A beam end processing structure and method for railway segment prefabricated assembly beam

Abstract

A railway segment prefabricated assembled beam end processing structure, the segment prefabricated assembled beam end segment is composed of a top plate, a web plate, and a bottom plate, the top plate is located at the top of the segment prefabricated assembled beam end segment, the web plate is located in the middle of the segment prefabricated assembled beam end segment, and the bottom plate is located at the bottom of the segment prefabricated assembled beam end segment, a top plate notch is provided in the middle of the top plate, an anchor is embedded in the top plate notch, cantilevers are provided on both sides of the top plate notch along the edge of the top plate, web plate notches are provided on both sides of the web plate, and the web plate notches are provided on both sides of the web plate. An embedded anchor is provided in the slot, a bottom plate slot is provided in the middle of the bottom plate, an embedded anchor is provided in the bottom plate slot, additional boots are provided on both sides of the bottom plate slot, a support is provided at the bottom of the bottom plate, and steel bundles are provided in the embedded anchors. The slot size opened in the above scheme is smaller, which has less impact on the structure and is not easy to crack after anchoring; the additional boot structure at the beam end can avoid excessive turning angle of the beam end and ensure the stiffness of the segmented prefabricated assembled beam; at the same time, after anchoring, a concave structure is formed in the middle of the beam end face for inspection and maintenance personnel to pass through.

Description

Technical Field

[0001] The invention belongs to the field of bridge structure construction, and in particular relates to a beam end processing structure and method for a railway segment prefabricated assembled beam. Background Art

[0002] When constructing prestressed concrete beams using the segmental prefabrication method, the steel strands need to be tensioned and anchored on the beam end faces at the construction site. Since the steel strands and tensioning jacks of the segmental prefabricated assembly beams are large in size, and the width of the railway bridge beam seam is only 10-15cm, the working space of the jacks is limited. The current solution is to open larger and deeper tensioning grooves on the beam end faces. However, this solution is inconvenient to operate the jacks, and the excessively large grooves are not conducive to the stress on the structure, and are prone to cracking after anchoring. If only the top plate cantilever is set, the distance between the support center and the beam seam center is too large, and the beam end rotation angle is too large under the action of live load, which reduces the stiffness of the beam. Summary of the invention

[0003] The present invention provides a railway segment prefabricated assembled beam end processing structure and method, aiming to solve the problems of the prior art and provide a railway segment prefabricated assembled beam end processing structure and method which has little impact on the structure, has a small beam end rotation angle, and is easy to maintain.

[0004] The technical solution adopted by the present invention to solve the problem is:

[0005] A railway segment prefabricated assembled beam end processing structure comprises a segment prefabricated assembled beam end segment, characterized in that the segment prefabricated assembled beam end segment consists of a top plate, a web plate, and a bottom plate, the top plate is located at the top of the segment prefabricated assembled beam end segment, the web plate is located in the middle of the segment prefabricated assembled beam end segment, the bottom plate is located at the bottom of the segment prefabricated assembled beam end segment, and at one side of the beam end face, a top plate notch is provided in the middle of the top plate, an anchor is embedded in the top plate notch, cantilevers are provided on both sides of the top plate notch along the edge of the top plate, web plate notches are provided on both sides of the web plate, embedded anchors are provided in the web plate notches, a bottom plate notch is provided in the middle of the bottom plate, embedded anchors are provided in the bottom plate notch, boots are provided on both sides of the bottom plate notch, a support is provided at the bottom of the bottom plate, and steel bundles are provided in the embedded anchors.

[0006] A "mouth"-shaped opening is arranged in the middle of the web.

[0007] The cantilever and the shoe are consistent in thickness relative to the beam end segment.

[0008] The end segment of the segmented prefabricated assembled beam is a prefabricated concrete beam segment.

[0009] Reinforcing ribs are embedded in the cantilever and the boot.

[0010] The cantilever and the shoe have the same length.

[0011] The steel bundle arranged in the embedded anchor is a tensioned steel bundle.

[0012] The steel bundles arranged in the top plate are tensioned at one end on the side away from the beam end, and the steel bundles arranged in the web plate and the steel bundles arranged in the bottom plate are tensioned at both ends.

[0013] The method for processing the ends of railway segment prefabricated assembled beams according to claim 1 is characterized in that:

[0014] Step 1: Make the segment template of the segment prefabricated assembly beam end according to the design size, and leave the top plate notch, web plate notch, bottom plate notch and the position of the cantilever and the shoe;

[0015] Step 2: Prefabricate the segmental assembly beams and make a steel cage inside the segmental template at the end of the beam, and set reinforcing steel bars at the cantilever and the boot position;

[0016] Step 3: Position and embed the steel bundle pipes, anchors and supports in the reserved top plate slots, web plate slots and bottom plate slots respectively.

[0017] Step 4: Use concrete to cast the segmental prefabricated assembled beam end segment formwork, vibrate and maintain.

[0018] Step 5. Transport the cast segmental prefabricated assembled beam end segments to the construction site, apply glue, and assemble them. Then, tension the steel bundles in the steel bundle pipes pre-buried in step 3, and fix the tensioned steel bundles by grouting. The steel bundles in the top plate are tensioned at one end on the side away from the beam end, and the steel bundles in the web and the bottom plate are tensioned at both ends.

[0019] Step six: implant anchor steel bars in the top plate grooves, web plate grooves and bottom plate grooves, seal the anchors, smooth the top plate grooves, web plate grooves and bottom plate grooves, and perform maintenance.

[0020] Beneficial effects of the present invention:

[0021] 1. The tensioning notch provided in the present invention is small in size, has little impact on the structure, and is not prone to cracking after anchoring.

[0022] 2. The shoe structure at the beam end of the present invention can prevent the beam end from turning too much, thereby ensuring the rigidity of the segmental prefabricated assembled beam.

[0023] 3. After the present invention sets the boots on both sides of the beam end surface, a concave structure can be formed with the middle end surface of the beam for inspection and maintenance personnel to walk along. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a front view of the present invention;

[0025] Figure 2 is a side view of the present invention;

[0026] Figure 3 It is the reinforcing steel bar arrangement diagram of the present invention.

[0027] in:

[0028] 1. Segmental prefabricated assembled beam end segment; 2. Cantilever; 3. Add boot; 4. Steel bundle; 5. Embedded anchor; 6. Top plate notch; 7. Steel bundle; 8. Embedded anchor; 9. Web notch; 10. Steel bundle; 11. Embedded anchor; 12. Bottom plate notch; 13. Support; 14. Reinforcement steel bar; 15. Reinforcement steel bar; 16. Top plate; 17. Web plate; 18. Bottom plate; 19. "Mouth" shaped opening. DETAILED DESCRIPTION

[0029] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and embodiments:

[0030] like Figure 1-3 As shown, a railway segment prefabricated assembled beam end processing structure includes a segment prefabricated assembled beam end segment, the segment prefabricated assembled beam end segment 1 is a concrete beam prefabricated segment, and is composed of a top plate 16, a web 17, and a bottom plate 18. The top plate 16 is located at the top of the segment prefabricated assembled beam end segment 1, the web 17 is located in the middle of the segment prefabricated assembled beam end segment 1, and the bottom plate 18 is located at the bottom of the segment prefabricated assembled beam end segment 1. On one side of the beam end face, a top plate notch 6 is provided in the middle of the top plate 16, and an anchor 5 is embedded in the top plate notch 6. Cantilevers 2 are provided on both sides of the top plate notch 6 along the edge of the top plate 16, and web notches 9 are provided on both sides of the web 17, and embedded anchors 8 are provided in the web notches 9. A bottom plate notch 12 is provided in the middle of the bottom plate 18, an embedded anchor 11 is provided in the bottom plate notch 12, and additional boots 13 are provided on both sides of the bottom plate notch 12. A support 13 is provided at the bottom of the bottom plate 18, and steel bundles 4, steel bundles 7, and steel bundles 10 are respectively provided in the embedded anchors 5, embedded anchors 8, and embedded anchors 11. A "mouth"-shaped opening 19 is provided in the middle of the web 17. The cantilever 2 and the additional boot 3 have the same thickness relative to the beam end segment, and reinforcing steel bars 14 and reinforcing steel bars 15 are respectively embedded in the cantilever 2 and the additional boot 3. The cantilever 2 and the additional boot 3 have the same length, and the steel bundles 4, steel bundles 7, and steel bundles 10 respectively provided in the embedded anchors 5, embedded anchors 8, and embedded anchors 11 are all tensioned steel bundles.

[0031] The steel bundle 4 provided in the top plate 16 is tensioned at one end on the side away from the beam end, and the steel bundle 7 provided in the web plate 17 and the steel bundle 10 provided in the bottom plate 18 are tensioned at both ends.

[0032] The method for processing the end of a railway segment prefabricated assembly beam is as follows:

[0033] Step 1: Make the segment template of the segment prefabricated assembly beam end according to the design size, and leave the top plate notch, web plate notch, bottom plate notch and the position of the cantilever and the shoe;

[0034] Step 2: Prefabricate the segmental assembly beams and make a steel cage inside the segmental template at the end of the beam, and set reinforcing steel bars at the cantilever and the boot position;

[0035] Step 3: Position and embed the steel bundle pipes, anchors and supports in the reserved top plate slots, web plate slots and bottom plate slots respectively.

[0036] Step 4: Use concrete to cast the segmental prefabricated assembled beam end segment formwork, vibrate and maintain.

[0037] Step 5. Transport the cast segmental prefabricated assembled beam end segments to the construction site, apply glue, and assemble them. Then, set the tensioning steel bundles in the steel bundle pipes pre-buried in step 3, and fix the tensioning steel bundles by grouting. The steel bundles in the top plate are tensioned at one end on the side away from the beam end, and the steel bundles in the web and the bottom plate are tensioned at both ends.

[0038] Step six: implant anchor steel bars in the top plate grooves, web plate grooves, and bottom plate grooves, use concrete to seal the anchors, smooth the top plate grooves, web plate grooves, and bottom plate grooves, and then maintain.

[0039] The notch size opened in the present invention is relatively small, has little impact on the structure, and is not easy to crack after anchoring. The specifications of the steel bundles of the railway segment prefabricated assembly beams are relatively large, generally above 19-7Φ5, and the jack tensioning working space is generally above 1m. For the steel bundle 4, a smaller notch can be opened to pass the bundle, and a single-end tensioning method can be adopted on the side away from the beam end. This is because the top plate steel bundle near the beam end mainly bears the additional force during the construction phase, and the prestress loss requirement is not high; while the web steel bundle and the bottom plate steel bundle bear the main load and cannot be tensioned in large quantities on a single end. The traditional solution is mainly to open a larger and deeper tensioning notch on the end face of the beam, and the notch depth reaches more than 45cm. In this way, the notch depth on both sides plus the beam seam width of 10-15cm can meet the working requirements of the jack. However, if the groove is too deep or too large, it will be inconvenient to operate the jack, and will be detrimental to the stress on the structure, and it will be easy to crack after anchoring. After the cantilever is set at 25 cm, the web groove 9 and the bottom plate groove 12 only need a depth of 20 cm to meet the jack tensioning space requirement; and the steel bundle 4 adopts a single-end tensioning method, and the top plate groove 6 is only used to pass the steel bundle 4, and 20 cm can also meet the requirement. The influence of the smaller tensioning groove on the structure is greatly reduced, and it is not easy to crack after anchoring.

[0040] The shoe structure in the present invention can avoid the beam end from turning too much, and ensure the rigidity of the segmental prefabricated assembled beam. After the cantilever is set on the top plate of the segmental prefabricated assembled beam, if the bottom plate shoe is not set, the distance from the center line of the support to the beam end is large. Taking the general reference drawing of railway engineering construction "Prestressed Concrete Continuous Beam of Ballastless Track of High-speed Railway with a Speed ​​of 350 km / h (Span 48+80+48m)" (Tongqiao (2017) 2368A-Ⅳ-1) as an example, the center line of the support before the top plate cantilever is set is 0.75m away from the beam end. If only a 25cm cantilever is set, the center line of the seat is 1m away from the beam end, which is greater than the requirement of 0.75m of the beam end overhang length in Section 7.3.7 of the "High-speed Railway Design Code" (TB10621-2014). If the limit value θ≤1‰ is still followed at this time, the upwarping value of the beam end is too large, causing the beam end track structure and fastener system to be overloaded. To this end, the present invention simultaneously sets a boot structure with the same length as the cantilever on the bottom plate, and at the same time moves the support outward to ensure that the cantilever length and the beam end angle meet the specification requirements.

[0041] After the present invention sets the boots on both sides of the beam end face, a concave structure can be formed with the middle end face of the beam for inspection and maintenance personnel to walk with. Ordinary railway bridges generally open a 20cm deep notch in the middle of the beam end face, and the notches on both sides of the beam seam and the beam seam together form a 50-65cm wide entry hole for inspection and maintenance personnel to check the support. The boots on both sides of the two end faces of the present invention can form a concave structure with the middle end face of the beam, and there is no need to open an entry hole again.

Claims

1. A method for processing the ends of railway segment prefabricated assembled beams, characterized in that: The railway segment prefabricated assembled beam end processing structure comprises: a segment prefabricated assembled beam end segment, the segment prefabricated assembled beam end segment is composed of a top plate, a web plate, and a bottom plate, the top plate is located at the top of the segment prefabricated assembled beam end segment, the web plate is located in the middle of the segment prefabricated assembled beam end segment, the bottom plate is located at the bottom of the segment prefabricated assembled beam end segment, a top plate notch is provided in the middle of the beam end face on one side, an anchor is embedded in the top plate notch, cantilevers are provided on both sides of the top plate notch along the edge of the top plate, web plate notches are provided on both sides of the web plate, embedded anchors are provided in the web plate notches, a bottom plate notch is provided in the middle of the bottom plate, embedded anchors are provided in the bottom plate notch, boots are provided on both sides of the bottom plate notch, a support is provided at the bottom of the bottom plate, and steel bundles are provided in the embedded anchors; The method for processing the end of a railway segment prefabricated assembly beam comprises the following steps: Step 1: Make the segment template of the segment prefabricated assembly beam end according to the design size, and leave the top plate notch, web plate notch, bottom plate notch and the position of the cantilever and the shoe; Step 2: Prefabricate the segmental assembly beams and make a steel cage inside the segmental template at the end of the beam, and set reinforcing steel bars at the cantilever and the boot position; Step 3: Position and embed the steel bundle pipes, anchors and supports in the reserved top plate notches, web plate notches and bottom plate notches respectively; Step 4: Cast the segmental prefabricated assembled beam end segmental formwork with concrete, vibrate and maintain; Step 5: transport the cast segment prefabricated assembled beam end segment to the construction site, apply glue, assemble, and then tension the steel bundle in the pre-buried steel bundle pipeline in step 3, and fix the tensioned steel bundle by grouting, wherein the steel bundle in the top plate is tensioned at one end away from the beam end, and the steel bundle in the web plate and the steel bundle in the bottom plate are tensioned at both ends; Step six: implant anchor steel bars in the top plate grooves, web plate grooves and bottom plate grooves, seal the anchors, smooth the top plate grooves, web plate grooves and bottom plate grooves, and perform maintenance.

2. A method for processing the ends of railway segment prefabricated assembled beams as claimed in claim 1, characterized in that: A "mouth"-shaped opening is provided in the middle of the web.

3. The method for processing the end of a railway segment prefabricated assembly beam according to claim 1, characterized in that: The cantilever and the shoe have the same thickness relative to the beam end segment.

4. The method for processing the end of a railway segment prefabricated assembly beam according to claim 1, characterized in that: The end segment of the segmented prefabricated assembled beam is a prefabricated concrete beam segment.

5. The method for processing the ends of railway segment prefabricated assembled beams according to claim 1, characterized in that: Reinforcing steel bars are pre-embedded in the cantilever and the added boot.

6. The method for processing the end of a railway segment prefabricated assembly beam according to claim 1, characterized in that: The cantilever and the shoe have the same length.

7. The method for processing the ends of railway segment prefabricated assembled beams according to claim 1, characterized in that: The steel bundle arranged in the embedded anchor is a tensioned steel bundle.

8. The method for processing the ends of railway segment prefabricated assembling beams according to claim 7, characterized in that: The steel bundles arranged in the top plate are tensioned at one end on the side away from the beam end, and the steel bundles arranged in the web plate and the steel bundles arranged in the bottom plate are tensioned at both ends.

Images