Small-section inverted-V-shaped steel pier and skewback connection anchoring structure based on transverse inward inclination

Abstract

The invention relates to the technical field of bridge pier anchoring structures, and discloses an anchoring structure for connecting a small-section inverted-V-shaped steel pier and an arch support based on transverse inward inclination, which comprises a steel anchor box welded on a transverse bridge direction wall plate and a longitudinal bridge direction wall plate of the inverted-V-shaped steel pier; the base is positioned on the top surface of the skewback and is matched and jointed with the steel anchor box; the prestress + PBL shear key system is used for connecting the steel anchor box, the base and the skewback into a whole; wherein the steel anchor box is formed by welding an integral anchor bearing plate, a steel grating chamber partition plate, a steel grating chamber sealing plate and a steel grating chamber bearing plate to form at least one grating chamber. The anchoring structure for connecting the small-section inverted-V-shaped steel piers and the skewback based on transverse inward inclination has good crack resistance and durability; the problem of how to ensure direct and effective force transmission when the single leg axis of the inverted-V-shaped steel pier is not perpendicular to the arch support with the horizontal top surface in the transverse bridge direction and the longitudinal bridge direction and the problem of fully utilizing the limited anchoring space when the cross section of the inverted-V-shaped steel pier is small can be solved.

Description

Technical Field

[0001] This invention relates to the field of bridge pier anchorage technology, specifically to an anchorage structure based on the connection between a transversely inclined small-section inverted V-shaped steel pier and an arch seat. Background Technology

[0002] In bridge engineering, inverted V-shaped steel piers are increasingly used in overpasses, urban bridges, and scenic bridges due to their lightweight design and aesthetic appeal. However, when the pier cross-section is small, traditional anchoring structures often cannot meet the requirements for arranging large-tonnage prestressed steel strands. Increasing the anchoring space by enlarging the pier cross-section weakens the lightweight advantage of the inverted V-shaped structure, leading to a decline in aesthetic appeal. Furthermore, the longitudinal inclination of the legs of the inverted V-shaped steel pier, combined with the basket-arch design, results in an inward lateral inclination. This creates complex spatial angles between the leg axis and the horizontal arch abutment top surface, making the transmission of internal forces (axial force, bending moment, and horizontal force) from the pier foot to the concrete arch abutment ineffective and indirect. This leads to significant stress concentration in the anchoring zone, making it prone to cracking, fatigue damage, and durability issues.

[0003] Common solutions include:

[0004] Enlarging the pier foot section: This is achieved by adding stiffening ribs and thickening the wall plates. While this method can alleviate the insufficient anchorage space, it significantly increases the amount of steel used, and stress concentration is prone to occur at the abrupt change in cross-section, reducing fatigue life. At the same time, the enlarged pier foot is inconsistent with the overall slender inverted V-shaped appearance, resulting in a poor aesthetic effect.

[0005] Pre-embedded anchor steel plates or anchor boxes are used: the anchor steel plates are pre-embedded in the arch abutment concrete, and the ends of the steel piers are connected to the pre-embedded parts by welding or bolting. This method is simple in construction, but the residual stress from welding is large, and the shear force transfer between the pre-embedded steel plate and the concrete mainly relies on friction and bonding, resulting in limited shear resistance and difficulty in withstanding large-tonnage horizontal forces. Under repeated loading, the interface between the steel plate and the concrete is prone to delamination and corrosion, affecting durability.

[0006] Post-anchoring technology is adopted: after the concrete construction of the arch abutment is completed, the steel pier is fixed by rebar or chemical anchors. This method is convenient to construct, but the rebar depth is limited by the thickness of the arch abutment, the pull-out bearing capacity is low, and the chemical adhesive has the risk of aging, resulting in poor long-term reliability. It is not suitable for long-span, heavy-load bridges.

[0007] Prestressed + PBL shear key combined anchorage: In recent years, research has combined prestressed technology with PBL (Perforated Bonded L-shaped) shear keys. This improves the interfacial shear resistance through the mechanical interlocking of the perforated steel plate and the concrete tenon, while simultaneously utilizing prestressed steel strands to provide axial anchorage force. However, existing PBL structures are mostly used for anchoring steel-concrete composite beams or steel tower columns. For the special structural form of "laterally inward-sloping small-section inverted V-shaped steel piers," a mature anchorage construction scheme is still lacking. In particular, how to rationally arrange prestressed steel strands within a small cross-sectional space and ensure the coordinated work of the shear key and concrete remains a technological gap.

[0008] In summary, existing technologies struggle to balance the anchoring requirements and aesthetic demands of small-section inverted V-shaped steel piers, exhibiting issues such as limited anchoring space, indirect force transmission paths, and insufficient crack resistance and durability. Therefore, a novel anchoring structure with a clear force mechanism, direct force transmission, compact construction, and harmonious aesthetics is urgently needed to address the key technical challenges of connecting small-section inverted V-shaped steel piers to concrete arch abutments. Summary of the Invention

[0009] (a) Technical problems to be solved

[0010] To address the shortcomings of existing technologies, this invention provides an anchoring structure based on the connection between a small-section inverted V-shaped steel pier with a laterally inclined profile and an arch seat, thereby solving the problems mentioned in the background art.

[0011] (II) Technical Solution

[0012] To achieve the above objectives, the present invention provides the following technical solution: an anchoring structure based on the connection between a transversely inwardly inclined small-section inverted V-shaped steel pier and an arch seat, comprising:

[0013] The steel anchor box is welded to the transverse and longitudinal bridge-direction wall panels of the inverted V-shaped steel pier.

[0014] A base, located on the top surface of the arch and mating with the steel anchor box;

[0015] A prestressed + PBL shear key system is used to connect the steel anchor box, the base and the arch into a whole;

[0016] The steel anchor box is formed by welding an integral anchor plate, a steel grating partition, a steel grating sealing plate and a steel grating bearing plate to form at least one grating.

[0017] The prestressed + PBL shear key system includes:

[0018] Prestressed steel strands, one end of which is anchored to an integral anchor plate and the other end of which is anchored inside the arch seat;

[0019] Perforated wall panels and perforated stiffening ribs are welded to the steel grating bearing plate and extend into the concrete base.

[0020] Perforated steel bars, the perforated steel bars being used to pass through holes in perforated stiffening ribs;

[0021] Epoxy concrete, which is poured on top of an integral anchor plate and wraps around the anchor head of the prestressed steel strand.

[0022] Preferably, the integral anchor plate has pre-drilled holes for steel strands, and the diameter of the steel strand holes matches the size of the expanded head of the steel strand anchor and the size of the working anchor plate of the anchor, and the hole spacing matches the working space of the tensioning jack.

[0023] Preferably, the steel grating bearing plate has two types of holes, one type for the prestressed steel strands to pass through, and the other type for the foundation concrete to be poured.

[0024] Preferably, the top surface of the base is perpendicular to the axis of the single leg of the inverted V-shaped steel pier, and the top surface contour is formed by offsetting the outer contour of the steel grating bearing plate by 8-15cm, with rounded corners.

[0025] Preferably, the base is made of shrinkage-compensating concrete, limiting the expansion rate to 4×10⁻⁶. -4 -6×10 -4 The base is reinforced with steel bars inside, and the sides of the base are also equipped with shaped steel mesh. The net protective layer thickness is not less than 20mm, and it is cast integrally with the arch.

[0026] Preferably, the prestressed steel strand is a sand-embedded epoxy steel strand, and the anchor is a retractable anchor that can be pulled back twice.

[0027] Preferably, the perforated wall panel and the perforated stiffening rib are 25-35mm thick, the diameter of the round holes on the perforated stiffening rib is 70-90mm and the spacing is 180-220mm, and the perforated steel bars are Φ20-Φ28mm steel bars.

[0028] Preferably, the epoxy concrete is poured to a height of 150-180mm to completely cover the tensioning end anchor head of the prestressed steel strand.

[0029] The construction method for the anchoring structure includes the following steps:

[0030] S1, Factory prefabrication

[0031] S11. Cut and process the steel anchor box components according to the design requirements: integral anchor plate, steel grating partition, steel grating sealing plate, and steel grating bearing plate; make prestressed steel strand through holes and foundation concrete pouring holes on the integral anchor plate and steel grating bearing plate respectively;

[0032] S12. Assembled steel anchor box: First, position and weld the integral anchor plate, steel grating partition and steel grating bearing plate, then weld the inverted V-shaped steel pier wall plate, and finally seal and weld the steel grating sealing plate to form a closed steel grating.

[0033] S13, prefabricated perforated wall panels and perforated stiffening ribs, with concrete pouring holes and steel bar through holes made on them, and then the two are vertically welded into a skeleton component of the prestressed + PBL shear key system, and then welded and fixed to the steel grating pressure plate.

[0034] S14. Apply an anti-corrosion coating to the outer surface of all steel structures that matches the design anti-corrosion service life of the bridge.

[0035] S2. On-site installation and positioning

[0036] S21. Hoist the prefabricated inverted V-shaped steel pier segment with steel anchor box into place, adjust the spatial posture of the steel anchor box so that the top surface of the steel grating pressure plate is flush with the top surface of the foundation to be poured, and ensure that the center line of the steel anchor box coincides with the axis of the single leg of the inverted V-shaped steel pier.

[0037] S22. Install metal corrugated pipes inside the steel anchor box and arch seat, insert the prestressed steel strands into the corrugated pipes, temporarily fix the tensioning end anchor to the outside of the integral anchor plate, and place the anchoring end inside the arch seat.

[0038] S23. Pass the reinforcing bars through the pre-drilled holes of the stiffening ribs, cut them according to the anchorage length requirements, and bend them to form the PBL shear key steel mesh.

[0039] S3, base and arch abutment were cast together.

[0040] S31. Support the combined formwork of the base and the arch;

[0041] S32. Lay out the reinforcement bars for the base and arch;

[0042] S33. The arch base is made of large-volume concrete. To avoid cracks caused by temperature stress, layering, low-heat cement, reasonable mix proportions, and cooling water pipes are adopted to reduce the temperature of the concrete during the pouring process.

[0043] S34. An epoxy grouting material filling cavity is reserved in the top 5cm range inside the steel anchor box, and the remaining cavity is used as a non-shrink high-strength cement mortar filling cavity.

[0044] S4. Prestressing tensioning and anchorage zone sealing

[0045] S41. After the foundation concrete, epoxy grouting material in the steel anchor box and non-shrink high-strength cement mortar have all reached the design strength, the sand-embedded epoxy steel strand is tensioned in stages using a single-end tensioning process. The tensioning control stress is executed according to the design value, and a low-retraction anchor that can be re-tensioned is used for locking.

[0046] S42. After tensioning is completed, cut off the excess steel strands and pour thick epoxy concrete on the monolithic anchor plate to completely wrap the anchor head at the tensioning end, forming a durable sealing layer.

[0047] S5. Quality Inspection

[0048] S51. Use ultrasonic or X-ray methods to test the grout density inside the steel anchor box.

[0049] S52. Perform a re-tension test on the prestressed steel strands, and the measured shrinkage value is ≤1mm;

[0050] S53. Check the concrete strength, shrinkage compensation rate, and appearance quality of the base and arch. After meeting the design and specification requirements, complete all construction.

[0051] (III) Beneficial Effects

[0052] Compared with the prior art, the present invention provides an anchoring structure based on the connection between a small cross-section inverted V-shaped steel pier with a laterally inclined inward slope and an arch seat, which has the following beneficial effects:

[0053] The anchoring structure of this invention focuses on "small space, strong anchoring" as its core breakthrough. Under the conditions of limited cross-section and complex inclination angle of the inverted V-shaped steel pier, the original inclined and indirect force transmission path is transformed into a clear and efficient axial force transmission path through the transition design of the top surface of the base perpendicular to the pier axis. This significantly improves the structure's comprehensive bearing capacity for axial force, bending moment and horizontal force. The prestressed + PBL shear key and epoxy concrete work together to suppress cracking and fatigue, and provide long-term corrosion protection, giving the system excellent durability.

[0054] The steel anchor box of this invention allows for a compact arrangement of prestressed steel strands, staggered anchoring of long and short steel strands, and an integrated cast-in-place foundation. These details make construction more convenient, the concrete denser, and completely eliminate the traditional practice of "increasing the cross-section," saving materials and shortening the construction period. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the anchoring structure of the present invention based on the connection between the transversely inclined small-section inverted V-shaped steel pier and the arch seat;

[0056] Figure 2 This is a partial schematic diagram of the anchoring structure of the present invention based on the connection between a small cross-section inverted V-shaped steel pier with a laterally inclined inward slope and an arch seat;

[0057] Figure 3 This is a three-dimensional schematic diagram of the steel anchor box of the present invention;

[0058] Figure 4 This is a three-dimensional schematic diagram of the base of the present invention;

[0059] Figure 5 This is a three-dimensional schematic diagram of the prestressed + PBL shear key system of the present invention;

[0060] Figure 6 This is a three-dimensional schematic diagram of the perforated wall panel and the perforated stiffening ribs of the present invention.

[0061] In the picture:

[0062] 1. Inverted V-shaped steel pier; 11. Transverse bridge wall panel; 12. Longitudinal bridge wall panel;

[0063] 2. Steel anchor box; 21. Integral anchor plate; 22. Steel grating partition; 23. Steel grating sealing plate; 24. Steel grating bearing plate;

[0064] 3. Base; 4. Arch base;

[0065] 5. Prestressed steel strands + PBL shear key system; 51. Prestressed steel strands; 52. Perforated steel bars; 53. Perforated wall panels; 54. Perforated stiffening ribs; 55. Epoxy concrete. Detailed Implementation

[0066] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0067] Example 1:

[0068] See attached document Figures 1 to 6 The anchoring structure based on the connection between the transversely inward-sloping small-section inverted V-shaped steel pier and the arch abutment includes:

[0069] The steel anchor box 2 is welded to the transverse bridge-direction wall plate 11 and the longitudinal bridge-direction wall plate 12 of the inverted V-shaped steel pier 1;

[0070] It should be noted here that the bottom of the inverted V-shaped steel pier 1 is composed of a transverse bridge-oriented wall panel 11 and a longitudinal bridge-oriented wall panel 12;

[0071] Base 3, which is located on the top surface of arch 4 and is matched and engaged with steel anchor box 2;

[0072] The prestressed + PBL shear key system 5 is used to connect the steel anchor box 2, the base 3 and the arch 4 into a whole.

[0073] Among them, the steel anchor box 2 is formed by welding an integral anchor plate 21, a steel grating partition 22, a steel grating sealing plate 23 and a steel grating pressure plate 24 to form at least one grating. The steel grating sealing plate 23 is welded last after the integral anchor plate 21, the steel grating partition 22 and the steel grating pressure plate 24 are welded.

[0074] The prestressed + PBL shear key system 5 includes:

[0075] The prestressed steel strand 51 has one end anchored to the integral anchor plate 21 and the other end anchored inside the arch seat 4.

[0076] The perforated wall panel 53 and the perforated stiffening rib 54 are both welded to the steel grating bearing plate 24 and extend into the concrete of the base 3.

[0077] Perforated steel bar 52, used to pass through the hole in the perforated stiffening rib 54;

[0078] Epoxy concrete 55 is poured on top of the monolithic anchor plate 21 and wraps the anchor head of the prestressed steel strand 51.

[0079] In this embodiment, the bottom cross-sectional dimensions of the single-leg anchorage section of the inverted V-shaped steel pier 1 are approximately 3.6 meters in the transverse direction and approximately 0.94 meters in the longitudinal direction. Stiffening ribs are arranged within the pier at approximately 50-centimeter intervals. Therefore, only a limited number of prestressed steel strands 51 can be arranged within the internal space of the pier.

[0080] Due to the small cross-section of the steel pier, the anchorage space outside the pier is also limited. To make full use of the space on the outer wall of the pier, an anchorage structure of the form of steel anchor box 2 was adopted. This anchorage structure can minimize the spacing between steel strands on the outer wall of the pier, allowing for the arrangement of more steel strands while still meeting the working space requirements of the jacks. In this way, the required number of steel strands for the anchorage calculation can be arranged without increasing the cross-section of the pier.

[0081] In this embodiment, the axis of the single leg of the inverted V-shaped steel pier 1 forms an angle of 75° with the horizontal line in the transverse direction of the bridge and an angle of approximately 80° with the horizontal line in the longitudinal direction of the bridge. Since the force transmission between the inclined pier leg and the horizontal arch seat 4 is not very direct and effective, a base 3 structure with its top surface perpendicular to the axis of the single leg of the inverted V-shaped steel pier 1 is designed for transition.

[0082] The top 5cm area of ​​the compartment of steel anchor box 2 is filled with EGM-100 epoxy grout, and the remaining area is filled with non-shrink high-strength cement mortar.

[0083] In this embodiment, all steel structure surfaces of the anchoring structure are fitted with anti-corrosion coatings according to the designed anti-corrosion service life.

[0084] The anchoring structure proposed in this invention has a clear force mechanism and direct force transmission, and has good crack resistance and durability.

[0085] The anchoring structure proposed in this invention can solve the problem of how to ensure the direct and effective force transmission of the arch seat 4 when the axis of the single leg of the inverted V-shaped steel pier 1 is not perpendicular to the top surface in both the transverse and longitudinal directions of the bridge.

[0086] The anchoring structure proposed in this invention can solve the problem of how to make full use of the limited anchoring space when the cross section of the inverted V-shaped steel pier 1 is small.

[0087] Specifically, the integral anchor plate 21 has pre-drilled holes for steel strands, and the diameter of the holes matches the size of the expanded head of the steel strand anchor and the size of the working anchor plate of the anchor. The spacing between the holes matches the working space of the tensioning jack.

[0088] The steel grating bearing plate 24 has two types of holes, one type of which is used for the prestressed steel strands 51 to pass through, and the other type of which is used for the concrete pouring of the base 3.

[0089] The top surface of the base 3 is perpendicular to the axis of the single leg of the inverted V-shaped steel pier 1. The top surface outline is formed by offsetting the outer outline of the steel grating bearing plate 24 by 8-15cm, and the corners of the top surface are rounded.

[0090] Base 3 is made of C55-C60 shrinkage-compensating concrete with a limited expansion rate of 4×10. -4 -6×10 -4 The base 3 is reinforced with steel bars inside, and the sides of the base 3 are also equipped with D5-CRB550 shaped steel mesh. The net protective layer thickness is not less than 20mm, and it is cast integrally with the arch base 4.

[0091] In this embodiment, the top surface of the base 3 is perpendicular to the axis of the single leg of the inverted V-shaped steel pier 1. The outline of the top surface of the base 3 is obtained by offsetting the outer contour of the steel grating bearing plate 24 by 10 cm.

[0092] The virtual bottom outline is obtained by moving the top surface outline of base 3 down 2.2 meters along the axis of the single leg of the inverted V-shaped steel pier 1 and then shifting it outward by 0.6 meters.

[0093] The top, bottom, and side surfaces can be obtained from the top surface outline and virtual bottom surface outline of base 3, thus creating a volume similar to a frustum. After being cut by the top surface of arch 4, the upper part of this volume is base 3. The minimum distance between the top surface of base 3 and the top surface of arch 4 is greater than 0.2 meters.

[0094] The base 3 is a reinforced concrete structure. The concrete used is C60 shrinkage-compensating concrete with a limited expansion rate of 4×10⁻⁶. -4 -6×10 -4 The interior is reinforced with HRB400 steel bars. The sides are fully covered with D5-CRB550 precast steel mesh, with a spacing of 10cm x 10cm, and the net protective layer thickness should be no less than 2cm. The base is poured together with arch base 4. Before construction, the concrete for base 3 must undergo a mix design test to ensure the fluidity, workability, retarding properties, and early strength of the pumped concrete.

[0095] Specifically, the epoxy concrete 55 is poured to a height of 150-180mm to completely cover the tensioning end anchor head of the prestressed steel strand 51.

[0096] In this embodiment, epoxy concrete 55 is poured 15.5 cm high above the monolithic anchor plate 21, covering the tensioning end anchor head of the prestressed steel strand 51, making it less susceptible to corrosion and having good durability, thereby ensuring the safety of the entire connection and anchoring structure.

[0097] The construction method for the anchorage structure includes the following steps:

[0098] S1, Factory prefabrication

[0099] S11. Cut and process the steel anchor box 2 according to the design requirements: integral anchor plate 21, steel grating partition 22, steel grating sealing plate 23, and steel grating bearing plate 24; make through holes for prestressed steel strands 51 and concrete pouring holes for the base on the integral anchor plate 21 and the steel grating bearing plate 24 respectively.

[0100] S12, Assembled steel anchor box 2: First, position weld the integral anchor plate 21, the steel grating partition plate 22 and the steel grating bearing plate 24, then weld the inverted V-shaped steel pier wall plate, and finally seal and weld the steel grating sealing plate 23 to form a closed steel grating.

[0101] S13, precast perforated wall panel 53 and perforated stiffening rib 54, with concrete pouring holes and steel bar 52 through holes made on them, and then the two are vertically welded into the skeleton component of the prestressed + PBL shear key system 5, and then welded and fixed to the steel grating pressure plate 24.

[0102] S14. Apply an anti-corrosion coating to the outer surface of all steel structures that matches the design anti-corrosion service life of the bridge.

[0103] S2. On-site installation and positioning

[0104] S21. Hoist the prefabricated inverted V-shaped steel pier segment with steel anchor box 2 into place, adjust the spatial posture of steel anchor box 2 so that the top surface of steel grid room bearing plate 24 is flush with the top surface of the base 3 to be poured, and ensure that the center line of steel anchor box 2 coincides with the axis of the single leg of the inverted V-shaped steel pier.

[0105] S22. Install metal corrugated pipes in the steel anchor box 2 and the arch seat 4, insert the prestressed steel strand 51 into the corrugated pipes, temporarily fix the tensioning end anchor on the outside of the integral anchor plate 21, and place the anchoring end in the arch seat 4.

[0106] S23. Pass the steel bar 52 through the reserved hole of the opening stiffening rib 54, cut it according to the anchorage length requirement and bend it for positioning to form the PBL shear key steel mesh.

[0107] S3, base 3 and arch 4 were cast together.

[0108] S31, Formwork combination of base 3 and arch 4;

[0109] S32, Install the reinforcing bars for base 3 and arch 4;

[0110] S33 and arch base 4 are large-volume concrete structures. To avoid cracking due to temperature stress, layering, low-heat cement, a reasonable mix ratio, and cooling water pipes were used during pouring to reduce the temperature of the concrete during the pouring process. However, it is essential to ensure that base 3 and arch base 4 are poured together and bonded as a whole.

[0111] S34. An epoxy grouting material filling cavity is reserved in the top 5cm range inside the steel anchor box 2, and the remaining cavity is used as a non-shrink high-strength cement mortar filling cavity.

[0112] S4. Prestressing tensioning and anchorage zone sealing

[0113] S41. After the concrete of the base 3, the epoxy grouting material in the steel anchor box 2 and the non-shrink high-strength cement mortar have all reached the design strength, the sand-embedded epoxy steel strand 51 is tensioned in stages using a single-end tensioning process. The tensioning control stress is executed according to the design value, and a low-retraction anchor that can be re-tensioned is used for locking.

[0114] S42. After tensioning is completed, cut off the excess steel strands and pour thick epoxy concrete 55 on the integral anchor plate 21 to completely wrap the anchor head at the tensioning end, forming a durable sealing layer.

[0115] S5. Quality Inspection

[0116] S51. Use ultrasonic or X-ray methods to test the grout density inside the steel anchor box 2.

[0117] S52. Perform a re-tension test on the prestressed steel strand 51. The measured shrinkage value is ≤1mm.

[0118] S53. Check the concrete strength, shrinkage compensation rate, and appearance quality of base 3 and arch 4. After meeting the design and specification requirements, complete all construction.

[0119] Example 2: The difference from Example 1 is that;

[0120] Prestressed steel strand 51 is Φ s 15.2 Sand-embedded epoxy steel strands, and the anchorages are retractable anchorages that can be pulled down twice to reduce prestress loss. The steel strands are anchored with staggered lengths to avoid stress concentration.

[0121] In this embodiment, the prestressed steel strand 51 in the prestressed + PBL shear key system 5 uses Φ 15-22 steel. s15.2 The prestressed steel strands are reinforced with sand and the anchorages are low-retraction anchorages capable of secondary retraction, which reduces prestress loss. The prestressed steel strands 51 are tensioned at one end, with the tensioning end anchored to the integral anchor plate 21, and the anchoring end located inside the arch seat 4. The prestressed steel strands 51 are designed with varying lengths to avoid all strands being anchored at the same cross-section, thus preventing concentrated stress. The steel strand corrugated pipes are metal corrugated pipes, model JBG-102Z. During construction, the protection and positioning of the prestressed metal corrugated pipes must be strengthened. The detailed layout of the stiffening frame of the arch seat 4 should be considered in conjunction with the positioning of the metal corrugated pipes of the prestressed steel strands 51 in the inverted V-shaped steel pier anchorage section.

[0122] Example 3: The difference from Example 1 is that;

[0123] The perforated wall panel 53 and the perforated stiffening rib 54 are 25-35mm thick. The diameter of the round holes on the perforated stiffening rib 54 is 70-90mm and the spacing is 180-220mm. The perforated steel bar 52 is HRB400 steel bar with diameter of Φ20-Φ28mm.

[0124] In this embodiment, the perforated stiffening rib 54 and the perforated wall plate 53 are made of Q345qD material with a plate thickness of 30 mm. The diameter of the circular holes reserved on the perforated stiffening rib 54 for the perforated reinforcing bars 52 is 8 cm, and the spacing between the holes is 20 cm. The perforated reinforcing bars 52 are HRB400 steel bars with a diameter of 25 mm. The length of the reinforcing bars should meet the anchorage length requirements.

[0125] The perforated stiffening rib 54 is vertically welded to the perforated wall plate 53, and the perforated stiffening rib 54 and the perforated wall plate 53 are vertically welded to the steel grating bearing plate 24. The perforated wall plate 53 has a 20 cm diameter casting hole to facilitate the dense pouring of concrete for the base 3 and the arch 4, and the concrete tenon passing through the hole allows for a better connection between the anchoring section structure and the base 3 and the arch 4.

[0126] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An anchoring structure for connecting a small-section inverted V-shaped steel pier with a transverse inclination to an arch seat, characterized in that, include: The steel anchor box (2) is welded to the transverse bridge wall plate (11) and the longitudinal bridge wall plate (12) of the inverted V-shaped steel pier (1); The base (3) is located on the top surface of the arch (4) and is matched and engaged with the steel anchor box (2); The prestressed + PBL shear key system (5) is used to connect the steel anchor box (2), the base (3) and the arch (4) into a whole. The steel anchor box (2) is formed by welding an integral anchor plate (21), a steel grating partition (22), a steel grating sealing plate (23), and a steel grating bearing plate (24) to form at least one grating. The prestressed + PBL shear key system (5) includes: Prestressed steel strand (51), one end of which is anchored to an integral anchor plate (21) and the other end is anchored inside the arch seat (4); Perforated wall panel (53) and perforated stiffening rib (54), the perforated wall panel (53) and perforated stiffening rib (54) are both welded to the steel grating bearing plate (24) and extend into the concrete of the base (3); Perforated steel bar (52), the perforated steel bar (52) is used to pass through the hole in the perforated stiffening rib (54); Epoxy concrete (55) is poured on top of the monolithic anchor plate (21) and wraps around the anchor head of the prestressed steel strand (51).

2. The anchoring structure based on the connection between the transversely inclined small-section inverted V-shaped steel pier and the arch seat as described in claim 1, characterized in that: The integral anchor plate (21) has pre-reserved steel strand holes, and the diameter of the steel strand holes matches the size of the steel strand anchor under the expansion head and the size of the working anchor plate of the anchor. The hole spacing matches the working space of the tensioning jack.

3. The anchoring structure based on the connection between the transversely inclined small-section inverted V-shaped steel pier and the arch seat as described in claim 1, characterized in that: The steel grating bearing plate (24) has two types of holes, one type of which is used for the prestressed steel strands (51) to pass through, and the other type of which is used for the concrete pouring of the base (3).

4. The anchoring structure based on the connection between the transversely inclined small-section inverted V-shaped steel pier and the arch seat according to claim 1, characterized in that: The top surface of the base (3) is perpendicular to the axis of the single leg of the inverted V-shaped steel pier (1), and the top surface profile is formed by offsetting the outer profile of the steel grating pressure plate (24) by 8-15cm, with rounded corners on the top surface.

5. The anchoring structure based on the connection between a small-section inverted V-shaped steel pier with transverse inclination and an arch seat as described in claim 1, characterized in that: The base (3) is made of shrinkage-compensating concrete, with a limited expansion rate of 4×10. -4 -6×10 -4 The base (3) is equipped with steel bars inside, and the side of the base (3) is also equipped with a shaped steel mesh. The net protective layer thickness is not less than 20mm, and it is cast integrally with the arch seat (4).

6. The anchoring structure based on the connection between the transversely inclined small-section inverted V-shaped steel pier and the arch seat according to claim 1, characterized in that: The prestressed steel strand (51) is a sand-embedded epoxy steel strand, and the anchor is a retractable anchor that can be pulled down twice.

7. The anchoring structure based on the connection between a small-section inverted V-shaped steel pier with transverse inclination and an arch seat as described in claim 1, characterized in that: The perforated wall panel (53) and the perforated stiffening rib (54) are 25-35mm thick. The diameter of the round holes on the perforated stiffening rib (54) is 70-90mm and the spacing is 180-220mm. The perforated steel bar (52) is a steel bar with a diameter of Φ20-Φ28mm.

8. The anchoring structure based on the connection between a small-section inverted V-shaped steel pier with transverse inclination and an arch seat as described in claim 1, characterized in that: The epoxy concrete (55) is poured to a height of 150-180 mm to completely cover the tensioning end anchor head of the prestressed steel strand (51).

9. The construction method of the anchoring structure as described in any one of claims 1-8, characterized in that, Includes the following steps: S1, Factory prefabrication S11. Cut and process the steel anchor box (2) plates according to the design requirements: integral anchor plate (21), steel grating partition (22), steel grating sealing plate (23), and steel grating bearing plate (24); make through holes for prestressed steel strands (51) and concrete pouring holes for the base on the integral anchor plate (21) and the steel grating bearing plate (24), respectively. S12, Assemble and weld steel anchor box (2): First, position and weld the integral anchor plate (21), steel grating partition (22) and steel grating bearing plate (24), then weld the inverted V-shaped steel pier wall plate, and finally seal and weld the steel grating sealing plate (23) to form a closed steel grating. S13, prefabricated perforated wall panel (53) and perforated stiffening rib (54), and concrete pouring holes and steel bar (52) through holes are made on them. Then the two are vertically welded into a skeleton component of prestressed + PBL shear key system (5), and then welded and fixed to the steel grating pressure plate (24). S14. Apply an anti-corrosion coating to the outer surface of all steel structures that matches the design anti-corrosion service life of the bridge. S2. On-site installation and positioning S21. Hoist the inverted V-shaped steel pier segment of the prefabricated steel anchor box (2) into place, adjust the spatial posture of the steel anchor box (2) so that the top surface of the steel grid room bearing plate (24) is flush with the top surface of the foundation (3) to be poured, and ensure that the center line of the steel anchor box (2) coincides with the axis of the single leg of the inverted V-shaped steel pier. S22. Install metal corrugated pipes in the steel anchor box (2) and arch seat (4), insert the prestressed steel strand (51) into the corrugated pipe, temporarily fix the tension end anchor on the outside of the integral anchor plate (21), and place the anchor end in the arch seat (4). S23. Pass the reinforcing bar (52) through the pre-drilled hole of the stiffening rib (54), cut it according to the anchorage length requirement and bend it to form a PBL shear key steel mesh. S3, base (3) and arch (4) are cast together S31, Support base (3) and arch base (4) combined formwork; S32, Arrange the reinforcement bars for the base (3) and arch (4); S33 and the arch seat (4) are large-volume concrete. In order to avoid cracks caused by temperature stress, layering, low-heat cement, reasonable mix ratio, and cooling water pipes are adopted to reduce the temperature during the concrete pouring process. S34. An epoxy grouting material filling cavity is reserved in the top 5cm range inside the steel anchor box (2), and the remaining cavity is used as a non-shrink high-strength cement mortar filling cavity. S4. Prestressing tensioning and anchorage zone sealing S41. After the concrete of the base (3), the epoxy grouting material in the steel anchor box (2) and the non-shrink high-strength cement mortar have all reached the design strength, the sand-embedded epoxy steel strand (51) is tensioned in stages using a single-end tensioning process. The tensioning control stress is executed according to the design value, and a low-retraction anchor that can be re-tensioned twice is used for locking. S42. After tensioning, cut off the excess steel strands and pour thick epoxy concrete (55) on top of the integral anchor plate (21) to completely wrap the anchor head at the tensioning end, forming a durable sealing layer. S5. Quality Inspection S51. Use ultrasonic or X-ray methods to test the grout density inside the steel anchor box (2); S52. The prestressed steel strand (51) is subjected to a re-tension test, and the measured shrinkage value is ≤1mm; S53. Check the concrete strength, shrinkage compensation rate and appearance quality of the base (3) and arch (4). After meeting the design and specification requirements, complete all construction.

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