Multi-road steel box girder bridge multi-system conversion installation method

Abstract

The present application relates to the technical field of bridge construction, and discloses a method for installing a steel box girder bridge across multiple roads by multiple system conversion, comprising: dividing the road-crossing part of the steel box girder bridge into a plurality of road-intersecting units, with both ends of each road-intersecting unit being located on the two sides of a preset number of lanes of the road being crossed, and each road-intersecting unit containing a plurality of segments of steel box girder; erecting a type 1 temporary pier and a type 2 temporary pier for temporarily supporting the steel box girder between the piers, with the type 1 temporary pier being arranged at the two ends of the road-intersecting unit; hoisting each steel box girder in the road-intersecting unit on the corresponding temporary pier and the pier, welding adjacent steel box girders together, removing the type 2 temporary pier below the road-intersecting unit after constructing a guardrail above the road-intersecting unit, and restoring traffic on the preset number of lanes below the road-intersecting unit; welding the remaining adjacent steel box girders together for the part of the steel box girder bridge that does not cross the road, removing the remaining temporary piers, and restoring traffic on all lanes of the road being crossed.

Description

Technical Field

[0001] This invention relates to the field of road and bridge construction technology, specifically to a method for the multiple system conversion and installation of a steel box girder bridge spanning multiple roads. Background Technology

[0002] For grade-separated intersections on highways or urban roads, where the construction of a steel box girder bridge spans multiple roads or more than six lanes at a time, the segmented hoisting construction method can only be used on existing operating roads, which may have a certain impact on the traffic flow of the existing lines. Summary of the Invention

[0003] This invention was made to solve the above-mentioned technical problems. Its purpose is to provide a method for the multiple system conversion and installation of steel box girder bridges spanning multiple roads, which can reduce the impact on the traffic of existing lines, shorten the road occupation construction time, and ensure the safe passage of construction and operation roads.

[0004] According to one embodiment of the present invention, a method for multiple system conversion installation of a steel box girder bridge spanning multiple roads is provided, comprising the following steps:

[0005] S1. Based on the road construction conditions, the road-crossing part of the steel box girder bridge is divided into several road-crossing units. The two ends of each road-crossing unit are located on both sides of the predetermined number of lanes of the road it crosses. Each road-crossing unit contains several segments of steel box girder.

[0006] S2. Erect Class I and Class II temporary piers between the bridge piers for temporary support of the steel box girder. The bearing capacity of Class I temporary piers is greater than that of Class II temporary piers. The Class I temporary piers are located at both ends of the road-related unit.

[0007] S3. According to the drawings, hoist each steel box girder in a road-related unit onto the corresponding temporary piers and bridge piers, weld adjacent steel box girders together, construct guardrails above the road-related unit, remove the Class II temporary piers below the road-related unit, and restore traffic to the preset number of lanes below the road-related unit.

[0008] S4. Repeat step S3 to construct the remaining road-related units;

[0009] S5. For the sections of the steel box girder bridge that do not cross the road, weld the remaining adjacent steel box girders together, remove the remaining temporary piers, and restore traffic to all lanes of the road that were crossed.

[0010] As one implementation method, after adjacent steel box girders are welded together in steps S3 to S4, non-destructive testing of the weld is also performed.

[0011] As one implementation, when there is a non-lane area below the road-related unit, the non-lane area is provided with the aforementioned type of temporary pier.

[0012] As one implementation, when the road-crossing unit contains five or more steel box girder segments, or when the length of the road-crossing unit exceeds four lane widths, or when the length of the road-crossing unit is more than 26 meters, counterweights are also provided at both ends of the road-crossing unit in steps S3 and S4.

[0013] In one implementation, the center of gravity of the counterweight coincides with the vertical centerline of the temporary pier or bridge pier.

[0014] As one implementation method, in steps S3 and S4, when the guardrail is a concrete guardrail, the supporting formwork of the guardrail needs to be removed before the second-class temporary piers are dismantled.

[0015] As one implementation method, in step S1, the maximum weight of a single segment of steel box girder is determined based on the road construction conditions and the hoisting equipment to be used, and then the number of steel box girders in the road-related unit is set.

[0016] As one implementation method, in step S5, after the weld inspection is completed, the counterweight is unloaded.

[0017] As one implementation method, step S5 also includes constructing guardrails and ancillary structures for sections that do not cross the road, until the bridge meets the acceptance standards.

[0018] Based on the above description and practice, the multi-system conversion installation method for steel box girder bridges spanning multiple roads described in this invention divides the road-spanning portion of the steel box girder bridge into several road-interfering units according to the road-related construction conditions. Each road-interfering unit contains several segments of steel box girder, which shortens the installation length of a single segment of steel box girder, reduces the difficulty of hoisting, and improves hoisting efficiency. This reduces the time that hoisting work occupies on existing lines, allowing for faster restoration of traffic.

[0019] In this installation method, each road-related unit is equipped with both Type I and Type II temporary piers. Once the guardrail construction above a road-related unit is completed, the Type II temporary piers below it can be removed, allowing traffic to resume on the predetermined number of lanes below that road-related unit. Compared to traditional bridge construction methods where temporary piers must be removed only after all guardrail construction on the road-related sections is completed, the installation method in this invention significantly reduces the impact on existing traffic flow below. Simultaneously, the remaining Type I temporary piers continue to support the road-related units above, ensuring the safe construction of the entire road-related section of the steel box girder bridge.

[0020] In this installation method, after the individual steel box girders in the road-related unit are welded together, they are transformed from simply supported beams into continuous beams, resulting in a change in the stress system. Therefore, a type I temporary pier with a large bearing capacity is set at both ends of the road-related unit to ensure that after the type II temporary piers below the road-related unit are removed, the road-related unit can continue to receive relatively stable temporary support, thus ensuring the safe construction of the entire steel box girder bridge. Attached Figure Description

[0021] Figure 1 This is a flowchart illustrating a method for the multiple system conversion and installation of a steel box girder bridge spanning multiple roads, as described in one embodiment of the present invention.

[0022] Figure 2 This is a structural schematic diagram of a steel box girder bridge spanning multiple roads, as described in one embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the structure of a steel box girder bridge in one embodiment of the present invention, after the steel box girder is hoisted onto temporary piers and bridge piers.

[0024] Figure 4 This is a schematic diagram of the structure behind the construction guardrails of each road-related unit in a steel box girder bridge according to one embodiment of the present invention.

[0025] Figure 5 This is a schematic diagram of the structure of a steel box girder bridge after the removal of the second type of temporary piers below each road-related unit in one embodiment of the present invention, wherein counterweights are provided for two road-related units.

[0026] Figure 6 This is a structural schematic diagram of the non-road-related part of the construction of a steel box girder bridge according to one embodiment of the present invention.

[0027] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0028] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be more comprehensive and complete, and will fully convey the concept of exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0029] This embodiment discloses a method for multiple system conversion and installation of a steel box girder bridge spanning multiple roads. Figure 1 The installation process is shown. Figures 2 to 6The diagram shows the structure of the steel box girder bridge during construction using this installation method. In the attached diagram: ZL1 to ZL20 are the longitudinal segment numbers of the steel box girder; YL1 to YL3 are the existing road numbers; LD1 to LD16 are the temporary pier numbers, among which LD4+, LD6+, LD9+, LD10+, LD13+, LD14+, and LD16+ (those with a "+" suffix) are Class I temporary piers, and the others are Class II temporary piers; LX1 to LX3 are the numbers of the road-related units; DT is the bridge pier; HL is the guardrail; and PZ is the counterweight.

[0030] In this embodiment, the method for multiple system conversions and installations of the steel box girder bridge spanning multiple roads mainly includes the following steps:

[0031] Step S1: Based on the road construction conditions, the road-crossing section of the steel box girder bridge is divided into several road-crossing units. The two ends of each road-crossing unit are located on both sides of a predetermined number of lanes of the road it crosses. Each road-crossing unit contains several segments of steel box girder.

[0032] like Figures 2 to 6 As shown, in this embodiment, the steel box girder bridge to be constructed spans three existing roads, namely YL1, YL2 and YL3. The bridge section above these three existing roads is the road crossing section, which is planned as three road-related units, namely LX1, LX2 and LX3, so that they can be constructed separately, adapting to the environmental conditions of the construction site and reducing the difficulty of hoisting.

[0033] Road-related unit LX1 consists of 6 steel box girder segments, namely ZL6 to ZL11; road-related unit LX2 consists of 4 steel box girder segments, namely ZL12 to ZL15; road-related unit LX3 consists of 2 steel box girder segments, namely ZL18 and ZL19.

[0034] In this step, based on the road construction conditions and the hoisting equipment to be used, the maximum weight of a single steel box girder segment is determined, and then the number of steel box girders in the road-related unit is set.

[0035] Step S2: Erect Class I and Class II temporary piers between the bridge piers to temporarily support the steel box girder. The bearing capacity of Class I temporary piers is greater than that of Class II temporary piers. The Class I temporary piers are set at both ends of the road-related unit.

[0036] like Figure 2As shown, temporary piers of type 1 (LD4+ and LD9+) are installed below the two ends of road-related unit LX1, temporary piers of type 1 (LD10+ and LD13+) are installed below the two ends of road-related unit LX2, and temporary piers of type 1 (LD14+ and LD16+) are installed below the two ends of road-related unit LX3. The middle section of road-related unit LX1 contains a non-lane area, which is the middle part of two existing roads. Since road-related unit LX1 is also relatively long, a temporary pier of type 1 (LD6+) is also installed in this area. Other parts of the road-related units are equipped with type 2 temporary piers.

[0037] When a single existing road has non-road areas such as green belts or median strips in the middle, a temporary pier can be set up in that area to improve the stability of the road-related units above during construction.

[0038] When hoisting the steel box girder, the two ends of a single segment of the steel box girder are respectively erected on adjacent temporary piers and bridge piers, forming a simply supported beam.

[0039] Step S3: According to the drawings, hoist each steel box girder in a road-related unit onto the corresponding temporary piers and bridge piers, weld adjacent steel box girders together, construct guardrails above the road-related unit, remove the Class II temporary piers below the road-related unit, and restore traffic to the preset number of lanes below the road-related unit.

[0040] Step S4: Repeat step S3 to construct the remaining road-related units.

[0041] like Figures 3 to 5 As shown, the steel box girders of a road-related unit are first hoisted onto temporary piers and bridge piers according to the drawings. Adjacent steel box girders are then welded together to form a complete structure for the road-related unit. Guardrails are then constructed on top of this structure. Once the guardrails are completed, no other work is required above them, allowing the removal of the secondary temporary piers below. The primary temporary piers, due to their greater load-bearing capacity, can continue to support the road-related unit. After the secondary temporary piers are removed, traffic can resume in the lanes where they were located, minimizing the impact on existing road traffic.

[0042] It should be noted that the bearing capacity of the first-class temporary piers needs to be calculated in advance based on factors such as the structure, length, and whether or not there are bridge piers supporting the road-related unit, to ensure that they can stably support the road-related unit above after the second-class temporary piers are removed.

[0043] In this embodiment, the three road-related units can be constructed sequentially, restoring some traffic beneath each unit upon completion. When the construction site allows for simultaneous operation of multiple pieces of equipment and has sufficient personnel and materials, the three road-related units can also be constructed concurrently, further reducing the impact on existing road traffic below.

[0044] Furthermore, after adjacent steel box girders are welded together, non-destructive testing of the welds is carried out to ensure that each weld meets the design standards.

[0045] In this embodiment, counterweights are installed at both ends of road-related units LX1 and LX2 to ensure that no significant deformation occurs in the middle after the removal of the Class II temporary piers and the transformation of the load-bearing system of the road-related units into continuous beams. Furthermore, the center of gravity of the counterweights coincides with the vertical centerline of the Class I temporary piers or bridge piers, which can better prevent abnormal deformation of the road-related units.

[0046] There are several ways to apply counterweights. They can be applied to the top of the beam, suspended from below the beam, or secured with ground anchors and cables to enhance beam end restraint and reduce mid-span deflection of the road-related unit.

[0047] It should be noted that in other embodiments, when the road-related unit contains five or more steel box girder segments, or when the length of the road-related unit exceeds four lane widths or the length of the road-related unit is more than 26 meters, counterweights are set at both ends of the road-related unit in steps S3 and S4, which can significantly reduce abnormal deformation in the middle of the road-related unit after the removal of the Class II temporary piers.

[0048] As one implementation method, when the guardrail is a concrete guardrail, the supporting formwork of the guardrail needs to be removed before the Class II temporary piers are dismantled to ensure that there are no further work procedures above the road unit.

[0049] Step S5: For the portion of the steel box girder bridge that does not cross the road, weld the remaining adjacent steel box girders together, remove the remaining temporary piers, and restore traffic to all lanes of the road that it crosses.

[0050] After completing steps S3 and S4, the various road-related units, as independent and complete structures, are not yet connected. Therefore, in step S5, construction is first carried out on the sections of the steel box girder bridge that do not cross the road. This includes hoisting the steel box girders to adjacent temporary piers and main piers, welding adjacent steel box girders together, welding the steel box girders between the various road-related units together, and welding the steel box girders at the ends of the road-related units to the sections that do not cross the road, thus forming a complete main structure for the entire steel girder bridge. At this point, the steel box girder bridge is supported by the piers below, and the remaining Class I temporary piers and Class II temporary sections can be removed. Consequently, all lanes of the road that it crosses can be reopened to traffic.

[0051] Furthermore, if a counterweight was set in the previous step, the counterweight needs to be unloaded in this step after all weld inspections are completed and before the temporary pier is removed.

[0052] Furthermore, step S5 also includes constructing guardrails and ancillary structures for sections that do not cross the road, until the bridge meets the acceptance standards.

[0053] The method for multiple system conversion and installation of steel box girder bridges spanning multiple roads in this embodiment divides the road-spanning portion of the steel box girder bridge into several road-interference units according to the road-related construction conditions. Each road-interference unit contains several steel box girder segments, which shortens the installation length of a single steel box girder segment, reduces the difficulty of hoisting, and improves the hoisting efficiency. This reduces the time that hoisting work occupies on existing lines, allowing traffic to be restored more quickly.

[0054] In this installation method, each road-related unit is equipped with both Type I and Type II temporary piers. Once the guardrail construction above a road-related unit is completed, the Type II temporary piers below it can be removed, allowing traffic to resume on the predetermined number of lanes below that road-related unit. Compared to traditional bridge construction methods where temporary piers must be removed only after all guardrail construction on the road-related sections is completed, the installation method in this invention significantly reduces the impact on existing traffic flow below. Simultaneously, the remaining Type I temporary piers continue to support the road-related units above, ensuring the safe construction of the entire road-related section of the steel box girder bridge.

[0055] In this installation method, after the individual steel box girders in the road-related unit are welded together, they are transformed from simply supported beams into continuous beams, resulting in a change in the stress system. Therefore, a type I temporary pier with a large bearing capacity is set at both ends of the road-related unit to ensure that after the type II temporary piers below the road-related unit are removed, the road-related unit can continue to receive relatively stable temporary support, thus ensuring the safe construction of the entire steel box girder bridge.

[0056] It should be noted that, in order to reduce the impact on existing road traffic during construction, secondary temporary piers that can be removed before the bridge is completed were installed to restore some traffic flow. However, this effect is contingent on the installation of primary temporary piers at key locations of the road-related units, ensuring that the road-related units remain stably supported even after the removal of the secondary temporary piers. In other words, in this multi-system conversion and installation method for the steel box girder bridge spanning multiple roads, there is a close connection between the primary and secondary temporary piers. Through synergy, they jointly solve the technical problem of impacting existing road traffic during bridge construction, producing a related technical effect: reducing the impact on existing road traffic. Removing either type of temporary pier would not produce the aforementioned effect of reducing the impact on existing road traffic.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for multiple system conversion and installation of a steel box girder bridge spanning multiple roads, characterized in that, Includes the following steps: S1. Based on the road construction conditions, the road-crossing part of the steel box girder bridge is divided into several road-crossing units. The two ends of each road-crossing unit are located on both sides of the predetermined number of lanes of the road it crosses. Each road-crossing unit contains several segments of steel box girder. S2. Erect Class I and Class II temporary piers between the bridge piers for temporary support of the steel box girder. The bearing capacity of Class I temporary piers is greater than that of Class II temporary piers. The Class I temporary piers are located at both ends of the road-related unit. S3. According to the drawings, hoist each steel box girder in a road-related unit onto the corresponding temporary piers and bridge piers, weld adjacent steel box girders together, construct guardrails above the road-related unit, remove the Class II temporary piers below the road-related unit, and restore traffic to the preset number of lanes below the road-related unit. S4. Repeat step S3 to construct the remaining road-related units; S5. For the sections of the steel box girder bridge that do not cross the road, weld the remaining adjacent steel box girders together, remove the remaining temporary piers, and restore traffic to all lanes of the road that were crossed.

2. The method for multiple system conversion and installation of steel box girder bridges spanning multiple roads as described in claim 1, characterized in that, In steps S3 to S4, after adjacent steel box girders are welded together, non-destructive testing of the weld is also performed.

3. The method for multiple system conversion and installation of steel box girder bridges spanning multiple roads as described in claim 1, characterized in that, When there is a non-lane area below the road-related unit, the non-lane area is provided with the aforementioned type of temporary pier.

4. The method for multiple system conversion and installation of steel box girder bridges spanning multiple roads as described in claim 1, characterized in that, When the road-crossing unit contains five or more steel box girder segments, or when the length of the road-crossing unit exceeds four lane widths, or when the length of the road-crossing unit is more than 26 meters, counterweights are also installed at both ends of the road-crossing unit in steps S3 and S4.

5. The method for multiple system conversion and installation of steel box girder bridges spanning multiple roads as described in claim 4, characterized in that, The center of gravity of the counterweight coincides with the vertical centerline of the temporary pier or bridge pier.

6. The method for multiple system conversion and installation of steel box girder bridges spanning multiple roads as described in claim 1, characterized in that, In steps S3 and S4, when the guardrail is a concrete guardrail, the supporting formwork of the guardrail needs to be removed before the Class II temporary piers are dismantled.

7. The method for multiple system conversion and installation of steel box girder bridges spanning multiple roads as described in claim 1, characterized in that, In step S1, based on the road construction conditions and the hoisting equipment to be used, the maximum weight of a single steel box girder segment is determined, and then the number of steel box girders in the road-related unit is set.

8. The method for multiple system conversion and installation of steel box girder bridges spanning multiple roads as described in claim 4, characterized in that, In step S5, after the weld inspection is completed, the counterweight is unloaded.

9. The method for multiple system conversion and installation of steel box girder bridges spanning multiple roads as described in claim 1, characterized in that, Step S5 also includes constructing guardrails and ancillary structures for sections that do not cross the road, until the bridge meets the acceptance standards.

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