Construction method for replacing crossing on existing railway line

Abstract

The present application relates to a kind of railway existing line renewal replacement intersection construction method, is erected under rail overhead support bracket on the intersection point existing railway subgrade, with front and rear rail connection;Excavation pile is made under the under rail overhead support bracket;Existing railway subgrade between the excavation pile of both sides is dug, and pile foundation is made;Self-compacting concrete is poured above pile foundation to under rail overhead support bracket, and new railway lower subgrade is formed;Under rail overhead support bracket is removed, and self-compacting concrete is poured above new railway lower subgrade, and new railway upper subgrade is formed, and track is installed, and existing railway ends driving, and is changed to new railway driving.The present application does not use bridge to cross existing railway to carry out intersection construction, but uses subgrade type to cross railway existing line, and the problem of new railway and existing railway subgrade intersection construction is solved by using under rail overhead support bracket under the control of rail connection point elevation, cannot be crossed by bridge, under the requirement of ensuring that existing railway does not interrupt driving, new railway and existing railway subgrade intersection construction.

Description

Technical Field

[0001] This invention relates to the field of railway existing line renovation and construction technology, specifically to a method for cross-construction of railway existing line renewal and replacement. Background Technology

[0002] With a significant increase in passenger traffic, the existing railway lines, characterized by low speed and low density, can no longer meet the new demands for fast and comfortable travel. Meanwhile, bulk freight transport and high-speed modern logistics require railways with greater traction capacity and faster transport speeds. The low standards of existing lines limit the load capacity and speed of freight cars, resulting in high transportation costs and low efficiency. Therefore, the upgrading of existing railways is urgently needed.

[0003] Early railways, limited by technology, featured winding lines and numerous small-radius curves, a key factor restricting speed increases. Current upgrades focus on optimizing the track's horizontal alignment, straightening it, and reducing gradients through deep trenches, viaducts, and long tunnels, thus smoothing the track and allowing heavier, faster trains to run. However, due to limitations imposed by terrain, rivers, and stations, current railway line upgrades inevitably involve intersections between new and existing lines. Clearance constraints prevent the use of large-span bridges. Therefore, minimizing disruption to existing operational lines while simultaneously improving construction quality and efficiency makes these intersections a significant challenge in the upgrade projects. Summary of the Invention

[0004] The purpose of this invention is to provide a method for the construction of cross-sections in the renovation and replacement of existing railway lines, so as to solve the problem that construction has a significant impact on the operation of existing lines when large-span bridges cannot be used to cross the cross-sections.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: Provides a construction method for the replacement and upgrading of existing railway lines, the construction method including: At the existing railway track maintenance window, an overhead support bracket is erected above the existing railway subgrade at the intersection point. The overhead support bracket is connected to the front and rear rails along the direction of the existing railway line. Drilled piles are constructed below the overhead support frame under the rail, and the drilled piles are located on both sides of the transverse side of the newly built railway subgrade. The existing railway subgrade between the bored piles on both sides below and on both sides of the overhead support bracket under the rail is removed and replaced with bored piles to support the overhead support bracket under the rail. Construct pile foundations beneath the area where the existing railway subgrade has been excavated; A self-compacting concrete was poured above the pile foundation to form an overhead support frame under the rail, thus forming the subgrade of the new railway. At the existing railway track maintenance window, the overhead support brackets under the rails and the existing rails and sleepers within their range are removed, and self-compacting concrete is poured on top of the lower roadbed of the new railway to form the upper roadbed of the new railway. Tracks are installed on top of the roadbed of the newly built railway, and the existing railway stops operating, switching to the operation of the newly built railway.

[0006] Furthermore, the overhead support bracket under the rail includes two longitudinal steel beams, with a crossbeam perpendicular to both beams fixed between them.

[0007] Furthermore, when erecting the overhead support bracket under the rail, first erect two steel beams, then insert the crossbeam under the existing rail and between two adjacent existing sleepers, fix the two ends of the crossbeam to the steel beam, and use fasteners to fix the existing rail to the crossbeam.

[0008] Furthermore, the overhead support bracket under the rail also includes corbels, which are fixed to both sides of the steel beam with bolts, and the crossbeams are fixed to the corbels with bolts.

[0009] Furthermore, after removing the existing railway subgrade below the overhead support bracket and between the bored piles on both sides, the bored piles are used to replace the steel beams in the overhead support bracket.

[0010] Furthermore, when excavating the existing railway subgrade below the overhead support brackets and between the bored piles on both sides, a combination of manual excavation and small mechanical equipment is used for construction.

[0011] Furthermore, when the clearance is low, pile foundations are constructed using manual methods.

[0012] Alternatively, when the clearance is high, pile foundations can be constructed using low-clearance rotary drilling.

[0013] Furthermore, cooling measures are taken when pouring the subgrade of newly built railways.

[0014] Furthermore, short-embedded steel bars are pre-embedded in the top of the lower roadbed of the newly built railway, which are then poured into the upper roadbed of the new railway.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a method for constructing new railway subgrades at intersections with existing railway lines. Instead of using bridges to cross existing railway lines, it employs a subgrade structure to cross the existing lines. By utilizing overhead support brackets under the rails, it solves the problem of constructing new subgrades at intersections with existing subgrades when the elevation of the connection point prevents bridge crossings during partial rerouting, while ensuring uninterrupted train service. Furthermore, the use of self-compacting concrete to pour the new subgrade beneath the existing subgrade overcomes the problem of insufficient space for vibration compaction when the new subgrade is located beneath the existing railway, shortening construction time and ensuring train passage over the new subgrade. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a partial circuit modification diagram provided in an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the layout of existing railways and newly built railways provided in an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of bored piles and pile foundation construction provided in an embodiment of the present invention.

[0020] Figure 4 This is a plan view of the overhead support bracket under the rail provided in an embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of self-compacting concrete pouring provided in an embodiment of the present invention.

[0022] The diagram is labeled as follows: 1-New railway, 2-Existing railway, 3-Overhead support frame under rail, 4-Pile foundation, 5-Lower subgrade of new railway, 6-Upper subgrade of new railway, 7-Drilled pile; 21 - First connection point, 22 - Second connection point, 23 - Intersection point; 31-Steel beam, 32-Sleeper, 33-Crossbeam, 34-Bolt, 35-Corner, 36-Intrusion alarm. Detailed Implementation

[0023] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0024] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "lateral", "longitudinal", "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.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "setting," etc., should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] Furthermore, in the description of this invention, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance. Of course, such terms can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in a sequence other than those illustrated or described herein.

[0027] It should also be noted that although the order of steps is mentioned in the method description, in some cases, steps may be performed in a different order than that described here, and this should not be interpreted as a restriction on the order of steps.

[0028] The renovation of existing railways inevitably involves intersections between new and existing lines. If clearance is limited, long-span bridges cannot be used to cross them.

[0029] like Figure 1 In the example scenario, the existing railway 2 was built earlier and uses a small-radius curve. In order to improve the speed of the train, a new railway 1 is built to replace the existing railway 2. The new railway 1 uses a large-radius curve or a straight line, which will cause the new railway 1 and the existing railway 2 to form an intersection point 23. During the construction of the new railway 1, the existing railway 2 continues to operate normally. After the construction of the new railway 1 is completed, the train runs on the new railway 1, and the existing railway 2 is abandoned and dismantled.

[0030] However, from Figure 1As can be seen from the diagram, the first connection point 21 and the second connection point 22 of the newly built railway 1 to the existing railway 2 require that the elevations of the newly built railway 1 and the existing railway 2 be consistent at these two points. Due to the short distance of the local realignment and the limited elevation difference, the newly built railway 1 cannot use a bridge to cross the existing railway 2 at intersection 23. Therefore, the newly built railway 1 can only use a roadbed type at intersection 23. The existing railway 2 is already in the roadbed type at the intersection, and the track surface of the newly built railway 1 is higher than that of the existing railway 2 at intersection 23.

[0031] like Figure 2 When constructing the new railway 1, backfilling is required at intersection 23. Normal construction requires foundation treatment first, followed by roadbed filling, and then vibration to ensure that the roadbed density of the new railway 1 meets the requirements. However, since the existing railway 2 needs to operate normally, the above method cannot be followed.

[0032] Therefore, this invention provides a method for cross-construction of existing railway line renewal and replacement, which ensures the normal operation of existing railway line 2 is not interrupted even when clearance is limited and a bridge cannot be used to cross it. Specifically, the construction method includes the following steps: S1: At the track maintenance window of the existing railway 2, an overhead support bracket 3 is erected above the roadbed of the existing railway 2 at the intersection 23. The overhead support bracket 3 is connected to the front and rear rails along the direction of the existing railway 2 line, and the trains of the existing railway 2 run normally.

[0033] The overhead support bracket 3 under the rail includes two longitudinal steel beams 31, and a crossbeam 33 perpendicular to the two steel beams 31 is fixed between them. The overhead support bracket 3 also includes brackets 35, which are fixed to both sides of the steel beams 31 by bolts 34, and the crossbeam 33 is fixed to the brackets 35 by bolts 34.

[0034] When erecting the overhead support bracket 3 under the rail, first erect two steel beams 31, then insert the crossbeam 33 under the existing rail and between two adjacent existing sleepers. Fix the two ends of the crossbeam 33 to the steel beams 31, and use fasteners to fix the existing rail to the crossbeam 33. The existing railway 2 remains in operation.

[0035] S2: Under the overhead support 3, bored piles 7 are constructed. The bored piles 7 are located on both sides of the roadbed of the new railway 1, and are arranged in two rows.

[0036] The purpose of bored pile 7 is to prevent collapse after the roadbed is excavated later, thus protecting the safe operation of the railway line.

[0037] S3: Excavate the existing railway 2 roadbed between the underside of the overhead support bracket 3 and the bored piles 7 on both sides, and replace the overhead support bracket 3 with the bored piles 7.

[0038] Specifically, after removing the existing railway 2 subgrade between the bored piles 7 on both sides below the overhead support bracket 3, the bored piles 7 are used to replace the steel beams 31 in the overhead support bracket 3.

[0039] When excavating the existing railway 2 subgrade between the under-rail overhead support bracket 3 and the bored piles 7 on both sides, the construction method is to use manual excavation combined with small mechanical equipment. When using mechanical excavation, an intrusion alarm device 36 is installed on the under-rail overhead support bracket 3 to strictly limit the height of the machinery and prevent it from colliding with the under-rail overhead support bracket 3.

[0040] S4: Construct pile foundation 4 below the excavation area of ​​the existing railway 2 roadbed.

[0041] When the clearance is low, the pile foundation 4 is constructed manually. When the clearance is high, the pile foundation 4 is constructed using a low-clearance rotary drilling rig, with strict limits on the height of the machinery to prevent collision with the overhead support 3 under the rail.

[0042] S5: Pour self-compacting concrete above the pile foundation 4 to the overhead support frame 3 under the rail, forming the subgrade 5 of the new railway.

[0043] Subgrade construction typically employs compaction methods. However, due to limited space beneath the existing railway 2, compaction is not feasible. Therefore, this embodiment directly employs concrete pouring for subgrade construction. Construction of the new railway subgrade 5 involves large-volume concrete work, requiring cooling measures such as embedding water pipes within the concrete. During pouring, the flowing water helps cool the concrete, ensuring its temperature does not exceed specified requirements. This invention not only avoids compaction operations but also significantly shortens construction time, ensuring trains can pass over the newly constructed railway 1.

[0044] S6: At the 2nd track maintenance window of the existing railway, remove the overhead support bracket 3 under the rail, and pour self-compacting concrete on the upper roadbed 5 of the new railway to form the upper roadbed 6 of the new railway.

[0045] When pouring the lower roadbed 5 of the new railway, the upper surface should be uneven to increase the contact area. At the same time, short embedded steel bars should be installed, with one end of the short embedded steel bars located in the lower roadbed 5 of the new railway and the other end poured into the upper roadbed 6 of the new railway, so that the upper and lower roadbeds form a whole.

[0046] S7: After the concrete reaches the required level, the track will be installed on top of the new railway's upper roadbed 6. The existing railway 2 will cease operation, and the new railway 1 will take over. At the same time, the roadbeds of the existing railway 2 and the new railway 1 that are close to each other will be removed to avoid interference.

[0047] The railway existing line renewal and replacement cross construction method of the present invention does not use bridges to cross existing railways for cross-point construction, but uses roadbed type to cross existing railway lines. This ensures that the elevation of the newly built railway 1 and the existing railway 2 is consistent at the first connection point 21 and the second connection point 22, and does not cause the existing railway 2 to be interrupted for a long time. It has high construction efficiency and low cost, and provides a new implementation idea for the cross-point construction of the renovation project.

[0048] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the ideas of this invention.

Claims

1. A method for cross-construction of existing railway line renewal and replacement, characterized by: The construction method includes: At the track window of the existing railway (2), an overhead support bracket (3) is erected above the roadbed of the existing railway (2) at the intersection (23). The overhead support bracket (3) is connected to the front and rear rails along the direction of the existing railway (2). Drilled piles (7) are constructed below the overhead support bracket (3) under the rail, and the drilled piles (7) are located on both sides of the roadbed of the new railway (1); The existing railway (2) subgrade between the under-rail overhead support bracket (3) and the bored piles (7) on both sides is removed, and the bored piles (7) are replaced with the under-rail overhead support bracket (3). Piles (4) are constructed below the excavation area of ​​the existing railway (2) roadbed. A self-compacted concrete was poured on top of the pile foundation (4) to form an overhead support bracket (3) under the rail, thus forming the lower roadbed (5) of the new railway. At the track window point of the existing railway (2), the overhead support bracket (3) under the rail and the existing rails and existing sleepers within its range are removed, and self-compacting concrete is poured on the lower roadbed (5) of the new railway to form the upper roadbed (6) of the new railway. Tracks are installed on the top of the upper roadbed (6) of the new railway, and the existing railway (2) stops running and is replaced by the new railway (1).

2. The method for cross-construction of existing railway line renewal and replacement according to claim 1, characterized in that: The overhead support bracket (3) under the rail includes two longitudinal steel beams (31), and a crossbeam (33) perpendicular to the two steel beams (31) is fixed between the two steel beams (31).

3. The method for cross-construction of existing railway line renewal and replacement according to claim 2, characterized in that: When erecting the overhead support bracket (3) under the rail, first erect two steel beams (31), then insert the crossbeam (33) under the existing rail and between two adjacent existing sleepers, fix the two ends of the crossbeam (33) to the steel beam (31), and use fasteners to fix the existing rail to the crossbeam (33).

4. The method for cross-construction of existing railway line renewal and replacement according to claim 3, characterized in that: The overhead support bracket (3) under the rail also includes a corbel (35), which is fixed to both sides of the steel beam (31) by bolts (34), and the crossbeam (33) is fixed to the corbel (35) by bolts (34).

5. The method for cross-construction of existing railway line renewal and replacement according to claim 4, characterized in that: After removing the existing railway (2) roadbed between the bored piles (7) on both sides below the overhead support bracket (3), the bored piles (7) are used to replace the steel beams (31) in the overhead support bracket (3).

6. The method for cross-construction of existing railway line renewal and replacement according to claim 5, characterized in that: When excavating the existing railway (2) subgrade between the overhead support bracket (3) and the bored piles (7) on both sides, manual excavation combined with small mechanical equipment is used for construction.

7. The method for cross-construction of existing railway line renewal and replacement according to claim 6, characterized in that: When the clearance is low, pile foundations are constructed (4) using manual methods.

8. The method for cross-construction of existing railway line renewal and replacement according to claim 6, characterized in that: When the clearance is high, pile foundations are constructed (4), and low-clearance rotary drilling is used for construction.

9. The method for cross-construction of existing railway line renewal and replacement according to claim 7 or 8, characterized in that: Cooling measures should be taken when pouring the subgrade of a newly built railway (5).

10. The method for cross-construction of existing railway line renewal and replacement according to claim 9, characterized in that: Short-embedded steel bars are pre-embedded on the top of the lower roadbed (5) of the new railway, and are subsequently poured into the upper roadbed (6) of the new railway.

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