Cable anchorage device for cable-stayed bridge and tensioning construction method

Abstract

The application discloses a stay cable anchorage device for a cable-stayed bridge and a tensioning construction method. The anchorage device comprises anchorage seat one and anchorage seat two which are formed in a split structure, and stay cable through holes are formed on the anchorage seat one and the anchorage seat two respectively; the anchorage seat one and the anchorage seat two are fixedly connected to opposite tower walls in a hollow cable tower; at least one pull rod assembly is connected between the anchorage seat one and the anchorage seat two, and the pull rod assembly applies horizontal tension to the anchorage seat one and the anchorage seat two which are fixed on the opposite tower walls of the hollow cable tower. The formed structure of the application is greatly reduced in size and weight, and the assembly precision technical requirement is low, the installation technical difficulty is small, and the technical requirement for the internal size of the cable tower is small due to the absence of the problem of steel corbelling.

Description

Technical Field

[0001] This invention relates to cable anchoring technology for cable-stayed bridges, specifically a cable anchoring device for cable-stayed bridges, and a tensioning construction method based on the anchoring device. Background Technology

[0002] A cable-stayed bridge, also known as a skeletal bridge, is a type of bridge in which the main beam is directly supported by numerous cables to pylons (i.e., bridge towers). It is a structural system composed of pressure-bearing pylons, tension-bearing cables, and bending-bearing beams.

[0003] In the structural system of a cable-stayed bridge, the forces exerted by the cables on the tower include horizontal components, vertical components, and horizontal unbalanced forces. To ensure the tower can reliably bear the load, steel anchor beams are arranged inside the hollow tower structure to anchor the opposing cable stays. Each steel anchor beam mainly consists of a steel anchor beam body and two sets of steel brackets. The two sets of steel brackets are fixedly connected to the opposite tower walls inside the hollow tower. The bottom ends of the steel anchor beam body rest on the corresponding steel brackets to which the tower is fixed. Sliding friction pairs are provided between the bottom ends of the steel anchor beam body and the corresponding steel brackets, and sliding friction pairs are also provided between the end faces of the steel anchor beam body and the corresponding tower walls. In this way, the tower bears the horizontal component of the cable tension (usually more than 80% of the horizontal tension) through the steel anchor beam body, and the vertical component and horizontal unbalanced forces (which are transferred to the tower by the steel brackets, usually less than 20% of the horizontal tension) through the steel brackets. Therefore, due to the relatively clear stress mechanism of steel anchor beams, they have been widely used in cable-stayed bridge structures, as detailed in the Chinese patent documents disclosed in the following technologies: “An anchorage structure for steel tower of cable-stayed bridge” (Publication No. CN 108978470 A, Publication Date December 11, 2018), “An anchorage structure and anchorage method for bridge tower of cable-stayed bridge” (Publication No. CN 108265614 A, Publication Date July 10, 2018), and “An anchorage structure for steel anchor beam tower with sliding friction pair” (Publication No. CN 209816660 U, Publication Date December 20, 2019).

[0004] Based on the operational characteristics of steel anchor beams within hollow cable towers, the steel anchor beam body is an integral beam structure composed of box-shaped tie plates and anchorage seats formed at both ends of the box-shaped tie plates. The box-shaped tie plates are welded together from a top plate, bottom plate, web plate, and side stiffening plates. The thickness of the top, bottom, and web plates of the box-shaped tie plates is typically over 30mm, while the thickness of the stiffening plates is typically 20mm. The steel brackets, serving as the supporting structure for the steel anchor beam body on the tower wall, are composed of stainless steel sliding plates, top plates, bottom plates, web plates, stiffening plates, and wall plates. The thickness of the steel bracket plates is generally 30mm. Therefore, the entire steel anchor beam structure is large in size and heavy in weight, making its manufacturing, transportation, and installation inconvenient. It even becomes a control load during hoisting construction and cannot effectively meet the construction technical requirements of the more aesthetically pleasing and compact cable towers designed in recent years.

[0005] The applicant discovered a technology in Chinese patent literature entitled "An Anchorage Structure for Cable-Stayed Bridge Towers with Built-in Steel Strand-Strut Braces" (Publication No. CN 113047171 A, Publication Date June 29, 2021). This technology connects two relatively independent sets of anchor beams into a whole using steel strand strut assemblies, replacing the box-shaped tie plates of the steel anchor beam body with steel strand strut assemblies. Compared to traditional steel anchor beams, this technology reduces the amount of heavy steel plates used because it replaces part of the box-shaped tie plates of the steel anchor beam body with steel strand strut assemblies. Furthermore, the two sets of anchor beams can be disassembled and assembled on the steel strand strut assemblies, greatly facilitating manufacturing and transportation after being disassembled into individual units, and the weight of the assembled whole is also lighter.

[0006] However, the technology disclosed in CN 113047171 A still employs the traditional steel anchor beam load-bearing method, where its two ends rest on a set of steel brackets inside the hollow pylon. The presence of these steel brackets still presents the technical problems of large structural dimensions and heavy weight. Furthermore, when the two sets of anchor beams in this technology are connected by steel strand struts and fitted with their corresponding steel brackets, it is difficult to achieve coplanarity, requiring extremely high assembly precision. Summary of the Invention

[0007] The technical objective of this invention is to provide a cable anchoring device for cable-stayed bridges that is conducive to miniaturization, lightweighting, and easy installation, and a tensioning construction method based on the above-mentioned cable-stayed bridge, taking into account the special characteristics of cable-stayed bridges and the shortcomings of existing technologies.

[0008] The technical objective of this invention is achieved through the following technical solution: a cable anchoring device for a cable-stayed bridge, comprising an anchoring seat one and an anchoring seat two formed in a split structure, wherein cable perforations are formed on the anchoring seat one and the anchoring seat two respectively.

[0009] The first anchor and the second anchor are fixedly connected to the opposite tower walls inside the hollow cable tower;

[0010] At least one tie rod assembly is connected between the first anchorage and the second anchorage, and the tie rod assembly applies a horizontal tension to the first anchorage and the second anchorage, which are fixed to the tower wall of the hollow cable tower.

[0011] The above-mentioned technical measures directly fix the two sets of anchor seats to the corresponding tower walls of the hollow cable tower. The assembled tie rod assembly applies a horizontal pre-tightening force to the two sets of anchor seats. That is, the tie rod assembly actively applies a pre-tightening force to the anchor seats directly fixed to the hollow cable tower in advance, eliminating the need to form a separate steel bracket load-bearing structure. This eliminates the need for a steel bracket, resulting in a significant reduction in the size and weight of the entire anchoring device. Furthermore, the absence of a steel bracket support reduces the technical requirements for assembly precision and installation difficulty.

[0012] The anchoring device described above uses two sets of anchor seats as anchoring components for the cables, directly bearing the cable force and adapting to different anchoring angles. The tie rod assembly connects the two sets of anchor seats, forming a stable structural system that achieves self-balancing under the action of the cables at both ends. The two sets of anchor seats and the intermediate pre-tensioned tie rod assembly can be disassembled and assembled. Disassembling them into individual units greatly facilitates manufacturing, transportation, and installation. When assembled as a whole, the tie rod assembly completely replaces the box-type tie plate, resulting in a significant weight reduction.

[0013] Therefore, the anchoring devices of the above-mentioned technical measures have the technical characteristics of small structural size, light weight, detachable and combinable, and easy installation. They have low technical requirements for the internal dimensions of the cable tower. They can be adapted to the construction technical requirements of traditional large cable towers, as well as the construction technical requirements of small cable towers with more beautiful shapes designed in recent years, and also the construction technical requirements of variable cross-section irregular cable towers with more beautiful shapes.

[0014] As one of the preferred solutions, the two side plates of the anchor seat one are respectively fixedly connected with outwardly protruding pressure-bearing lugs;

[0015] On the two side plates of the second anchor, there are respectively outwardly protruding pressure-bearing lugs.

[0016] Inside the hollow cable tower, at least one set of tie rod insertion channels are provided on the same side bearing lug between anchor seat one and anchor seat two;

[0017] At least two tie rod assemblies are connected between the first anchor and the second anchor. Each tie rod assembly is inserted into the same set of tie rod insertion channels between the first anchor and the second anchor, and the number of tie rod assemblies inserted on both sides of the first anchor and the second anchor is equal.

[0018] The two sets of anchor seats described above form a through-type structure for the tie rod assembly on both sides. This ensures that the two sets of anchor seats are stably, reliably and evenly stressed, and facilitates the tie rod assembly to be inserted and formed between the two sets of anchor seats, making pre-tightening and force application easier.

[0019] Furthermore, the pressure-bearing lug is composed of an inner pressure-bearing plate and an outer pressure-bearing plate arranged at intervals, as well as multiple support plates supporting between the inner pressure-bearing plate and the outer pressure-bearing plate;

[0020] The inner bearing plate and the outer bearing plate are respectively fixed to the corresponding side plate along the vertical direction of the anchor seat. The outer side of the outer bearing plate is used to bear the horizontal tensile force of the tie rod assembly.

[0021] Multiple support plates are arranged along the vertical spacing of their respective anchorages, and at least one set of adjacent support plates has a tie rod insertion channel on the inner bearing plate and the outer bearing plate.

[0022] Furthermore, the outer bearing plate of the pressure-bearing lug is thicker than the inner bearing plate.

[0023] The pressure-bearing lugs of the above-mentioned technical measures have the technical characteristics of stable force distribution and easy installation of tie rod assemblies.

[0024] As one of the preferred solutions, the tie rod assembly mainly consists of a double-ended tie rod, and a ball washer and nut assembly connected to each end of the tie rod;

[0025] The tie rod assembly applies a horizontal tension to the anchorage with a spherical washer.

[0026] The tie rod assembly of the above-mentioned technical measures can adaptively apply axial force, and has low technical requirements for axial force application. This results in low technical requirements for the assembly accuracy of the two sets of anchor seats, making it easy to assemble the two sets of anchor seats through the tie rod assembly to form a stable structural system.

[0027] Furthermore, each end of the tie rod assembly contains a torque sensor in its nut assembly;

[0028] The torque sensor is used to monitor the horizontal tension of the tie rod assembly.

[0029] The tie rod assembly of the above-mentioned technical measures can dynamically monitor the locking force, making it easy to detect loosening faults in a timely manner, so as to ensure that the anchoring device can be used stably.

[0030] As one of the preferred solutions, the anchor seat mainly consists of a wall panel, two side plates spaced apart on one side of the wall panel, multiple support plates supported between the two side plates, and anchor plates arranged diagonally on the top side of the two side plates.

[0031] The wall panel has cable perforations and is used to fix the wall panel to the corresponding tower wall inside the hollow cable tower.

[0032] The anchor plate has cable perforations, and the cable perforations on the anchor plate correspond axially to the cable perforations on the wall plate; the axial direction of the cable perforations between the anchor plate and the wall plate forms an acute angle with the axial direction of the hollow tower.

[0033] As one of the preferred solutions, the second anchorage mainly consists of a wall panel, two side plates spaced apart on one side of the wall panel, multiple support plates between the two side plates, and anchor plates arranged diagonally on the top side of the two side plates.

[0034] The wall panel has cable perforations and is used to fix the wall panel to the corresponding tower wall inside the hollow cable tower.

[0035] The anchor plate has cable perforations, and the cable perforations on the anchor plate correspond axially to the cable perforations on the wall plate; the axial direction of the cable perforations between the anchor plate and the wall plate forms an acute angle with the axial direction of the hollow tower.

[0036] The anchorages (anchorage one or anchorage two) of the aforementioned technical measures, apart from their assembly with the tie rod assembly, are used for fixing to the tower wall of the hollow cable tower and anchoring the installed cables, without involving any redundant structures. Compared to the technology in publication number CN113047171 A, it does not have an axially protruding joint used for connecting the steel strand strut assembly. This reduces the amount of heavy steel plates used, resulting in a more compact structure, smaller size, and lighter weight.

[0037] A tensioning construction method for the cable anchoring device of the above-mentioned cable-stayed bridge, wherein the tensioning construction method is to perform the tensioning of the tie rod assembly inserted between the anchor seat 1 and anchor seat 2 arranged opposite to each other in the hollow tower in multiple stages, and to perform the tensioning of the cables inserted between anchor seat 1 and anchor seat 2 in multiple stages, and the tensioning of the tie rod assembly and the tensioning of the cables are alternated with the tension rod assembly being performed first.

[0038] Furthermore, the construction method specifically includes the following operational steps:

[0039] Step 1. Tension each tie rod assembly inserted between anchorage seat 1 and anchorage seat 2, which are arranged opposite each other inside the hollow cable tower, to 25-30% of the design value;

[0040] Step 2. Tension the cables installed on anchorage one and anchorage two to 25-30% of the design value to complete the first stage of force self-balancing;

[0041] Step 3. Tension each tie rod assembly inserted between anchor seat one and anchor seat two to 50-65% of the design value;

[0042] Step 4. Tension the cables installed on anchorage one and anchorage two to 50-65% of the design value to complete the second stage of force self-balancing;

[0043] Step 5. Tension each tie rod assembly inserted between anchor seat one and anchor seat two to 75-100% of the design value;

[0044] Step 6. Tension the cables installed on anchorage one and anchorage two to 75-100% of the design value to complete the third stage of force self-balancing;

[0045] If the tensioning of the tie rod assembly and the tensioning of the cable have reached 100% of the design value after the third stage of force application and self-balancing is completed, then the tensioning construction is finished.

[0046] If the tension of the tie rod assembly and the tension of the cable do not reach 100% of the design value after the third stage of force application self-balancing is completed, then proceed to steps 7 and 8 as follows;

[0047] Step 7. Tension each tie rod assembly inserted between anchor seat one and anchor seat two to 100% of the design value;

[0048] Step 8. Tension the cables installed on anchorage one and anchorage two to 100% of the design value to complete the fourth stage of force self-balancing.

[0049] The above-mentioned tensioning construction method is suitable for the stress-bearing structural system of the above-mentioned anchoring device, so as to control the horizontal force to be stably transmitted to the tower wall one by one, ensuring that the hollow tower can be stressed smoothly and reliably, and preventing stress imbalance.

[0050] The beneficial technical effects of the present invention are as follows: The above-mentioned technical measures directly fix two sets of anchor seats to the corresponding tower walls of the hollow cable tower, and apply horizontal pre-tightening force to the two sets of anchor seats by the assembled and connected tie rod assembly. That is, the tie rod assembly actively applies pre-tightening force to the anchor seats directly fixed on the hollow cable tower in advance, eliminating the need to form a separate steel bracket load-bearing structure, thereby saving the steel bracket. This greatly reduces the size and weight of the entire anchoring device, and also reduces the assembly precision requirements and installation difficulty due to the absence of the steel bracket support problem.

[0051] The anchoring device described above uses two sets of anchor seats as anchoring components for the cables, directly bearing the cable force and adapting to different anchoring angles. The tie rod assembly connects the two sets of anchor seats, forming a stable structural system that achieves self-balancing under the action of the cables at both ends. The two sets of anchor seats and the intermediate pre-tensioned tie rod assembly can be disassembled and assembled. Disassembling them into individual units greatly facilitates manufacturing, transportation, and installation. When assembled as a whole, the tie rod assembly completely replaces the box-type tie plate, resulting in a significant weight reduction.

[0052] Compared with the technology disclosed in CN 113047171 A, the above-mentioned technical measures reduce the amount of heavy steel plates used, resulting in a more compact structure, smaller size, and lighter weight.

[0053] Therefore, the present invention has the technical characteristics of small structural size, light weight, detachable and combinable structure, and easy installation. It has low technical requirements for the internal dimensions of the cable tower, and can be adapted to the construction technical requirements of traditional large cable towers, as well as the construction technical requirements of small cable towers with more beautiful shapes designed in recent years, and also the construction technical requirements of variable cross-section irregular cable towers with more beautiful shapes. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of one structure of the present invention.

[0055] Figure 2 for Figure 1 Top view.

[0056] Figure 3 This is a perspective view of the present invention.

[0057] Figure 4 This is a perspective view of the present invention.

[0058] Figure 5 This is a reference diagram showing one usage state of the present invention.

[0059] The symbols in the diagram have the following meanings: 1—Anchor seat one; 11—Side plate; 12—Support plate one; 13—Stretching plate; 14—Anchor plate; 15—Cable perforation; 16—Pressure bearing lug; 17—Wall panel; 161—Inner pressure plate; 162—Outer pressure plate; 163—Support plate two; 164—Tie rod insertion channel; 2—Anchor seat two; 3—Tie rod assembly; 4—Hollow pylon; 41—Tower wall one; 42—Tower wall two. Detailed Implementation

[0060] This invention relates to cable anchoring technology for cable-stayed bridges, specifically a cable anchoring device for cable-stayed bridges and a tensioning construction method based on this anchoring device. The main technical solution of this invention will be specifically described below with reference to several embodiments. Embodiment 1 is illustrated in conjunction with the accompanying drawings—that is… Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 The technical solution of the present invention will be clearly and thoroughly explained; although other embodiments are not shown in separate drawings, their main structure can still be referred to the drawings of Embodiment 1.

[0061] It should be noted that the accompanying drawings of this invention are schematic, and unnecessary details have been simplified to clarify the technical objectives of this invention, so as to avoid obscuring the technical solutions contributed by this invention to the prior art. Furthermore, the terms "approximately" or "basically" used below to refer to quantities or fit relationships mean that reasonable assembly and processing errors are allowed in the industry, and do not literally describe absolute quantities or fit relationships.

[0062] Example 1

[0063] See Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the present invention includes an anchor seat 1, an anchor seat 2, and a four-bar tie rod assembly 3, which are formed in a split structure.

[0064] Specifically, anchorage 1 and anchorage 2 are fixedly connected to the opposite tower walls inside the hollow tower 4. That is, anchorage 1 is fixedly connected to the inner side of tower wall 41 of the hollow tower 4, and anchorage 2 is fixedly connected to the inner side of tower wall 42 of the hollow tower 4, forming a basic opposite arrangement. The structures of anchorage 1 and anchorage 2 are the same. Anchorage 1 will be described in detail as an example, and anchorage 2 will not be described in detail.

[0065] Anchor seat 1 mainly consists of a wall panel 17, two side plates 11 spaced apart on one side of the wall panel 17, multiple support plates 12 supported between the two side plates 11, and anchor plates 14 arranged diagonally on the top side of the two side plates 11. The wall panel 17 is used for fixed connection to the corresponding tower wall inside the hollow cable tower 4. If the hollow cable tower 4 is a steel frame structure, the wall panel 17 is fixed to the corresponding tower wall by bolt connection and / or welding; if the hollow cable tower 4 is a reinforced concrete structure, it is fixed to the corresponding tower wall 4 by anchor bolts and / or anchor rods. The wall panel 17 has cable perforations corresponding to the cable perforations on the corresponding tower wall of the hollow cable tower 4. The two side plates 11 are approximately hexagonal spindle-shaped structures, with their longer vertical sides fixedly connected to the wall panel 17. Their top sides, opposite to the wall panel 17, are used to fix the anchor plates 14 and any possible bearing plates. The two side plates 11 are arranged side by side at a horizontal distance on one side of the wall panel 17. Multiple support plates 12 are horizontally braced between the two side plates 11. As above, anchor plates 14 are obliquely fixed to the top side of the two side plates 11. Cable perforations are also provided on the anchor plates 14, and the cable perforations on the anchor plates 14 correspond axially to the cable perforations on the wall plates 17. That is, the anchor plates 14 have cable perforations corresponding to the cable perforations on the corresponding tower wall of the hollow tower 4. In other words, cable perforations 15 extending in the same axial direction are formed on the anchor plates 14 and the wall plates 17. When the anchor seat 1 is fixedly connected to the corresponding tower wall (i.e., tower wall 41) inside the hollow tower 4, the axial direction of the cable perforation 15 between the anchor plates 14 and the wall plates 17 forms an acute angle with the axial direction of the hollow tower 4. The size of the acute angle is determined according to the height position of the anchor seat 1 inside the hollow tower 4 (i.e., the oblique angle of the anchored cable).

[0066] To facilitate connection with the tie rod assembly 3, protruding pressure-bearing lugs 16 are fixedly connected to the two side plates of the anchor seat 1. Each pressure-bearing lug 16 consists of an inner pressure-bearing plate 161 and an outer pressure-bearing plate 162 arranged at intervals, and multiple support plates 163 supporting the inner and outer pressure-bearing plates 161 and 162. The inner and outer pressure-bearing plates 161 and 162 are fixedly connected vertically along their respective side plates 11, and are spaced side-by-side horizontally along their respective side plates 11. The outer side of the outer pressure-bearing plate serves to bear the horizontal tension of the tie rod assembly 3; therefore, the thickness of the outer pressure-bearing plate 162 is greater than the thickness of the inner pressure-bearing plate 161. The multiple support plates 163 are arranged at vertical intervals along their respective side plates 11. Tie rod grooves, i.e. tie rod insertion channels 164, are formed on the upper and lower positions of the pressure bearing lug 16. Each tie rod insertion channel 164 is formed along the transverse direction of the pressure bearing lug 16 and is located on the inner pressure plate 161 and outer pressure plate 162 between the adjacent support plates 163 at the current position.

[0067] Inside the hollow cable tower 4, two corresponding tie rod insertion channels on the same side between anchor seat 1 and anchor seat 2 are used as a group for inserting the same tie rod assembly 3. As described above, two sets of tie rod insertion channels are provided on the bearing lugs on the same side between anchor seat 1 and anchor seat 2, arranged in upper and lower positions.

[0068] The tie rod assembly 3 mainly consists of a double-ended tie rod, and a ball washer and nut assembly connected to each end of the tie rod. The four tie rod assemblies 3 are divided into left and right groups. The two tie rod assemblies 3 of the left group are respectively installed in the two sets of tie rod insertion channels on the left bearing lug between anchor seat 1 and anchor seat 2. The two tie rod assemblies 3 of the right group are respectively installed in the two sets of tie rod insertion channels on the right bearing lug between anchor seat 1 and anchor seat 2. Each tie rod assembly 3 applies a horizontal tensile force to the anchor seat it is attached to using a ball washer. In other words, there are a total of four tie rod assemblies 3 on the left and right sides connecting anchor seat 1 and anchor seat 2. Each tie rod assembly 3 is installed in the same tie rod insertion channel between anchor seat 1 and anchor seat 2, and the number of tie rod assemblies 3 installed on both sides between anchor seat 1 and anchor seat 2 is equal. The tie rod assemblies 3 apply a horizontal tension to the hollow cable tower 4 relative to the anchor seat 1 and anchor seat 2 fixed on the tower wall.

[0069] In a cable-stayed bridge structure, taking the tensioning and anchoring of a single cable with a design force of approximately 5000 kN and an inclination angle of approximately 35° at the same location as an example, its horizontal component force is:

[0070] F≈Tcosθ=5000*cos35°≈4000kN;

[0071] Considering a safety factor of 2.0, the design value for each tie rod assembly is:

[0072] 4000 / 4*2=2000KN;

[0073] The design strength value of the tie rod assembly is:

[0074] [σ] = 760 MPa;

[0075] The diameter of the tie rod assembly is approximately:

[0076]

[0077] In other words, selecting four tie rods with a diameter of approximately 60mm is sufficient to meet the force requirements.

[0078] Taking the aforementioned stress as an example, in the tensioning construction of a cable-stayed bridge, the tensioning of the tie rod assembly inserted between anchorage 1 and anchorage 2, which are arranged opposite each other inside the hollow pylon, is carried out in three stages. Similarly, the tensioning of the cables inserted into anchorage 1 and anchorage 2 is also carried out in three stages, with the tensioning of the tie rod assembly and the tensioning of the cables alternating, with the tie rod assembly tensioning first. Specifically, the following operational steps are included:

[0079] Step 1. Tension each tie rod assembly inserted between anchorage 1 and anchorage 2, which are arranged opposite each other inside the hollow cable tower, to about 30% of the design value (about 600KN);

[0080] Step 2. Tension the cables installed on anchorage one and anchorage two to approximately 30% of the design value (approximately 1500KN) to complete the first stage of force self-balancing;

[0081] Step 3. Tension each tie rod assembly inserted between anchor seat one and anchor seat two to 60% of the design value (approximately 1200KN);

[0082] Step 4. Tension the cables installed on anchorage one and anchorage two to 60% of the design value (approximately 3000KN) to complete the second stage of force self-balancing;

[0083] Step 5. Tension each tie rod assembly inserted between anchor seat one and anchor seat two to 100% of the design value (approximately 2000KN);

[0084] Step 6. Tension the cables installed on anchorage 1 and anchorage 2 to 100% of the design value (approximately 5000KN) to complete the third stage of force self-balancing;

[0085] At this point, the tensioning of the tie rod assembly and the tensioning of the cable have reached 100% of the design value, and the tensioning construction at the current position is completed.

[0086] Example 2

[0087] The rest of the content of this embodiment is the same as that of embodiment 1, except that:

[0088] Each end of the tie rod assembly contains a torque sensor (i.e., a torque washer) in its nut assembly. The torque sensor is connected to an online monitoring system to monitor the horizontal tension of the tie rod assembly.

[0089] Example 3

[0090] The present invention includes a first anchor seat, a second anchor seat, and a six-bar tie rod assembly, which are formed in a split structure.

[0091] Specifically, anchorage one and anchorage two are fixedly connected to opposite tower walls inside the hollow cable tower. Anchorage one is fixedly connected to the inner side of tower wall one, and anchorage two is fixedly connected to the inner side of tower wall two, forming a roughly opposite arrangement. Anchorage one and anchorage two have the same structure; therefore, anchorage one will be described in detail below, while anchorage two will not be elaborated upon.

[0092] Anchorage seat 1 mainly consists of a wall panel, two side plates spaced apart on one side of the wall panel, multiple support plates supported between the two side plates, and anchor plates arranged diagonally on the top sides of the two side plates. The wall panel is used for fixed connection to the corresponding tower wall inside the hollow cable tower. If the hollow cable tower is a steel frame structure, the wall panel is fixed to the corresponding tower wall by bolts and / or welding; if the hollow cable tower is a reinforced concrete structure, it is fixed to the corresponding tower wall by anchor bolts and / or anchor rods. The wall panel has cable perforations corresponding to the cable perforations on the corresponding tower wall of the hollow cable tower. The two side plates are approximately hexagonal, with their longer vertical sides fixedly connected to the wall panel. Their top diagonal sides, opposite to the wall panel, are used to fix the anchor plates and any possible bearing plates. The two side plates are arranged side-by-side at a horizontal spacing on one side of the wall panel. Multiple support plates are horizontally braced between the two side plates. As described above, the anchor plate is obliquely fixed to the top side of both side plates. The anchor plate also has cable perforations, and these perforations correspond axially to those on the wall plate. In other words, the anchor plate has cable perforations corresponding to those on the corresponding tower wall of the hollow pylon. Both the anchor plate and the wall plate have cable perforations extending in the same axial direction. When the anchor seat is fixedly connected to the corresponding tower wall (i.e., tower wall one) inside the hollow pylon, the axial direction of the cable perforation between the anchor plate and the wall plate forms an acute angle with the axial direction of the hollow pylon. The size of this acute angle is determined by the height position of the anchor seat one within the hollow pylon (i.e., the oblique angle of the anchored cable).

[0093] To facilitate connection with the tie rod assembly, protruding pressure-bearing lugs are fixedly connected to the two side plates of the anchor seat 1. Each pressure-bearing lug consists of an inner pressure-bearing plate and an outer pressure-bearing plate arranged at intervals, and multiple support plates 2 supporting the inner and outer pressure-bearing plates. The inner and outer pressure-bearing plates are fixedly connected vertically along their respective side plates, and spaced side-by-side horizontally along their respective side plates. The outer side of the outer pressure-bearing plate serves to bear the horizontal tension of the tie rod assembly; therefore, the thickness of the outer pressure-bearing plate is greater than that of the inner pressure-bearing plate. The multiple support plates 2 are arranged at vertical intervals along their respective side plates. Tie rod grooves—i.e., tie rod insertion channels—are formed at the upper, middle, and lower positions of the pressure-bearing lugs. Each tie rod insertion channel is formed horizontally along the pressure-bearing lug, located on the inner and outer pressure-bearing plates between adjacent support plates 2 at the current position.

[0094] Inside the hollow cable tower, the two corresponding tie rod mounting channels on the same side between anchor seat one and anchor seat two are used as a group for mounting the same tie rod assembly. As described above, three sets of tie rod mounting channels are arranged in upper, middle and lower positions on the bearing lugs on the same side between anchor seat one and anchor seat two.

[0095] The tie rod assembly mainly consists of double-ended tie rods, and spherical washers and nut assemblies connecting each end of the tie rods. The six tie rod assemblies are divided into left and right groups. The three tie rod assemblies in the left group are inserted into the three sets of tie rod insertion channels on the left-side bearing lugs between anchorage 1 and anchorage 2. The three tie rod assemblies in the right group are inserted into the three sets of tie rod insertion channels on the right-side bearing lugs between anchorage 1 and anchorage 2. Each tie rod assembly applies a horizontal tensile force to its corresponding anchorage using a spherical washer. In other words, there are a total of six tie rod assemblies connecting anchorage 1 and anchorage 2, with each tie rod assembly inserted into the same set of tie rod insertion channels between anchorage 1 and anchorage 2. The number of tie rod assemblies inserted on both sides between anchorage 1 and anchorage 2 is equal. The tie rod assemblies apply a horizontal tensile force to the hollow cable tower relative to anchorage 1 and anchorage 2 fixed to the tower wall.

[0096] In a cable-stayed bridge structure, taking the tensioning and anchoring of two cables with a design force of approximately 5000 KN and an inclination angle of approximately 35° at the same location as an example, the horizontal component of the force is:

[0097] F≈Tcosθ=4000*cos35°≈8000kN;

[0098] Considering a safety factor of 2.0, the design value for each tie rod assembly is approximately:

[0099] 8000 / 6*2=2667KN;

[0100] The design strength value of the tie rod assembly is:

[0101] [σ] = 760 MPa;

[0102] The diameter of the tie rod assembly is approximately:

[0103]

[0104] In other words, selecting six tie rods with a diameter of approximately 70mm is sufficient to meet the force requirements.

[0105] Taking the aforementioned stress as an example, in the tensioning construction of a cable-stayed bridge, the tensioning of the tie rod assemblies inserted between anchorages 1 and 2, which are arranged opposite each other inside the hollow pylon, is carried out in four stages. Similarly, the tensioning of the cables inserted into anchorages 1 and 2 is also carried out in four stages, with the tensioning of the tie rod assemblies alternating with the tensioning of the cables, starting with the tension rod assemblies. Specifically, the following operational steps are included:

[0106] Step 1. Tension each tie rod assembly inserted between anchorage 1 and anchorage 2, which are arranged opposite each other inside the hollow cable tower, to about 25% of the design value (about 667KN);

[0107] Step 2. Tension the cables installed on anchorage one and anchorage two to approximately 25% of the design value (approximately 1250KN) to complete the first stage of force self-balancing;

[0108] Step 3. Tension each tie rod assembly inserted between anchor seat one and anchor seat two to 50% of the design value (approximately 1333KN);

[0109] Step 4. Tension the cables installed on anchorage one and anchorage two to 50% of the design value (approximately 3000KN) to complete the second stage of force self-balancing;

[0110] Step 5. Tension each tie rod assembly inserted between anchor seat one and anchor seat two to 75% of the design value (approximately 2000KN);

[0111] Step 6. Tension the cables installed on anchorage 1 and anchorage 2 to 75% of the design value (approximately 5000KN) to complete the third stage of force self-balancing;

[0112] Step 7. Tension each tie rod assembly inserted between anchor seat one and anchor seat two to 100% of the design value (approximately 2667KN);

[0113] Step 8. Tension the cables installed on anchorage 1 and anchorage 2 to 100% of the design value (approximately 5000KN) to complete the fourth stage of force self-balancing.

[0114] At this point, the tensioning of the tie rod assembly and the tensioning of the cable have reached 100% of the design value, and the tensioning construction at the current position is completed.

[0115] Example 4

[0116] The rest of the content of this embodiment is the same as that of embodiment 3, except that:

[0117] Each end of the tie rod assembly contains a torque sensor (i.e., a torque washer) in its nut assembly. The torque sensor is connected to an online monitoring system to monitor the horizontal tension of the tie rod assembly.

[0118] The above embodiments are only used to illustrate the present invention and are not intended to limit it.

[0119] Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications can still be made to the above embodiments, or equivalent substitutions can be made to some of the technical features. For example, the tie rod assembly can be any other even number. When the tie rod assembly is a single rod, the two sides of the anchor seat do not need to have pressure-bearing lugs, and the pressure-bearing lugs can be formed directly at the center of the end face of the anchor seat. However, this will increase the technical difficulty and is not the preferred option. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the present invention.

Claims

1. A cable anchorage device for cable-stayed bridge, comprising an anchorage seat one (1) and an anchorage seat two (2) formed in a split structure, a cable through hole is formed on each of the anchorage seat one (1) and the anchorage seat two (2); Characterized in that: The anchorage seat one (1) and the anchorage seat two (2) are fixedly connected to the opposite tower walls in the hollow pylon (4); Pressure ear seats are fixedly connected to the two side plates of the anchorage seat one (1); Pressure ear seats are fixedly connected to the two side plates of the anchorage seat two (2); At least one group of pull rod through channels is formed on the same side pressure ear seats between the anchorage seat one (1) and the anchorage seat two (2) in the hollow pylon (4); At least two pull rod assemblies (3) are connected between the anchorage seat one (1) and the anchorage seat two (2), each pull rod assembly (3) is through the same group of pull rod through channels between the anchorage seat one (1) and the anchorage seat two (2), and the number of pull rod assemblies (3) through the two sides is equal; The pull rod assembly (3) exerts horizontal tension on the anchorage seat one (1) and the anchorage seat two (2) fixed on the opposite tower walls of the hollow pylon (4).

2. The cable anchorage device for cable-stayed bridge according to claim 1, characterized in that: The pressure ear seat is composed of an inner pressure bearing plate, an outer pressure bearing plate, and a plurality of support plates two supported between the inner pressure bearing plate and the outer pressure bearing plate arranged at intervals; The inner pressure bearing plate and the outer pressure bearing plate are respectively fixed on the corresponding side plates along the vertical direction of the anchorage seat, and the outer side of the outer pressure bearing plate is used to bear the horizontal tension of the pull rod assembly (3); A plurality of support plates two are arranged at intervals along the vertical direction of the anchorage seat, and a pull rod through channel is formed on the inner pressure bearing plate and the outer pressure bearing plate between at least one group of adjacent support plates two.

3. The cable anchorage device for cable-stayed bridge according to claim 2, characterized in that: The thickness of the outer pressure bearing plate of the pressure ear seat is greater than the thickness of the inner pressure bearing plate.

4. The cable anchorage device for cable-stayed bridge according to claim 1 or 2, characterized in that: The pull rod assembly (3) is mainly composed of a double-headed pull rod, and a spherical washer and a nut assembly connected to each end of the pull rod; The pull rod assembly (3) exerts horizontal tension on the anchorage seat through the spherical washer.

5. The cable anchorage device for cable-stayed bridge according to claim 4, characterized in that: The nut assembly at each end of the pull rod assembly (3) contains a torque sensor; The torque sensor is used to monitor the horizontal tension of the pull rod assembly (3).

6. The cable anchorage device for cable-stayed bridge according to claim 1, characterized in that: The anchorage seat one (1) is mainly composed of a wall plate, two side plates arranged at intervals on one side of the wall plate, a plurality of support plates one supported between the two side plates, and an anchor pad arranged obliquely at the top side of the two side plates; A cable through hole is formed on the wall plate, and the wall plate is used to be fixedly connected to the corresponding tower wall in the hollow pylon (4). The anchor pad plate is provided with a cable hole, and the cable hole of the anchor pad plate is axially corresponding to the cable hole of the wall plate; the axial direction of the cable hole between the anchor pad plate and the wall plate forms an acute angle with the axial direction of the hollow cable tower (4).

7. The cable anchoring device for a cable-stayed bridge according to claim 1, characterized in that: The anchor seat two (2) is mainly composed of a wall plate, two side plates arranged at a distance on one side of the wall plate, a plurality of support plates supported between the two side plates, an anchor pad plate arranged obliquely at the top side of the two side plates; The wall plate is provided with a cable hole, and the wall plate is used for fixedly connecting to the corresponding tower wall in the hollow cable tower (4); The anchor pad plate is provided with a cable hole, and the cable hole of the anchor pad plate is axially corresponding to the cable hole of the wall plate; the axial direction of the cable hole between the anchor pad plate and the wall plate forms an acute angle with the axial direction of the hollow cable tower (4).

8. A tensioning construction method of the cable anchoring device for a cable-stayed bridge according to any one of claims 1 to 7, characterized in that: The tensioning construction method is that the tensioning of the cable rod assembly arranged between the anchor seat one and the anchor seat two arranged oppositely in the hollow cable tower is carried out in multiple stages, the tensioning of the cable arranged in the anchor seat one and the anchor seat two is carried out in multiple stages, and the tensioning of the cable rod assembly and the tensioning of the cable are alternately carried out with the cable rod assembly first.

9. The tensioning construction method of the inhaul cable anchorage device for a cable-stayed bridge according to claim 8, characterized by, The construction method specifically includes the following operation steps: Step 1. Tension each cable rod assembly arranged between the anchor seat one and the anchor seat two arranged oppositely in the hollow cable tower to 25-30% of the design value; Step 2. Tension the cable arranged in the anchor seat one and the anchor seat two to 25-30% of the design value, and complete the first stage of force self-balancing; Step 3. Tension each cable rod assembly arranged between the anchor seat one and the anchor seat two to 50-65% of the design value; Step 4. Tension the cable arranged in the anchor seat one and the anchor seat two to 50-65% of the design value, and complete the second stage of force self-balancing; Step 5. Tension each cable rod assembly arranged between the anchor seat one and the anchor seat two to 75-100% of the design value; Step 6. Tension the cable arranged in the anchor seat one and the anchor seat two to 75-100% of the design value, and complete the third stage of force self-balancing; If the tensioning of the cable rod assembly and the tensioning of the cable reach 100% of the design value after the completion of the third stage of force self-balancing, the tensioning construction is ended; If the tensioning of the cable rod assembly and the tensioning of the cable do not reach 100% of the design value after the completion of the third stage of force self-balancing, the following steps 7 and 8 are carried out; Step 7. Tension each cable rod assembly arranged between the anchor seat one and the anchor seat two to 100% of the design value; Step 8. Tension the cable arranged in the anchor seat one and the anchor seat two to 100% of the design value, and complete the fourth stage of force self-balancing.

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