transformation of the stress conversion frame.

[0016] By adopting the above technical solution, the concrete beam section is constructed by the hanging basket suspended casting method, and the stress conversion frame is directly modified by the hanging basket at the construction site without setting up an additional structure to install the stress conversion frame to the concrete beam section, thereby reducing damage to the concrete beam section and reducing the modification time of the stress conversion frame, thereby improving the modification efficiency of the stress conversion frame.

[0017] Preferably, the first adjusting jack is a through-hole prestressed jack, and the sling passes through a through-hole of the first adjusting jack.

[0018] By adopting the above technical solution, the tensioning force of the through-type prestressed jack is large, and the tensioning direction is stable, and the height of the steel beam can be adjusted in two directions.

[0019] Preferably, a plurality of the first adjusting jacks and the lifting lugs are respectively provided, and the plurality of the first adjusting jacks and the plurality of the lifting lugs correspond to each other in position and quantity. The plurality of the first adjusting jacks are symmetrically arranged with respect to the vertical plane passing through the axis of the concrete beam segment, and the plurality of the lifting lugs are symmetrically arranged with respect to the vertical plane passing through the axis of the steel beam.

[0020] By adopting the above technical solution, after the stress conversion is completed, one end of the steel beam connecting the suspension cable is automatically aligned with the concrete beam segment, and there is no need to adjust the position in the width direction of one end of the steel beam connecting the suspension cable, which is convenient for positioning the steel beam.

[0021] Preferably, the second adjusting jack is a three-way jack, and one adjusting direction of the second adjusting jack is parallel to the installation axis of the steel beam.

[0022] By adopting the above technical solution, the second adjusting jack can cooperate with the stress conversion frame to adjust the distance between the steel beam and the concrete beam segment.

[0023] Preferably, after the stress conversion frame, the first adjusting jacks and the suspension cables are installed, a loading test needs to be carried out on the stress conversion frame to check whether the bearing capacity of the stress conversion frame is qualified.

[0024] By adopting the above technical solution, since the weight of the steel beam is large, which is larger than the weight of the concrete beam segment poured during the construction of the hanging basket, the bearing capacity of the stress conversion frame needs to be rechecked to ensure the safety during the stress conversion process.

[0025] Preferably, first, tie a lifting rope on the suspension cable, and let the lifting rope hang down to the transport ship on the water surface, then connect the lifting rope to the lifting lug of the steel beam, and then start the first adjusting jack to lift one end of the steel beam 20 cm away from the ship deck, and measure the deformation of the stress conversion frame. If the deformation of the stress conversion frame is not greater than the set value, it means that the bearing capacity of the stress conversion frame is qualified; if the deformation of the stress conversion frame is greater than the set value, it means that the bearing capacity of the stress conversion frame is unqualified.

[0026] By adopting the above technical solution, the lifting height of the steel beam on the ship deck is small, which is relatively safe, and can simulate the deformation of the stress conversion frame after the stress conversion, and the test result is accurate.

[0027] In summary, the present application at least includes the following beneficial technical effects: after the steel beam is hoisted to the installation position by a floating crane, one end of the steel beam is supported by the second adjusting jack, and the other end of the steel beam is hoisted by the stress conversion frame, the first adjusting jacks and the suspension cables to complete the conversion of the hoisting acting force of the steel beam; then, the position of the steel beam is adjusted by the chain block, the first adjusting jacks and the second adjusting jack, which is convenient for accurately positioning the steel beam and improving the hoisting efficiency of the steel beam. Description of the Drawings

[0028] Figure 1 It is a construction schematic diagram of the erection of the side-span steel girder of a continuous rigid frame in an embodiment of the present application.

[0029] Figure 2 It is another construction schematic diagram of the erection of the side-span steel girder of a continuous rigid frame in an embodiment of the present application.

[0030] Figure 3 It is an installation schematic diagram of the stress conversion frame in an embodiment of the present application.

[0031] Description of the reference signs:

[0032] 1. Steel girder; 2. Concrete beam segment; 3. Stress conversion frame; 4. First adjusting jack; 5. Chain block; 6. Suspension cable; 7. Suspension ear; 8. Second adjusting jack; 9. Floating crane; 10. Pier; 11. Hook. Detailed implementation manners

[0033] The following will Figures 1-3 further describe the present application in detail.

[0034] An embodiment of the present application discloses a method for erecting the side-span steel girder of a continuous rigid frame.

[0035] Referring to Figure 1 、 Figure 2 and Figure 3 , a method for erecting the side-span steel girder of a continuous rigid frame includes the following steps:

[0036] S1. When casting the concrete beam segment 2 connected to the steel beam 1, a steel joint is embedded at one end of the concrete beam segment 2 where it is connected to the steel beam 1. After the strength of the concrete beam segment 2 reaches the design requirements, a stress conversion frame 3 is installed on the concrete beam segment 2, and multiple first adjusting jacks 4 are installed on the stress conversion frame 3. The multiple first adjusting jacks 4 are evenly distributed along the width direction of the concrete beam segment 2, and the multiple first adjusting jacks 4 are symmetrically arranged with respect to the vertical plane where the axis of the concrete beam segment 2 is located. Each first adjusting jack 4 is connected to a sling 6, and a hook 11 is provided at the lower end of the sling 6. The first adjusting jack 4 is a through-hole prestressing jack, and the sling 6 passes through the through-hole of the first adjusting jack 4, and the first adjusting jack 4 drives the sling 6 to lift and lower. After the stress conversion frame 3, the first adjusting jacks 4 and the slings 6 are installed, a loading test needs to be carried out on the stress conversion frame 3 to check whether the bearing capacity of the stress conversion frame 3 is qualified. If the bearing capacity of the stress conversion frame 3 is unqualified, the stress conversion frame 3 is strengthened to improve the bearing capacity of the stress conversion frame 3 until the bearing capacity of the stress conversion frame 3 is qualified. Multiple hoist cranes 5 are installed on the stress conversion frame 3. The hoist cranes 5 are arranged on the side of the first adjusting jacks 4 facing the concrete beam segment 2, and the multiple hoist cranes 5 are evenly distributed along the width direction of the concrete beam segment 2. When in use, the hoist cranes 5 are connected to the steel beam 1, and the hoist cranes 5 pull the steel beam 1 towards the concrete beam segment 2 to adjust the gap between the steel beam 1 and the concrete beam segment 2. By controlling the different pulling forces of each hoist crane 5 on the steel beam 1, the steel beam 1 can be offset in the width direction, so as to adjust the position of the steel beam 1 in the width direction.

[0037] S2. Install multiple second adjusting jacks 8 on the piers of the side span. The second adjusting jacks 8 are three-way jacks. The X directions of the multiple second adjusting jacks 8 are parallel to each other, and the X direction of the second adjusting jacks 8 is parallel to the axis of the continuous rigid frame. After the second adjusting jacks 8 are installed, check whether the directions of the second adjusting jacks 8 are correct.

[0038] S3. The mid-span end of the steel beam 1 is the end connected to the concrete beam segment 2, and the side-span end of the steel beam 1 is the end installed on the side-span pier 10. Weld multiple lifting lugs 7 at the mid-span end of the steel beam 1. The multiple lifting lugs 7 correspond one-to-one in position and quantity to the multiple first adjusting jacks 4. The distance between adjacent two lifting lugs 7 is equal to the distance between adjacent two first adjusting jacks 4. The multiple lifting lugs 7 are evenly distributed along the width direction of the steel beam 1, and the multiple lifting lugs 7 are symmetrically arranged with respect to the vertical plane where the axis of the steel beam 1 is located. Then, the steel beam 1 is integrally lifted to the installation position by a floating crane 9, and the mid-span end of the steel beam 1 is moved under the corresponding sling 6, and the lifting lugs 7 are moved under the sling 6. The side-span end of the steel beam 1 is supported on the second adjusting jacks 8. Adjust the position of the side-span end of the steel beam 1 by the second adjusting jacks 8 so that the side-span end of the steel beam 1 is aligned in height and width with the concrete beam segment 2 that is also supported on the side-span pier 10.

[0039] S4. Start the first adjusting jack 4 to lower the sling 6 to the lifting lug 7, then connect the hook 11 to the lifting lug 7. After all the hooks 11 are connected to the lifting lug 7, start the first adjusting jack 4 to apply an upward force to the sling 6, so that the sling 6 is tightened upward. The sling 6 applies an upward force to the steel beam 1. The forces of the sling 6 and the second adjusting jack 8 on the steel beam 1 replace the force of the floating crane 9 on the steel beam 1. The stress conversion frame 3, the first adjusting jack 4 and the sling 6 replace the floating crane 9 to perform subsequent hoisting of the steel beam 1.

[0040] S5. Start the first adjusting jack 4 and the second adjusting jack 8 to adjust the position of the steel beam 1, so that the upper surface of the mid-span end of the steel beam 1 is flush with the upper surface of the concrete beam segment 2, and the distance between the mid-span end of the steel beam 1 and the concrete beam segment 2 is within the design range. Then weld and fix the steel joint of the mid-span end of the steel beam 1 and the concrete beam segment 2. Weld steel plates respectively below and on both sides of the space between the mid-span end of the steel beam 1 and the concrete beam segment 2, then weld and tie steel bars between the mid-span end of the steel beam 1 and the concrete beam segment 2, and then pour concrete between the mid-span end of the steel beam 1 and the concrete beam segment 2, so that the steel beam 1 and the concrete beam segment 2 are firmly connected and smoothly transition.

[0041] S6. After the strength of the concrete between the steel beam 1 and the concrete beam segment 2 reaches the requirement, install a reaction beam between the pier at the side span and the steel beam 1. The reaction beam supports the side-span end of the steel beam 1, and then remove the second adjusting jack 8. Then release the connection between the floating crane 9 and the steel beam 1, and release the connection between the sling 6 and the lifting lug 7, and remove the stress conversion frame 3. Finally, perform expansion joint construction on the gap between the side-span end of the steel beam 1 and the concrete beam segment 2 supported by the same side-span pier 10.

[0042] In this embodiment, the concrete beam segment 2 is constructed by the cantilever casting method with a hanging basket. The stress conversion frame 3 is transformed from the traveling mechanism, the cantilever mechanism and the rear anchor mechanism of the hanging basket. The installation method of the stress conversion frame 3 is the same as that of the hanging basket, and the usage method of the stress conversion frame 3 is the same as that of the hanging basket. The transformation method is as follows: after the strength of the concrete beam segment 2 connecting the steel beam 1 reaches the requirement, remove the load-bearing mechanism and the formwork mechanism of the hanging basket, retain the traveling mechanism, the cantilever mechanism and the rear anchor mechanism of the hanging basket, and then move the traveling mechanism and the cantilever mechanism forward to the concrete beam segment 2 connecting the steel beam 1. The cantilever of the cantilever mechanism extends outside the concrete beam segment 2 and is arranged above the installation position of the steel beam 1, and then lock and fix the traveling mechanism, that is, complete the transformation of the stress conversion frame 3. Before moving the traveling mechanism and the cantilever mechanism forward, according to the design load of the hanging basket and the total weight of the steel beam 1, add steel pipe connections between the cantilevers of the cantilever mechanism to improve the load of the cantilever mechanism. Before moving the traveling mechanism and the cantilever mechanism forward, install the first adjusting jack 4 and the hoist 5 on the cantilever of the cantilever mechanism.

[0043] The method for the loading test of the stress conversion frame 3 in this embodiment is as follows: First, tie a lifting rope to the lifting hook 11 and let the lifting rope hang down to the transport ship on the water surface below. The transport ship adjusts its direction so that the lifting lugs 7 of the steel beam 1 are aligned with the lifting rope, and then tie the lifting rope to the lifting lugs 7 of the steel beam 1. Then start the first adjusting jack 4 to lift the mid-span end of the steel beam 1 20 cm away from the ship deck and keep it stable, and check whether there are cracks in the stress conversion frame 3. If there are cracks in the stress conversion frame 3, immediately place sleepers between the mid-span end of the steel beam 1 and the ship deck. The sleepers support the steel beam 1, then start the first adjusting jack 4 to relax the sling 6 and disconnect the connection between the sling 6 and the lifting lug 7, and then replace the stress conversion frame 3. After confirming that there are no cracks in the stress conversion frame 3, measure the deformation of the stress conversion frame 3. If the deformation of the stress conversion frame 3 is not greater than the set value, it means that the bearing capacity of the stress conversion frame 3 is qualified; if the deformation of the stress conversion frame 3 is greater than the set value, it means that the bearing capacity of the stress conversion frame 3 is unqualified. If the bearing capacity of the stress conversion frame 3 is unqualified, steel pipes need to be added between the cantilevers of the stress conversion frame 3 to improve the bearing capacity of the stress conversion frame 3, and then conduct the loading test again until the bearing capacity of the stress conversion frame 3 is qualified.

[0044] The implementation principle of the method for erecting the side-span steel beam of a continuous rigid frame in an embodiment of the present application is as follows: The method for erecting the steel beam 1 in this embodiment is used for the precise positioning of the steel beam 1 and is applicable to the erection of the steel beam 1 of a bridge constructed by the cantilever casting method using a hanging basket for the concrete beam segment 2, especially applicable to the erection of the steel beam 1 with a length greater than 50 m. After the steel beam 1 is hoisted to the installation position by the floating crane 9, the side-span end of the steel beam 1 is supported by the second adjusting jack 8, and after the stress conversion of the mid-span end of the steel beam 1 through the stress conversion frame 3, the first adjusting jack 4 and the sling 6, the mid-span end of the steel beam 1 is hoisted by the stress conversion frame 3, the first adjusting jack 4 and the sling 6. Through the first adjusting jack 4, the second adjusting jack 8 and the hoist 5, the steel beam 1 is precisely positioned, thus solving the problem that the floating crane 9 is easily affected by external factors such as flowing water and cannot precisely position the steel beam 1. After stress conversion, adjust the tension of the first adjusting jack 4 on the sling 6, thereby adjusting the height of the mid-span end of the steel beam 1. By adjusting different first adjusting jacks 4 to adjust the height of different positions of the steel beam 1, the angle of the steel beam 1 is adjusted. By adjusting the hoist 5 and the second adjusting jack 8 to adjust the position of the steel beam 1 in the axial and width directions, the distance between the mid-span end of the steel beam 1 and the concrete beam segment 2 is adjusted, and the steel beam 1 and the concrete beam segment 2 are aligned. After stress conversion in this embodiment, the steel beam 1 can be quickly and precisely positioned, improving the hoisting efficiency of the steel beam 1.

[0045] The above are all preferred embodiments of the present application. Without restricting the protection scope of the present application accordingly, therefore: All equivalent changes made according to the structure, shape, and principle of the present application shall be covered within the protection scope of the present application.

Claims

1. A method for erecting a steel girder in the side span of a continuous rigid frame, characterized in that, it includes the following steps: Install a stress conversion frame (3) on the concrete beam segment (2), install a first adjusting jack (4) and a hoist (5) on the stress conversion frame (3), the hoist (5) is arranged on the side of the first adjusting jack (4) facing the concrete beam segment (2), and the first adjusting jack (4) is connected with a suspension cable (6); Install a second adjusting jack (8) on the pier in the side span; Weld a lifting lug (7) at one end of the steel girder (1), lift the whole steel girder (1) to the installation position by a floating crane (9), the end of the steel girder (1) with the lifting lug (7) is lifted below the suspension cable (6), and the other end of the steel girder (1) is supported on the second adjusting jack (8); Connect the lifting lug (7) with the suspension cable (6), connect the hoist (5) with the steel girder (1), apply an upward force to the suspension cable (6) through the first adjusting jack (4), and the forces of the suspension cable (6) and the second adjusting jack (8) on the steel girder (1) replace the force of the floating crane (9) on the steel girder (1); Adjust the position of the steel girder (1) through the first adjusting jack (4), the second adjusting jack (8) and the hoist (5), then weld the steel joint between the steel girder (1) and the concrete beam segment (2), and then pour concrete between the steel girder (1) and the concrete beam segment (2); After the strength of the concrete between the steel girder (1) and the concrete beam segment (2) reaches the requirement, install a reaction beam between the pier in the side span and the steel girder (1), then remove the second adjusting jack (8), and then release the connection between the suspension cable (6) and the lifting lug (7), and remove the stress conversion frame (3).

2. The method for erecting a steel girder in the side span of a continuous rigid frame according to claim 1, characterized in that: The stress conversion frame (3) is transformed from the traveling mechanism, cantilever mechanism and rear anchor mechanism of a hanging basket, and the installation and use method of the stress conversion frame (3) is the same as that of the hanging basket.

3. The method for erecting a steel girder in the side span of a continuous rigid frame according to claim 2, characterized in that: The concrete beam segment (2) is constructed by the hanging basket cantilever casting method. After the strength of the concrete beam segment (2) connecting the steel girder (1) reaches the requirement, remove the load-bearing mechanism and formwork mechanism of the hanging basket, retain the traveling mechanism, cantilever mechanism and rear anchor mechanism of the hanging basket, then install several first adjusting jacks (4) on the cantilever of the cantilever mechanism, and then move the traveling mechanism and the cantilever mechanism forward, and the cantilever of the cantilever mechanism extends outside the concrete beam segment (2) to complete the transformation of the stress conversion frame (3).

4. The method for erecting a steel girder in the side span of a continuous rigid frame according to claim 3, characterized in that: The first adjusting jack (4) is a through-type prestressing jack, and the suspension cable (6) passes through the through-hole of the first adjusting jack (4).

5. The method for erecting a steel girder in the side span of a continuous rigid frame according to claim 3, characterized in that: The first adjusting jacks (4) and the lifting lugs (7) are respectively provided with a plurality of them. The plurality of the first adjusting jacks (4) and the plurality of the lifting lugs (7) are in one-to-one correspondence in terms of position and quantity. The plurality of the first adjusting jacks (4) are symmetrically arranged with respect to the vertical plane passing through the axis of the concrete beam segment (2), and the plurality of the lifting lugs (7) are symmetrically arranged with respect to the vertical plane passing through the axis of the steel beam (1).

6. A method for erecting a continuous rigid frame side-span steel beam according to claim 3, characterized in that: The second adjusting jack (8) is a three-way jack, and one adjusting direction of the second adjusting jack (8) is parallel to the installation axis of the steel beam (1).

7. A method for erecting a continuous rigid frame side-span steel beam according to claim 3, characterized in that: After the stress conversion frame (3), the first adjusting jacks (4) and the suspension cables (6) are installed, a loading test needs to be carried out on the stress conversion frame (3) to check whether the bearing capacity of the stress conversion frame (3) is qualified.

8. A method for erecting a continuous rigid frame side-span steel beam according to claim 7, characterized in that: The method for the loading test of the stress conversion frame (3) is as follows: First, tie a lifting rope on the suspension cable (6), and let the lifting rope hang down to the transport ship on the water surface, then connect the lifting rope to the lifting lug (7) of the steel beam (1). After that, start the first adjusting jack (4) to lift one end of the steel beam (1) 20 cm away from the ship deck, and measure the deformation of the stress conversion frame (3). If the deformation of the stress conversion frame (3) is not greater than the set value, it means that the bearing capacity of the stress conversion frame (3) is qualified; if the deformation of the stress conversion frame (3) is greater than the set value, it means that the bearing capacity of the stress conversion frame (3) is unqualified.

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