Double-l type pushing replacement method for double-hole frame bridge underpassing railway by highway widening

Abstract

The application discloses a double-L type pushing replacement method for a highway widening underpass railway double-hole frame bridge, and comprises the following steps: excavating a working face on both sides of the highway to prefabricate left and right two reinforced concrete frames; overhead existing railway lines are closed, and the right side of the highway is closed, and the left side of the highway is kept open; the right side of the reinforced concrete frame is pushed from the prefabricated position to the right side of the highway along the railway direction; the right side of the original structure of the reinforced concrete frame is cut by a rope saw, and the right side of the prefabricated reinforced concrete frame is pushed into the design position under the railway along the highway direction and is in place; traffic is guided to the right side to keep open, and the left side is closed; the left side of the reinforced concrete frame is in place, and the partition wall between the two reinforced concrete frames is filled. The application divides the frame bridge into two parts, realizes uninterrupted traffic replacement, and prefabricates the frame bridge on the outer side of the highway, thereby saving construction time and reducing operation loss of up and down traffic.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering technology, specifically to a method for replacing a double-L-shaped jacking bridge in a double-span frame bridge that passes under a railway during highway widening. Background Technology

[0002] With economic and social development, many places have realized that the current standard design of four-lane expressways cannot meet the needs of economic and social development. Upgrading and expanding expressways is a relatively economical and effective solution for increasing their capacity. Constructing underpasses with frame bridges at existing railway crossings is a common structural form for expressway widening. The challenge lies in finding effective methods to replace these existing frame bridges while minimizing the impact on expressway operations and ensuring uninterrupted railway operations, and minimizing the duration of disruption to expressway widening and reconstruction.

[0003] Currently, when replacing a double-span frame bridge under a railway via jacking, the approach involves closing the underpass, prefabricating the new frame bridge, and then, once conditions are met for jacking, blocking railway traffic, dismantling the corresponding track bed and rails within a specified time, demolishing the original frame bridge, replacing it via jacking, and finally restoring traffic. This approach is only feasible when the underpass is a low-grade highway and the railway crossing can be temporarily interrupted for demolition. However, in the case of high-grade roads, prolonged road occupancy for construction, such as on expressways, would cause significant losses to operations and restrict regional traffic flow, inconveniencing economic and social development and people's daily lives. This approach also affects railway operations, especially for high-speed railways and major passenger railways, making it practically unfeasible. Summary of the Invention

[0004] To address the aforementioned shortcomings in existing technologies, the present invention aims to provide a double-L-shaped jacking replacement method for a double-span frame bridge under a railway during highway widening. This method divides the frame bridge into two sections, achieving a replacement without disrupting traffic. Furthermore, by prefabricating the frame bridge on the outer side of the highway, construction time is saved, and operational losses for both directions of traffic are reduced.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0006] A method for replacing a double-L-shaped jacking bridge with a double-span frame bridge under a railway during highway widening is provided. The method includes the following steps:

[0007] Step 1: Precast two reinforced concrete frames, left and right, at the mining faces on both sides of the highway.

[0008] Step 2: Elevate the existing railway line, close the right lane of the road, and keep the left lane of the road open;

[0009] Step 3: The existing right-side reinforced concrete frame is supported by a full-span scaffold at the prefabrication location of the right span and the bottom slab and back of the jacking pit in the two jacking directions.

[0010] Step 4: Push the right-side reinforced concrete frame from its prefabrication position along the railway direction to the right-side position of the highway;

[0011] Step 5: Use a wire saw to cut and demolish the existing right-side reinforced concrete frame in situ, and push the right-side precast reinforced concrete frame along the road direction to the designed position under the railway.

[0012] Step 6: After the right reinforced concrete frame is pushed into place, traffic is diverted to keep the right side open and the left side closed; repeat steps 3-5 to put the left reinforced concrete frame into place and fill the partition wall between the two reinforced concrete frames.

[0013] Furthermore, in step 2, a temporary steel beam is used for overhead protection. One end of the temporary steel beam is set on the top of the partition wall in the old frame bridge, and the other end is set on a temporary support pile set outside the precast frame beam structure space.

[0014] Furthermore, in step 4, when pushing along the road direction, a space is left between the outer side of the frame back wall at the central divider and the existing frame partition wall for the optical cable.

[0015] Furthermore, in step 5, the old frame is cut and separated along the underside corner of the top plate on the outer side of the old partition wall using a wire saw, the old frame is removed, and the precast frame is continuously pushed into place to fill the upper track bed and rail.

[0016] The beneficial effects of this invention are as follows:

[0017] This invention involves appropriately widening and adjusting the width of the partition wall in the frame bridge under the railway, allowing for alternating traffic flow on the left and right sides of the highway and jacking construction. This ensures uninterrupted passage over the railway and operation of the underpass highway at a certain capacity, thereby minimizing operational losses for both directions of traffic and maximizing the protection of regional economic and social development and people's travel needs. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the jacking construction of the right-side reinforced concrete frame provided in an embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the jacking construction of the left-side reinforced concrete frame provided in an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the filling of the central partition wall after the left and right reinforced concrete frames are in place, provided in an embodiment of the present invention. Detailed Implementation

[0021] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0022] Example

[0023] like Figure 1-3 As shown, a method for replacing a double-L-shaped frame bridge under a railway during highway widening is described. This method includes the following steps:

[0024] Step 1: Excavate and protect the frame foundation pit, construct the bottom slab and back of the jacking working pit, and prefabricate the left and right reinforced concrete frames at the working face on both sides of the highway.

[0025] Step 2: Elevate the existing railway line, close the right lane of the highway, and keep the left lane of the highway open; specifically, use the railway steel temporary beams for elevated protection, with one end of the steel temporary beam set on the top of the partition wall in the old frame bridge and the other end set on temporary support piles set outside the precast frame beam structure space.

[0026] Step 3: The existing right-side reinforced concrete frame is supported by a full-span scaffold at the prefabrication location of the right span and the bottom slab and back of the jacking pit in the two jacking directions.

[0027] Step 4: Push the right-side reinforced concrete frame from the prefabrication position along the railway direction to the right-side position of the highway (first jacking position) (maintaining the left-side traffic flow); as a preferred method, when pushing along the highway direction, leave space for the optical cable of the central divider between the outer line of the frame back wall and the existing frame partition wall.

[0028] Step 5: Cut the existing right-side reinforced concrete frame along the underside corner of the outer top plate of the old central partition wall using a wire saw. Then, push the precast right-side reinforced concrete frame from the right-side position of the highway (the position where it was first pushed into place) along the highway direction to the design position under the railway (to ensure the left-side traffic flow of the highway) and put it into place; fill the upper track bed and track.

[0029] Step 6: After the right reinforced concrete frame is pushed into place, traffic is diverted to keep the right side open and the left side closed; repeat steps 3-5 to put the left reinforced concrete frame into place, and fill the gap between the two reinforced concrete frames with reinforced concrete to complete the replacement.

[0030] Due to construction reasons, the width of the central median strip is slightly increased in this method. This can be gradually transitioned during the roadbed widening construction within a certain range at both ends of the underpass. During the replacement of the frame bridge by jacking, the construction sequence of the left and right lanes can be adjusted according to the actual construction situation.

[0031] This invention involves appropriately widening and adjusting the width of the partition wall in the frame bridge under the railway, allowing for alternating traffic flow on the left and right sides of the highway and jacking construction. This ensures uninterrupted passage over the railway and operation of the underpass highway at a certain capacity, thereby minimizing operational losses for both directions of traffic and maximizing the protection of regional economic and social development and people's travel needs.

[0032] 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 the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0033] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for replacing a double-L-shaped jacking bridge with a double-span frame bridge under a railway during highway widening, characterized in that... Includes the following steps: Step 1: Precast two reinforced concrete frames, left and right, at the mining faces on both sides of the highway. Step 2: Elevate the existing railway line, close the right lane of the road, and keep the left lane of the road open; Step 3: The existing right-side reinforced concrete frame is supported by a full-span scaffold at the prefabrication location of the right span and the bottom slab and back of the working pits in the two jacking directions and positions. Step 4: Push the right-side reinforced concrete frame from its prefabrication position along the railway direction to the right-side position of the highway; Step 5: Use a wire saw to cut and demolish the existing right-side reinforced concrete frame of the original structure, and push the right-side precast reinforced concrete frame along the road direction to the designed position under the railway. Step 6: After the right reinforced concrete frame is pushed into place, traffic is diverted to keep the right side open and the left side closed; repeat steps 3-5 to put the left reinforced concrete frame into place and fill the partition wall between the two reinforced concrete frames.

2. The method for replacing a double-L-shaped frame bridge under a railway during highway widening as described in claim 1, characterized in that: In step 2, railway steel temporary beams are used for overhead protection. One end of the steel temporary beam is set on the top of the partition wall in the existing structure, and the other end is set on the temporary support piles set outside the space of the reinforced concrete frame structure.

3. The method for replacing a double-span frame bridge with a double-L-shaped jacking underpass for highway widening as described in claim 1, characterized in that: In step 4, when pushing along the road, a space is left between the outer side of the frame back wall at the central median and the existing central partition wall for the optical cable.

4. The method for replacing a double-span frame bridge with a double-L-shaped jacking underpass for highway widening as described in claim 1, characterized in that: In step 5, the existing right-side reinforced concrete frame of the structure is cut and separated along the underside corner of the top plate on the outer side of the old central partition wall using a wire saw. The existing right-side reinforced concrete frame of the structure is then demolished, and the right-side precast reinforced concrete frame is continuously pushed into place to fill the upper track bed and rail.

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