Closing method of large-span steel box girder bridge

Abstract

The invention discloses a closure method for a large-span steel box girder bridge. The closure method comprises the following steps that S1, the width of a closure opening is monitored regularly; s2, selecting a closure period; s3, an opposite-pulling tool is installed between the top faces of the first steel box girder and the second steel box girder on the large mileage side and the small mileage side of the closure opening, and the width of the closure opening is temporarily locked through the opposite-pulling tool; s4, a crane is arranged on the top face of each of the first steel box girder and the second steel box girder, and the closure section is hoisted into the closure opening through the two cranes; s5, the width of a welding seam between the small mileage side of the closure section and the first steel box girder is adjusted through the opposite-pull tool and the two cranes; s6, a temporary positioning horse plate is welded in a welding seam of the small mileage side of the closure section; s7, the width of a welding seam on the large-mileage side of the closure section is adjusted through an opposite-pulling tool; s8, a temporary positioning horse plate is welded in a welding seam of the large-mileage side of the closure section; and S9, symmetrically welding the large-mileage side circular seam and the small-mileage side circular seam of the closure section. The method is easy to operate, the construction cost can be reduced, and the construction quality is improved.

Description

Technical Field

[0001] The invention relates to the field of bridge construction, and in particular to a method for closing a long-span steel box girder bridge. Background Art

[0002] Before the closure construction of a large-span steel box girder bridge, the width of the closure mouth varies greatly due to the influence of sunlight, temperature, etc., which has a great impact on the closure construction. Generally, the width of the closure mouth at a certain time at night is selected as the target, and the closure section is constructed by adjusting the width of the closure mouth and matching the length of the closure section. The main construction methods include top-pushing closure, temperature-matched closure, rigid frame closure and other processes.

[0003] The so-called top-pushing closure is to set a bracket at the support of the steel box girder, install a jack on the bracket, push and adjust the width of the closure mouth according to the length of the closure section, lift the closure section into the closure mouth at a specified time, and finally temporarily lock and weld the closure section. This method achieves closure by pushing and adjusting the width of the closure mouth with a jack.

[0004] The above-mentioned jacking closure method requires burying a jacking reaction seat between the bottom of the steel box girder and the top of the pier, and using a large jack for jacking operations. The equipment required is large and the operation is difficult. The space for pier top operations is narrow, which poses certain safety risks.

[0005] The so-called temperature-matched closure is to match the closure section according to the width change of the closure mouth in a specified period of time, lift the closure section, wait for the specified period of time to lift the closure section into the closure mouth, and finally temporarily lock and weld the closure section. This method achieves closure by adjusting the length of the closure section.

[0006] The above-mentioned temperature-matching and closure method is to match and cut the length of the closure section according to the predetermined temperature, and then install the closure section. This method changes the design dimensions of the structure of the closure section and cannot actively adjust the width of the closure mouth. When the temperature changes and the length of the closure section changes, the width of the closure mouth will change accordingly, affecting the closure construction and even making it impossible to close the joint.

[0007] The so-called rigid rigid frame closure is to set a rigid frame at the closure mouth to lock the width of the closure mouth according to the length of the closure section, lift the closure section into the closure mouth at a specified time, and finally temporarily lock and weld the closure section. This method uses the rigid frame of the closure mouth to bear the load caused by the width change of the closure mouth during the closure, so as to achieve the width locking of the closure mouth during construction.

[0008] The above-mentioned rigid frame joint closing method first uses a large steel frame to forcibly constrain the width of the joint opening, and then performs the joint closing construction. This solution requires the rigid frame to have considerable rigidity, is complex to construct, consumes a lot of mechanical labor, and the rigid frame has a large deadweight, which affects the construction line shape of the joint opening. Summary of the invention

[0009] The purpose of the present invention is to overcome the existing defects and provide a method for closing a large-span steel box girder bridge, which is not only simple and safe to operate, but also can reduce construction costs and improve construction quality.

[0010] The technical solution to achieve the above object is: a method for closing a long-span steel box girder bridge, comprising the following steps:

[0011] S1, regularly monitor the width of the closure;

[0012] S2, select the period with relatively stable temperature as the closure period;

[0013] S3, installing a tensioning fixture between the top surface of the first steel box girder on the short mileage side of the closure and the top surface of the second steel box girder on the long mileage side of the closure, and temporarily locking the width of the closure by the tensioning fixture;

[0014] S4, arranging a crane on the top surface of the first steel box girder and the top surface of the second steel box girder respectively, and hoisting the closure section into the closure opening by the two cranes;

[0015] S5, adjust the weld width between the small mileage side of the joint section and the first steel box girder by using the tensioning fixture and two cranes;

[0016] S6, first weld a temporary positioning plate in the weld between the small mileage side of the joint section and the first steel box girder;

[0017] S7, adjusting the weld width between the large mileage side of the joint section and the second steel box girder by means of the tensioning tool;

[0018] S8, a temporary positioning plate is also welded in the weld between the large mileage side of the joint section and the second steel box girder;

[0019] S9, symmetrically weld the large mileage side annular seams of the joint section and the small mileage side annular seams of the joint section.

[0020] The above-mentioned method for closing a long-span steel box girder bridge, wherein when performing step S1, comprises the following steps:

[0021] ① Monitoring control points are arranged on both sides of the closure mouth, and each monitoring control point has visual communication with each other, so as to establish an independent bridge construction control network consistent with the construction drawings;

[0022] ② Monitor the width of the closure and the ambient temperature for 72 hours, with a monitoring interval of 1 hour, and use the monitoring results as the basis for determining the closure period and cutting parameters;

[0023] In the above-mentioned method for closing a large-span steel box girder bridge, when performing step S2, based on the 72-hour monitoring result of the width of the closure mouth, a time period when the width change of the closure mouth is stable is selected as the closure period, and the width of the closure mouth is determined in combination with the temperature forecast result during the closure period.

[0024] The above-mentioned method for closing a large-span steel box girder bridge, wherein, when performing step S3, the tensioning tooling comprises at least two pairs of tensioning brackets, two tensioning jacks and two tensioning steel strands; the two pairs of tensioning brackets are installed on the top surface of the first steel box girder and the top surface of the second steel box girder at intervals and one-to-one, and each tensioning bracket comprises an anchor plate with a through hole in the center and two toggle plates fixed on the front surfaces of both sides of the anchor plate one-to-one; the two tensioning jacks are both installed on the top surface of the first steel box girder and are located one-to-one behind the anchor plates of the two tensioning brackets located on the first steel box girder; one ends of the two tensioning steel strands pass through the through holes of the two tensioning brackets located on the first steel box girder and the through holes of the two tensioning jacks one-to-one in sequence, and the other ends of the two tensioning steel strands are anchored one-to-one in the through holes of the two tensioning brackets located on the second steel box girder.

[0025] The above-mentioned method for closing a long-span steel box girder bridge, wherein when performing step S4, comprises the following steps:

[0026] ① First, transport the closure section to the bottom of the closure mouth by barge, and then monitor and adjust the position and levelness of the closure section to ensure smooth lifting of the closure section;

[0027] ② Two cranes are connected to the joint section through special lifting equipment and are ready for lifting;

[0028] ③ Carry out preliminary loading before lifting, load the lifting cylinders of the two cranes with 30 to 40 tons, check the tightness of the slings of the two cranes, and ensure that each sling is evenly stressed;

[0029] ④ Load the joint section in stages at a ratio of 20%, 40%, 60%, 70%, 80%, 90%, 95%, and 100% of its own weight until the two cranes lift the joint section off the barge; keep the joint section stationary at a distance of 350 to 450 mm from the support of the barge, observe for 10 minutes, and check the transverse and longitudinal inclinations of the joint section;

[0030] ⑤ Lift the closure section as a whole and ensure the synchronization of the lifting cylinders of the two cranes during the lifting process;

[0031] When performing step S5, the following steps are included:

[0032] ① After the joint section is lifted into place, the vertical position, horizontal position and longitudinal position of the joint section are preliminarily adjusted through the self-displacement of the lifting cylinders of the two cranes;

[0033] ② When the temperature is relatively stable, adjust the weld width reserved on the small mileage side of the joint section by moving the pulling tooling and two cranes.

[0034] In the above-mentioned method for closure of a large-span steel box girder bridge, when performing steps S6 and 8, there are three groups of temporary positioning horse plates, firstly a group of temporary positioning horse plates located at the web position of the closure section is welded, and then two groups of temporary positioning horse plates located at the top plate position and the bottom plate position of the closure section correspondingly are welded simultaneously.

[0035] The above-mentioned method for closing a long-span steel box girder bridge, wherein when performing step S9, comprises the following steps:

[0036] ① First, remove the tensioning tooling and disconnect the joint section from the two cranes;

[0037] ② Symmetrically weld the web, top and bottom plate welds on the small mileage side of the joint section and the web, top and bottom plate welds on the large mileage side of the joint section.

[0038] The closure method of the long-span steel box girder bridge of the present invention has the following beneficial effects:

[0039] (1) The present invention uses flexible steel strands for pulling and closure. Compared with the traditional closure process, less tooling and equipment are used, and the direct investment is small;

[0040] (2) The construction operation is simple, and all construction operation steps are carried out on the bridge deck, which is relatively safe;

[0041] (3) The precision control is intuitive and accurate. The tensioning stroke of the tensioning steel strands is precisely controlled by the tensioning jack in the tensioning tooling, so as to achieve the purpose of accurately controlling the weld of the joint section. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1a It is a structural schematic diagram of the tensioning bracket when performing step S1 of the method for closing a long-span steel box girder bridge of the present invention;

[0043] Figure 1b yes Figure 1a Side view of

[0044] Figure 2 It is a top view of the arrangement of the tensioning tooling when performing step S1 of the method for closing a long-span steel box girder bridge of the present invention;

[0045] Figure 3is a schematic diagram of the state when performing step S4 of the method for closing a long-span steel box girder bridge of the present invention;

[0046] Figure 4 It is a schematic diagram of the welding sequence of the weld seams during step S9 of the method for closure of a large-span steel box girder bridge of the present invention. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings.

[0048] See also Figures 1a to 4 The method for closing a long-span steel box girder bridge of the present invention comprises the following steps:

[0049] S1, regularly monitor the width of the closure; including the following steps:

[0050] ① Monitoring control points are arranged on both sides of the closure, and each monitoring control point has visual communication with each other, so as to establish an independent construction control network for the steel box girder bridge consistent with the construction drawing;

[0051] ② Monitor the width of the closure and the ambient temperature for 72 hours, with a monitoring interval of 1 hour, and use the monitoring results as the basis for determining the closure period and cutting parameters;

[0052] S2, select the period with relatively stable temperature as the closure period; according to the 72-hour monitoring results of the width of the closure mouth, analyze the temperature change trend of the day, select the period with stable width change of the closure mouth as the closure period, and determine the width of the closure mouth in combination with the temperature forecast results during the closure period; the closure period is generally between 9 pm and before sunrise the next day;

[0053] S3, installing a tensioning fixture between the top surface of the first steel box girder 201 on the small mileage side of the closure and the top surface of the second steel box girder 202 on the large mileage side of the closure, and temporarily locking the width of the closure 100 by the tensioning fixture; including the following steps:

[0054] ① Install the tensioning tooling, which includes at least two pairs of tensioning brackets 1, two tensioning jacks 2 and two tensioning steel strands 3; the two pairs of tensioning brackets 1 are installed on the top surface of the first steel box girder 201 and the top surface of the second steel box girder 202 at intervals and one-to-one, and each tensioning bracket 1 includes an anchor plate 11 with a perforated hole in the center and two toggle plates 12 fixed on the front surfaces of both sides of the anchor plate 11 one-to-one; the two tensioning jacks 2 are installed on the first steel box On the top surface of the beam 201 and correspondingly behind the anchor plates 11 of the two tensioning braces 1 on the first steel box beam 201; one end of the two tensioning steel strands 3 pass through the through holes of the two tensioning braces 1 on the first steel box beam 201 and the through holes of the two tensioning jacks 2 in sequence, and the other ends of the two tensioning steel strands 3 are respectively anchored in the through holes of the two tensioning braces 1 on the second steel box beam 202 through anchors 3A;

[0055] ② Determine the tensioning force of the two tensioning steel strands 3 according to the monitoring result of the width change of the closure 100, and tension the two tensioning steel strands 3 by two tensioning jacks 2 to temporarily lock the width of the closure 100;

[0056] S4, arranging a crane 300 on the top surface of the first steel box girder 201 and the top surface of the second steel box girder 202 respectively, and hoisting the closure section 200 into the closure opening 100 by the two cranes 300; including the following steps:

[0057] ① First, transport the closure section 200 to the bottom of the closure mouth 100 by barge, and then monitor and adjust the position and levelness of the closure section 200 to ensure smooth lifting of the closure section 200;

[0058] ② Two cranes 300 are connected to the joint section 200 through special lifting equipment and are ready for lifting;

[0059] ③ Carry out preliminary loading before lifting, load 30-40 tons on the lifting cylinders 30 of the two cranes 300, check the tightness of the slings of the two cranes 300, and ensure that each sling is evenly stressed;

[0060] ④ Load the joint section 200 in stages according to the ratio of 20%, 40%, 60%, 70%, 80%, 90%, 95% and 100% of its own weight until the two cranes 300 lift the joint section 200 off the barge; keep the joint section 200 still at a distance of 350 to 450 mm from the support of the barge, observe for 10 minutes, and check the transverse and longitudinal inclinations of the joint section 200;

[0061] ⑤ Lift the joint section 200 as a whole, and ensure the synchronization of the lifting cylinders 30 of the two cranes 300 during the lifting process;

[0062] S5, adjusting the weld width between the small mileage side of the joint section 200 and the first steel box girder 201 by means of a pulling tool and two cranes; including the following steps:

[0063] ① After the closure section 200 enters the closure opening 100, the vertical position, the horizontal position and the longitudinal position of the closure section 200 are preliminarily adjusted by the self-displacement of the lifting cylinders 30 of the two cranes 300;

[0064] ② When the temperature is relatively stable, adjust the weld width reserved on the small mileage side of the joint section 100 by tensioning two tensioning steel strands 3 and moving two cranes 300.

[0065] S6, first weld a temporary positioning plate in the weld between the small mileage side of the joint section and the first steel box girder 201; there are three groups of temporary positioning plates, first weld a group of temporary positioning plates located at the web position of the joint section, and then simultaneously weld two groups of temporary positioning plates located at the top plate position and the bottom plate position of the joint section corresponding to each other;

[0066] S7, adjusting the weld width between the large mileage side of the joint section 200 and the second steel box girder 201 by tensioning two tensioning steel strands 3;

[0067] S8, temporary positioning plates are also welded in the weld between the large mileage side of the joint section 200 and the second steel box girder 201; there are three groups of temporary positioning plates, firstly weld one group of temporary positioning plates located at the web position of the joint section, and then simultaneously weld two groups of temporary positioning plates located at the top plate position and the bottom plate position of the joint section corresponding to each other;

[0068] S9, symmetrical welding of the small mileage side annular seams of the closure section and the large mileage side annular seams of the closure section, including the following processes:

[0069] ① First, release the tensioning tooling and release the connection between the joint section 200 and the two cranes 300;

[0070] ② Symmetrically weld the web, top and bottom plate welds on the small mileage side of the joint section and the web, top and bottom plate welds on the large mileage side of the joint section.

[0071] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, or some or all of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for closing a long-span steel box girder bridge, characterized in that: The closure method comprises the following steps: S1, regularly monitor the width of the closure; S2, select the period with relatively stable temperature as the closure period; S3, installing a tensioning fixture between the top surface of the first steel box girder on the short mileage side of the closure and the top surface of the second steel box girder on the long mileage side of the closure, and temporarily locking the width of the closure by the tensioning fixture; S4, arranging a crane on the top surface of the first steel box girder and the top surface of the second steel box girder respectively, and hoisting the closure section into the closure opening by the two cranes; S5, adjusting the weld width between the small mileage side of the joint section and the first steel box girder by using the tensioning fixture and the two cranes; S6, first weld a temporary positioning plate in the weld between the small mileage side of the joint section and the first steel box girder; S7, adjusting the weld width between the large mileage side of the joint section and the second steel box girder by means of the tensioning tool; S8, a temporary positioning plate is also welded in the weld between the large mileage side of the joint section and the second steel box girder; S9, symmetrically weld the large mileage side annular seams of the joint section and the small mileage side annular seams of the joint section.

2. The method for closing a long-span steel box girder bridge according to claim 1, characterized in that: When performing step S1, the following steps are included: ① Monitoring control points are arranged on both sides of the closure mouth, and each monitoring control point has visual communication with each other, so as to establish an independent bridge construction control network consistent with the construction drawings; ② Monitor the width of the closure and the ambient temperature for 72 hours, with a monitoring interval of 1 hour. Use the monitoring results as the basis for determining the closure period and cutting parameters.

3. The method for closing a long-span steel box girder bridge according to claim 1, characterized in that: When performing step S2, based on the 72-hour monitoring result of the width of the closure mouth, a time period when the width of the closure mouth changes stably is selected as the closure period, and the width of the closure mouth is determined in combination with the temperature forecast result during the closure period.

4. The method for closing a long-span steel box girder bridge according to claim 1, characterized in that: When performing step S3, the tensioning tooling includes at least two pairs of tensioning brackets, two tensioning jacks and two tensioning steel strands; the two pairs of tensioning brackets are installed on the top surface of the first steel box girder and the top surface of the second steel box girder at intervals and one-to-one, and each tensioning bracket includes an anchor plate with a through hole in the center and two toggle plates fixed on the front surfaces of both sides of the anchor plate one-to-one; the two tensioning jacks are both installed on the top surface of the first steel box girder and are located one-to-one behind the anchor plates of the two tensioning brackets located on the first steel box girder; one ends of the two tensioning steel strands pass through the through holes of the two tensioning brackets located on the first steel box girder and the through holes of the two tensioning jacks in sequence, and the other ends of the two tensioning steel strands are anchored one-to-one in the through holes of the two tensioning brackets located on the second steel box girder.

5. The method for closing a long-span steel box girder bridge according to claim 1, characterized in that: When performing step S4, the following steps are included: ① First, transport the closure section to the bottom of the closure mouth by barge, and then monitor and adjust the position and levelness of the closure section to ensure smooth lifting of the closure section; ② Two cranes are connected to the joint section through special lifting equipment and are ready for lifting; ③ Carry out preliminary loading before lifting, load the lifting cylinders of the two cranes with 30 to 40 tons, check the tightness of the slings of the two cranes, and ensure that each sling is evenly stressed; ④ Load the joint section in stages at a ratio of 20%, 40%, 60%, 70%, 80%, 90%, 95%, and 100% of its own weight until the two cranes lift the joint section off the barge; keep the joint section stationary at a distance of 350 to 450 mm from the support of the barge, observe for 10 minutes, and check the transverse and longitudinal inclinations of the joint section; ⑤ Lift the closure section as a whole and ensure the synchronization of the lifting cylinders of the two cranes during the lifting process; When performing step S5, the following steps are included: ① After the joint section is lifted into place, the vertical position, horizontal position and longitudinal position of the joint section are preliminarily adjusted through the self-displacement of the lifting cylinders of the two cranes; ② When the temperature is relatively stable, adjust the weld width reserved on the small mileage side of the joint section by moving the pulling tooling and two cranes.

6. The method for closing a long-span steel box girder bridge according to claim 1, characterized in that: When performing steps S6 and 8, there are three groups of temporary positioning horse plates. First, one group of temporary positioning horse plates located at the web position of the joint section is welded, and then two groups of temporary positioning horse plates located at the top plate position and the bottom plate position of the joint section correspondingly are welded simultaneously.

7. The method for closing a long-span steel box girder bridge according to claim 1, characterized in that: When performing step S9, the following steps are included: ① First, remove the tensioning tooling and disconnect the joint section from the two cranes; ② Symmetrically weld the web, top and bottom plate welds on the small mileage side of the joint section and the web, top and bottom plate welds on the large mileage side of the joint section.

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