A cast-in-place and prefabricated combined structure and construction method for bridge rail connection

Abstract

The present invention discloses a combined structure of bridge track connection combining cast-in-place and prefabrication, which is used for connecting a newly built railway with an existing line on a bridge, and comprises a large frame of cast-in-place structure and a small frame of prefabricated structure; the large frame of cast-in-place 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 on the outside; the lower part of the large frame is reinforced by a pile foundation, and its upper end face is flush with the upper end face of the bridge pier; a plurality of prefabricated small frames are transversely arranged on the large frame, and straddled between two adjacent large frames and on the bridge pier; the newly built railway, the existing line and the turnout device are arranged above the small frame, and are used as a bridge between the newly built railway and the existing line. The present invention solves the problem of track connection on the bridge, can greatly save the construction period, reduce the downtime of the existing line, and reduce social costs.

Description

Technical Field

[0001] The invention belongs to the field of reconstruction and expansion of existing railway lines, and specifically relates to a new bridge track connection technology combining cast-in-place and prefabrication. Background Art

[0002] The connection of newly built railways with existing lines is usually completed at the roadbed section. Currently, there is no engineering example of achieving track connection on a bridge on an existing railway.

[0003] The railway connection is inseparable from the turnout structure, which is complex in force, easy to damage, and difficult to replace. In order to ensure the durability of the turnout structure and the safety of the railway, the specification requires that the turnout structure must be arranged on the overall continuous bridge deck when it is located on the bridge. At the same time, the distance between the turnout tip and the beam joint must be greater than or equal to 18m. Therefore, when the turnout is located on the bridge, the traditional method is to use a multi-hole continuous beam and control the span-flexure ratio to no more than 1 / 4000. The span is generally no more than 48m. According to the model and length of the turnout, 6-32m, 4-32m or 3-32m equal-width or variable-width continuous beams are often used.

[0004] If the track connection technology of the roadbed section is copied to guide the track connection on the bridge, that is, the operation of the existing line will be interrupted, and the existing superstructure beams and bridge piers will be dismantled, and the turnout continuous beams and supporting bridge piers and foundations will be constructed according to a newly designed design, this plan has obvious disadvantages. The operation of the existing line needs to be interrupted, and the construction of the new turnout bridge and piers needs to be completed as quickly as possible according to the design drawings. It is conservatively estimated that it will take about half a year to interrupt the operation of the existing line, and the price and cost are relatively high.

[0005] Therefore, achieving track connection on the bridge often requires high engineering costs and takes a long time. The long construction period significantly increases the economic and social costs.

[0006] However, in some railway projects, it is necessary to connect the newly built railway with the existing railway on a bridge at a certain construction site, but the existing technology lacks such a bridge connection form and a complete set of technologies to solve these problems. Summary of the invention

[0007] In response to at least one of the above defects or improvement needs in the prior art, the present invention provides a combined structure form and construction method for bridge track connection that combines cast-in-place and prefabrication, forming a complete set of technology to solve the problem of bridge track connection, which can greatly save construction period, reduce the downtime of existing lines, and reduce social costs. It also proposes a brand-new structural form, makes important innovations, and proposes a matching set of construction technology to match the structural form, which can be widely promoted and applied, providing a complete solution for the reconstruction and expansion projects of similar existing railway lines.

[0008] To achieve the above-mentioned purpose, according to one aspect of the present invention, a construction method for track connection on a bridge combining cast-in-place and prefabrication is provided, which is used for connecting a newly built railway with an existing line on a bridge, and includes the following steps:

[0009] Step 1:

[0010] Without interrupting the operation of the existing line, a pile foundation is constructed between two adjacent bridge piers of the existing line to reinforce the roadbed below the existing line, and a large frame is cast on the pile foundation and under the bridge of the existing line. Its width is greater than that of the bridge of the existing line and is eccentrically set toward the new railway to be built outside. Between the two adjacent large frames, in the outer direction of the middle bridge pier, the main reinforcement of the top plate of the large frame extends out, making it a reserved steel bar joint for the cast-in-place belt of the large frames on both sides;

[0011] Step 2:

[0012] Simultaneously, a small frame that can be hoisted is prefabricated in the factory and transported to the construction site;

[0013] Step 3:

[0014] After the cast-in-place large frame reaches the concrete age and design strength, the operation of the existing line is temporarily suspended, the existing line bridge with simple supports on the upper part of the pier is dismantled, and part of the pier body cap is chiseled off to make the pier elevation flush with the top of the large frame; the construction pouring is completed at the cast-in-place joint zone of the large frame;

[0015] Step 4:

[0016] When the cast-in-place joint strip of the large frame reaches the age, the prefabricated small frame is hoisted and erected on the large frame to form a longitudinal continuous support for the line, which is used as the construction foundation for new railways, existing lines and turnout devices, and new bridges;

[0017] Step 5:

[0018] The second section of the bridge deck including the ballast ancillary works is laid on the small frame, and the new railway, existing line and switch devices are constructed to complete track laying and connection. Finally, the new railway and existing line are reopened to traffic together.

[0019] Preferably, in step one, the pile foundation is constructed by high-pressure rotary jetting.

[0020] Preferably, in the step 1, at the place where the main reinforcement of the top plate of the large frame extends out, the number of steel bars that need to be extended to serve as joints is increased.

[0021] Preferably, in step 2, when the small frame is prefabricated, the maximum length of the small frame in the transverse direction of the line is required to be equal to or less than the width of the large frame, and the minimum length can ensure the installation of new railways, existing lines and turnout devices.

[0022] Preferably, in the step 2, the small frames are prefabricated in two categories, including an intermediate small frame and a spanning small frame;

[0023] In the step 4, a plurality of the intermediate small frames are hoisted and installed directly above the large frame, and a single spanning small frame is hoisted and installed between two adjacent large frames and supported on the bridge piers.

[0024] Preferably, in step 4, before the cast-in-place joint strips of the large frame reach the age, a number of the intermediate small frames are hoisted and installed directly above the large frame; after the cast-in-place joint strips of the large frame reach the age, the remaining single spanning small frames are hoisted and installed between two adjacent large frames and supported on the piers.

[0025] To achieve the above-mentioned purpose, according to another aspect of the present invention, a combined structure of bridge track connection combining cast-in-place and prefabrication is provided, which is used for connecting a newly built railway with an existing line on a bridge, wherein:

[0026] It includes large frames of cast-in-place structures and small frames of prefabricated structures;

[0027] The cast-in-place large frame is arranged between two adjacent bridge piers of the existing line, and its width is greater than the width of the original existing bridge, and is eccentrically arranged toward the newly built railway outside; the lower part of the large frame is reinforced by a pile foundation, and its upper end surface is flush with the upper end surface of the bridge pier; the two adjacent large frames are connected to each other in the outer direction of the middle bridge pier by extending a number of pre-buried reserved steel bar joints and cast-in-place concrete of the joint belt toward each other;

[0028] The prefabricated small frames are horizontally arranged on the large frame, and straddled between two adjacent large frames and on the piers; the newly built railway, the existing line and the switch device are arranged above the small frames, and are used as a bridge between the newly built railway and the existing line.

[0029] Preferably, the maximum length of the small frame in the transverse direction of the line is equal to or less than the width of the large frame, and the minimum length thereof can ensure the installation of a new railway, an existing line and a switch device.

[0030] Preferably, the small frame includes an intermediate small frame and a spanning small frame;

[0031] A plurality of the intermediate small frames are arranged directly above the large frames, and a single spanning small frame is spanned between two adjacent large frames and supported on the bridge piers.

[0032] Preferably, the intermediate small frame and the spanning small frame have the same length in the transverse direction of the line.

[0033] The above-mentioned preferred technical features can be combined with each other as long as they do not conflict with each other.

[0034] In general, the above technical solution conceived by the present invention has the following beneficial effects compared with the prior art:

[0035] 1. The present invention proposes a new cast-in-place and prefabricated combined structure and construction method for bridge track connection, forming a complete set of technology to solve the bridge track connection problem, which can greatly save the construction period, reduce the downtime of existing lines, and reduce social costs.

[0036] 2. The present invention also proposes a new structural form, which uses a cast-in-place large frame and a prefabricated small frame as the main structure. The feasibility of the scheme is guaranteed by reserving steel bar joints. The use of this structural form to achieve bridge connection has made important innovations in the construction of the project.

[0037] 3. The present invention proposes a complete set of construction technologies in accordance with the structural form and the conditions of the project site, clarifies the construction sequence and construction methods, and ensures the feasibility of the structural form.

[0038] 4. The complete set of bridge track connection technology of the present invention provides a perfect solution for the reconstruction and expansion projects of similar existing railway lines, and can be widely promoted and applied to promote the development of the railway industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a side view schematic diagram of the combined structure of the cast-in-situ and prefabricated bridge rail connection of the present invention;

[0040] Figure 2 It is a top view schematic diagram of the combined structure of the cast-in-situ and prefabricated bridge rail connection of the present invention;

[0041] Figure 3 This is one of the process schematic diagrams of the construction method of the combined structure of the bridge track connected by combining cast-in-situ and prefabrication according to the present invention;

[0042] Figure 4 yes Figure 3 A top view schematic diagram of

[0043] Figure 5 This is the second process schematic diagram of the construction method of the combined structure of the bridge track connection combining the cast-in-situ and prefabricated structures of the present invention;

[0044] Figure 6 yes Figure 5 A top view schematic diagram of

[0045] Figure 7 This is the third process schematic diagram of the construction method of the combined structure of the bridge track connected by combining cast-in-situ and prefabrication of the present invention;

[0046] Figure 8 yes Figure 7 A top view schematic diagram of

[0047] Fig. 9 This is the fourth process schematic diagram of the construction method of the combined structure of the bridge track connected by combining cast-in-situ and prefabrication of the present invention;

[0048] Fig.10 yes Fig. 9 Schematic diagram of top view

[0049] In the structural diagram of the construction process, some components are appropriately omitted for the sake of simplicity and clarity of subsequent structures / steps. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is 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 intended to limit the present invention. In addition, the technical features involved in each embodiment 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 is further described in detail below in conjunction with specific embodiments.

[0051] As a preferred embodiment of the present invention, Figure 1-2 As shown, the present invention provides a new cast-in-place and prefabricated combined structure for connecting tracks on a bridge, which is used to connect a newly built railway 20 with an existing line 10 on a bridge, and includes a large frame 1 of a cast-in-place structure and a small frame 2 of a prefabricated structure.

[0052] The cast-in-place large frame 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 is eccentrically arranged toward the newly built railway 20 on the outside; the lower part of the large frame 1 is reinforced by a pile foundation 4, and its upper end surface is flush with the upper end surface of the pier 3; between two adjacent large frames 1, in the outer direction of the middle pier 3, they are connected to each other by extending a number of pre-buried reserved steel bar joints 5 toward each other and cast-in-place concrete of the joint belt.

[0053] The prefabricated small frames 2 are horizontally arranged on the large frame 1, and span between two adjacent large frames and on the piers 3; the newly built railway 20, the existing line 10 and the switch device are arranged above the small frames 2, and are used as a bridge between the newly built railway 20 and the existing line 10.

[0054] The maximum length of the small frame 2 in the transverse direction of the line is equal to or less than the width of the large frame 1, and the minimum length thereof can ensure the installation of a new railway 20, an existing line 10 and a switch device.

[0055] The small frame 2 includes an intermediate small frame 21 and a spanning small frame 22; a plurality of the intermediate small frames 21 are arranged directly above the large frame 1, and a single spanning small frame 22 is spanned between two adjacent large frames and supported on the pier 3. Preferably, the intermediate small frame 21 and the spanning small frame 22 have the same length in the transverse direction of the line.

[0056] like Figure 3-10 As shown, the following describes the construction method of the bridge track connection combining cast-in-situ and prefabrication of the present invention, which is used to connect the newly built railway 20 with the existing line 10 on the bridge, wherein the following steps are included:

[0057] Step 1:

[0058] like Figure 3-4 As shown, 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 a large frame 1 is cast on the pile foundation 4 and under the bridge 11 of the existing line. Its width is greater than the width of the bridge 11 of the existing line, and it is eccentrically arranged toward the new railway 20 to be built outside; between two adjacent large frames 1, in the outer direction of the middle bridge pier 3, the main reinforcement of the top plate of the large frame 1 extends out, so that it becomes a reserved steel bar joint 5 for the cast-in-place strips of the large frames on both sides. Preferably, in the step one, the construction of the pile foundation 4 adopts the method of high-pressure rotary jet pile. Preferably, in the step one, at the place where the main reinforcement of the top plate of the large frame 1 extends out, the number of steel bars that need to be extended as joints is increased.

[0059] Step 2:

[0060] Simultaneously, a small frame 2 that can be hoisted is prefabricated in the factory and transported to the construction site. Preferably, in the step 2, when the small frame 2 is prefabricated, the maximum length of the small frame 2 in the transverse direction of the line is required to be equal to or less than the width of the large frame 1, and the minimum length can ensure the installation of a new railway 20, an existing line 10 and a turnout device. Preferably, in the step 2, the small frame 2 is divided into two categories for prefabrication, including an intermediate small frame 21 and a spanning small frame 22. Preferably, the intermediate small frame 21 and the spanning small frame 22 have equal lengths in the transverse direction of the line.

[0061] Step 3:

[0062] like Figure 5-6As shown, after the cast-in-place large frame 1 reaches the concrete age and design strength, the operation of the existing line 10 is temporarily interrupted, the existing line bridge 11 with simple supports on the upper part of the pier 3 is dismantled, and part of the pier body top cap is chiseled off so that the elevation of the pier 3 is flush with the top of the large frame 1 (it takes one day); the construction and pouring are completed at the cast-in-place joint strip of the large frame (it takes ten days). The new railway is connected to the existing railway on the bridge, and the required width is greater than the original beam width. The transverse width of the existing piers is insufficient and can only support part of the small frame. The cast-in-place joint strip of the large frame of the present invention not only connects the large frame longitudinally, but also provides good support for the small frame.

[0063] Step 4:

[0064] like Figure 7-8 As shown, after the cast-in-place joint strip of the large frame reaches the age, the prefabricated small frame 2 is hoisted and erected on the large frame 1 to form a longitudinal continuous support for the line, which is used as the construction foundation of the new railway 20, the existing line 10 and the turnout device and the new bridge (it takes one day). Preferably, in the step four, a number of the intermediate small frames 21 are hoisted and erected directly above the large frame 1, and a single spanning small frame 22 is hoisted and spanned between two adjacent large frames and supported on the pier 3. Preferably, in the step four, before the cast-in-place joint strip of the large frame reaches the age, a number of the intermediate small frames 21 are hoisted and erected directly above the large frame 1; after the cast-in-place joint strip of the large frame reaches the age, the remaining single spanning small frame 22 is hoisted and spanned between two adjacent large frames and supported on the pier 3.

[0065] Step 5:

[0066] like Figure 9-10 As shown, the second bridge deck including ballast ancillary works is laid on the small frame 2, the new railway 20, the existing line 10 and the switch device are constructed, the track laying and connection are completed, and finally the new railway 20 and the existing line 10 are reopened to traffic together.

[0067] 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.

[0068] As a further preferred solution, the shape of the large frame 1 and / or the small frame 2 in a top view is a trapezoid, or a combination of a trapezoid and an equal-width rectangle.

[0069] In the present invention, the large frame is cast-in-place under the existing line bridge, so the operation of the existing line can be not interrupted, and the small frame can be prefabricated simultaneously. After prefabrication, it is directly hoisted on the large frame. Before hoisting, the simply supported beam above the large frame needs to be removed. This combination of prefabrication and cast-in-place can greatly save construction time.

[0070] Through the above technical solution, the present invention achieves the following significant beneficial effects:

[0071] The present invention proposes a new cast-in-place and prefabricated combined structure and construction method for track connection on a bridge, forming a complete set of technology to solve the problem of track connection on a bridge, which can greatly save the construction period, reduce the downtime of existing lines, and reduce social costs.

[0072] The present invention also proposes a new structural form, which uses a cast-in-place large frame and a prefabricated small frame as the main structure, and ensures the feasibility of the scheme by reserving steel bar joints. The use of this structural form to achieve track connection on the bridge has made important innovations in the construction of the project.

[0073] The present invention proposes a complete set of construction technologies in accordance with the structural form and the conditions of the project site, clarifies the construction sequence and construction method, and ensures the feasibility of the structural form.

[0074] The complete set of bridge track connection technology 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 promote the development of the railway industry.

[0075] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A construction method for connecting a new railway (20) with an existing railway (10) on a bridge by combining cast-in-place and prefabrication, 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 a large frame (1) is cast on the pile foundation (4) and under the bridge (11) of the existing line. The large frame (1) has a width greater than that of the bridge (11) of the existing line and is eccentrically arranged toward the new railway (20) to be built on the outside. Between the two adjacent large frames (1) and in the outer direction of the middle bridge pier (3), the main reinforcement of the top plate of the large frame (1) extends out to form a reserved reinforcement joint (5) for the cast-in-place belts of the large frames on both sides. Step 2: Simultaneously, a small frame (2) that can be hoisted is prefabricated in the factory and transported to the construction site; Step 3: After the cast-in-place large frame (1) reaches the concrete age and design strength, the operation of the existing line (10) is temporarily suspended, the existing line bridge (11) with simple support on the upper part of the pier (3) is dismantled, and part of the pier body cap is chiseled off so that the elevation of the pier (3) is flush with the top of the large frame (1); the construction and pouring are completed at the cast-in-place joint zone of the large frame; Step 4: When the cast-in-place joint strip of the large frame reaches the age, the prefabricated small frame (2) is hoisted and erected on the large frame (1) to form a longitudinal continuous support for the line, which is used as the construction foundation for the new railway (20), the existing line (10) and the turnout device and the new bridge; Step 5: The bridge deck including the ballast auxiliary works is laid on the small frame (2), and the new railway (20), the existing line (10) and the turnout device are constructed to complete the track laying and connection. Finally, the new railway (20) and the existing line (10) are reopened to traffic together.

2. The construction method of the bridge track connection combining cast-in-situ and prefabrication as claimed in claim 1, characterized in that: In the step 1, the construction of the pile foundation (4) is carried out by high-pressure jetting piles.

3. The construction method of the bridge track connection combining cast-in-situ and prefabrication as claimed in claim 1, characterized in that: In the step 1, at the point where the main reinforcement of the top plate of the large frame (1) extends out, the number of reinforcement bars that need to be extended out to form a joint is increased.

4. The construction method of the bridge track connection combining cast-in-situ and prefabrication as claimed in claim 1, characterized in that: In the step 2, when the small frame (2) is prefabricated, the maximum length of the small frame (2) in the transverse direction of the line is required to be equal to or less than the width of the large frame (1), and the minimum length can ensure the installation of a new railway (20), an existing line (10) and a switch device.

5. The construction method of the bridge track connection combining cast-in-situ and prefabrication as claimed in claim 4 is characterized by: In the step 2, the small frames (2) are divided into two types for prefabrication, including an intermediate small frame (21) and a spanning small frame (22); In step 4, a plurality of the intermediate small frames (21) are hoisted and installed directly above the large frame (1), and a single spanning small frame (22) is hoisted and installed between two adjacent large frames and supported on the bridge piers (3).

6. The construction method of the bridge track connection combining cast-in-situ and prefabrication as claimed in claim 5, characterized in that: In step 4, before the cast-in-place joint strip of the large frame reaches its age, a number of the intermediate small frames (21) are hoisted and installed directly above the large frame (1); after the cast-in-place joint strip of the large frame reaches its age, the remaining single spanning small frames (22) are hoisted and installed between two adjacent large frames and supported on the piers (3).

7. A cast-in-place and prefabricated combined track-connecting structure on a bridge, used for connecting a newly built railway (20) with an existing railway (10) on a bridge, characterized in that: It includes a large frame (1) of a cast-in-place structure and a small frame (2) of a prefabricated structure; The cast-in-place large frame (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 existing line bridge, and is eccentrically arranged toward the newly built railway (20) on the outside; the lower part of the large frame (1) is reinforced by a pile foundation (4), and its upper end surface is flush with the upper end surface of the bridge pier (3); the two adjacent large frames (1) are connected to each other in the outer direction of the middle bridge pier (3) by extending a plurality of pre-buried reserved steel bar joints (5) toward each other and the cast-in-place concrete of the joint belt; A plurality of prefabricated small frames (2) are transversely arranged on the large frame (1), and are straddled between two adjacent large frames and on the piers (3); a newly built railway (20), an existing line (10) and a switch device are arranged above the small frames (2) to serve as a bridge between the newly built railway (20) and the existing line (10).

8. The cast-in-situ and prefabricated combined bridge track structure as claimed in claim 7, characterized in that: The maximum length of the small frame (2) in the transverse direction of the line is equal to or less than the width of the large frame (1), and its minimum length can ensure the installation of a newly built railway (20), an existing line (10) and a turnout device.

9. The cast-in-situ and prefabricated combined bridge track structure as claimed in claim 8, characterized in that: The small frame (2) comprises an intermediate small frame (21) and a spanning small frame (22); A plurality of the intermediate small frames (21) are arranged directly above the large frame (1), and a single spanning small frame (22) is spanned between two adjacent large frames and supported on the bridge pier (3).

10. The cast-in-situ and prefabricated bridge track combination structure as claimed in claim 9, characterized in that: The intermediate small frame (21) and the spanning small frame (22) have the same length in the transverse direction of the line.

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