Multi-time system conversion installation method for steel box girder bridge crossing multiple roads

Abstract

The invention relates to the technical field of bridge construction, and discloses a multi-time system conversion mounting method for a steel box girder bridge crossing multiple roads, which comprises the following steps: dividing a road crossing part of the steel box girder bridge into a plurality of road-related units, and respectively positioning two ends of each road-related unit on two sides of a preset number of lanes of the crossing road, each road-related unit comprises a plurality of sections of steel box girders; first-class temporary piers and second-class temporary piers which are used for temporarily supporting the steel box girders are erected between the piers, and the first-class temporary piers are arranged at the two ends of the road-related unit; all steel box girders in the road-related unit are hoisted on the corresponding temporary piers and piers, the adjacent steel box girders are welded together, and after guardrails are constructed above the road-related unit, the second-class temporary piers below the road-related unit are dismantled, so that the preset number of lanes below the road-related unit recover traffic; and the part, not crossing the road, in the steel box girder bridge is constructed, the remaining adjacent steel box girders are welded together, the remaining temporary piers are removed, and traffic of all lanes of the crossing road is recovered.

Description

Technical Field

[0001] The present invention relates to the technical field of road and bridge construction, and in particular to a multiple system conversion installation method for a steel box girder bridge spanning multiple roads. Background Art

[0002] In highway or urban road grade separation projects, when constructing steel box girder bridges that span multiple roads or more than six lanes at a time, only the segmented lifting construction method can be used on existing roads in operation, which will have a certain impact on the traffic on existing lines. Summary of the Invention

[0003] The present invention is made to solve the above-mentioned technical problems. Its purpose is to provide a multiple system conversion and installation method for steel box girder bridges across 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. Divide the road-spanning portion of the steel box girder bridge into a number of inter-road units based on the road construction conditions. The two ends of each inter-road unit are located on both sides of a preset number of lanes of the road spanned. Each inter-road unit contains a number of steel box girder segments.

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

[0007] S3. Hoist each steel box girder in a road-related unit onto the corresponding temporary piers and bridge piers according to the drawings, weld adjacent steel box girders together, construct guardrails above the road-related unit, and remove the second-class temporary piers below the road-related unit, so that traffic can resume on a preset number of lanes below the road-related unit;

[0008] S4, repeat step S3 to construct the remaining road-related units;

[0009] S5. Construct the portion of the steel box girder bridge that does not span the road, weld the remaining adjacent steel box girders together, remove the remaining temporary piers, and restore traffic to all lanes of the spanned road.

[0010] As an embodiment, in step S3 to step S4, after the adjacent steel box girders are welded together, non-destructive testing of the welds is also performed.

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

[0012] As an embodiment, when the road-related unit includes a steel box girder with more than five segments or the length of the road-related unit exceeds the width of four lanes or the length of the road-related unit is more than 26 meters, in steps S3 and S4, counterweights are also set at both ends of the road-related unit.

[0013] As an embodiment, the center of gravity of the counterweight coincides with the vertical center line of the type of temporary pier or bridge pier.

[0014] As an embodiment, in step S3 and step S4, when the guardrail is a concrete guardrail, the supporting formwork of the guardrail needs to be removed before removing the second-class temporary pier.

[0015] As an embodiment, in step S1, the maximum weight of the steel box girder of a single segment is determined according to the road construction conditions and the lifting equipment to be used, and then the number of steel box girders in the road unit is set.

[0016] As an embodiment, in step S5, after the weld inspection is completed, the counterweight is unloaded.

[0017] As an embodiment, step S5 also includes constructing guardrails and auxiliary structures on the portion that does not cross the road until the bridge completion acceptance standard is met.

[0018] According to the above description and practice, the multiple system conversion installation method for steel box girder bridges spanning multiple roads described in the present invention divides the road-spanning part of the steel box girder bridge into several inter-road units according to the road construction conditions. Each road-spanning unit contains several sections of steel box girders, which shortens the installation length of a single-segment steel box girder, reduces the difficulty of lifting, and improves the lifting efficiency, thereby reducing the time that the lifting work occupies the existing line and can restore traffic more quickly.

[0019] In this installation method, Class I and Class II temporary piers are installed beneath each road-facing unit. Once the guardrail construction above a road-facing unit is completed, the Class II temporary piers below it can be removed, allowing traffic to resume on a predetermined number of lanes below the road-facing unit. Compared to traditional bridge construction, which requires waiting until guardrail construction is complete on all road-facing sections before removing the temporary piers, the installation method of this invention significantly reduces the impact on traffic on existing lines below. Furthermore, the remaining Class I temporary piers continue to support the road-facing unit above, ensuring safe construction of the entire road-facing section of the steel box girder bridge.

[0020] In this installation method, after the steel box girders in the road-related unit are welded together, they are converted from simply supported beams to continuous beams, and there is a force system conversion. Therefore, a type of temporary pier with a larger bearing capacity is set at both ends of the road-related unit to ensure that after the type II temporary pier under the road-related unit is removed, the road-related unit can continue to obtain relatively stable temporary support, ensuring that the construction of the entire steel box girder bridge can be carried out safely. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a flowchart of a method for multiple system conversion and installation of a steel box girder bridge spanning multiple roads according to an embodiment of the present invention.

[0022] Figure 2 The figure is a schematic structural diagram of a steel box girder bridge spanning multiple roads involved in one embodiment of the present invention.

[0023] Figure 3 It is a schematic structural diagram of the steel box girder of the road-related portion of the steel box girder bridge involved in one embodiment of the present invention after being hoisted on temporary piers and bridge piers.

[0024] Figure 4 This is a schematic structural diagram of each road-related unit in a steel box girder bridge after guardrails are constructed in one embodiment of the present invention.

[0025] Figure 5 This is a structural schematic diagram of each road-related unit in a steel box girder bridge involved in an embodiment of the present invention after the second-class temporary piers below are removed, wherein two road-related units are provided with counterweights.

[0026] Figure 6 It is a structural schematic diagram of the non-road-related portion of the steel box girder bridge during construction in one embodiment of the present invention.

[0027] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0028] The exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments can be embodied 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 thorough and complete and will fully convey the concepts of the 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 installation of a steel box girder bridge spanning multiple roads. Figure 1 The installation method flow is shown. Figures 2 to 6The structure of the steel box girder bridge during construction according to this installation method is shown in the figure. In the figure, 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, with LD4+, LD6+, LD9+, LD10+, LD13+, LD14+, and LD16+, which have a "+" suffix, being Class I temporary piers, and the others being Class II temporary piers; LX1 to LX3 are the road-related unit numbers; DT is the bridge pier; HL is the guardrail; and PZ is the counterweight.

[0030] In this embodiment, the multiple system conversion installation method 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 spanning portion of the steel box girder bridge is divided into a number of inter-road units. The two ends of each inter-road unit are located on both sides of a preset number of lanes of the road spanned, and each inter-road unit contains a number of steel box girders.

[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 portion above the three existing roads is the road-spanning portion, which is planned to be divided into three road-related units, namely LX1, LX2 and LX3, so that they can be constructed separately to adapt to the environmental conditions of the construction site and reduce the difficulty of lifting.

[0033] The road unit LX1 contains 6 sections of steel box girders, namely ZL6 to ZL11; the road unit LX2 contains 4 sections of steel box girders, namely ZL12 to ZL15; the road unit LX3 contains 2 sections of steel box girders, namely ZL18 and ZL19.

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

[0035] Step S2: Set up a type I temporary pier and a type II temporary pier between the bridge piers for temporarily supporting the steel box girder. The bearing capacity of the type I temporary pier is greater than that of the type II temporary pier. The type I temporary pier is set at the two ends of the road-related unit.

[0036] like Figure 2As shown, temporary piers LD4+ and LD9+ are installed below the ends of road unit LX1, LD10+ and LD13+ are installed below the ends of road unit LX2, and LD14+ and LD16+ are installed below the ends of road unit LX3. A non-lane area lies below the center of road unit LX1, forming the middle section between two existing roads. Because road unit LX1 is also quite long, a temporary pier LD6+ is also installed in this area. Second-class temporary piers are installed in the rest of the road unit.

[0037] When there is a non-road area such as a green belt or isolation belt in the middle of a single existing road, a type of temporary pier can also be set up in this area to improve the stability of the upper road-related units during construction.

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

[0039] Step S3: hoist each steel box girder in a road-related unit onto the corresponding temporary piers and bridge piers according to the drawings, weld adjacent steel box girders together, construct guardrails above the road-related unit, remove the second-class temporary piers below the road-related unit, and restore traffic to a 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 individual steel box girders within 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 road-related unit structure. Guardrails are then constructed above the piers. Once the guardrails are completed, no further work can be done on top of them, allowing the Class II temporary piers below to be removed. Due to their greater load-bearing capacity, the Class I temporary piers can continue to support the road-related unit. Once the Class II temporary piers are removed, traffic can resume on 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 pier needs to be calculated in advance based on the structure, length, presence or absence of pier support and other factors of the road-related unit, to ensure that it can stably support the road-related unit above after the second-class temporary pier is removed.

[0043] The three road-related units in this embodiment can be constructed sequentially, with each completed unit restoring some traffic below it. If the construction site allows for multiple devices to operate simultaneously and has sufficient workers and materials, the three road-related units can also be constructed simultaneously, further minimizing the impact on existing road traffic below.

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

[0045] In this embodiment, counterweights are installed at both ends of the road-related units LX1 and LX2 to prevent significant deformation in the middle of the units after the Class II temporary piers are removed and the load-bearing system of the units is converted to a continuous beam. Furthermore, the center of gravity of the counterweights coincides with the vertical centerline of the Class I temporary piers or bridge piers, further preventing abnormal deformation of the road-related units.

[0046] There are many ways to apply counterweights. They can be piled on top of the beam, heavy objects can be suspended below the beam, or ground anchors can be used in conjunction with cable tensioning to strengthen the beam end constraints and reduce the mid-span deflection of the road unit.

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

[0048] As an implementation method, when the guardrail is a concrete guardrail, before removing the second-class temporary pier, the supporting formwork of the guardrail needs to be removed to ensure that there is no operating process above the road-related unit.

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

[0050] After completing steps S3 and S4, each road-related unit remains as an independent, complete structure, yet unconnected. Therefore, in step S5, construction is first performed on the portion of the steel box girder bridge that does not span the road. This involves hoisting the steel box girders onto adjacent temporary piers and bridge piers, welding adjacent steel box girders together, welding the steel box girders between each road-related unit together, and welding the steel box girders at the ends of the road-related units to the steel box girders that do not span 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 underlying piers, and the remaining Class I temporary piers and Class II temporary sections can be removed. Accordingly, traffic can be restored to all lanes of the spanned road.

[0051] Furthermore, if a counterweight is set in the previous step, in this step, after completing all weld inspections and before dismantling a type of temporary pier, the counterweight needs to be unloaded.

[0052] Furthermore, in step S5, it also includes constructing guardrails and auxiliary structures in the part that does not cross the road until the bridge acceptance standard is met.

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

[0054] In this installation method, Class I and Class II temporary piers are installed beneath each road-facing unit. Once the guardrail construction above a road-facing unit is completed, the Class II temporary piers below it can be removed, allowing traffic to resume on a predetermined number of lanes below the road-facing unit. Compared to traditional bridge construction, which requires waiting until guardrail construction is complete on all road-facing sections before removing the temporary piers, the installation method of this invention significantly reduces the impact on traffic on existing lines below. Furthermore, the remaining Class I temporary piers continue to support the road-facing unit above, ensuring safe construction of the entire road-facing section of the steel box girder bridge.

[0055] In this installation method, after the steel box girders in the road-related unit are welded together, they are converted from simply supported beams to continuous beams, and there is a force system conversion. Therefore, a type of temporary pier with a larger bearing capacity is set at both ends of the road-related unit to ensure that after the type II temporary pier under the road-related unit is removed, the road-related unit can continue to obtain relatively stable temporary support, ensuring that the construction of the entire steel box girder bridge can be carried out safely.

[0056] It should be noted that in order to reduce the impact on existing road traffic during the construction process, a second type of temporary piers that can be removed in advance before the bridge is completed are set up to restore some traffic. However, the premise for achieving this effect is that a first type of temporary pier is set up at the characteristic position of the road-related unit. When the second type of temporary pier is removed, the road-related unit can still be firmly supported. In other words, in the multiple system conversion and installation method of the steel box girder bridge spanning multiple roads, there is a close connection between the first type of temporary pier and the second type of temporary pier, and through synergy, they jointly solve the technical problems that affect the existing road traffic during the construction of the cross-road bridge and produce related technical effects, that is, reducing the impact on the existing road traffic. Removing any of the temporary piers will not produce the above-mentioned technical 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 limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for multiple system conversion installation of a steel box girder bridge spanning multiple roads, characterized in that: The steps include: S1. Divide the road-spanning portion of the steel box girder bridge into a number of inter-road units based on the road construction conditions. The two ends of each inter-road unit are located on both sides of a preset number of lanes of the road spanned. Each inter-road unit contains a number of steel box girder segments. S2. Erecting Class I and Class II temporary piers between the piers for temporarily supporting the steel box girder. The bearing capacity of the Class I temporary piers is greater than that of the Class II temporary piers. The Class I temporary piers are located at both ends of the road-related unit. S3. Hoist each steel box girder in a road-related unit onto the corresponding temporary piers and bridge piers according to the drawings, weld adjacent steel box girders together, construct guardrails above the road-related unit, and remove the second-class temporary piers below the road-related unit, so that traffic can resume on a preset number of lanes below the road-related unit; S4, repeat step S3 to construct the remaining road-related units; S5. Construct the portion of the steel box girder bridge that does not span the road, weld the remaining adjacent steel box girders together, remove the remaining temporary piers, and restore traffic to all lanes of the spanned road.

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

3. The method for multiple system conversion and installation of a steel box girder bridge spanning multiple roads as claimed 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 first type of temporary pier.

4. The method for multiple system conversion and installation of a steel box girder bridge spanning multiple roads as claimed in claim 1, characterized in that: When the road-related unit includes a steel box girder with more than five segments or the length of the road-related unit exceeds four lane widths or the length of the road-related unit is more than 26 meters, in steps S3 and S4, counterweights are also set at both ends of the road-related unit.

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

6. The method for multiple system conversion and installation of a steel box girder bridge spanning multiple roads as claimed in claim 1, characterized in that: In step S3 and step S4, when the guardrail is a concrete guardrail, the supporting formwork of the guardrail needs to be removed before removing the second-class temporary pier.

7. The method for multiple system conversion and installation of a steel box girder bridge spanning multiple roads as claimed in claim 1, characterized in that: In step S1, the maximum weight of the steel box girder of a single segment is determined according to the road construction conditions and the lifting equipment to be used, and then the number of steel box girders in the road unit is set.

8. The method for multiple system conversion and installation of a steel box girder bridge spanning multiple roads as claimed 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 a steel box girder bridge spanning multiple roads as claimed in claim 1, characterized in that: In step S5, the guardrails and auxiliary structures of the portion that does not cross the road are also constructed until the bridge acceptance standards are met.

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