A method for expanding construction of a railway multi-hole frame bridge in service

Abstract

The application discloses a kind of expansion construction methods of existing railway multi-hole frame bridge keeping traffic, adopt the construction of separate hole and adopt bridge to realize traffic, maintain the normal traffic of traffic, avoid the inconvenience brought by cutting off traffic, simultaneously, bridge is used as the support structure of roof pouring construction, without setting additional formwork support structure, both guarantee the stability of support, and avoid the influence of support structure on traffic, while meeting the traffic demand, guarantee the safety and reliability of roof construction.

Description

Technical Field

[0001] This invention relates to the field of railway frame bridge expansion technology, specifically to an expansion construction method for maintaining traffic flow on existing railway multi-span frame bridges. Background Technology

[0002] To improve traffic efficiency, it is necessary to streamline the existing traffic network in preparation for its integration. However, as this integration progresses, the insufficient capacity of existing single-track railways becomes apparent, necessitating expansion and addition of new lines to address traffic bottlenecks. When expanding and adding new lines, the existing single-track railway's frame bridges need to be upgraded simultaneously. However, this upgrade presents two challenges: firstly, the upgrade process will severely impact traffic flow on the original frame bridges, requiring traffic diversion; secondly, it is crucial to determine the optimal construction method for the frame bridges to ensure both integration with the existing lines and efficient construction. The simplest way to divert traffic is to cut off traffic and allow vehicles and pedestrians to detour. However, cutting off traffic has a significant impact and is not suitable for busy areas. Another traffic diversion method is to construct the frame bridge in phases and sections to maintain partial traffic capacity. However, this method requires coordination with the construction of the frame bridge. Common frame bridge construction methods, such as segmented prefabrication and assembly and the jacking construction of prefabricated box culverts, cannot simultaneously accommodate traffic, making line expansion more difficult and severely impacting construction progress. This invention provides a method for expanding existing railway multi-span frame bridges while maintaining traffic flow, solving the above problems. Summary of the Invention

[0003] This invention provides a method for expanding an existing railway multi-span frame bridge while maintaining traffic flow. The method employs segmented construction to maintain partial traffic capacity, maintains traffic flow by setting up temporary bridges, and utilizes the temporary bridges as supporting structures for the top slab pouring construction, thus balancing the safety of both traffic flow and top slab construction.

[0004] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: A method for expanding an existing railway multi-span frame bridge while maintaining traffic flow includes the following steps: S1, Construction subgrade support structure: Construction of the support structure for the subgrade on both sides of the newly built frame bridge, and removal of the cantilever of the original frame bridge in the middle span; S2, Construction pit support structure: The road surface below the central span of the newly built frame bridge is demolished to carry out road surface pit support construction; S3, Temporary Bridge and Foundation Pit Construction: Construct temporary bridge piles within the road surface foundation pit support area, construct the temporary bridge frame on the temporary bridge piles, and pave or remove the temporary bridge pavement according to traffic conditions. During normal traffic, a temporary bridge road surface is laid on the temporary bridge frame for passage. When traffic is suspended, the temporary bridge road surface is removed and the road foundation pit is excavated. S4, Construction of the central span of the frame bridge: First, construct the bottom slab of the central span of the new frame bridge, and then construct the partition wall and top slab of the central span of the new frame bridge. S5, Side opening construction of frame bridge: First construct the side opening on one side of the newly built frame bridge, then construct the side opening on the other side of the newly built frame bridge. S6, Demolition of temporary bridge: After the construction of the partition walls and top slabs of the two side spans of the new frame bridge is completed, the temporary bridge road surface of the middle span and side spans is removed, the temporary bridge frame is demolished, the temporary bridge piles are cut, and then the construction of the road surface inside the new frame bridge is carried out.

[0005] Furthermore, the specific operation of step S3 is as follows: S31, When constructing temporary bridge piles, first construct the foundation of the temporary bridge piles, and then construct steel pipe piles on the foundation of the temporary bridge piles to form temporary bridge piles; S32, Construct the temporary bridge frame on top of the steel pipe piles of the temporary bridge; S33, When laying the temporary bridge pavement, the temporary bridge roadbed box is slid onto the temporary bridge frame to form the temporary bridge pavement. When removing the temporary bridge pavement, the temporary bridge roadbed box is slid from the temporary bridge frame to one side of the temporary bridge frame, exposing the temporary bridge frame. S34, after removing the temporary bridge pavement, excavation work is carried out through the temporary bridge frame to excavate the pavement pit below the temporary bridge frame.

[0006] Furthermore, the specific operation of step S4 is as follows: S41, after the roadbed pit is excavated, high-pressure jet grouting piles are used to seal the bottom, and then the subbase and base slab are constructed to complete the base slab construction. S42. After the bottom slab is completed, the top slab support piles are first constructed on the temporary bridge frame, and then the top slab support frame is constructed on the top slab support piles. After the top slab support frame is completed, the temporary bridge support structure is formed. S43, erect the partition wall formwork, then erect the top slab formwork on the top slab support frame, and finally pour the concrete.

[0007] Furthermore, the temporary bridge support structure includes a temporary bridge pile foundation, steel pipe piles, a temporary bridge frame, top plate support piles, and a top plate support frame. The temporary bridge pile foundation is located in the road surface pit, the lower part of the steel pipe piles is located in the temporary bridge pile foundation, the temporary bridge frame is located on top of the steel pipe piles, the top plate support piles are set on top of the steel pipe piles, the top plate support piles are vertically aligned with the steel pipe piles, and the top plate support frame is set on top of the top plate support piles.

[0008] Furthermore, the specific operation of step S1 is as follows: S11, protective piles and capping beams are constructed on both sides of the newly built frame bridge roadbed; S12, Construction of the water-stop curtain is carried out on the outside of the protective piles and the cap beam; S13, remove the cantilever of the original frame bridge's central span.

[0009] Furthermore, during the construction of the side holes, the following steps are taken: dismantling the side wall and cantilever of the side hole, supporting the foundation pit of the construction road, constructing the temporary bridge, constructing the foundation pit of the construction road, constructing the bottom slab of the side hole, and constructing the side wall and top slab of the side hole.

[0010] The beneficial effects of this invention are as follows: The use of multi-span construction and temporary bridges to facilitate traffic flow maintained normal traffic flow and avoided the inconvenience caused by traffic disruption. At the same time, the temporary bridges served as the supporting structure for the roof slab pouring, eliminating the need for additional formwork support structures. This ensured the stability of the support structure and avoided the impact of any additional support structure on traffic, thus meeting traffic needs while guaranteeing the safety and reliability of the roof slab construction. Attached Figure Description

[0011] Figure 1 This is a schematic vertical sectional view of the newly constructed frame bridge according to the present invention; Figure 2 This is a schematic cross-sectional view of the newly constructed frame bridge according to the present invention; Figure 3 This is a top view of the newly constructed frame bridge according to the present invention; Figure 4 This is a top view schematic diagram of the roadbed support structure of the present invention; Figure 5 This is a schematic diagram of the overall state of the three-hole foundation pit support structure of the present invention; Figure 6 This is a schematic diagram of the overall structure of the temporary bridge support structure of the present invention; Figure 7 This is a front view schematic diagram of the temporary bridge support structure of the present invention.

[0012] Attached reference numerals: 100, central hole; 200, side hole; 1, foundation pit support; 2, temporary bridge pile foundation; 3, temporary bridge frame; 4, road surface foundation pit; 5, bottom slab; 6, top slab support pile; 7, top slab support frame; 8, partition wall; 9, top slab; 10, water-stop curtain; 11, protective pile. Detailed Implementation

[0013] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0014] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0015] like Figure 1 , 2 As shown in Figure 3, a specific embodiment of the present invention involves expanding an existing single-track railway into a double-track railway, with a frame bridge installed at the intersection of the railway and ground traffic. Because the existing frame bridge is located in a busy traffic area with high traffic volume, detours cannot be used for traffic diversion. Furthermore, the existing frame bridge is a three-span frame structure, and pipelines and inspection wells are located above the U-shaped channel and the bottom slab of the existing frame bridge, making segmented prefabrication and prefabricated box culvert jacking construction methods impossible. Therefore, to balance traffic flow with the stability and safety of the frame bridge expansion construction, a phased and zoned construction method is adopted. The central span 100 is constructed first, while maintaining the passage of the side spans 200. The side spans are constructed after the central span 100 is completed. During construction, temporary bridges are used to achieve time-based passage, and these temporary bridges also serve as supporting structures for the top slab pouring construction, ensuring the safety of the top slab construction.

[0016] like Figure 1 , 4 As shown in Figure 5, the present invention provides a method for expanding an existing multi-span frame bridge of a railway while maintaining traffic flow, comprising the following steps: S1, constructing a roadbed support structure to support the roadbed on both sides of the frame bridge; S2, constructing a foundation pit support structure to provide support for subsequent road surface excavation; S3, constructing a temporary bridge, enabling time-segmented traffic after the temporary bridge is completed, laying the road surface when traffic is needed, and removing the road surface when the foundation pit is excavated; S4, after the road surface foundation pit is completed, constructing the central span of the frame bridge, first constructing the bottom slab, then simultaneously pouring the partition wall and top slab, using the temporary bridge as a formwork support during pouring; S5, after the central span is completed, constructing the two side spans of the frame bridge one by one according to the same operation; S6, after the side spans are completed, removing the temporary bridge, and then constructing the road surface inside the newly built frame bridge to complete the construction.

[0017] like Figure 1 , 5As shown in Figures 6 and 7, during construction, the frame bridge is constructed by first constructing the central hole 100, and then constructing the side holes 200 one by one. When constructing each hole, the road surface pit support 1 is constructed first, and the temporary bridge pile foundation 2 is constructed within the road surface pit support. After the temporary bridge pile foundation 2 is completed, the temporary bridge frame 3 is constructed. The temporary bridge frame 3 is then used to facilitate traffic passage and suspension. During passage, traffic flows smoothly; during suspension, the road surface pit 4 is excavated and the bottom slab 5 is constructed through the temporary bridge frame 3. After the bottom slab 5 is completed, the temporary bridge frame 3 is then constructed. The top slab support piles 6 and the top slab support frame 7 are installed on the bridge frame 3. The top slab support piles 6 support the top slab support frame 7 on the temporary bridge frame 3. The height of the top slab support piles 6 ensures that the distance between the top slab support frame 7 and the temporary bridge frame 3 can be maintained for normal passage. The top slab support frame 7 serves as the formwork support structure during the construction of the top slab. Then, the top slab support piles 6 and the top slab support frame 7 are used as supports for the pouring of the partition wall 8 and the top slab 9. After the construction of the central hole 100 is completed, the two side holes 200 are constructed one by one according to the above operation. The construction method of this invention adopts phased construction in a segmented manner to minimize the impact on traffic. When constructing each hole, a temporary bridge is set up to allow construction and traffic to alternate. Moreover, the temporary bridge also serves as the formwork support structure for concrete pouring. The temporary bridge plays a role in balancing construction and traffic throughout the construction process, minimizing the impact on traffic and effectively ensuring construction efficiency.

[0018] Further, in step S1, construct the roadbed support structure: construct the support structure for the roadbed on both sides of the newly built frame bridge, and demolish the cantilever of the original frame bridge's central span.

[0019] Furthermore, the specific operation of step S1 is as follows: S11, the construction of protective piles 11 and capping beams is carried out on the roadbed outside the retaining walls on both sides of the newly built frame bridge U-shaped channel; Φ1.25m protective piles and capping beams are used, with a spacing of 1.5m and L=21m; S12, the construction of the water-stop curtain 10 is carried out on the outside of the protective pile 11 and the cap beam. The water-stop curtain is located in the transverse range on both sides of the newly built frame bridge and adopts the Φ0.6m double-row high-pressure jet grouting pile water-stop curtain. S13, remove the cantilever of the original frame bridge's central span; during removal, use a Φ50mm water drill to drill hoisting holes and wire saw cutting holes, and use a crane for hoisting, with each slab measuring 0.8m×1.2m×0.4m.

[0020] Further, in step S2, the foundation pit support structure is constructed: the road surface below the central hole of the newly built frame bridge is demolished. A Φ500mm water drill is used to demolish a portion of the road surface and the existing U-shaped channel bottom plate structure of the frame bridge. Then, Larssen steel sheet piles are driven as the foundation pit excavation support and water-stopping structure to complete the construction of the road surface foundation pit support 1.

[0021] Further, in step S3, temporary bridge and foundation pit construction: while carrying out the road foundation pit support 1 construction, temporary bridge piles are constructed within the road foundation pit support area, and then the temporary bridge frame is constructed on the temporary bridge piles. The temporary bridge pavement is laid or removed according to the traffic conditions. During normal traffic, the temporary bridge pavement is laid on the temporary bridge frame for traffic. When traffic is suspended, the temporary bridge pavement is removed and the road foundation pit is excavated.

[0022] Furthermore, the specific operation of step S3 is as follows: S31, When constructing temporary bridge piles, first construct temporary bridge pile foundation 2 within the road surface pit support area, and then construct steel pipe piles on temporary bridge pile foundation 2 to form temporary bridge piles. S32, Welding of the temporary bridge frame 3 is carried out on the top of the steel pipe pile of the temporary bridge pile. The temporary bridge frame 3 serves as the foundation for the placement of the temporary bridge roadbed box, ensuring the stable placement and easy removal of the roadbed box. S33, when laying the temporary bridge road surface, the temporary bridge roadbed box is slid onto the temporary bridge frame 3 to form the temporary bridge road surface. At this time, vehicles can pass normally on the temporary bridge road surface. When removing the temporary bridge road surface, the temporary bridge roadbed box is slid from the temporary bridge frame 3 to one side of the temporary bridge frame 3, exposing the temporary bridge frame 3. At this time, traffic is suspended. S34, after removing the temporary bridge road surface, the temporary bridge frame 3 is exposed. The original road surface structure and U-shaped trough bottom plate structure under the temporary bridge frame are broken through the temporary bridge frame 3, and the road surface pit 4 under the temporary bridge frame is excavated.

[0023] Further, in step S4, construction of the central span of the frame bridge: first construct the bottom slab of the newly built central span of the frame bridge, and then construct the partition wall 8 and top slab 9 of the newly built central span of the frame bridge.

[0024] Furthermore, the specific operation of step S4 is as follows: S41, after the excavation of road foundation pit 4 is completed, the bottom of the road foundation pit is sealed with Φ0.6m high-pressure jet grouting piles with a spacing of 0.4m and L=0.5m. Then, the subbase and bottom slab are constructed. The subbase consists of 0.2m of C25 plain concrete subbase + 0.5m of graded crushed stone subbase. The bottom slab is 1.1m thick reinforced concrete. The construction of the bottom slab is completed. S42. After the bottom slab is completed, the top slab support piles 6 are first constructed on the temporary bridge frame 3, and then the top slab support frame 7 is constructed on the top slab support piles 6. After the top slab support frame 7 is completed, the temporary bridge support structure is formed. S43, the partition wall formwork is erected. The partition wall 8 is constructed using wooden formwork tie-down construction, and the top slab support pile 6 is used as the formwork support structure. Then, the top slab formwork is erected on the top slab support frame 7. The top slab formwork uses the top slab support frame 7 as the main rib, steel-clad wood as the secondary rib, and wooden formwork as the bottom formwork. The reinforcing steel is tied, and finally, concrete is poured.

[0025] like Figure 6 , 7 As shown, the temporary bridge support structure further includes a temporary bridge pile foundation 2, steel pipe piles, a temporary bridge frame 3, a top plate support pile 6, and a top plate support frame 7. The temporary bridge pile foundation 2 is located in the road surface pit, the lower part of the steel pipe pile is located in the temporary bridge pile foundation 2, the temporary bridge frame 3 is located at the top of the steel pipe pile, the top plate support pile 6 is set on the top of the steel pipe pile, the top plate support pile 6 is vertically aligned with the steel pipe pile, and the top plate support frame 7 is set on the top of the top plate support pile 6.

[0026] Furthermore, during the construction of the temporary bridge pile foundation 2, holes are first drilled, then a reinforcing cage is placed and concrete is poured. Before the concrete solidifies, steel pipe piles are placed in the temporary bridge pile foundation 2 so that the steel pipe piles are formed together with the temporary bridge pile foundation. Then, the temporary bridge frame 3 is welded on top of the steel pipe piles. The temporary bridge frame 3 is an I-beam frame. When the temporary bridge roadbed box is placed, it is inserted into the compartments of the temporary bridge frame. The road panels on the surface of the temporary bridge roadbed box are spliced ​​together to form a complete road surface for passage. When the temporary bridge roadbed box needs to be removed, it is lifted upward and slid to one side to expose the temporary bridge frame 3. The top plate support pile 6 is a steel pipe, which is set on the corresponding steel pipe pile. The top plate support frame 7 is a closely spaced I-beam frame, which is welded to the top of the top plate support pile.

[0027] Furthermore, since the central span is for four lanes, five pile foundations and steel pipe piles are set along the direction of traffic flow to form four temporary bridges, ensuring stable support. Three piles are set for the top slab support to avoid dense placement that may affect vehicle traffic.

[0028] Further, in step S5, the construction of the side openings of the frame bridge: first construct the side openings on one side of the newly built frame bridge, and then construct the side openings on the other side of the newly built frame bridge. During the construction of the side openings, the following sequence shall be followed: demolition of the side wall and cantilever of the side opening, construction of the road surface pit support, construction of a temporary bridge, construction of the road surface pit, construction of the bottom slab of the side opening, and construction of the side wall and top slab of the side opening.

[0029] Furthermore, during the construction of the side walls and top slab, the side walls are supported by single-sided formwork, and the formwork support during the construction of the side walls and top slab is achieved through a temporary bridge support structure.

[0030] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A construction method for expanding an existing multi-span frame bridge of railway while maintaining traffic flow, characterized in that, Includes the following steps, S1, Construction subgrade support structure: Construction of the support structure for the subgrade on both sides of the newly built frame bridge, and removal of the cantilever of the original frame bridge in the middle span; S2, Construction pit support structure: The road surface below the central span of the newly built frame bridge is demolished to carry out road surface pit support construction; S3, Temporary Bridge and Foundation Pit Construction: Construct temporary bridge piles within the road surface foundation pit support area, construct the temporary bridge frame on the temporary bridge piles, and pave or remove the temporary bridge pavement according to traffic conditions. During normal traffic, a temporary bridge road surface is laid on the temporary bridge frame for passage. When traffic is suspended, the temporary bridge road surface is removed and the road foundation pit is excavated. S4, Construction of the central span of the frame bridge: First, construct the bottom slab of the central span of the new frame bridge, and then construct the partition wall and top slab of the central span of the new frame bridge. S5, Side opening construction of frame bridge: First construct the side opening on one side of the newly built frame bridge, then construct the side opening on the other side of the newly built frame bridge. S6, Demolition of temporary bridge: After the construction of the partition walls and top slabs of the two side spans of the new frame bridge is completed, the temporary bridge road surface of the middle span and side spans is removed, the temporary bridge frame is demolished, the temporary bridge piles are cut, and then the construction of the road surface inside the new frame bridge is carried out.

2. The method for expanding an existing railway multi-span frame bridge while maintaining traffic flow, as described in claim 1, is characterized in that... The specific operation of step S3 is as follows: S31, When constructing temporary bridge piles, first construct the foundation of the temporary bridge piles, and then construct steel pipe piles on the foundation of the temporary bridge piles to form temporary bridge piles; S32, Construct the temporary bridge frame on top of the steel pipe piles of the temporary bridge; S33, When laying the temporary bridge pavement, the temporary bridge roadbed box is slid onto the temporary bridge frame to form the temporary bridge pavement. When removing the temporary bridge pavement, the temporary bridge roadbed box is slid from the temporary bridge frame to one side of the temporary bridge frame, exposing the temporary bridge frame. S34, after removing the temporary bridge pavement, excavation work is carried out through the temporary bridge frame to excavate the pavement pit below the temporary bridge frame.

3. The method for expanding an existing railway multi-span frame bridge while maintaining traffic flow, as described in claim 1, is characterized in that... The specific operation of step S4 is as follows: S41, after the roadbed pit is excavated, high-pressure jet grouting piles are used to seal the bottom, and then the subbase and base slab are constructed to complete the base slab construction. S42. After the bottom slab is completed, the top slab support piles are first constructed on the temporary bridge frame, and then the top slab support frame is constructed on the top slab support piles. After the top slab support frame is completed, the temporary bridge support structure is formed. S43, erect the partition wall formwork, then erect the top slab formwork on the top slab support frame, and finally pour the concrete.

4. The method for expanding an existing railway multi-span frame bridge while maintaining traffic flow, as described in claim 3, is characterized in that... The temporary bridge support structure includes a temporary bridge pile foundation, steel pipe piles, a temporary bridge frame, top plate support piles, and a top plate support frame. The temporary bridge pile foundation is located in the road surface pit. The lower part of the steel pipe piles is located in the temporary bridge pile foundation. The temporary bridge frame is located on top of the steel pipe piles. The top plate support piles are set on top of the steel pipe piles and are vertically aligned with the steel pipe piles. The top plate support frame is set on top of the top plate support piles.

5. The method for expanding an existing railway multi-span frame bridge while maintaining traffic flow, as described in claim 1, is characterized in that... The specific operation of step S1 is as follows: S11, protective piles and capping beams are constructed on both sides of the newly built frame bridge roadbed; S12, Construction of the water-stop curtain is carried out on the outside of the protective piles and the cap beam; S13, remove the cantilever of the original frame bridge's central span.

6. The method for expanding an existing railway multi-span frame bridge while maintaining traffic flow, as described in claim 1, is characterized in that... During the construction of the side hole, the following steps shall be taken: removal of the side hole sidewall and side hole cantilever, construction road surface pit support, construction temporary bridge, construction road surface pit, construction side hole bottom slab, construction side hole sidewall and top slab.

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