Inner cavity template type inhaul cable anchoring system and mounting method thereof

Abstract

According to the inner cavity formwork type inhaul cable anchoring system and the installation method thereof, more horizontal force and unbalanced force are borne through the multiple separated steel anchor box sections, vertical force is transmitted to the concrete tower wall, the mechanical characteristics of steel and concrete materials are fully considered, the tensile strength of a main tensile plate of the steel anchor box sections is exerted, and the tensile strength of the main tensile plate of the steel anchor box sections is improved. And meanwhile, a tower cable anchoring area is optimized into a steel tooth block and annular steel anchor box structure by utilizing an anti-pulling and non-shearing force transmission key, a traditional force transmission key and a rubber pad. According to the invention, the stress state of the tower wall can be effectively improved, the thickness of the tower wall is reduced, tower wall circumferential prestressed steel beams do not need to be arranged, meanwhile, the inner side size of the bridge tower is relatively regular, the construction is relatively convenient, the quality is easy to guarantee, the bridge tower can be used as a tower column inner film, the later welding construction is also convenient by arranging the steel tooth block structure, and the use and popularization values are relatively high.

Description

Technical Field

[0001] The invention relates to the technical field of bridge engineering, and in particular to an inner cavity template type cable anchoring system and an installation method thereof. Background Art

[0002] In modern large-span cable-stayed bridge structures, the height of the cable tower increases with the increase in span, which also makes the horizontal tension of the cable borne by the concrete, the shear force caused by local bending, and the bending moment are all very large, which will inevitably lead to horizontal cracks in the plane of the concrete tower column, seriously affecting the overall safety and long-term normal use and life of the cable-stayed bridge. Due to the poor tensile performance of concrete, the cross-section and thickness of the cable tower must be large and a considerable number of prestressed steel bars must be configured to meet the force requirements, which increases the construction difficulty and project cost.

[0003] The cable tower structure of a cable-stayed bridge is an important force-bearing structure that evenly transfers the local concentrated force of the cable to the tower column. According to the arrangement of the cables, the number and shape of the cables, the tower shape and structure, etc., the commonly used concrete cable tower anchoring construction schemes for cable-stayed bridges mainly include the following forms: prestressed tooth block anchoring method, steel anchor beam anchoring method, and steel anchor box anchoring method.

[0004] Prestressed anchoring means that the cable is anchored on the bulge on the inner side of the hollow tower column wall, and circumferential plane prestressing or longitudinal and transverse plane prestressing is set in the anchoring area to balance the tensile stress generated on the tower wall. However, this anchoring structure has a large prestressing loss, and a large number of prestressed tendons need to be arranged, which makes the high-altitude prestressing process work volume relatively large, and the construction quality and precision are difficult to control.

[0005] When the steel anchor beam is anchored, the cable is anchored on the anchor blocks at both ends of the steel anchor beam, and the steel anchor beam is supported on the corbel convex block on the inner side of the hollow tower column transverse wall. As an independent anchoring component, the steel anchor beam itself balances the horizontal force of the cables on both sides, but some unbalanced horizontal forces may still cause the tower column concrete to crack under tension, so it is necessary to arrange prestressed tendons in the cable tower anchoring area, and there are certain requirements for the internal space of the tower column.

[0006] When the steel anchor box is anchored, it is subjected to greater tensile force, while the concrete tower wall is subjected to greater pressure and less tensile force. Its stress behavior is relatively complex, and the concrete in the anchoring area is prone to cracking. Prestressed tendons still need to be arranged, and it is an on-site high-altitude operation, which requires high installation accuracy. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention proposes an inner cavity template type cable anchoring system and its installation method. The anchoring system combines the advantages of traditional concrete tooth blocks, steel anchor beams and steel anchor boxes, and uses pull-out-resistant but non-shear-resistant force transmission keys, traditional shear keys and rubber pads to optimize the cable tower anchoring area into a steel tooth block and annular steel anchor box structure. The specific technical solution is as follows:

[0008] An inner cavity template type cable anchoring system comprises a concrete cable tower having a cavity with a rectangular cross section, wherein the concrete cable tower comprises two oppositely arranged transverse bridge tower walls and a longitudinal bridge tower wall connecting the two transverse bridge tower walls;

[0009] A steel anchor box, comprising a plurality of steel anchor box segments, which are sequentially arranged in the cavity from bottom to top, wherein the steel anchor box segment comprises two oppositely arranged side pull plates and an end plate connecting the two side pull plates, the two end plates are arranged in a transverse bridge direction and are respectively connected to the transverse bridge tower wall, and the two side pull plates are arranged in a longitudinal bridge direction and are respectively connected to the longitudinal bridge tower wall;

[0010] A plurality of inclined cable anchoring tooth blocks are arranged on the inner side of the side pull plate, a traditional force transmission key and a pull-out resistant but not shear resistant force transmission key are arranged on the outer side of the side pull plate, and a traditional force transmission key and a rubber pad are arranged on the outer side of the end plate.

[0011] Furthermore, the inclined cable anchoring tooth blocks are welded and fixed to the positions near the two ends of the side pull plate, the traditional force transfer key is welded and fixed to the middle part of the side pull plate, and the pull-out resistant but not shear resistant force transfer key is welded and fixed to the positions near the two ends of the side pull plate corresponding to the inclined cable anchoring tooth blocks.

[0012] Furthermore, the rubber pad is bonded and fixed to the end plate, and the traditional force transmission key is welded and fixed to the end plate.

[0013] Furthermore, the steel anchor box segment and the concrete cable tower are connected via a traditional force transfer key and / or a pull-out resistant but not shear resistant force transfer key.

[0014] Furthermore, each steel anchor box segment is provided with a plurality of pairs of inclined cables.

[0015] Furthermore, the two transverse bridge tower walls are provided with holes for the inclined cables to pass through, and the end plates are provided with holes coaxial with the holes, and the opening positions of the holes correspond to the steel tooth blocks for anchoring the inclined cables.

[0016] The present invention also provides an installation method of an inner cavity template type cable anchoring system, which is used to install the inner cavity template type cable anchoring system. The installation method comprises the following steps:

[0017] S1. Prefabricate multiple steel anchor box segments;

[0018] S2. Force transfer keys and rubber pads are arranged on the outside of the steel anchor box segment;

[0019] S3. Assemble multiple steel anchor box segments in sequence, install the outer formwork, tie the steel bars, and pour the tower wall concrete at the same time.

[0020] Furthermore, the step S1 specifically includes: welding two side plates and two end plates into a steel anchor box segment through fillet welds, and welding and fixing a plurality of inclined cable anchor steel tooth blocks inside the steel anchor box segment, wherein the inclined cable anchor steel tooth blocks are fixed at positions near both ends of the side plates.

[0021] Furthermore, step S2 specifically includes: welding and fixing a traditional force transmission key on the outer side of the end plate and the outer side of the middle part of the side pull plate, welding and fixing a pull-out resistant but not shear resistant force transmission key on the outer side of the side pull plate near both ends corresponding to the inclined cable anchor tooth block, and bonding a rubber pad on the outer side of the end plate.

[0022] Furthermore, the step S3 specifically includes: assembling a plurality of steel anchor box segments from bottom to top in sequence, installing an outer formwork, tying steel bars, pouring tower wall concrete, and connecting the concrete tower wall and the steel anchor box via force transfer keys.

[0023] The inner cavity template type cable anchoring system and installation method thereof proposed by the present invention have the following beneficial effects:

[0024] 1. The inner cavity template type cable tower anchoring system and installation method thereof proposed in the present invention can effectively improve the stress state of the tower wall, reduce the thickness of the tower wall and eliminate the need to set up annular prestressed steel strands on the tower wall.

[0025] 2. The present invention proposes an inner cavity template type cable tower anchoring system and an installation method thereof. The inner side dimensions of the bridge tower are relatively regular, the construction is relatively convenient, the quality is easy to ensure, and it can be used as the inner membrane of the tower column.

[0026] 3. The inner cavity template type cable tower anchoring system and the installation method thereof proposed by the present invention facilitate the subsequent welding construction by setting a steel tooth block structure, and have a high use and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of an inner cavity template type cable tower anchoring system proposed by the present invention;

[0028] Figure 2 It is a schematic cross-sectional view of a steel anchor box segment in an inner cavity template type cable tower anchoring system proposed by the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the accompanying drawings provided by the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. According to the following description, the advantages and features of the present invention will be more clear. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0030] In the description of the present invention, unless otherwise clearly stipulated and limited, the terms "connection" and "connected" should be interpreted in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] In the description of the present invention, terms such as "up", "down", "left", "right", "front", "back", "center", "horizontal", "vertical", "top", "bottom", "inside" and "outside" and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of description and simplification of operation, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0032] In order to solve the problems of great construction difficulty, large construction workload and high installation precision requirements of the cable tower anchoring method in the prior art, the present invention proposes an inner cavity template type cable tower anchoring structure and an installation method thereof. The anchoring system combines the advantages of traditional concrete tooth blocks, steel anchor beams and steel anchor boxes, utilizes pull-out-resistant but not shear-resistant force transfer keys, traditional shear keys and rubber pads, and optimizes the cable tower anchoring area into a steel tooth block and annular steel anchor box structure.

[0033] The following is a detailed description of an inner cavity template type cable tower anchoring structure and an installation method thereof proposed by the present invention.

[0034] Example 1

[0035] This embodiment provides an inner cavity template type cable tower anchoring system, see Figure 1 As shown, it includes a concrete cable tower 10 and a plurality of steel anchor box segments 20. The steel anchor box segments 20 are used to anchor the inclined cables 30. At the same time, the steel anchor box segments 20 and the outer concrete cable tower 10 form a combined structure to jointly bear the cable force of the inclined cables 30.

[0036] In this embodiment, the concrete cable tower 10 has a cavity 11 with a rectangular cross section, and the concrete cable tower 10 includes two transverse bridge tower walls 12 and two longitudinal bridge tower walls 13. The two transverse bridge tower walls 12 are arranged opposite to each other, and the two ends of each transverse bridge tower wall 12 are respectively combined with the ends of the two adjacent longitudinal bridge tower walls 13.

[0037] In this embodiment, a plurality of steel anchor box segments 20 form a steel anchor box, and the plurality of steel anchor box segments 20 are arranged vertically in the rectangular cavity 11 of the concrete cable tower 10 in sequence from bottom to top. The steel anchor box segment 20 includes two oppositely arranged side plates 21 and two oppositely arranged end plates 22, and the two ends of each side plate 21 are respectively fixedly connected to the ends of two adjacent end plates 22. The two end plates 22 are arranged in the transverse bridge direction and are respectively fixedly connected to the transverse bridge tower wall 12, and the two side plates 21 are arranged in the longitudinal bridge direction and are respectively fixedly connected to the longitudinal bridge tower wall 13.

[0038] In this embodiment, the concrete cable tower 10 is cast by concrete, and the side plates 21 and the end plates 22 of the steel anchor box segment 20 are both made of steel, and the side plates 21 and the end plates 22 are welded and fixed.

[0039] In the present embodiment, a plurality of inclined cable anchoring tooth blocks 23 are welded and fixed inside each steel anchor box segment 20, and the inclined cable anchoring tooth blocks 23 are fixed on the two side plates 21 near the two ends; a force transmission key is fixed on the outside of the steel anchor box segment 20, and the force transmission key includes a traditional force transmission key 24 and a pull-out resistant but not shear resistant force transmission key 25, and the outer sides of the two end plates 22 and the outer sides of the middle parts of the two side plates 21 are welded and fixed with traditional force transmission keys 24, and the outer sides of the two side plates 21 near the two ends (i.e., the positions corresponding to the inclined cable anchoring tooth blocks 23) are welded and fixed with pull-out resistant but not shear resistant force transmission keys 25; and rubber pads 26 are also provided on the outer sides of the two end plates 21 of the steel anchor box segment 20.

[0040] Optionally, the thickness of the rubber pad is 5 to 10 cm.

[0041] In this embodiment, holes for the inclined cables 30 to pass through are provided on the two transverse bridge tower walls 12, and holes coaxial with the holes are provided on the end plates 22, and the opening positions of the holes correspond to the positions of the inclined cable anchoring steel tooth blocks 23. The ends of the inclined cables 30 pass through the holes of the transverse bridge tower walls 12 and the holes of the end plates 22 in sequence, and then are anchored on the inclined cable anchoring steel tooth blocks 23.

[0042] The horizontal component of the anchored inclined cable 30 of the above-mentioned anchoring system is mainly borne by the side plate 21. In order to reduce the tensile force borne by the concrete of the longitudinal bridge tower wall 13 and avoid the setting of annular prestressed steel strands, a pull-out-resistant but non-shear-resistant force transmission key 25 is used in the area corresponding to the side plate 21 and the anchoring steel tooth block 23, which only restrains the warping of the side plate and does not transmit the shear force to the concrete side wall of the bridge tower. A traditional shear key is used in the middle part of the side plate 21 to play the role of supporting the anchor of the side plate 21, and at the same time transmit the unbalanced horizontal tensile force of the side and middle span cables and the vertical component of the cable to the longitudinal bridge tower wall 13. A rubber pad 26 is set on the outside of the end plate 22, combined with the pull-out-resistant but non-shear-resistant force transmission key 25, so as to ensure that the side plate can freely expand and contract along the bridge direction. A traditional shear key 24 is set on the outside of the end plate 22 to ensure that the vertical component of the cable is transmitted to the concrete side wall of the bridge tower.

[0043] The present embodiment provides an inner cavity formwork type cable tower anchoring system, which fully utilizes the tensile properties of steel and the compressive properties of concrete, and uses the side tension plates and the inner cavities of the end plates as inner formwork for casting the side walls of the bridge tower. It has the advantages of simple and clear force transmission path, simple structure, and convenient construction, inspection and maintenance.

[0044] Example 2

[0045] This embodiment provides an installation method of an inner cavity template type cable tower anchor system, which is used to install the inner cavity template type cable tower anchor structure provided in the above embodiment 1. The installation method specifically includes the following steps:

[0046] S1. Prefabricate multiple steel anchor box segments;

[0047] Specifically, each steel anchor box segment 20 is assembled by two side plates 21 and two end plates 22, and is formed by fillet welding. The cross section of the steel anchor box segment 20 is rectangular, and the length of the side plates 21 is greater than the length of the end plates 22. At the same time, when the steel anchor box segment 20 is prefabricated in the project, a plurality of inclined cable anchoring steel tooth blocks 23 can be welded and fixed inside the steel anchor box segment 20, and the inclined cable anchoring steel tooth blocks 23 are fixed on the side plates of the steel anchor box segment 20 at positions near both ends.

[0048] S2. Force transfer keys and rubber pads are arranged on the outside of the steel anchor box segment;

[0049] Specifically, force transfer keys are welded and fixed on the outside of each steel anchor box segment 20, and the force transfer keys include traditional force transfer keys 24 and pull-out resistant but not shear resistant force transfer keys 25. Traditional force transfer keys 24 are welded and fixed on the outside of the end plate 22 and the outside of the middle part of the side pull plate 21, and pull-out resistant but not shear resistant force transfer keys 25 are welded and fixed on the outside of the side pull plate 21 near the two ends (i.e., the position corresponding to the anchor tooth block of the inclined cable).

[0050] Rubber pads 26 are arranged on the outer sides of the two end plates 22 of each steel anchor box segment 20. The end plates 22 and the rubber pads 26 can be bonded and fixed. The thickness of the rubber pads 26 is 5 to 10 cm.

[0051] S3. Assemble multiple steel anchor box segments in sequence, install the outer formwork, tie the steel bars, and pour the tower wall concrete at the same time.

[0052] Specifically, multiple steel anchor box segments 20 are assembled from bottom to top, and at the same time, the outer formwork is installed, the steel bars are tied, and the tower wall concrete is poured. The concrete tower wall and the steel anchor box are connected by force transmission keys.

[0053] In this embodiment, after the first steel anchor box segment is hoisted, it can be used as the inner mold for pouring the tower wall concrete. It is only necessary to install the outer template of the tower wall, tie the steel bars, and pour the tower wall concrete to complete the first segment of the bridge tower. Then, with the current steel anchor box segment as the guide, positioning and support foundation, continue to hoist and fix the steel anchor box segment upwards, pour the tower wall concrete, and repeat this cycle to complete the pouring of the entire bridge tower segment by segment.

[0054] Furthermore, traditional shear keys are used to connect the steel anchor boxes in the middle of the two tower walls along the bridge (function one: fix the side tension plates of the steel anchor boxes to reduce their side free length; function two: transmit the unbalanced horizontal force of the cable-stayed bridge to the concrete of the side walls of the bridge towers), while the two sides are connected to the steel anchor boxes with pull-out-resistant but not shear-resistant force transfer keys, which ensures that most of the horizontal force of the cable-stayed bridge is borne by the side tension plates of the steel anchor boxes, while the vertical force of the inclined cables is transmitted to the tower walls through traditional shear keys and converted into vertical pressure of the bridge towers, thereby ensuring that the concrete of the side walls of the bridge towers only bears the unbalanced horizontal tension and vertical component of the inclined cables, thereby giving full play to the mechanical properties of the respective materials of the steel anchor boxes and the concrete tower walls.

[0055] Furthermore, in order to ensure that the horizontal force of the inclined cable is borne by the side tension plate of the steel anchor box and reduce the horizontal tension of the concrete side wall of the bridge tower along the bridge, butyl rubber pads are bonded to the outside of the end plate to ensure that the side tension plate can be freely extended and retracted, thereby further ensuring that the horizontal force of the cable is borne by the side tension plate of the steel anchor box and the side wall of the bridge tower respectively.

[0056] The present embodiment provides an installation method for an inner cavity formwork type cable tower anchoring system. When the cable of the cable-stayed bridge is tensioned, the multi-section separated steel anchor box segments can bear more horizontal forces and unbalanced forces, and transmit the vertical forces to the concrete tower wall. The mechanical properties of steel and concrete materials are fully considered, the tensile strength of the main tension plate of the steel anchor box segment is brought into play, and large tensile stress from the longitudinal bridge to the tower wall is avoided, that is, the complex construction caused by setting the cable tower annular prestress or longitudinal and transverse prestress is avoided.

[0057] Those skilled in the art should understand that the present invention can be implemented in many other specific forms without departing from the spirit and scope of the present invention. Based on the embodiments of the present invention, any changes and modifications made by ordinary technicians in the field of the present invention according to the above disclosure are within the scope of protection of the claims.

Claims

1. An inner cavity template type cable anchoring system, characterized in that: It comprises a concrete cable tower (10) having a cavity (11) with a rectangular cross section, wherein the concrete cable tower (10) comprises two oppositely arranged transverse bridge tower walls (12) and a longitudinal bridge tower wall (13) connecting the two transverse bridge tower walls (12); A steel anchor box, comprising a plurality of steel anchor box segments (20), which are sequentially arranged in the cavity (11) from bottom to top, wherein the steel anchor box segments (20) comprise two oppositely arranged side pull plates (21) and an end plate (22) connecting the two side pull plates (21), wherein the two end plates (22) are arranged in a transverse bridge direction and are respectively connected to the transverse bridge tower wall (12), and the two side pull plates (21) are arranged in a longitudinal bridge direction and are respectively connected to the longitudinal bridge tower wall (13); A plurality of inclined cable anchoring tooth blocks (23) are arranged on the inner side of the side pull plate (21), a conventional force transmission key (24) and a pull-out resistant but not shear resistant force transmission key (25) are arranged on the outer side of the side pull plate (21), and a conventional force transmission key (24) and a rubber pad (26) are arranged on the outer side of the end plate.

2. The inner cavity template type cable anchoring system according to claim 1 is characterized in that: The inclined cable anchoring tooth block (23) is welded and fixed to the positions near the two ends of the side pull plate (21), the traditional force transmission key is welded and fixed to the middle part of the side pull plate (21), and the pull-out resistant but not shear resistant force transmission key (25) is welded and fixed to the positions near the two ends of the side pull plate (21) corresponding to the inclined cable anchoring tooth block (23).

3. The inner cavity template type cable anchoring system according to claim 2 is characterized in that: The rubber pad (26) is bonded and fixed to the end plate (22), and the traditional force transmission key (24) is welded and fixed to the end plate (22).

4. The inner cavity template type cable anchoring system according to claim 3 is characterized in that: The steel anchor box segment (20) is connected to the concrete cable tower (10) via a conventional force transfer key (24) and / or a pull-out resistant but not shear resistant force transfer key (25).

5. The inner cavity template type cable anchoring system according to claim 1 is characterized in that: Each steel anchor box segment (20) is provided with a plurality of pairs of inclined cables (30).

6. The inner cavity template type cable anchoring system according to claim 5, characterized in that: The two transverse bridge tower walls (12) are provided with holes for the inclined cables (30) to pass through, and the end plates (22) are provided with holes coaxial with the holes, and the opening positions of the holes correspond to the inclined cable anchoring steel tooth blocks (23).

7. A method for installing an inner cavity template type cable anchoring system, used for installing the inner cavity template type cable anchoring system according to any one of claims 1 to 6, characterized in that: The installation method comprises the following steps: S1, prefabricating a plurality of steel anchor box segments (20); S2, arranging a force transmission key and a rubber pad (26) on the outer side of the steel anchor box segment (20); S3, assembling a plurality of steel anchor box segments (20) in sequence, installing the outer formwork, tying the steel bars, and pouring the tower wall concrete at the same time.

8. The installation method of the inner cavity template type cable anchoring system according to claim 7 is characterized in that: The step S1 specifically comprises: welding two side plates (21) and two end plates (22) into a steel anchor box segment (20) by fillet welds, and welding and fixing a plurality of inclined cable anchoring steel tooth blocks (23) inside the steel anchor box segment (20), wherein the inclined cable anchoring steel tooth blocks (23) are fixed at positions near both ends of the side plates (21).

9. The installation method of the inner cavity template type cable anchoring system according to claim 7, characterized in that: The step S2 specifically comprises: welding and fixing a conventional force transmission key (24) on the outer side of the end plate (22) and the outer side of the middle part of the side pull plate (21), welding and fixing a pull-out resistant but non-shear resistant force transmission key (25) on the outer side of the side pull plate (21) near both ends and at a position corresponding to the inclined cable anchoring tooth block (23), and bonding a rubber pad (26) on the outer side of the end plate (22).

10. The installation method of the inner cavity template type cable anchoring system according to claim 7, characterized in that: The step S3 specifically comprises: assembling a plurality of steel anchor box segments (20) in sequence from bottom to top, installing an outer formwork, tying steel bars, pouring tower wall concrete, and connecting the concrete tower wall and the steel anchor box via force transmission keys.

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