An external steel strand-strut cable-stayed bridge tower anchoring structure

Abstract

The present invention discloses an external steel strand-strut anchoring structure for a cable-stayed bridge pylon, comprising two anchor beams, namely anchor beam No. I and anchor beam No. II. Anchor beam No. I and anchor beam No. II are relatively fixed to the pylon wall, and a steel strand-strut combination structure is provided between anchor beam No. I and anchor beam No. II to bear the horizontal forces between the anchor beams. In the present invention, the anchor beams decompose the cable forces of the diagonal cables into vertical and horizontal forces. The vertical force is borne by the pylon concrete, while the horizontal force is borne by the steel strand-strut combination structure. This fully utilizes the material properties of the steel plates and steel strands. Because the steel strands have a large tensile bearing capacity, the amount of steel used can be reduced. The anchor beams are fixed at one end and movable at the other end, which can reduce the horizontal forces on the pylon and reduce the risk of cracking in the pylon concrete. The steel anchor beam structure of the present invention achieves modular assembly, offers flexible assembly methods, and is relatively convenient for construction.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge design, and in particular relates to an external steel strand-strut cable-stayed bridge tower anchoring structure. Background Art

[0002] The anchoring of the cable-stayed cables at the tower end is an important component related to structural safety. The commonly used anchoring methods in China are circumferential prestressing, steel anchor beams and steel anchor boxes. Circumferential prestressing is mainly used in small and medium-span bridges, and steel anchor beams are mainly used in highway bridges with small live load effects. Steel anchor box structures are widely used in railway cable-stayed bridges. However, due to the large amount of steel used, they are not easy to install and there is still a risk of cracking in the bridge tower concrete. This type of anchoring structure is still under development and improvement.

[0003] Traditional steel anchor boxes consist of anchor beams and steel crossbeams. To reduce the horizontal forces on the pylons, the stiffness distribution principle requires larger steel crossbeams, resulting in a heavier overall hoisting weight. This invention thoroughly studies the force transmission mechanism of the steel anchor box and, leveraging the compression-bearing properties of pylon concrete and tension-bearing steel, designs a pylon anchor structure that ensures reliable force bearing while reducing hoisting weight, requiring less steel, facilitating installation, and minimizing the risk of pylon concrete cracking. Summary of the Invention

[0004] The present invention is proposed to solve the problems existing in the prior art, and its purpose is to provide an external steel strand-strut cable-stayed bridge tower anchoring structure.

[0005] The technical solution of the present invention is: an external steel strand-strut cable-stayed bridge tower anchorage structure, including two anchor beams, the two anchor beams are anchor beam No. 1 and anchor beam No. 2, the anchor beam No. 1 and anchor beam No. 2 are relatively fixed on the tower wall of the bridge tower, and a steel strand-strut combination structure is arranged between the anchor beam No. 1 and anchor beam No. 2 to bear the horizontal force between the anchor beams.

[0006] Furthermore, the No. 1 anchor beam is a fixed anchor beam, and the No. 1 anchor beam is combined with the bridge tower concrete into a whole through shear nails.

[0007] Furthermore, the anchor beam No. II is a movable anchor beam, and the bridge tower forms a movable installation position corresponding to the anchor beam No. II. The movable installation position is surrounded by four side wall steel plates, and the anchor beam No. II is placed in the movable installation position.

[0008] Furthermore, the side wall steel plates are fixed to the bridge tower concrete through shear nails.

[0009] Furthermore, the No. 1 anchor beam and the No. 2 anchor beam have the same structure, and a cable connector for fixing the inclined cable is provided in the anchor beam, and the cable connector is connected to the web.

[0010] Furthermore, the cable connector includes a support plate, and the end of the support plate is provided with a pressure plate and an anchor plate.

[0011] Furthermore, support plate stiffening ribs are formed on the outer wall of the end portion of the support plate to reinforce the support plate.

[0012] Furthermore, the steel strand-strut combination structure includes end anchor plates, and compression-only struts and steel strand groups are arranged between two end anchor plates.

[0013] Furthermore, the anchoring position between the end anchor plate and the anchor beam is provided with stiffening ribs for reinforcing the end anchor plate.

[0014] In the present invention, the anchor beam decomposes the cable force into vertical force and horizontal force. The vertical force is borne by the bridge tower concrete, and the horizontal force is borne by a steel strand-strut combination structure, which fully utilizes the material properties of the steel plate and steel strand. Since the steel strand has a large tensile bearing capacity, the amount of steel used can be reduced. The anchor beam adopts a structural system with one end fixed and the other end movable, which can reduce the horizontal force borne by the bridge tower and reduce the risk of cracking of the bridge tower concrete. The steel anchor beam structure of the present invention realizes modular assembly, has a flexible assembly method, and is relatively convenient to construct. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a perspective view of the structure of the present invention;

[0016] Figure 2 This is a schematic diagram of the installation of the steel strand-strut combination structure of the present invention;

[0017] Figure 3 It is a schematic diagram of the structure of 100 in the present invention;

[0018] in:

[0019] 100 Anchor beam 101 Anchor plate

[0020] 102 pressure plate 103 support plate

[0021] 104 Support plate stiffener 105 Web

[0022] 106 top plate 107 bottom plate

[0023] 108 stainless steel plate layer 109 polytetrafluoroethylene layer

[0024] 200 Steel strand-strut combination structure

[0025] 201 End anchor plate 202 Stiffening rib

[0026] 203 Compression support rod only 204 Temporary tension support plate

[0027] 205 Steel Strand Group. DETAILED DESCRIPTION

[0028] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and embodiments:

[0029] like Figure 1 As shown, an external steel strand-strut cable-stayed bridge tower anchorage structure includes two anchor beams 100, which are anchor beam No. I and anchor beam No. II respectively. The anchor beam No. I and anchor beam No. II are relatively fixed on the tower wall of the bridge tower. A steel strand-strut combination structure 200 is provided between the anchor beam No. I and anchor beam No. II for bearing the horizontal force between the anchor beams.

[0030] The No. 1 anchor beam is a fixed anchor beam, and the No. 1 anchor beam is combined with the bridge tower concrete into a whole through shear nails.

[0031] The anchor beam No. II is a movable anchor beam, and the bridge tower forms a movable installation position corresponding to the anchor beam No. II. The movable installation position is surrounded by four side wall steel plates, and the anchor beam No. II is placed in the movable installation position.

[0032] The side wall steel plates are fixed to the bridge tower concrete through shear nails.

[0033] The anchor beam No. I and the anchor beam No. II have the same structure. A cable connector for fixing the inclined cable is provided in the anchor beam 100 , and the cable connector is connected to the web 105 .

[0034] The cable connector includes a support plate 103 , and a pressure plate 102 and an anchor plate 101 are provided at the end of the support plate 103 .

[0035] Support plate stiffening ribs 104 are formed at the outer wall of the end of the support plate 103 to reinforce the support plate 103 .

[0036] The steel strand-strut combination structure 200 includes end anchor plates 201 , and a compression-only strut 203 and a steel strand group 205 are disposed between two end anchor plates 201 .

[0037] The anchoring position between the end anchor plate 201 and the anchor beam 100 is provided with a stiffening rib 202 for reinforcing the end anchor plate 201 .

[0038] The anchor beam 100 includes a rectangular beam structure, with an inclined web 105 formed on one side of the beam. The cable connector is provided in the beam structure, and the anchor plate 101 is located at the inclined end surface of the web 105 .

[0039] The anchor beam No. II is a movable anchor beam, and a polytetrafluoroethylene layer 109 is provided at the four side walls thereof. A stainless steel plate layer 108 is provided at the outer wall of the polytetrafluoroethylene layer 109 .

[0040] The four side walls of the movable mounting position include a top plate 106 , a bottom plate 107 and two side plates, and the four side walls together form a rectangular structure.

[0041] The four stainless steel plate layers 108 can slide along the lower end of the top plate 106 , the upper end of the bottom plate 107 , and the inner walls of the two side plates.

[0042] The anchor beam No. II is a movable anchor beam relative to the anchor beam No. I. By being arranged to be movable with the bridge tower, the horizontal force borne by the bridge tower can be reduced, thereby lowering the risk of cracking of the bridge tower concrete.

[0043] The cable connector is arranged obliquely.

[0044] The cable connector is subjected to the cable force of the inclined cable, which is divided into vertical and horizontal components. The anchor beam 100 transmits the vertical and horizontal components to the bridge tower wall and the steel strand-strut combination structure 200 respectively, and the steel strand-strut combination structure 200 bears the horizontal component.

[0045] The steel strand group 205 in the steel strand-strut combination structure 200 plays a tensile role. The steel strand-strut combination structure 200 transmits the horizontal component of the inclined cable. The steel strand group 205 is anchored on the anchor plates 201 at both ends. The number of steel strands is determined according to the balanced cable force of the inclined cables on both sides. Compared with steel materials that withstand the same tensile force, the ultimate tensile strength can be improved and the amount of steel plates used can be reduced.

[0046] The steel strand-strut combination structure is further provided with a compression-only strut 203 between the end anchor plates 201 on both sides, which is used to apply initial tension to the steel strand. The compression-only strut 203 is connected to the end anchor plates in the form of double nuts.

[0047] A through hole is formed in the end anchor plate 201, and only the compression support rod 203 is a double-headed long screw. Two nuts are provided at the threaded part of each end. The outer nut is movable and the inner nut is fixed. The outer nut is movable so that when it is subjected to the initial tension of the steel strand, only the compression support rod 203 is not subjected to force.

[0048] Preferably, the movement amounts of all compression-only struts 203 are kept consistent, that is, the gap amounts between the outer nuts on the compression-only struts 203 and the end anchor plates 201 are the same.

[0049] A temporary tensioning support plate 204 for initially tensioning the steel strand group 205 is further provided between the two end anchor plates 201 .

[0050] The installation method of the present invention is as follows:

[0051] First, the anchor beams 100 at both ends are assembled on site, including the installation of the movable anchor beam polytetrafluoroethylene layer 109 , the stainless steel plate layer 108 , and the end anchor plates 201 .

[0052] Then, temporary tensioning plates 204, compression-only struts 203, and steel strand groups 205 are installed between the end anchor plates 201, and the same initial tension is applied to the steel strand groups 205 to compress the compression struts 203.

[0053] Finally, the entire structure is hoisted into the tower for installation, and the temporary tensioning support plate 204 is removed after the tensioning of the inclined cables is completed.

[0054] Another installation method of the present invention

[0055] First, the anchor beam 100 and the steel strand-strut assembly structure 200 are hoisted into the tower in blocks.

[0056] Then, the anchor beam 100 and the end anchor plate 201 are assembled in the tower.

[0057] Then, temporary tensioning plates 204, compression-only struts 203, and steel strand groups 205 are installed between the end anchor plates 201, and the same initial tension is applied to the steel strand groups 205 to compress the compression struts 203.

[0058] Finally, after the stay cables are tensioned, the temporary tensioning support plate 204 is removed.

[0059] In the present invention, the anchor beam decomposes the cable force into vertical force and horizontal force. The vertical force is borne by the bridge tower concrete, and the horizontal force is borne by a steel strand-strut combination structure, which fully utilizes the material properties of the steel plate and steel strand. Since the steel strand has a large tensile bearing capacity, the amount of steel used can be reduced. The anchor beam adopts a structural system with one end fixed and the other end movable, which can reduce the horizontal force borne by the bridge tower and reduce the risk of cracking of the bridge tower concrete. The steel anchor beam structure of the present invention realizes modular assembly, has a flexible assembly method, and is relatively convenient to construct.

Claims

1. An external steel strand-strut cable-stayed bridge tower anchoring structure, comprising two anchoring beams (100), characterized in that: The two anchor beams (100) are anchor beam No. I and anchor beam No. II, respectively. The anchor beam No. I and anchor beam No. II are relatively fixed on the tower wall of the bridge. A steel strand-strut combination structure (200) for bearing the horizontal force between the anchor beams is provided between the anchor beam No. I and anchor beam No. II. The anchor beam No. II is a movable anchor beam, and the bridge tower forms a movable installation position corresponding to the anchor beam No. II. The movable installation position is surrounded by four side wall steel plates, and the anchor beam No. II is placed in the movable installation position; The anchor beam No. II is a movable anchor beam, and a polytetrafluoroethylene layer (109) is provided on the four side walls thereof as an inner layer, and a stainless steel plate layer (108) is provided on the outer wall of the polytetrafluoroethylene layer (109); The four side walls of the movable mounting position include a top plate (106), a bottom plate (107) and two side plates, and the four side walls enclose a rectangular structure; The four stainless steel plate layers (108) are capable of sliding along the lower end of the top plate (106), the upper end of the bottom plate (107), and the inner walls of the two side plates; The anchor beam No. II is a movable anchor beam compared to the anchor beam No. I. By being movable with the bridge tower, it can reduce the horizontal force on the bridge tower and reduce the risk of cracking of the bridge tower concrete. The anchor beam No. I and the anchor beam No. II have the same structure, and a cable connector for fixing the inclined cable is provided in the anchor beam (100), and the cable connector is connected to the web (105); The cable connector is subjected to the cable force of the inclined cable, which is divided into a vertical component and a horizontal component. The anchor beam (100) transmits the vertical component and the horizontal component to the tower wall and the steel strand-strut combination structure (200), respectively. The steel strand-strut combination structure (200) bears the horizontal component. The steel strand group (205) in the steel strand-strut combination structure (200) plays a tensile role. The steel strand-strut combination structure (200) transmits the horizontal component of the inclined cable. The steel strand group (205) is anchored on the anchor plates (201) at both ends. The steel strand-strut combination structure is further provided with a compression-only strut (203) between the end anchor plates (201) on both sides, which is used to apply initial tension to the steel strand. The compression-only strut (203) is connected to the end anchor plates in the form of double nuts.

2. The external steel strand-strut cable-stayed bridge tower anchoring structure according to claim 1, characterized in that: The No. 1 anchor beam is a fixed anchor beam, and the No. 1 anchor beam is combined with the bridge tower concrete into a whole through shear nails.

3. The external steel strand-strut cable-stayed bridge tower anchoring structure according to claim 1, characterized in that: The side wall steel plates are fixed to the bridge tower concrete through shear nails.

4. The external steel strand-strut cable-stayed bridge tower anchoring structure according to claim 1, characterized in that: The cable connector comprises a support plate (103), and a pressure plate (102) and an anchor plate (101) are provided at the end of the support plate (103).

5. The external steel strand-strut cable-stayed bridge tower anchoring structure according to claim 4, characterized in that: Support plate stiffening ribs (104) are formed at the outer wall of the end of the support plate (103) to reinforce the support plate (103).

6. The external steel strand-strut cable-stayed bridge tower anchoring structure according to claim 1, characterized in that: The anchoring position between the end anchor plate (201) and the anchor beam (100) is provided with a stiffening rib (202) for reinforcing the anchoring rib.

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