A prestressed connection device for railway prefabricated assembled bridge piers

Abstract

The present invention discloses a prestressed connection device for railway prefabricated piers, specifically relates to a device that pre-anchors prestressed steel bars to the pier foundation, passes through the prefabricated piers and prefabricated crossbeams, applies prestress by tensioning prestressed steel strands in the tensioning grooves reserved in the prefabricated crossbeams, and finally performs pressure reduction of the prestressed pipeline, seals the anchor, and completes the connection of the prefabricated piers, belonging to the technical field of bridge and culvert engineering. The prestressed connection device for railway prefabricated piers is a connection anchoring system that effectively realizes the connection of the foundation, the pier body and the crossbeam, and eliminates cracks at the assembly joints by applying prestress, thereby ensuring the durability and normal use of the piers.

Description

Technical Field

[0001] The present invention relates to a prestressed connection device for railway prefabricated assembled bridge piers, and more specifically to a device for pre-anchoring prestressed steel bars to a bridge pier foundation, passing through a prefabricated bridge pier and a prefabricated cross beam, applying prestress by tensioning a prestressed steel strand in a tensioning groove reserved in the prefabricated cross beam, and finally performing a prestressed pipeline pressure drop and anchor sealing to complete the connection of the prefabricated assembled bridge piers, and belongs to the technical field of bridge and culvert engineering. Background Art

[0002] Traditional railway bridge piers are cast-in-place, requiring a large number of workers to set up supports and formwork and tie steel bars at the construction site. The process is complicated, the environment is polluted, the construction time is long, the efficiency is low, the construction noise cannot be effectively controlled, and the construction equipment and auxiliary facilities need to be repeatedly configured, resulting in large resource and energy consumption. The railway prefabricated pier construction technology can achieve the green construction goals of standardized prefabrication of components in factories, mechanized assembly on site, shortened construction period, and reduced adverse impacts on the environment.

[0003] Traditional railway cast-in-place bridge piers are concrete structures or reinforced concrete structures, which are eccentrically compressed components. The common design idea of ​​railway prefabricated and assembled bridge piers is to divide the cast-in-place bridge piers into blocks according to the needs of factory prefabrication and assembly, and connect them by grouting sleeves, socket-type, metal bellows or high-performance concrete wet joints. The connection method does not change the component type and stress characteristics of the bridge piers. The bridge pier joints are in a tensile state under the action of horizontal forces, and cracks appear in the concrete. Oxygen, water molecules, and carbon dioxide in the air invade the cracks and react electrochemically with the bridge pier steel bars to generate rust (a mixture of iron oxide, iron hydroxide, and a small amount of ferrous carbonate, etc.). The volume of the generated rust expands by about 7-9 times. The expansion force caused by the volume expansion causes the concrete bonded to the steel bars to crack and peel off. In addition, the texture of the rust is loose, and air continues to enter the concrete gaps caused by the expansion of the rust, which aggravates the steel bar corrosion process, resulting in the continuous reduction of the cross-section of the bridge pier from the surface to the inside; the cross-section of the steel bar from the surface to the inside; and the bond strength between the steel bar and the concrete is reduced. The above-mentioned diseases affect the normal use of the bridge piers, and reduce the durability of the bridge piers and the overall service life of the bridge piers. Summary of the invention

[0004] The purpose of the present invention is to provide a prestressed connection device for railway prefabricated assembled bridge piers, which provides effective connection and anchoring performance for the railway prefabricated assembled bridge piers.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is a prestressed connection device for railway prefabricated assembled bridge piers, including a single-end tensioning anchor, cast-in-place solid section concrete, embedded steel bars, a prefabricated hollow bridge pier body, a prestressed duct, prestressed steel bars, a grouting hole, a grouting hole, a bridge pier positioning hole, a prefabricated crossbeam, a crossbeam positioning hole, a sealant, a sealing gasket, a mortar cushion layer, and a foundation. The embedded steel bars are embedded in the part of the foundation corresponding to the cast-in-place solid section concrete of the hollow pier, and the single-end tensioning anchor is embedded in the foundation after the prestressed steel bars are installed. In the anchor hole, the prestressed steel bars are connected with steel wire ropes. The first section of the prefabricated hollow pier is placed horizontally. The steel wire rope is inserted into the prestressed hole on the bottom surface of the first section of the prefabricated hollow pier, and is led out from the prestressed hole on the top surface to pull out the prestressed steel bars. The prefabricated hollow pier body is vertically suspended by a crane, and the prestressed steel bars are pulled out by another crane. The mortar cushion layer is poured on the top surface of the anchor hole, the first section of the prefabricated hollow pier body is assembled, and the position is adjusted so that the pier body is horizontal. The second section of the prefabricated hollow pier body is placed horizontally, and the steel wire rope is inserted from the second section of the prefabricated hollow pier body to the prefabricated hollow pier body. The prestressed steel bars are inserted into the prestressed channel on the bottom surface of the central pier body, and drawn out from the prestressed channel on the top surface; a crane is used to vertically suspend the second section of the prefabricated hollow pier body, and another crane is used to pull the prestressed steel bars; sealant is applied to the top surface of the first section of the prefabricated hollow pier body, and sealing gaskets are installed at the prestressed channel on the joint surface; the second section of the prefabricated hollow pier body is assembled based on the pier positioning falcon, and the position is adjusted so that the second section of the prefabricated hollow pier body is in a horizontal state; the steel wire rope is inserted into the prestressed channel on the bottom surface of the prefabricated crossbeam, and the prestressed steel bars are drawn out from the prestressed channel on the top surface; the steel wire rope is inserted into the prestressed channel on the bottom surface of the prefabricated crossbeam, and the prestressed steel bars are drawn out from the prefabricated crossbeam; the prefabricated ... top surface of the prefabricated crossbeam; the prefabricated steel wire rope is inserted into the prestressed channel on the top surface of the prefabricated crossbeam; the pre The prestressed steel bars are pulled out from the prestressed holes on the top surface; the precast beam is suspended vertically by one crane, and the prestressed steel bars are pulled out from the prestressed holes on the top surface of the precast beam by another crane; sealant is applied to the top surface of the second section of the precast hollow pier, and sealing gaskets are installed at the prestressed holes on the joint surface; the beams are assembled based on the beam positioning falcon, and the positions are adjusted to make the precast beams horizontal; the prestressed steel bars are tensioned and the anchors are sealed; mortar is pressed into the grouting holes at the bottom of the pier body to seal the prestressed steel bars; and the solid section concrete is poured into the grouting holes.

[0006] In the present invention, by setting a mortar cushion layer, it is ensured that the first section of the prefabricated hollow pier body is closely bonded to the foundation, and the prefabricated hollow pier body is adjusted to be in a horizontal state. By setting a pier positioning device, the second section of the prefabricated hollow pier body is accurately positioned, the horizontal deviation between the prefabricated hollow pier bodies is eliminated, and the accessory bending moment generated by the assembly of the pier bodies is eliminated. By setting a prefabricated cap beam positioning device, the prefabricated crossbeam is accurately positioned, and the horizontal deviation between the prefabricated crossbeam and the second section of the prefabricated hollow pier body is eliminated. By setting a sealing gasket, the gap at the prestressed duct of the splicing seam is eliminated, ensuring that the prestressed duct does not leak grout. By setting a grouting hole, it is used to pour the solid section concrete after the prefabricated hollow pier body is assembled. By pouring the solid section concrete, the interference force of the fixed end of the hollow pier is reduced, and the structural safety is ensured. The solid section concrete is shrinkage compensating concrete, which ensures that the solid section concrete is closely bonded to the prefabricated hollow pier, so that the inner wall of the bottom pier of the prefabricated hollow pier body and the post-cast solid section concrete are integrated. By setting grouting holes, grouting of prestressed pipes is achieved, ensuring that the prestressed steel bars, the prefabricated hollow pier body, the prefabricated crossbeam and the foundation are subjected to coordinated force. By setting prestressed steel bars, prestress is applied to the prefabricated hollow pier body, so that the pier body section is compressed, cracks in the joints are eliminated, and corrosive substances are blocked from invading the pier body, ensuring the durability of the joints and the normal use of the pier as a whole. By using special hydraulic steel formwork, it is ensured that the dimensions of the prefabricated hollow pier body and the positioning pier meet the assembly accuracy requirements. The special hydraulic steel formwork is conducive to the demoulding of the inner mold of the prefabricated hollow pier and the positioning pier. By using embedded steel bars, the connection between the cast-in-place solid section concrete and the foundation and the prefabricated hollow pier body is strengthened, and the integrity of the three is enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present invention will be further described in detail below with reference to the accompanying drawings.

[0008] Figure 1 It is a schematic diagram of the structure of the connecting device of the present invention after being disassembled.

[0009] Figure 2 It is a schematic diagram of the structure of the connecting device of the present invention after splicing. DETAILED DESCRIPTION

[0010] See also Figure 1 , Figure 2A prestressed connection device for a railway prefabricated assembled bridge pier includes a single-end tensioning anchor 1, a cast-in-place solid section concrete 2, embedded steel bars 3, a prefabricated hollow pier body 4, a prestressed channel 5, prestressed steel bars 6, a grouting hole 7, a grouting hole 8, a pier positioning hook 9, a prefabricated crossbeam 10, a crossbeam positioning hook 11, a sealant 12, a sealing gasket 13, a mortar cushion 14, and a foundation 15. The embedded steel bars 3 are embedded in the foundation 15 corresponding to the position of the cast-in-place solid section concrete 2 of the prefabricated hollow pier body 4. The single-end tension anchor 1 is embedded in the foundation anchor hole after installing the prestressed steel bars 6. The prestressed steel bars 6 are connected with steel wire ropes. The first section of the prefabricated hollow pier body 4 is placed horizontally, and the steel wire rope is inserted into the prestressed channel 5 on the bottom surface of the first section of the prefabricated hollow pier body 6, and is led out from the prestressed channel 5 on the top surface to pull out the prestressed steel bars 6; the prefabricated hollow pier body 4 is vertically suspended by one crane, and the prestressed steel bars 6 are pulled out by another crane; sand is poured on the top surface of the anchor hole. The mortar cushion layer 14 is used to assemble the first section of the prefabricated hollow pier body 4 and adjust the position so that the first section of the prefabricated hollow pier body 4 is in a horizontal state; the second section of the prefabricated hollow pier body 4 is placed horizontally, and the steel wire rope is inserted into the prestressed channel 5 on the bottom surface of the second section of the prefabricated hollow pier body 4, and is led out from the prestressed channel 5 on the top surface to pull out the prestressed steel bars 6; a crane is used to vertically suspend the second section of the prefabricated hollow pier body 4, and another crane is used to pull the prestressed steel bars 6; a sealant 12 is applied to the top surface of the first section of the prefabricated hollow pier body 4, and a sealant 12 is applied to the prestressed channel 5 on the joint surface. Install the sealing gasket 13; assemble the second section of the prefabricated hollow pier body 4 with the pier positioning falcon 9 as the reference, and adjust the position so that the second section of the prefabricated hollow pier body 4 is in a horizontal state; insert the steel wire rope from the prestressed hole 5 on the bottom surface of the prefabricated cross beam 10, lead it out from the prestressed hole 5 on the top surface, and pull out the prestressed steel bar 6; use a crane to vertically suspend the prefabricated cross beam 10, and another crane to pull the prestressed steel bar 6 led out from the prestressed hole 5 on the top surface of the prefabricated cross beam 10; apply sealant 12 on the top surface of the second section of the prefabricated hollow pier body 4, and prestress the joint surface A sealing gasket 13 is installed at the hole 5, and the prefabricated crossbeam 10 is assembled with the crossbeam positioning hook 11 as a reference, and the position is adjusted so that the prefabricated crossbeam 10 is in a horizontal state; the prestressed steel bars 6 are tensioned and the anchors are sealed; the grouting holes 8 are located at the lower part of the pier body 4 and mortar is pressed into the grouting holes 8 to seal the prestressed steel bars 6; the grouting holes 7 are located above the grouting holes 8 and the solid section concrete 2 is poured into the grouting holes 7, the pier positioning hooks 9 are arranged vertically at intervals and are prefabricated at the same time as the prefabricated hollow pier body 4; the crossbeam positioning hooks 11 are prefabricated at the same time as the assembled prefabricated crossbeams 10.

[0011] The prefabricated hollow pier body 4 is made of high-performance concrete, which complies with the current industry regulations "Technical Specification for Application of High-Performance Concrete" (CECS 207) and the current industry specifications "Railway Concrete" (TB / T3275) and "Railway Concrete Structure Durability Design Specification" (TB 10005).

[0012] The material of the mortar cushion layer 14 is high-strength non-shrinkage mortar, and its 28d compressive strength should be no less than 60MPa and one grade higher than the strength grade of the connected components (7MPa), ensuring the material strength of the joints; the mortar cushion layer should be made of hard, well-graded medium sand, the fineness modulus should be no less than 2.6, and the 28d vertical expansion rate should be controlled at 0.02%~0.10%, ensuring the volume stability of the joint material and effectively reducing the prestress loss; the initial setting time of the mortar cushion layer 14 should be greater than 2h, ensuring the installation operation time of the prefabricated hollow pier body 4 and ensuring the installation accuracy. The above characteristics all ensure the high durability and structural safety of the joints of the railway prefabricated assembled piers.

[0013] Before the construction of sealant 12, the extrusion and chemical stability tests shall be carried out. The test methods and technical standards of sealant 12 shall comply with the requirements of the current industry standard "Interim Technical Conditions for Prefabricated and Assembled Simple-Supported Beams of Prestressed Concrete Segments for Railways" (TJ / GW162). Ensure that sealant 12 is easy to apply and scrape without sagging during construction, and has good aging resistance and strong alkali corrosion resistance.

[0014] The standard strength of prestressed steel bar 6 is 1860MPa.

Claims

1. A connection method for a prestressed connection device of a railway prefabricated assembled bridge pier, wherein the prestressed connection device of the railway prefabricated assembled bridge pier comprises a single-end tension anchor (1), a cast-in-place solid section concrete (2), embedded steel bars (3), a prefabricated hollow pier body (4), a prestressed duct (5), prestressed steel bars (6), a grouting hole (7), a grouting hole (8), a pier positioning hole (9), a prefabricated crossbeam (10), a crossbeam positioning hole (11), a sealant (12), a sealing gasket (13), a mortar cushion layer (14), and a foundation (15). Its characteristics are: The embedded steel bars (3) are embedded in the part of the foundation corresponding to the cast-in-place solid section concrete (2) of the prefabricated hollow pier body (4); the single-end tensioning anchor (1) is installed with the prestressed steel bars (6) and then embedded in the foundation anchor hole; the prestressed steel bars (6) are connected with steel wire ropes; the first section of the prefabricated hollow pier body (4) is placed horizontally; the steel wire rope is inserted into the prestressed hole (5) on the bottom surface of the first section of the prefabricated hollow pier body (4) and led out from the prestressed hole (5) on the top surface to pull out the prestressed steel bars (6); one crane is used to vertically suspend the prefabricated hollow pier body (4) and another crane is used to pull the prestressed steel bars (6); a mortar cushion layer (1) is poured on the top surface of the anchor hole. 4), assembling the first section of the prefabricated hollow pier body (4), and adjusting the position so that the first section of the prefabricated hollow pier body (4) is in a horizontal state; placing the second section of the prefabricated hollow pier body (4) horizontally, inserting the steel wire rope into the prestressed hole (5) on the bottom surface of the second section of the prefabricated hollow pier body (4), leading it out from the prestressed hole (5) on the top surface, and pulling out the prestressed steel bars (6); using a crane to vertically suspend the second section of the prefabricated hollow pier body (4), and another crane to pull the prestressed steel bars (6); applying a sealant (12) on the top surface of the first section of the prefabricated hollow pier body (4), and installing a sealing gasket at the prestressed hole (5) on the joint surface (13); assemble the second section of the prefabricated hollow pier body (4) with the pier positioning hook (9) as a reference, and adjust the position so that the second section of the prefabricated hollow pier body (4) is in a horizontal state; insert the steel wire rope from the prestressed hole (5) on the bottom surface of the prefabricated cross beam (10), lead it out from the prestressed hole (5) on the top surface, and pull out the prestressed steel bars (6); use a crane to vertically suspend the prefabricated cross beam (10), and use another crane to pull the prestressed steel bars (6) led out from the prestressed hole (5) on the top surface of the prefabricated cross beam (10); apply sealant (12) on the top surface of the second section of the prefabricated hollow pier body (4), and seal the prestressed hole (5) on the joint surface. The sealing gasket (13) is installed, and the prefabricated crossbeam (10) is assembled with the crossbeam positioning falcon (11) as a reference, and the position is adjusted so that the prefabricated crossbeam (10) is in a horizontal state; the prestressed steel bars (6) are tensioned and the anchors are sealed; the grouting holes (8) are located at the lower part of the pier body (4) and mortar is pressed into the grouting holes (8) to seal the prestressed steel bars (6); the grouting holes (7) are located above the grouting holes (8) and the solid section concrete (2) is poured into the grouting holes (7); the pier positioning falcons (9) are arranged vertically at intervals and are prefabricated at the same time as the prefabricated hollow pier body (4); the crossbeam positioning falcons (11) are prefabricated at the same time as the assembled prefabricated crossbeam (10).

2. A connection method for a prestressed connection device of a railway prefabricated pier according to claim 1, Its characteristics are: The material of the mortar cushion layer (14) is high-strength non-shrinkage mortar, whose 28d compressive strength is not less than 60MPa and is 7MPa higher than the strength grade of the connected component. The mortar cushion layer is made of hard, well-graded medium sand, with a fineness modulus of not less than 2.6, and a 28d vertical expansion rate controlled within 0.02%~0.10%. The initial setting time of the mortar cushion layer (14) is greater than 2h.

3. A connection method for a prestressed connection device of a railway prefabricated pier according to claim 1, Its characteristics are: The standard strength of prestressed steel bars (6) is 1860 MPa.

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