An integral cast-in-place frame bridge connection structure and construction method

Abstract

The present invention discloses an on-bridge connection structure for an integral cast-in-place frame bridge, which is used for the connection of a newly-built railway and an existing line on the bridge. Specifically, it includes a frame beam, a cantilever post-cast segment, and a bridge pier of a cast-in-place structure. The cast-in-place frame beam is arranged between two adjacent bridge piers of the existing line, and its width is greater than the width of the original existing line bridge and is eccentrically arranged towards the newly-built railway on the outside. The lower part of the frame beam is reinforced by pile foundations, and the elevation of its upper end face is higher than that of the upper end face of the bridge pier. The lower end face of the cantilever post-cast segment is supported on the top of the bridge pier. A newly-built railway, an existing line, and a turnout device are arranged above the frame beam and the cantilever post-cast segment, which are used as the bridge for the connection of the newly-built railway and the existing line. The present invention solves the problem of on-bridge connection, can greatly reduce the project cost, and save the construction period. Compared with the method of constructing a new-designed continuous turnout beam to achieve on-bridge connection, it has the advantages of rapid and convenient construction and significant cost reduction.

Description

Technical Field

[0001] The present invention belongs to the field of reconstruction and expansion of existing railway lines, and particularly relates to a new technology for connecting tracks on an integrally cast-in-place frame bridge. Background Art

[0002] The connection of a newly built railway and an existing line is mostly completed in the subgrade section. Currently, there is no engineering example of connecting tracks on a bridge in an already built railway.

[0003] The connection of railway tracks is inevitably related to the turnout structure. The turnout structure is complex in force, easy to be damaged, and difficult to replace. To ensure the durability of the turnout structure and the safety of the railway, the code requires that when the turnout structure is located on a bridge, it must be arranged on an integral continuous bridge deck. At the same time, the distance between the turnout point and the beam joint must be greater than or equal to 18 m. Therefore, when the turnout is located on a bridge, the traditional method mostly uses multi-span continuous beams, and the deflection-span ratio is controlled not to be greater than 1 / 4000, and the general span is not greater than 48 m. According to the type and length of the turnout, 6 - 32 m, 4 - 32 m, or 3 - 32 m equal-width or variable-width continuous beams are mostly used.

[0004] If the track connection technology in the subgrade section is blindly copied to guide the track connection on the bridge, that is, the operation of the existing line is interrupted, and the existing superstructure beam body and bridge pier are demolished, and the construction of the turnout continuous beam and the supporting bridge pier and foundation designed anew is carried out. This scheme has obvious disadvantages. It is necessary to interrupt the operation of the existing line and complete the construction of the new turnout bridge and bridge pier according to the design drawings at the fastest speed. Conservatively estimated, the interruption of the operation of the existing line requires about half a year, and the cost and expense are relatively large.

[0005] Therefore, realizing track connection on a bridge often requires a relatively high engineering cost and a long time-consuming. The long construction period significantly increases the economic cost and social cost.

[0006] However, in some railway projects, it is necessary to realize the connection of a newly built railway and an existing railway on a bridge at a certain construction site, and the existing technology lacks this form of track connection on the bridge and a complete set of technologies to solve these problems. Summary of the Invention

[0007] In view of at least one of the above defects or improvement requirements in the prior art, the present invention provides a track connection structure and construction method on an integrally cast-in-place frame bridge, and proposes to use the form of cast-in-place frame to realize track connection on the bridge, forming a complete set of technologies to solve the problem of track connection on the bridge, which can greatly reduce the project cost and save the construction period. Compared with the practice of newly designing and constructing a turnout continuous beam to realize track connection on the bridge, it has the advantages of rapid and convenient construction and significantly reduced cost.

[0008] To achieve the above object, according to one aspect of the present invention, there is provided a track connection structure on an integrally cast-in-place frame bridge for realizing the connection of a newly built railway and an existing line on the bridge, wherein:

[0009] Including frame beams, cantilever post-cast sections and bridge piers of cast-in-place structures;

[0010] The cast-in-place frame beam is arranged between two adjacent bridge piers of the existing line, and its width is greater than the width of the original bridge of the existing line, and is eccentrically arranged toward the newly built railway outside; the lower part of the frame beam is reinforced by a pile foundation, and the elevation of its upper end surface is higher than the upper end surface of the bridge pier;

[0011] One or more piers are provided between two adjacent frame beams and transverse to the line;

[0012] Two adjacent frame beams are connected to each other by extending a number of pre-buried reserved steel bar joints and cantilever post-cast sections of the joint belts toward each other;

[0013] The lower end surface of the cantilever post-cast section is supported on the top of the pier;

[0014] A newly built railway, an existing line and a switch device are arranged above the frame beam and the cantilever post-cast section, and are used as a bridge between the newly built railway and the existing line.

[0015] Preferably, when the lateral spacing between the newly built railway and the existing line is less than or equal to the predetermined safety distance, only one pier is provided between two adjacent frame beams, and the newly built railway and the existing line share the pier, and the single pier supports the entire cantilever post-cast section there.

[0016] Preferably, when the lateral spacing between the newly built railway and the existing line is greater than the predetermined safety distance, there are multiple bridge piers between two adjacent frame beams, and the newly built railway and the existing line each have their own bridge piers, and the multiple bridge piers jointly support the entire cantilever post-cast section there.

[0017] Preferably, the pile foundation is a high-pressure jet-jet pile.

[0018] To achieve the above-mentioned purpose, according to another aspect of the present invention, a construction method for track connection on an integral cast-in-place frame bridge is provided, which is used for connecting a newly built railway with an existing line on a bridge, and comprises the following steps:

[0019] Step 1:

[0020] Without interrupting the operation of the existing line, pile foundations are constructed between two adjacent bridge piers on the existing line to reinforce the roadbed below the existing line; and new bridge piers are built side by side horizontally on the side of the original bridge piers of the existing line close to the new railway to be built;

[0021] Step 2:

[0022] Temporarily suspend the operation of the existing line, dismantle the existing line bridge with simple supports above the piers, and retain the piers under the bridge;

[0023] Step 3:

[0024] At the position after demolishing the simply supported existing line bridge beam, between two adjacent piers of the existing line and on the pile foundation, a cast-in-place frame beam is immediately constructed, and its width is greater than the width of the original existing line bridge, and it is eccentrically arranged towards the to-be-built new railway on the outside. The elevation of the upper end surface exceeds the upper end surface of the pier and reaches the track surface elevation of the original existing line bridge; between two adjacent frame beams, the main reinforcement bars of the top slab of the frame beam extend out to form reserved steel bar joints for the cast-in-place belts on both sides of the frame.

[0025] Step Four:

[0026] Between two adjacent piers and on the piers, the cantilever post-cast sections where the frames of the reserved steel bar joints extend are connected to each other.

[0027] Step Five:

[0028] After the frame beam and the cantilever post-cast section both reach the age, the second-stage permanent load of the bridge deck including ballast ancillary works is laid on the frame beam and the cantilever post-cast section. The new railway, the existing line and the turnout device are constructed, the track laying and connection are completed, and finally the new railway and the existing line are restored to traffic together.

[0029] Preferably, in the said Step One, the pile foundation is constructed by the method of driving high-pressure jet grouting piles.

[0030] Preferably, in the said Step One, when the lateral distance between the new railway and the existing line is less than or equal to the predetermined safety distance, there is only one pier between two adjacent frame beams. The new railway and the existing line share this pier, and this single pier supports the entire cantilever post-cast section at this place.

[0031] When the lateral distance between the new railway and the existing line is greater than the predetermined safety distance, there are multiple piers between two adjacent frame beams. The new railway and the existing line respectively have their own piers below, and multiple piers jointly support the entire cantilever post-cast section at this place.

[0032] Preferably, in the said Step One, the piers newly built side by side horizontally are independent of the original piers, and their bearing platforms are not connected to form a whole.

[0033] Preferably, in the said Step Three, at the place where the main reinforcement bars of the top slab of the frame beam extend out, the number of the steel bars that need to extend out to be joints is increased.

[0034] As long as the above-mentioned preferred technical features do not conflict with each other, they can be combined with each other.

[0035] Generally speaking, compared with the prior art, the above technical solution conceived by the present invention has the following beneficial effects:

[0036] 1. The present invention proposes to achieve on-bridge connection by using the form of cast-in-place frame, forming a complete set of technologies to solve the problem of on-bridge connection, which can greatly reduce the project cost and save the construction period. Compared with the method of constructing a continuous beam of turnout by all-new design to achieve on-bridge connection, it has the advantages of rapid and convenient construction and significant cost reduction.

[0037] 2. The present invention proposes a new structural form to achieve on-bridge connection. This structure takes the cast-in-place large frame as the main body and reserves post-cast strips and steel bar joints. After the post-cast strips are poured, a continuous beam structure is formed, ensuring the feasibility of the scheme. Using this structural form to achieve on-bridge connection makes an important innovation for the project construction.

[0038] 3. The present invention proposes a supporting complete set of construction technologies in combination with this structural form and the situation of the project construction site, clarifies the construction sequence and construction methods, and ensures the feasibility of this structural form.

[0039] 4. The complete set of technologies for on-bridge connection of the present invention provides a perfect solution for the reconstruction and expansion projects of similar existing railway lines, can be widely promoted and applied, and promotes the development of the railway industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a side view schematic diagram of the on-bridge connection structure of the integral cast-in-place frame of the present invention;

[0041] Figure 2 is a top view schematic diagram of the on-bridge connection structure of the integral cast-in-place frame of the present invention;

[0042] Figure 3 is one of the process schematic diagrams of the construction method of the on-bridge connection structure of the integral cast-in-place frame of the present invention;

[0043] Figure 4 is Figure 3 a top view schematic diagram of;

[0044] Figure 5 is another process schematic diagram of the construction method of the on-bridge connection structure of the integral cast-in-place frame of the present invention;

[0045] Figure 6 is Figure 5 a top view schematic diagram of;

[0046] Figure 7 is the third process schematic diagram of the construction method of the on-bridge connection structure of the integral cast-in-place frame of the present invention;

[0047] Figure 8 is Figure 7 a top view schematic diagram of;

[0048] Figure 9It is the fourth process schematic diagram of the construction method of the on-bridge connection structure of the integral cast-in-place frame bridge of the present invention;

[0049] Figure 10 It is Figure 9 a top view schematic diagram of;

[0050] In the construction process structure schematic diagram, for the sake of simplicity and clarity of subsequent structures / steps, some components are appropriately omitted and not shown. Specific embodiments

[0051] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. The present invention will be further described in detail below in conjunction with the specific embodiments.

[0052] As a preferred embodiment of the present invention, as Figure 1-2 shown, the present invention provides an on-bridge connection structure for an integral cast-in-place frame bridge, which is used to realize the connection of a newly built railway 20 and an existing line 10 on the bridge. Among them: it includes a frame beam 1 of a cast-in-place structure, a cantilever post-cast section 2, and a pier 3.

[0053] The cast-in-place frame beam 1 is arranged between two adjacent piers 3 of the existing line 10, and its width is greater than the width of the original existing line bridge, and it is eccentrically arranged towards the newly built railway 20 on the outside; the lower part of the frame beam 1 is reinforced by pile foundations 4, and the elevation of its upper end surface is higher than the upper end surface of the pier 3 and reaches the rail surface elevation of the original existing line bridge. Preferably, the pile foundation 4 is a high-pressure jet grouting pile.

[0054] One or multiple piers 3 in the line transverse direction are arranged between two adjacent frame beams 1. Preferably, when the lateral distance between the newly built railway 20 and the existing line 10 is less than or equal to a predetermined safety distance, only one pier 3 is arranged between two adjacent frame beams 1, and the newly built railway 20 and the existing line 10 share this pier, and the single pier supports the entire cantilever post-cast section 2 at this place. When the lateral distance between the newly built railway 20 and the existing line 10 is greater than the predetermined safety distance, there are multiple piers 3 between two adjacent frame beams 1, and the newly built railway 20 and the existing line 10 respectively have their own piers, and the multiple piers jointly support the entire cantilever post-cast section 2 at this place.

[0055] Between two adjacent frame beams 1, they are connected to each other by extending a number of pre-buried reserved steel bar joints 5 and the cantilever post-cast section 2 with joints to each other.

[0056] The lower end surface of the cantilever post-cast section 2 is supported on the top of the pier 3.

[0057] Above the frame beam 1 and the cast-in-place cantilever post-cast section 2, a new railway 20, an existing line 10 and a turnout device are provided and used as a bridge for the new railway 20 and the existing line 10.

[0058] The present invention proposes to adopt the form of a cast-in-place frame to realize the connection on the bridge, forming a complete set of technologies to solve the problem of connection on the bridge, which can greatly reduce the project cost and save the construction period. Compared with the method of constructing a continuous turnout beam from scratch to realize the connection on the bridge, it has the advantages of rapid and convenient construction and significant cost reduction.

[0059] The present invention proposes a new structural form to realize the connection on the bridge. This structure takes the cast-in-place large frame as the main body and reserves the post-cast strip and steel bar joints. After the post-cast strip is poured, a continuous beam structure is formed, ensuring the feasibility of the scheme. Using this structural form to realize the connection on the bridge makes an important innovation for the project construction.

[0060] As Figure 3-10 shown, the following introduces the construction method of the integral cast-in-place frame connection on the bridge of the present invention, which is used to realize the connection on the bridge between the new railway 20 and the existing line 10. Among them, the following steps are included:

[0061] Step 1:

[0062] Starting from the initial state as Figure 3-4 shown, without interrupting the operation of the existing line 10, construct pile foundations 4 between two adjacent piers 3 of the existing line to reinforce the subgrade under the existing line; and horizontally and side by side, newly build piers 3 on the side of the original pier of the existing line close to the to-be-built new railway 20, as Figure 5-6 shown.

[0063] Preferably, in the first step, the pile foundation 4 is constructed by the method of jet grouting piles.

[0064] Preferably, in the first step, when the horizontal distance between the new railway 20 and the existing line 10 is less than or equal to the predetermined safety distance, only one pier 3 is provided between two adjacent frame beams 1, and the new railway 20 and the existing line 10 share this pier, and this single pier supports the entire cantilever post-cast section 2 at this place. When the horizontal distance between the new railway 20 and the existing line 10 is greater than the predetermined safety distance, there are multiple piers 3 between two adjacent frame beams 1, and the new railway 20 and the existing line 10 respectively have their own piers, and multiple piers jointly support the entire cantilever post-cast section 2 at this place.

[0065] Preferably, in the first step, the horizontally and side-by-side newly built piers are independent of the original piers, and their caissons are not connected to form a whole.

[0066] Step 2:

[0067] As Figure 5-6 shown, temporarily interrupt the operation of the existing line 10, demolish the simply supported existing line bridge 11 on the upper part of the pier 3, and retain the pier under the bridge.

[0068] Step Three:

[0069] As Figure 7-8 shown, at the position after demolishing the simply supported existing line bridge 11 beam, between two adjacent piers 3 of the existing line and on the pile foundation 4, immediately cast-in-place the frame beam 1, and its width is greater than the width of the original existing line bridge, and it is eccentrically set towards the to-be-built new railway 20 on the outside, and the elevation of the upper end surface exceeds the upper end surface of the pier 3 and reaches the track surface elevation of the original existing line bridge 11; between two adjacent frame beams 1, the main reinforcement of the top slab of the frame beam 1 extends out to form a reserved steel bar joint 5 for the cast-in-place belt on both sides of the reserved frame beam. Preferably, in the said Step Three, at the position where the main reinforcement of the top slab of the frame beam 1 extends out, the number of steel bars that need to extend out for the joint is increased.

[0070] Step Four:

[0071] As Figure 9-10 shown, between two adjacent piers 3 and on the pier 3, cast-in-place the cantilever post-cast section 2 where the frame of the reserved steel bar joint 5 extends out to be connected to each other.

[0072] Step Five:

[0073] After both the frame beam 1 and the cantilever post-cast section 2 reach the age, lay the second permanent load of the bridge deck including the ballast ancillary project on the frame beam 1 and the cantilever post-cast section 2, construct the new railway 20, the existing line 10 and the turnout device, complete the track laying and connection, and finally the new railway 20 and the existing line 10 resume traffic together. The finally formed structural form is as Figure 1-2 shown.

[0074] The construction schedule of this embodiment is as follows:

[0075]

[0076]

[0077] The present invention does not limit the number of spans. For more spans, the construction method is the same, and only the same structure needs to be added.

[0078] As a further preferred solution, the shape of the frame beam 1 and the cantilever post-cast section 2 in the top view is selected as a trapezoid, or the frame beam 1 is a combination of a trapezoid and an equal-width rectangle.

[0079] Through the above on-bridge connection technology, the present invention has achieved the following remarkable beneficial effects:

[0080] The present invention proposes to achieve on-bridge connection by using the form of cast-in-place frame, forming a complete set of technologies to solve the problem of on-bridge connection, which can greatly reduce the project cost and save the construction period. Compared with the practice of newly designing and constructing a turnout continuous beam to achieve on-bridge connection, it has the advantages of rapid and convenient construction and significant cost reduction.

[0081] The present invention proposes a new structural form to achieve on-bridge connection. The structure takes the cast-in-place large frame as the main body and reserves post-cast strips and steel bar joints. After the post-cast strips are poured, a continuous beam structure is formed, ensuring the feasibility of the scheme. Using this structural form to achieve on-bridge connection makes an important innovation for the project construction.

[0082] The present invention proposes a supporting complete set of construction technologies in combination with this structural form and the situation of the project work points, clarifies the construction sequence and construction methods, and ensures the feasibility of this structural form.

[0083] The complete set of technologies for on-bridge connection of the present invention provides a perfect solution for the reconstruction and expansion projects of similar existing railway lines, can be widely promoted and applied, and promotes the development of the railway industry.

[0084] Those skilled in the art can easily understand that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An integral cast-in-place frame bridge track connection structure, used for connecting a newly built railway (20) with an existing railway (10) on a bridge, Features: It comprises a frame beam (1) of a cast-in-place structure, a cantilever post-cast section (2), and a bridge pier (3); The cast-in-place frame beam (1) is arranged between two adjacent bridge piers (3) of the existing line (10), and its width is greater than the width of the original bridge of the existing line, and is eccentrically arranged toward the newly built railway (20) on the outside; the lower part of the frame beam (1) is reinforced by a pile foundation (4), and the elevation of its upper end surface is higher than the upper end surface of the bridge pier (3); A plurality of bridge piers (3) are arranged transversely of the line between two adjacent frame beams (1); the newly-built bridge piers and the original bridge piers arranged transversely are independent of each other, and the caps of the two piers are not connected to each other to form a whole; Two adjacent frame beams (1) are connected to each other by extending a plurality of pre-buried reserved steel bar joints (5) and a cantilever post-cast section (2) of the joint band toward each other; The lower end surface of the cantilever post-cast section (2) is supported on the top of the pier (3); A newly built railway (20), an existing line (10) and a turnout device are arranged above the frame beam (1) and the cantilever post-cast section (2), and are used as a bridge between the newly built railway (20) and the existing line (10).

2. The integral cast-in-place frame bridge upper track connection structure as claimed in claim 1, Features: When the lateral spacing between the newly constructed railway (20) and the existing line (10) is less than or equal to a predetermined safety distance, only one pier (3) is provided between two adjacent frame beams (1), the newly constructed railway (20) and the existing line (10) share the pier, and the single pier supports the entire cantilever post-cast section (2) at that location.

3. The integral cast-in-place frame bridge upper track connection structure as claimed in claim 1, Features: When the lateral spacing between the newly constructed railway (20) and the existing line (10) is greater than a predetermined safety distance, a plurality of bridge piers (3) are provided between two adjacent frame beams (1), and each of the newly constructed railway (20) and the existing line (10) has its own bridge pier, and the plurality of bridge piers jointly support the entire cantilever post-cast section (2) there.

4. The integral cast-in-place frame bridge upper track connection structure as claimed in claim 1, Features: The pile foundation (4) is a high-pressure jet-jet pile.

5. A method for connecting rails on an integral cast-in-place frame bridge, used for connecting a newly built railway (20) with an existing railway (10) on a bridge. It is characterized in that The steps include: Step 1: Without interrupting the operation of the existing line (10), a pile foundation (4) is constructed between two adjacent bridge piers (3) of the existing line to reinforce the roadbed below the existing line; and new bridge piers (3) are constructed side by side horizontally on the side of the original bridge pier of the existing line close to the new railway (20) to be built; Step 2: Temporarily suspending the operation of the existing line (10), dismantling the existing line bridge (11) simply supported above the bridge pier (3), and retaining the bridge pier under the bridge; Step 3: At the position after demolishing the simply supported existing line bridge (11) beam, between two adjacent piers (3) of the existing line and on the pile foundation (4), a cast-in-place frame beam (1) is immediately constructed, and its width is greater than the width of the original existing line bridge, and it is eccentrically set towards the newly built railway (20) to be constructed on the outside. The elevation of the upper end surface exceeds the upper end surface of the pier (3) and reaches the track surface elevation of the original existing line bridge (11); between two adjacent frame beams (1), the main reinforcement bars of the top slab of the frame beam (1) extend out to form a reserved steel bar joint (5) for the cast-in-place belt on both sides of the frame. Step Four: Between two adjacent piers (3) and on the piers (3), the cantilever post-cast segments (2) where the frames of the reserved steel bar joints (5) extend are connected to each other. Step Five: After the frame beam (1) and the cantilever post-cast segment (2) both reach the age, the second-stage permanent load of the bridge deck including the ballast auxiliary project is laid on the frame beam (1) and the cantilever post-cast segment (2). The newly built railway (20), the existing line (10) and the turnout device are constructed, the track laying and connection are completed, and finally the newly built railway (20) and the existing line (10) are restored to traffic together.

6. The construction method for connecting tracks on the integrally cast-in-place frame bridge as described in claim 5, characterized in that: In the said Step One, the pile foundation (4) is constructed by the method of driving high-pressure jet grouting piles.

7. The construction method for connecting tracks on the integrally cast-in-place frame bridge as described in claim 5, characterized in that: In the said Step One, when the lateral distance between the newly built railway (20) and the existing line (10) is less than or equal to the predetermined safety distance, there is only one pier (3) between two adjacent frame beams (1). The newly built railway (20) and the existing line (10) share this pier, and a single such pier supports the entire cantilever post-cast segment (2) at this place; When the lateral distance between the newly built railway (20) and the existing line (10) is greater than the predetermined safety distance, there are multiple piers (3) between two adjacent frame beams (1). The newly built railway (20) and the existing line (10) respectively have their own piers below, and multiple piers jointly support the entire cantilever post-cast segment (2) at this place.

8. The construction method for connecting tracks on the integrally cast-in-place frame bridge as described in claim 7, characterized in that: In the said Step One, the piers newly built side by side horizontally are independent of the original piers, and their caissons are not connected to form a whole.

9. The construction method for connecting tracks on the integrally cast-in-place frame bridge as described in claim 5, characterized in that: In the said Step Three, at the place where the main reinforcement bars of the top slab of the frame beam (1) extend out, the number of the steel bars that need to extend out to be joints is increased.

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