A horizontal rotation method for the UHPC upper bearing platform of a bridge and its construction method

Abstract

The invention discloses a UHPC upper bearing platform of a bridge by the horizontal rotation method and its construction method. The UHPC upper bearing platform is a truss structure, internally provided with steel bars or prestressed steel bars, and internally embedded with traction cable anchors. It is composed of a UHPC ring beam and UHPC connecting beams. The UHPC connecting beams are connected to the lower part of the bridge pier. The periphery of the UHPC ring beam is wound with traction cable steel strands, traction cable support steel bars or steel belts are arranged, and a steel plate is attached to the bottom. The steel plate is in contact with the slideway to form a support foot to prevent the rotating bridge from overturning. Transverse steel bars and transverse prestressed steel bars pass through the UHPC upper bearing platform and the lower part of the bridge pier. A number of transverse steel bars extend from the hollow area of the upper bearing platform, which match a number of longitudinal steel bars extending from the top of the lower bearing platform. After the rotation, the hinge is sealed. The steel bars in the hollow area of the UHPC upper bearing platform are tied and concrete is poured, so that the upper and lower bearing platforms form an integral body. The vertical prestressed steel bars of the upper and lower bearing platforms are tensioned, which can strengthen the vertical connection between the upper and lower bearing platforms. The upper bearing platform and its construction method have the advantages of small volume of the bearing platform, large hinge sealing operation surface, convenient construction, etc., which are beneficial to reducing the project cost and improving the project quality.

Description

Technical Field

[0001] The present invention relates to the technical field of the construction technology of the slewing bridge by the horizontal rotation method, and specifically relates to a UHPC upper bearing platform of a bridge by the horizontal rotation method and a construction method thereof. Background Art

[0002] The construction of the slewing bridge refers to a construction method in which the bridge structure is fabricated (cast or spliced) at a non-designed axis position and then slewed into place. This method has little impact on the existing line and is suitable for the construction of bridges across canyons, rivers, railways, highways, etc. With the continuous increase in the scale of domestic transportation infrastructure construction, this technology has been widely applied in engineering.

[0003] The key technologies of the construction of the slewing bridge are: being able to rotate, rotating stably, and rotating accurately. Among them, the stable rotation is controlled by the anti-overturning system, which generally consists of an upper bearing platform and a supporting foot. To ensure the stable rotation of the bridge, the upper bearing platform often needs to have a sufficient thickness, which leads to the problem of a large volume of the existing upper bearing platform. And this problem, due to the construction requirement that the bearing platform cannot be exposed on the ground, directly results in the adverse situation of the deepening of the foundation pit and the significant increase in the cost.

[0004] After the slewing of the bridge is completed, in order to achieve the effective transfer of the load, the upper and lower disks need to be sealed. However, due to the small distance between the upper and lower bearing platforms, the sealing hinge working surface is limited. Therefore, the concrete between the existing upper and lower bearing platforms is prone to the situation of incomplete compaction during pouring and has poor integrity. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention proposes a UHPC upper bearing platform with a small thickness, a small volume, and a larger sealing hinge working surface and a construction method thereof.

[0006] To achieve the above object, the present invention is realized through the following technical solutions: A UHPC upper bearing platform of a bridge by the horizontal rotation method, comprising

[0007] A UHPC upper bearing platform with a space lattice structure, and a bridge pier and a lower bearing platform are respectively arranged at the upper and lower ends of the UHPC upper bearing platform;

[0008] The UHPC upper bearing platform includes a UHPC ring beam arranged on the outer circle. Symmetric UHPC connecting beams are arranged on the inner end face of the UHPC ring beam, and transverse prestressing tendons are arranged inside the UHPC connecting beams. A traction cable is wound around the outer circle of the UHPC ring beam, and a traction cable anchor is arranged inside the UHPC upper bearing platform and connected to one end of the traction cable. An upper spherical hinge is arranged at the bottom ends of the UHPC ring beam and the UHPC connecting beams.

[0009] Furthermore, a reaction seat is provided on the outer side of the lower bearing platform, a lower spherical hinge is provided in the middle of the upper end surface of the lower bearing platform, an upper spherical hinge is arranged above the lower spherical hinge, a slideway corresponding to the UHPC ring beam is arranged on the outer side of the upper end surface of the lower bearing platform, and longitudinal prestressed tendons are arranged inside the slideway of the lower bearing platform.

[0010] Furthermore, the outer contour projection of the UHPC ring beam is circular, and its vertical projection falls vertically inside the slideway. The gap between the bottom surface of the UHPC ring beam and the slideway is 0 mm to 30 mm, and a steel plate with an adhesion friction coefficient of 0.1 to 0.3 is attached to the bottom surface of the UHPC ring beam, and the width of the steel plate is smaller than the width of the slideway.

[0011] Furthermore, the height of the UHPC connecting beam is equal or increasing from the outside to the inside, and the bottom elevation of the UHPC connecting beam is higher than the bottom elevation of the UHPC ring beam.

[0012] Furthermore, transverse prestressed ducts are provided in the UHPC ring beam, the UHPC connecting beam and the lower part of the bridge pier. The diameter of the transverse prestressed ducts is larger than the diameter of the transverse prestressed tendons, and the transverse prestressed tendons pass through the transverse prestressed ducts, which is the post-tensioning method.

[0013] Furthermore, a construction method for the UHPC upper bearing platform of a bridge by the horizontal rotation method is characterized by including the following construction steps:

[0014] S1. The lower bearing platform is cast in two times: the pile head is broken, the steel bars of the lower bearing platform are tied. If longitudinal prestressed tendons are provided in the lower bearing platform, core-pulling pipes are installed during the first concrete casting, and then maintenance is carried out. After the concrete strength of the first casting of the lower bearing platform reaches the specified requirements, the support steel frames of the lower spherical hinge and the slideway are placed, the support steel frames of the lower spherical hinge and the slideway are positioned, the bottom steel bars and the steel bars of the reaction seat are tied, and the second concrete casting of the lower bearing platform is completed, and then maintenance is carried out.

[0015] S2. Installation of the upper spherical hinge: Clean the sundries on the lower spherical hinge, then lay the polytetrafluoroethylene sliders, apply butter for lubrication, hoist the upper spherical hinge, and wind the tape at the gap of the spherical hinge to prevent sundries from entering.

[0016] S3. Construction of the lower part of the bridge pier: Set up the formwork for the lower part of the bridge pier, tie the steel bars. If transverse prestressed tendons are provided, transverse prestressed tendon ducts need to be reserved, and then the concrete for the lower part of the bridge pier is cast. After the concrete of the bridge pier reaches the strength requirements, the formwork support for the lower part of the bridge pier is removed.

[0017] S4, Casting of the upper UHPC bearing platform: Set up temporary supports and formwork for the upper UHPC bearing platform. Place steel plates matching the slideways at the bottom of the UHPC ring beam. Tie the steel bars. The pier is at the connection height with the UHPC connecting beam, and the transverse steel bars extend laterally around by 30 to 60 times the diameter of the steel bars, so that the UHPC connecting beam and the pier (6) have a reliable connection. At the same time, the upper UHPC bearing platform and the later-cast concrete in the hollow area form an integral whole. Embed the traction cable anchorages and reserve the ducts for the transverse prestressed steel bars. Complete the UHPC casting, cure, remove the formwork, and tension the transverse prestressed steel bars.

[0018] S5, Construction of the upper part of the pier and the superstructure: Tie the steel bars in the middle and upper parts of the pier, set up formwork, check the stability of the support of the slewing device, then cast the concrete in the middle and upper parts of the pier. After the pier concrete reaches the strength requirement, remove the formwork supports in the middle and upper parts of the pier and start the construction of the bridge deck structure.

[0019] S6, Installation of the traction cables: One end of the traction cable has been anchored in the upper UHPC bearing platform, led out and wound outside the UHPC, and the other end passes through the traction machines on both sides of the reaction seats of the lower bearing platform.

[0020] S7, Slewing: After the slewing starts, slowly tension the traction cables, observe the horizontal condition of the slewing bridge in real time, and at the same time observe whether there are large gaps between the steel plates at the bottom of the UHPC ring beam and the slideways. Adjust the counterweight in time when there is a large eccentricity.

[0021] S8, Casting of the concrete in the hollow area: After the bridge slewing is completed, use an instrument to correct the position, seal the gap between the bottom of the UHPC ring beam and the lower bearing platform with mortar, extend the transverse and longitudinal steel bars in the hollow area of the upper UHPC bearing platform, carry out steel bar tying. According to the requirements of the sealing plate, if no prestressed steel bars are set, directly cast the concrete in the hollow area. If vertical prestressed steel bars need to be set, reserve the ducts for the longitudinal prestressed steel bars, then cast the concrete in the hollow area and cure. After the later-cast concrete reaches the specified requirements, tension the longitudinal prestressed steel bars. Beneficial effects

[0022] The present invention provides an upper UHPC bearing platform of a bridge by the horizontal rotation method and its construction method. Compared with the prior art, it has the following beneficial effects:

[0023] (1) Using ultra-high-strength materials reduces the thickness and volume of the traditional upper bearing platform, thereby reducing the excavation depth of the foundation pit and lowering the project cost;

[0024] (2) Provide a more sufficient working surface for the hinge sealing work, making the vertical connection construction of the upper and lower bearing platforms convenient and reliable, and effectively ensuring the casting quality of the hinge sealing concrete;

[0025] (3) The bottom of the upper UHPC bearing platform rests on the slideways of the lower bearing platform, eliminating the setting of traditional bearing feet (concrete-filled steel tubes), and it can effectively prevent the slewing bridge from overturning by itself. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic structural diagram of the present invention;

[0027] Figure 2 is a schematic structural diagram of the present invention;

[0028] Figure 3 is a schematic structural diagram of the present invention;

[0029] Figure 4 is a schematic structural diagram of the configuration of the steel bars and prestressed tendons of the upper UHPC bearing platform before the rotation of the present invention;

[0030] Figure 5 is a schematic structural diagram of the steel bar configuration in the hollow area of the upper UHPC bearing platform after the rotation of the present invention;

[0031] Figure 6 is a schematic structural diagram of the rotation structure of the upper UHPC bearing platform of the present invention;

[0032] Figure 7 is a schematic structural diagram of the upper UHPC bearing platform of the present invention;

[0033] Figure 8 is a schematic structural diagram of the upper UHPC bearing platform of the present invention;

[0034] Figure 9 is a schematic structural diagram of the upper UHPC bearing platform of the present invention;

[0035] Figure 10 is a schematic structural diagram of the upper UHPC bearing platform of the present invention;

[0036] Figure 11 is a schematic structural diagram of the upper UHPC bearing platform of the present invention;

[0037] In the figure: lower bearing platform - 1, lower spherical hinge - 2, slideway - 3, reaction seat - 4, upper spherical hinge - 5, bridge pier - 6, horizontal prestressed tendon - 7, upper UHPC bearing platform - 8, UHPC ring beam - 81, UHPC connecting beam - 82, traction cable - 9, longitudinal prestressed tendon - 10. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] Please refer to Figures 1-11, the present invention provides a technical solution: a UHPC upper bearing platform for a bridge by the horizontal rotation method, including a UHPC upper bearing platform 8 with a space lattice structure. The UHPC material is used because UHPC has ultra-high strength, high toughness and high durability, with a compressive strength greater than 120 MPa, a flexural strength reaching 25 MPa, and a material durability of more than 200 years. It is composed of materials such as silica fume, cement, water reducer, fine aggregate and steel fiber. There are a pier 6 and a lower bearing platform 1 at the upper and lower ends of the UHPC upper bearing platform 8 respectively. There is a reaction seat 4 on the outside of the lower bearing platform 1. There is a lower spherical hinge 2 in the middle of the upper end face of the lower bearing platform 1, and an upper spherical hinge 5 is arranged above the lower spherical hinge 2. There is a slideway 3 corresponding to the UHPC ring beam 81 on the outside of the upper end face of the lower bearing platform 1. There is a longitudinal prestressed tendon 10 inside the lower bearing platform 1 in the slideway 3.

[0040] The upper UHPC bearing platform 8 includes a UHPC ring beam 81 arranged on the outer circle. The inner end face of the UHPC ring beam 81 is symmetrically provided with UHPC connecting beams 82. The UHPC connecting beams 82 are connected to the lower part of the pier 6. And there are horizontal prestressed steel bars 7 inside the UHPC connecting beams 82. Corresponding to the UHPC ring beam 81, the UHPC connecting beams 82 and the lower part of the pier 6, there are horizontal prestressed ducts. The diameter of the horizontal prestressed ducts is larger than the diameter of the horizontal prestressed steel bars 7. And the horizontal prestressed steel bars 7 pass through the horizontal prestressed ducts, which is the post-tensioning method. The outer circle of the UHPC ring beam 81 is wound with a traction cable 9. And there is a traction cable anchor in the upper UHPC bearing platform 8 connected to one end of the traction cable 9. The outer contour projection of the UHPC ring beam 81 is circular and vertically projects onto the slideway 3. And traction cable support steel bars or steel strips are arranged around to prevent stress concentration and local crushing of the UHPC ring beam 81. The gap between the bottom surface of the UHPC ring beam 81 and the slideway 3 is 0 mm to 30 mm. And a steel plate with an adhesion friction coefficient of 0.1 to 0.3 is attached to the bottom surface of the UHPC ring beam 81. And the width of the steel plate is smaller than the width of the slideway 3. The height of the UHPC connecting beams 82 is equal or increasing from the outside to the inside. The bottom elevation of the UHPC connecting beams 82 is higher than the bottom elevation of the UHPC ring beam 81. And there are longitudinal steel bars, horizontal steel bars and stirrups in the upper UHPC bearing platform 8. The horizontal steel bars pass through the UHPC ring beam 81, the UHPC connecting beams 82 and the lower part of the pier 6. And horizontal steel bars extend out in the hollow area of the upper UHPC bearing platform 8 for the UHPC ring beam 81, the UHPC connecting beams 82 and the pier 6. And longitudinal steel bars or prestressed steel bars extend out from the top surface of the lower bearing platform 1. The extending lengths of the horizontal steel bars and the longitudinal steel bars are 30 to 60 times the diameter of the steel bars. The extending length of the longitudinal prestressed steel bars 10 is greater than the height of the upper UHPC bearing platform 1. And the horizontal steel bars and the longitudinal steel bars are matched. After the bridge is rotated and in place, the horizontal steel bars and the longitudinal steel bars are spliced to form a steel bar framework in the hollow area of the upper UHPC bearing platform 8. And when the hinge is sealed in the hollow area of the upper UHPC bearing platform 8, concrete is poured. The concrete fills the hollow area of the upper UHPC bearing platform 8 and the gap between the upper UHPC bearing platform 8 and the lower bearing platform 1, which can be slightly expanded concrete, and the strength is not lower than the concrete strength of the pier 6. According to the requirements of the sealing plate, longitudinal prestressed steel bars 10 can be arranged in the reinforced concrete in the hollow area of the upper UHPC bearing platform 8. Corresponding longitudinal prestressed ducts are provided. The diameter of the longitudinal prestressed ducts is larger than the diameter of the longitudinal prestressed steel bars 10. The longitudinal prestressed steel bars 10 of the lower bearing platform 1 pass through the longitudinal prestressed ducts. The upper UHPC bearing platform 8 and the lower bearing platform 1 are vertically connected and strengthened through the longitudinal prestressed steel bars 10.

[0041] Among them, there can also be only a common reinforced concrete post-cast strip between the upper UHPC bearing platform 8 and the pier 6. At this time, pre-tensioned steel wires are arranged in the upper UHPC bearing platform 8 to reduce the member size.

[0042] Among them, according to the above structure, a construction method for the upper UHPC bearing platform of a horizontally rotated bridge is implemented, including the following construction steps:

[0043] S1. The lower bearing platform 1 is cast in two times: the pile heads are broken, the steel bars of the lower bearing platform 1 are tied. If the longitudinal prestressed steel bars 10 are set in the lower bearing platform 1, the core-drawing pipes are installed during the first concrete casting, and then curing is carried out. After the concrete strength of the first casting of the lower bearing platform 1 reaches the specified requirements, the support steel frames of the lower spherical hinge 2 and the slideway 3 are placed, the support steel frames of the lower spherical hinge 2 and the slideway 3 are positioned, the bottom slab steel bars and the reaction seat steel bars are tied, and the second concrete casting of the lower bearing platform 1 is completed, and then curing is carried out.

[0044] S2. Installation of the upper spherical hinge 5: The sundries of the lower spherical hinge 2 are cleaned, then the polytetrafluoroethylene sliders are laid, butter is applied for lubrication, the upper spherical hinge 5 is hoisted, and tapes are wound at the gaps of the spherical hinge to prevent sundries from entering.

[0045] S3. Construction of the lower part of the bridge pier 6: The formwork for the lower part of the bridge pier 6 is erected, the steel bars are tied. If the transverse prestressed steel bars 7 are set, the ducts for the transverse prestressed steel bars need to be reserved. Then the concrete for the lower part of the bridge pier 6 is cast. After the concrete of the bridge pier 6 reaches the strength requirements, the formwork support for the lower part of the bridge pier 6 is removed.

[0046] S4. Casting of the UHPC upper bearing platform 8: Temporary supports are erected and the formwork for the UHPC upper bearing platform 8 is erected. Steel plates matching the slideway 3 are placed at the bottom surface of the UHPC ring beam 81, the steel bars are tied. At the connection height of the bridge pier 6 and the UHPC connecting beam 82, the transverse steel bars extend laterally by 30 - 60 times the diameter of the steel bars around, so that the UHPC connecting beam 82 and the bridge pier 6 have a reliable connection. At the same time, the UHPC upper bearing platform 8 and the later-cast concrete in the hollow area form an integral body, the traction cable anchors are embedded, the ducts for the transverse prestressed steel bars are reserved, the UHPC casting is completed, curing and formwork removal are carried out, and the transverse prestressed steel bars 7 are tensioned.

[0047] S5. Construction of the upper part of the bridge pier 6 and the superstructure: The steel bars in the middle and upper parts of the bridge pier 6 are tied, the formwork is erected, the stability of the support of the swivel device is checked. Then the concrete in the middle and upper parts of the bridge pier 6 is cast. After the concrete of the bridge pier 6 reaches the strength requirements, the formwork support for the middle and upper parts of the bridge pier 6 is removed, and the construction of the bridge deck structure is started.

[0048] S6. Installation of the traction cable 9: One end of the traction cable 9 has been anchored in the UHPC upper bearing platform 8, it is led out and wound outside the UHPC 81, and the other end passes through the traction machines of the reaction seats 4 on both sides of the lower bearing platform 1.

[0049] S7. Swiveling: After the swiveling starts, the traction cable 9 is slowly tensioned, the horizontal situation of the swivel bridge is observed in real time, and at the same time, it is also observed whether there are large gaps between the steel plate at the bottom of the UHPC ring beam 81 and the slideway 3. If there is a large eccentricity, the counterweight is adjusted in time.

[0050] S8, Concrete pouring in the hollow area: After the bridge rotation is completed, the instrument is used to correct the position. The gap between the bottom of the UHPC ring beam 81 and the lower bearing platform 1 is sealed with mortar. The horizontal and vertical steel bars in the hollow area of the UHPC upper bearing platform 8 are extended, and steel bar binding is carried out. According to the requirements of the sealing plate, if no prestressed tendons are set, the concrete in the hollow area is directly poured. If vertical prestressed tendons need to be set, longitudinal prestressed tendon ducts are reserved, and then the concrete in the hollow area is poured and cured. After the post-poured concrete reaches the specified requirements, the longitudinal prestressed tendons 10 are tensioned.

[0051] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A horizontally rotating method bridge UHPC upper bearing platform, comprising the UHPC upper bearing platform (8) with a space lattice structure, the upper and lower ends of the UHPC upper bearing platform (8) are respectively provided with a bridge pier (6) and a lower bearing platform (1), a reaction support (4) is arranged outside the lower bearing platform (1), a lower spherical hinge (2) is arranged in the middle of the upper end face of the lower bearing platform (1), an upper spherical hinge (5) is arranged above the lower spherical hinge (2), a slideway (3) corresponding to the UHPC ring beam (81) is arranged on the outer side of the upper end face of the lower bearing platform (1), and a longitudinal prestressed tendon (10) is arranged inside the lower bearing platform (1) within the slideway (3); the UHPC upper bearing platform (8) comprises a UHPC ring beam (81) arranged on the outer circle, UHPC connecting beams (82) are symmetrically arranged on the inner end face of the UHPC ring beam (81), and transverse prestressed tendons (7) are arranged inside between the UHPC connecting beams (82). A traction cable (9) is wound around the outer circle of the UHPC ring beam (81), and a traction cable anchor is arranged inside the UHPC upper bearing platform (8) and connected to one end of the traction cable (9). The outer contour projection of the UHPC ring beam (81) is circular and vertically projects and falls within the slideway (3). The gap between the bottom surface of the UHPC ring beam (81) and the slideway (3) is 0 mm to 30 mm, and a steel plate with an adhesion friction coefficient of 0.1 to 0.3 is attached to the bottom surface of the UHPC ring beam (81), and the width of the steel plate is less than the width of the slideway (3). The height of the UHPC connecting beam (82) is equal or increasing from the outside to the inside. The bottom elevation of the UHPC connecting beam (82) is greater than the bottom elevation of the UHPC ring beam (81). Transverse prestressed ducts are arranged in the UHPC ring beam (81), the UHPC connecting beam (82) and the lower part of the bridge pier (6). The diameter of the transverse prestressed duct is larger than the diameter of the transverse prestressed tendon (7), and the transverse prestressed tendon (7) passes through the transverse prestressed duct, which is a post-tensioning method.

2. The construction method of the UHPC upper bearing platform of the bridge by the horizontal rotation method according to claim 1, characterized in that, It includes the following construction steps: S1. The lower bearing platform (1) is poured in two times: the pile head is broken, the steel bars of the lower bearing platform (1) are tied. If the longitudinal prestressed tendon (10) is set in the lower bearing platform (1), a core-pulling pipe is installed during the first concrete pouring, and then maintenance is carried out. After the concrete strength of the first pouring of the lower bearing platform (1) reaches the specified requirements, the support steel frames of the lower spherical hinge (2) and the slideway (3) are placed, the support steel frames of the lower spherical hinge (2) and the slideway (3) are positioned, the bottom steel bars and the reaction support steel bars are tied, and the second concrete pouring of the lower bearing platform (1) is completed, and then maintenance is carried out; S2. Installation of the upper spherical hinge (5): Clean the sundries of the lower spherical hinge (2), then lay the polytetrafluoroethylene slider, apply butter for lubrication, hoist the upper spherical hinge (5), and wind the tape at the spherical hinge gap to prevent sundries from entering; S3. Construction of the lower part of the bridge pier (6): Set up the formwork for the lower part of the bridge pier (6), tie the steel bars. If the transverse prestressed tendon (7) is set, the transverse prestressed tendon duct needs to be reserved, and then the concrete for the lower part of the bridge pier (6) is poured. After the concrete of the bridge pier (6) reaches the strength requirements, the formwork support for the lower part of the bridge pier (6) is removed; S4, Pouring of the upper UHPC bearing platform (8): Set up temporary supports and formwork for the upper UHPC bearing platform (8). Place steel plates matching the slideway (3) at the bottom of the UHPC ring beam (81). Bind the steel bars. The pier (6) is at the connection height with the UHPC connecting beam (82), and the transverse steel bars extend laterally around by 30 to 60 times the diameter of the steel bars, so that the UHPC connecting beam (82) and the pier (6) have a reliable connection. At the same time, the upper UHPC bearing platform (8) and the later-poured concrete in the hollow area form an integral whole. Embed the traction cable anchor, reserve the duct for the horizontal prestressed steel bars, complete the UHPC pouring, cure, remove the formwork, and tension the horizontal prestressed steel bars (7); S5, Construction of the upper part of the pier (6) and the superstructure: Bind the steel bars in the middle and upper parts of the pier (6), set up formwork, check the stability of the support of the slewing device, then pour the concrete in the middle and upper parts of the pier (6). After the concrete of the pier (6) reaches the strength requirement, remove the formwork support in the middle and upper parts of the pier (6) and start the construction of the bridge deck structure; S6, Installation of the traction cable (9): One end of the traction cable (9) has been anchored in the upper UHPC bearing platform (8), led out and wound outside the UHPC (81), and the other end passes through the traction machines of the reaction seats (4) on both sides of the lower bearing platform (1); S7, Slewing: Slowly tension the traction cable (9) after the slewing starts, observe the horizontal condition of the slewing bridge in real time, and also observe whether there are large gaps between the steel plate at the bottom of the UHPC ring beam (81) and the slideway (3). Adjust the counterweight in time when there is a large eccentricity; S8, Pouring of the concrete in the hollow area: After the bridge slewing is completed, correct the position with instruments, seal the gap between the bottom of the UHPC ring beam (81) and the lower bearing platform (1) with mortar, extend the transverse and longitudinal steel bars in the hollow area of the upper UHPC bearing platform (8), carry out steel bar binding. According to the requirements of the sealing plate, if no prestressed steel bars are set, directly pour the concrete in the hollow area. If vertical prestressed steel bars need to be set, reserve the duct for the longitudinal prestressed steel bars, then pour the concrete in the hollow area and cure. After the later-poured concrete reaches the specified requirements, tension the longitudinal prestressed steel bars (10).

Images