A structure and construction method for a precast assembled cable-stayed bridge concrete pylon

Abstract

This invention discloses a structure and construction method for a precast, assembled concrete cable-stayed bridge tower, overcoming the problems of large workload, long construction period, and difficulty in ensuring quality in traditional concrete cable-stayed bridge structures. The technical solution includes: a tower foundation, a tower platform, and a tower body arranged sequentially from bottom to top; the tower body consists of a lower tower column, a middle tower column, and an upper tower column; a cast-in-place section is provided between the bottom of the lower tower column and the tower platform; both the lower and middle tower columns are composed of several tower column segments, and the upper tower column is composed of several anchoring segments; a main beam is provided in the middle of the middle tower column; each tower column segment consists of two first precast blocks and two second precast blocks; the first and second precast blocks are arranged alternately and spliced ​​into a frustum-shaped structure; the anchoring segments are spliced ​​into a frustum-shaped structure by third and fourth precast blocks; and cable stays are provided on both sides adjacent to the splice joint of each anchoring segment.

Description

Technical Field

[0001] This invention belongs to the field of civil engineering bridge technology, specifically relating to the structure and construction method of a prefabricated assembled concrete cable-stayed bridge tower. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Bridges are used in the construction of highways, railways, urban roads, and water conservancy infrastructure to cross rivers or other obstacles. Cable-stayed bridges are bridges with pylons, stay cables, and main girders as their main load-bearing components. They are cable-stayed bridges with the second-highest span capacity after suspension bridges. The pylons of cable-stayed bridges are the main load-bearing components, primarily bearing eccentric pressure. They are generally constructed using high-compressive-strength materials such as concrete, steel-concrete composite, and steel. Concrete pylons have high stiffness and are relatively economical in cost, accounting for the largest proportion of long-span cable-stayed bridges and are the most widely used.

[0004] Although the number of cable-stayed bridge concrete pylons is enormous, currently, traditional cable-stayed bridge concrete pylons are constructed using conventional slipform or formwork casting methods. However, when the span of a cable-stayed bridge exceeds a certain length or the height of the pylon exceeds a certain height, there are issues with casting ultra-high pylons on-site. These issues include a large on-site workforce, a significant amount of work at height, long construction time, and high safety risks. The efficiency of slipform or formwork casting on-site is prone to a sharp decline, resulting in longer construction periods and a sharp increase in costs. At the same time, the on-site casting of ultra-high pylons is greatly affected by environmental factors, making it difficult to guarantee quality and durability, leading to more structural durability defects and affecting the lifespan of the bridge. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a structure and construction method for a precast assembled cable-stayed bridge concrete pylon, which improves the rapid construction capability of the pylon from the aspects of structural design and internal stress mechanism, and overcomes the problems of large workload, long construction period and difficulty in guaranteeing quality in the on-site pouring of traditional concrete pylon structures.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] In a first aspect, the present invention provides a structure for a prefabricated assembled concrete cable-stayed bridge tower, comprising:

[0008] The structure consists of, from bottom to top, the tower foundation, the tower platform, and the tower body.

[0009] The tower body is composed of a lower tower column, a middle tower column, and an upper tower column; a cast-in-place section is provided between the bottom of the lower tower column and the tower foundation; both the lower and middle tower columns are composed of several tower column segments; the upper tower column is composed of several anchoring segments; a main beam is provided in the middle of the middle tower column.

[0010] The tower column segment is composed of two first precast block segments and two second precast block segments; both the first precast block segments and the second precast block segments are L-shaped structures, the first precast block segments and the second precast block segments are arranged alternately and spliced ​​into a quadrangular frustum structure, and the splicing seam is also inclined at a set angle relative to the plumb line.

[0011] The anchoring segment has two U-shaped precast blocks, namely the third precast block and the fourth precast block. The third precast block and the fourth precast block are spliced ​​into a truncated quadrangular structure, and the splice joint is inclined at a set angle relative to the plumb line. The third precast block and the fourth precast block are provided with inclined cables on the two sides adjacent to the splice joint.

[0012] Furthermore, the first, second, third, and fourth precast blocks are provided with segment splicing anchor blocks on the inner and outer sides of the segments at the splicing joints. The splicing anchor blocks are provided with segment prestressing tendons for splicing between the precast blocks.

[0013] Furthermore, the first and second precast block segments of the tower column segments that are adjacent to each other are arranged alternately, with notched joints at both ends of the first precast block segment and convex joints at both ends of the second precast block segment.

[0014] Furthermore, the third and fourth precast blocks of the adjacent anchoring segments are arranged alternately, with notched joints at both ends of the third precast block and convex joints at both ends of the fourth precast block.

[0015] Furthermore, the tower column segment and the anchoring segment are provided with a trapezoidal boss at the connection in the height direction. The trapezoidal boss is provided with pin holes at certain intervals, and a positioning steel pin is provided in the pin hole for guiding and positioning.

[0016] Furthermore, cast-in-place wet joints are provided on the outer and inner sides of the trapezoidal protrusions at the height connection points of the tower column segments and the anchorage segments; vertical main reinforcement bars are provided in the height direction at the wet joints of the tower column segments and the anchorage segments.

[0017] Furthermore, the concrete strength grade of the wet joint is not lower than that of the precast block segment.

[0018] Furthermore, the third and fourth precast block segments in the anchoring section are provided with cable anchor blocks for cable anchoring.

[0019] Furthermore, a horizontal plate is provided at the lower end of the stay cable anchor block, and a stay cable anchoring prestressing strand is provided in the horizontal plate to bear the tension of the stay cable.

[0020] Secondly, the present invention also provides a construction method for a prefabricated assembled concrete pylon structure of a cable-stayed bridge, the specific steps of which include:

[0021] S1. Construct the tower foundation at the tower location, and construct the tower pier on the tower foundation; simultaneously, prefabricate the first and second prefabricated blocks of the lower and middle tower columns, as well as the third and fourth prefabricated blocks of the upper tower column, from bottom to top.

[0022] S2. Cast the bottom section of the lower tower column on the tower support platform, pre-embed the vertical main reinforcement of the tower column, and trim the trapezoidal protrusion at the wet joint.

[0023] S3. Insert the positioning steel pin into the pin hole of the trapezoidal boss, and apply structural adhesive to the top surface of the trapezoidal boss;

[0024] S4. Hoist the first precast block of the tower column segment, apply structural adhesive to the tongue and groove joint, then hoist the second precast block of the tower column segment, insert the prestressed tendons into the segment splicing anchor blocks and tension, anchor, and grout to complete the connection between the precast blocks, until the set number of tower column segments are completed; for the upper tower column, after the third and fourth precast blocks are connected, insert cables at the horizontal plate to anchor the prestressed tendons and tension, anchor, and grout.

[0025] S5. After connecting the vertical main reinforcement in the wet joint of the segment between several tower column segments and anchorage segments, and tying the other reinforcement in the corresponding parts, pour the wet joint concrete to complete the connection between several tower column segments and anchorage segments.

[0026] Repeat steps S3 through S5 to complete the assembly of the lower, middle, and upper tower columns sequentially from top to bottom.

[0027] Compared with the prior art, the advantages and positive effects of this invention are:

[0028] The tower column segments and anchorage segments of this invention are divided into 4 or 2 prefabricated blocks for assembly, which reduces the weight of a single prefabricated block, facilitates implementation, and improves adaptability to ultra-high cable towers and large-sized cable towers. The inclined joints between the prefabricated blocks ensure connection strength. Since the concrete cable tower is assembled from multiple prefabricated blocks, it can be prefabricated in a factory environment, which easily improves the quality of concrete. Moreover, its shrinkage and creep are completed in the free state of the prefabricated blocks, reducing or even eliminating shrinkage stress. During on-site hoisting, only a small number of wet joints of the segments are poured on-site, which significantly improves construction efficiency, shortens the construction period, and greatly reduces the amount of high-altitude work and personnel input, making it more environmentally friendly.

[0029] The protrusions and positioning steel pins between the segments of this invention make it easier to hoist and position the precast blocks, improve the accuracy of the connection with the vertical main reinforcement of the completed segments, and make the connection operation of the main reinforcement more convenient. The anchorage area of ​​the upper tower column cable uses a precast horizontal plate and prestressing, which not only makes the splicing between the blocks tighter, but also balances the tension of the cable, realizes concrete prestressed anchorage, and saves a lot of steel and subsequent maintenance costs. Attached Figure Description

[0030] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0031] Figure 1 This is a schematic diagram of the overall structure of the prefabricated assembled cable-stayed bridge concrete tower of the present invention;

[0032] Figure 2 This is a schematic diagram of the prefabricated block structure of the tower column segment of the lower and middle tower columns of the present invention;

[0033] Figure 3 This is a cross-sectional structural diagram of each prefabricated block segment of the tower column section of the lower and middle tower columns of the present invention;

[0034] Figure 4 This is a schematic diagram of the prefabricated block structure of the anchoring segment of the upper tower column of the present invention;

[0035] Figure 5 This is a schematic diagram of the vertical cross-sectional structure of the wet joint between the upper and lower segments of the present invention;

[0036] Figure 6 This is a partial schematic diagram of the vertical cross-section of the wet joint between the upper and lower segments of the present invention.

[0037] In the diagram: 1. Lower tower column; 2. Middle tower column; 3. Upper tower column; 4. Tower column segment; 5. Anchorage segment; 6. First precast block segment; 7. Second precast block segment; 8. Third precast block segment; 9. Fourth precast block segment; 10. Block splicing anchor block; 11. Notched joint; 12. Raised joint; 13. Wet joint; 14. Trapezoidal boss; 15. Block prestressed tendon; 17. Vertical main reinforcement; 18. Tower foundation; 19. Tower abutment; 20. Cast-in-place section at the tower base; 21. Positioning steel pin; 22. Horizontal plate; 23. Main beam; 24. Stay cable; 25. Stay cable anchor block. Detailed Implementation

[0038] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0039] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless otherwise expressly indicated by the invention, the singular form is also intended to include the plural form. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0040] To address the aforementioned technical problems, the structure of the present invention will be further described below with reference to the accompanying drawings. The prefabricated, assembled concrete pylon structure of the cable-stayed bridge according to the present invention has a simpler structure, clearer stress distribution, and better prefabrication and factory-based construction conditions, such as… Figures 1-6 As shown, the structure includes, from bottom to top, a tower foundation 18, a tower platform 19, and a tower body; the tower body consists of a lower tower column 1, a middle tower column 2, and an upper tower column 3; a cast-in-place section 20 is provided between the bottom of the lower tower column 1 and the tower platform 19; both the lower tower column 1 and the middle tower column 2 are composed of several tower column segments 4; the upper tower column 3 is composed of several anchoring segments 5; a main beam 23 is provided in the middle of the middle tower column 2; each tower column segment 4 is composed of two first precast block segments 6 and two second precast block segments 7; the first precast block segments 6 and... The second precast block segment 7 is L-shaped. The first precast block segment 6 and the second precast block segment 7 are arranged alternately and spliced ​​into a frustum-shaped structure. The splice joint is also inclined at a set angle relative to the plumb line. The anchoring segment 5 has two U-shaped precast blocks, namely the third precast block segment 8 and the fourth precast block segment 9. The third precast block segment 8 and the fourth precast block segment 9 are spliced ​​into a frustum-shaped structure. The splice joint is inclined at a set angle relative to the plumb line. The third precast block segment 8 and the fourth precast block segment 9 are provided with inclined cables 24 on the two sides adjacent to the splice joint.

[0041] The first precast block segment 6, the second precast block segment 7, the third precast block segment 8 and the fourth precast block segment 9 are provided with block splicing anchor blocks 10 on the inner and outer sides of the segments at the splicing joint. The splicing anchor blocks are provided with splicing block prestressing tendons 15 for splicing between each precast block segment. By tensioning, anchoring and grouting the block prestressing tendons 15, the splicing between each precast block segment is realized.

[0042] The first precast block segment 6 and the second precast block segment 7 of the tower column segments 4 that are adjacent to each other are arranged alternately. The first precast block segment 6 has a notched joint 11 at both ends, and the second precast block segment 7 has a convex joint 12 at both ends.

[0043] The third precast block segment 8 and the fourth precast block segment 9 of the anchoring segments 5 are arranged alternately. The third precast block segment 8 has a notched joint 11 at both ends, and the fourth precast block segment 9 has a convex joint 12 at both ends.

[0044] The tower column segment 4 and the anchoring segment 5 are provided with a trapezoidal boss 14 at the connection in the height direction. The trapezoidal boss 14 is provided with pin holes at certain intervals, and a positioning steel pin 21 is provided in the pin hole for guiding and positioning.

[0045] On the outer and inner sides of the trapezoidal protrusion 14 at the connection of the tower column segment 4 in the height direction and the connection of the anchoring segment 5 in the height direction, there are cast-in-place wet joints 13; the tower column segment 4 and the anchoring segment 5 are provided with segmental vertical main reinforcement 17 in the height direction at the wet joint 13.

[0046] The concrete strength grade of the wet joint 13 shall not be lower than that of the precast block segment.

[0047] The third precast block segment 8 and the fourth precast block segment 9 in the anchoring segment 5 are provided with cable anchor blocks 25 for anchoring the cable 24.

[0048] A horizontal plate 22 is provided at the lower end of the cable anchor block 25. The horizontal plate 22 contains cable anchoring prestressed tendons. After the splicing between the third precast block segment 8 and the fourth precast block segment 9 is completed, the cable anchoring prestressed tendons are tensioned, anchored, and grouted, so that the cable anchoring prestressed tendons can bear the tension of the cable 24.

[0049] This invention also provides a construction method for a precast assembled concrete pylon structure of a cable-stayed bridge, the specific steps of which include:

[0050] S1. Construct a tower foundation 18 at the tower location, and construct a tower pier 19 on the tower foundation 18; simultaneously, prefabricate the first prefabricated block segment 6 and the second prefabricated block segment 7 of the lower tower column 1 and the middle tower column 2 from bottom to top, as well as the third prefabricated block segment 8 and the fourth prefabricated block segment 9 of the upper tower column 3.

[0051] S2. Cast the bottom section 20 of the lower tower column 1 on the tower foundation 19, and pre-embed the vertical main reinforcement 17 of the tower column, and repair the trapezoidal protrusion 14 at the wet joint 13.

[0052] S3. Insert the positioning steel pin 21 into the pin hole of the trapezoidal boss 14, and apply structural adhesive to the top surface of the trapezoidal boss 14.

[0053] S4. Hoist the first precast block 6 of the tower column segment 4, apply structural adhesive to the tongue and groove joint, then hoist the second precast block 7 of the tower column segment 4, insert the prestressed tendon 15 into the block splicing anchor block 10 and tension, anchor, and grout to complete the connection between the precast blocks, until the set number of tower column segments 4 are completed; for the upper tower column 3, after the third precast block 8 and the fourth precast block 9 are connected, insert the cable anchoring prestressed tendon at the horizontal plate 22 and tension, anchor, and grout.

[0054] S5. After connecting the vertical main reinforcement 17 in the wet joint 13 between several tower column segments 4 and anchorage segments 5, and binding the other reinforcements in the corresponding parts, pour the concrete of the wet joint 13 to complete the connection between several tower column segments 4 and anchorage segments 5.

[0055] Repeat steps S3 through S5 to complete the assembly of the lower tower column 1, middle tower column 2, and upper tower column 3 sequentially from top to bottom.

[0056] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A structure for a precast, assembled concrete cable-stayed bridge tower, characterized in that, include: The structure consists of, from bottom to top, the tower foundation, the tower platform, and the tower body. The tower body is composed of a lower tower column, a middle tower column, and an upper tower column; a cast-in-place section is provided between the bottom of the lower tower column and the tower foundation; both the lower and middle tower columns are composed of several tower column segments; the upper tower column is composed of several anchoring segments; a main beam is provided in the middle of the middle tower column. The tower column segment is composed of two first precast block segments and two second precast block segments; both the first precast block segments and the second precast block segments are L-shaped structures, the first precast block segments and the second precast block segments are arranged alternately and spliced ​​into a quadrangular frustum structure, and the splicing seam is also inclined at a set angle relative to the plumb line. The anchoring segment has two U-shaped precast blocks, namely the third precast block and the fourth precast block. The third precast block and the fourth precast block are spliced ​​into a truncated quadrangular structure, and the splice joint is inclined at a set angle relative to the plumb line. The third precast block and the fourth precast block are provided with inclined cables on the two sides adjacent to the splice joint. The first, second, third, and fourth precast blocks are provided with segment splicing anchor blocks on the inner and outer sides of the segments at the splicing joints. The splicing anchor blocks are provided with segment prestressed tendons for splicing between the precast blocks. The third and fourth precast block segments in the anchoring section are provided with cable anchor blocks for cable anchoring.

2. The structure of a precast assembled cable-stayed bridge concrete pylon as described in claim 1, characterized in that, The first and second precast blocks of the tower column segments that are adjacent to each other are arranged alternately. The first precast block has notched joints at both ends, and the second precast block has convex joints at both ends.

3. The structure of a precast assembled cable-stayed bridge concrete pylon as described in claim 1, characterized in that, The third and fourth precast blocks of the anchoring segments are arranged alternately, with notched joints at both ends of the third precast block and convex joints at both ends of the fourth precast block.

4. The structure of a precast assembled cable-stayed bridge concrete pylon as described in claim 1, characterized in that, The tower column segment and the anchoring segment are provided with a trapezoidal boss at the connection in the height direction. The trapezoidal boss is provided with pin holes at certain intervals, and a positioning steel pin is provided in the pin hole for guiding and positioning.

5. The structure of a precast assembled cable-stayed bridge concrete pylon as described in claim 1, characterized in that, The outer and inner sides of the trapezoidal protrusions at the height connection points of the tower column segments and the anchorage segments are provided with cast-in-place wet joints; the tower column segments and the anchorage segments are provided with segmental vertical main reinforcements at the height of the wet joints.

6. The structure of a precast assembled cable-stayed bridge concrete pylon as described in claim 5, characterized in that, The concrete strength grade of the wet joint shall not be lower than that of the precast block segment.

7. The structure of a precast assembled cable-stayed bridge concrete pylon as described in claim 1, characterized in that, A horizontal plate is provided at the lower end of the stay cable anchor block, and a stay cable anchoring prestressing strand is provided in the horizontal plate to bear the tension of the stay cable.

8. A construction method for a precast assembled concrete pylon structure for a cable-stayed bridge as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Construct the tower foundation at the tower location, and construct the tower pier on the tower foundation; simultaneously, prefabricate the first and second prefabricated blocks of the lower and middle tower columns, as well as the third and fourth prefabricated blocks of the upper tower column, from bottom to top. S2. Cast the bottom section of the lower tower column on the tower support platform, pre-embed the vertical main reinforcement of the tower column, and trim the trapezoidal protrusion at the wet joint. S3. Insert the positioning steel pin into the pin hole of the trapezoidal boss, and apply structural adhesive to the top surface of the trapezoidal boss; S4. Hoist the first precast block of the tower column segment, apply structural adhesive to the tongue and groove joint, then hoist the second precast block of the tower column segment, insert the prestressed tendons into the segment splicing anchor blocks and tension, anchor, and grout to complete the connection between the precast blocks, until the set number of tower column segments are completed; for the upper tower column, after the third and fourth precast blocks are connected, insert cables at the horizontal plate to anchor the prestressed tendons and tension, anchor, and grout. S5. After connecting the vertical main reinforcement in the wet joint of the segment between several tower column segments and anchorage segments, and tying the other reinforcement in the corresponding parts, pour the wet joint concrete to complete the connection between several tower column segments and anchorage segments. Repeat steps S3 through S5 to complete the assembly of the lower, middle, and upper tower columns sequentially from top to bottom.

Images