Arch-shaped force transmission device for combined area of single-column tower and construction method thereof

Abstract

The present application relates to a kind of arch force transmission device for single-column tower combination area and its construction method.The device includes bridge tower, Π type girder, middle beam and arch beam, the bottom of the bridge tower sequentially passes through Π type girder and middle beam, the bridge tower is fixed with Π type girder by middle beam, the middle beam and arch beam are arranged below Π type girder, the two ends of the middle beam are connected with Π type girder, and the two ends of the arch beam are respectively connected with the two ends of the middle beam.In prior art, the force of cable of tower beam fixed system single-column tower cable-stayed bridge to girder can produce larger horizontal component, and is transmitted to bridge tower along girder, and larger local stress is generated on bridge tower.By setting arch beam in certain area on both sides of bridge tower, the arch beam has certain arc along longitudinal direction and vertical direction, longitudinal arch effect is provided under the condition of guaranteeing that only compressive stress is borne by itself, force transmitted along longitudinal direction is dispersed to prestressed middle beam, and stress on bridge tower is reduced.

Description

Technical Field

[0001] This invention relates to the field of single-tower cable-stayed bridge design, and in particular to an arch-shaped force transmission device for the single-column tower junction area and its construction method. Background Technology

[0002] In a single-tower cable-stayed bridge structure with a tower-girder fixed-bond system, the stay cables, while providing vertical support to the main girder, also generate horizontal forces on the main girder, which are then transmitted to the tower. Upon reaching the tower-girder fixed-bond zone, the cumulative effect of multiple cables causes the tower to bear significant horizontal forces, jeopardizing its safety and adding considerable challenges to the design process. Traditional design methods often employ strengthening the tower-girder fixed-bond zone, which increases the difficulty and cost of structural design and construction, and fails to effectively solve this problem.

[0003] Chinese patent CN202210180373.6 discloses a partially cable-stayed bridge tower-beam-pier consolidation system. This patent changes the existing force transmission path of the cable-stayed bridge tower, allowing the vertical load borne by the tower to be directly transferred to the pier through the transverse diaphragm, avoiding cracking of the concrete due to uneven hydrothermal development during the pouring of large-volume concrete. Chinese patent CN201810300297.1 discloses an arch-bearing cable-stayed bridge structure without a tower-tower crossbeam. The upper ends of two tower columns are fixed together to form an arch structure spanning the main span beam segment, providing a wide field of vision and better landscape effect compared to traditional bridge structures.

[0004] While the above patents have optimized the tower-beam consolidation system, they have not significantly improved the stress on the bridge tower. Summary of the Invention

[0005] The purpose of this invention is to provide an arched force transmission device and its construction method for the single-tower joint area of ​​a tower-beam integrated cable-stayed bridge to improve the excessive stress on the bridge tower. In existing technologies, the force exerted by the cables on the main beam of a tower-beam integrated cable-stayed bridge generates a large horizontal component, which is transmitted along the main beam to the bridge tower, generating significant local stress on the tower. This invention addresses this by setting arched crossbeams in a certain area on both sides of the bridge tower. These arched crossbeams have a certain curvature in both the longitudinal and vertical directions. While ensuring that they only bear compressive stress, they provide a longitudinal arching effect, distributing the longitudinally transmitted force to the prestressed crossbeams and reducing the stress on the bridge tower.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] An arched force transmission device for use in the joint zone of a single-column tower includes a bridge tower, a Π-shaped main beam, a central crossbeam, and an arched crossbeam.

[0008] The bottom of the bridge tower passes through the Π-shaped main beam and the middle cross beam in sequence, and the bridge tower is fixed to the Π-shaped main beam through the middle cross beam.

[0009] The central crossbeam and the arched crossbeam are located below the Π-shaped main beam, and the two ends of the central crossbeam are connected to the Π-shaped main beam.

[0010] The two ends of the arched crossbeam are respectively connected to the two ends of the central crossbeam.

[0011] Furthermore, the Π-shaped main beam consists of a left support, a right support, and a connecting beam. The two ends of the connecting beam are connected to either the left or right support, and the two ends of the middle crossbeam are connected to either the left or right support. The bottom end of the bridge tower passes through the connecting beam.

[0012] Furthermore, one end of the arched crossbeam is connected to the junction of the middle crossbeam and the left support, and the other end of the arched crossbeam is connected to the junction of the middle crossbeam and the right support.

[0013] Furthermore, the middle crossbeam is equipped with steel strands.

[0014] Furthermore, the thickness of the arched crossbeam is 75-85mm, preferably 80mm.

[0015] Furthermore, the longitudinal linearity of the arched beam is a catenary with a rise-to-span ratio of 1 / 3, the vertical linearity of the arched beam is a quadratic curve, and the bottom edge of the arched beam is a 1.5-order curve along the transverse direction of the arched beam, thereby realizing the change of the height of the arched beam along the transverse direction and optimizing the weight reduction of the arched beam.

[0016] Furthermore, the present invention also provides a method for constructing an arched force transmission device for the joint area of ​​a single-column tower, the specific steps of which are as follows:

[0017] S1. Determine the specific shape of the arched beam;

[0018] S2. Calculate the tension F at both ends of the central beam at the two arch feet of the arched beam using the principle of force equilibrium.

[0019] S3. Use tension F to configure the steel strands in the crossbeam.

[0020] Furthermore, in step S1, the step of determining the specific shape of the arched beam is as follows:

[0021] S1-1. Determine the initial rectangle: Measure the transverse width of the middle beam and the vertical height of the Π-shaped main beam. L and H are used as the transverse span and vertical height of the arch beam, respectively. Set the initial rectangle with width L and height H.

[0022] S1-2, Set the lower edge of the initial rectangle obtained in step S1-1 as a 1.5-order curve along the horizontal direction;

[0023] S1-3. Discretize the initial rectangle obtained in step S1-1 into several nodes that interact with each other to obtain an arched beam.

[0024] Furthermore, in steps S1-3, the arched beam is shaped using equation (Ⅰ), and the initial rectangle obtained in step S1 is discretized into several points that interact with each other, thus obtaining the specific shape of the arched beam:

[0025]

[0026]

[0027]

[0028] In the formula:

[0029] x i —Unknown node x-coordinate;

[0030] y i —Unknown node y-coordinate;

[0031] z i —Unknown node z-coordinate;

[0032] p x-z —The external loads in the x, y, and z directions of the unknown nodes are calculated from the internal forces on the relevant cross sections of the Π-shaped main beam;

[0033] x 1-4 —The x-coordinates of the four nodes connected to the unknown node;

[0034] y 1-4 —The y-coordinates of the four nodes connected to the unknown node;

[0035] z 1-4 —The z-coordinates of the four nodes connected to the unknown node;

[0036] q a-d —Force density value of unknown nodes connected together.

[0037] Furthermore, the internal forces of the Π-shaped main beam section are calculated by finite element software and extracted from existing software.

[0038] Furthermore, in step S1-3, more than 200 nodes are selected within the initial rectangle mentioned in step S1-1, and the number of nodes is specifically arranged according to the area of ​​the initial rectangle.

[0039] Furthermore, in step S2, the tension F is calculated using equation (II):

[0040] F·h=∑F i ·d i Formula II

[0041] In the formula:

[0042] h—Longitudinal rise of the arched beam;

[0043] F i —The arched beam is subjected to longitudinal forces;

[0044] d i —Archive beam crown to longitudinal force F i The straight-line distance.

[0045] Furthermore, in step S3, the load-bearing capacity of the steel strand is 4-6 times that of the tensile force F.

[0046] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0047] 1. This method uses an arched crossbeam and a prestressed intermediate crossbeam system to disperse the pressure transmitted longitudinally to the bridge tower to both sides, effectively changing the force transmission path. The prestressed intermediate crossbeam bears the pressure from the main beam on both sides of the bridge tower, effectively reducing the stress on the bridge tower, optimizing the stress distribution in the tower-beam consolidation area, increasing the mechanical properties of the structure, and improving the safety and durability of the single-tower cable-stayed bridge.

[0048] 2. This method optimizes the structure by arranging arched crossbeams and prestressed main beams. It does not change the existing main beam design in the tower-beam consolidation zone, nor does it strengthen the bridge tower. The method is simple and convenient, and the overall stress of the bridge will not be affected by local structural changes in the tower-beam consolidation zone.

[0049] 3. This method uses a highly efficient arch structure and prestressed system, which has high mechanical efficiency and achieves significant optimization effects with less material consumption. It does not change the main structure, is convenient to construct, and has good economic benefits.

[0050] 4. This invention provides a longitudinal arch effect by setting up an arched crossbeam, which changes the longitudinal force transmission path of the bridge. While changing the longitudinal force transmission path, in order to ensure the stress performance of the arched crossbeam, it is also necessary to ensure that the arched crossbeam itself only bears compressive stress, and to distribute the forces transmitted along the longitudinal direction to both ends of the prestressed crossbeam. By having the prestressed crossbeam bear these loads, the bridge tower avoids directly bearing the force from the main beam, thus reducing the stress on the bridge tower. Attached Figure Description

[0051] Figure 1 A structural diagram of the arched force transmission device used in the joint area of ​​a single-column tower;

[0052] Figure 2 A schematic diagram of the bottom structure of the arched force transmission device used in the joint area of ​​a single-column tower;

[0053] Figure 3 This is a diagram showing the connection between the central crossbeam and the bridge tower.

[0054] Figure 4 This is a layout diagram of the Π-shaped main beam;

[0055] Figure 5 This is a layout diagram of the central crossbeam;

[0056] Figure 6 The form-finding diagram for the arched crossbeam;

[0057] Figure 7 This is a front view of the arched beam;

[0058] Figure 8 This is a top view of the arched beam;

[0059] Figure 9 This is a side view of the arched beam;

[0060] Figure 10 This is a diagram showing the arrangement of the central crossbeam and the arched crossbeam.

[0061] The following are the symbols in the attached diagram: 1. Bridge tower, 2. Π-shaped main beam, 3. Middle crossbeam, 4. Arched crossbeam, 5. Steel strand, 6. Left support, 7. Right support, 8. Connecting beam, L. Horizontal width of the middle crossbeam, H. Vertical height of the Π-shaped main beam, T. Thickness of the arched crossbeam, a. Bottom edge of the arched crossbeam. Detailed Implementation

[0062] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0063] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0064] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0065] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0066] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0067] Example 1

[0068] See Figures 1 to 10 This embodiment provides an arched force transmission device for the joint area of ​​a single-column tower, including a bridge tower 1, a Π-shaped main beam 2, a central crossbeam 3, and an arched crossbeam 4.

[0069] The bottom end of the bridge tower 1 passes through the Π-shaped main beam 2 and the middle cross beam 3 in sequence, and the bridge tower 1 is fixed to the Π-shaped main beam 2 through the middle cross beam 3.

[0070] The central crossbeam 3 and the arched crossbeam 4 are located below the Π-shaped main beam 2, and the two ends of the central crossbeam 3 are connected to the Π-shaped main beam 2.

[0071] The two ends of the arched crossbeam 4 are respectively connected to the two ends of the middle crossbeam 3.

[0072] In this embodiment, the Π-shaped main beam 2 is composed of a left support 6, a right support 7 and a connecting beam 8. The two ends of the connecting beam 8 are connected to the left support 6 or the right support 7 respectively. The two ends of the middle cross beam 3 are connected to the left support 6 or the right support 7 respectively. The bottom end of the bridge tower 1 passes through the connecting beam 8.

[0073] In this embodiment, one end of the arched crossbeam 4 is connected to the middle crossbeam 3 and the left support 6, and the other end of the arched crossbeam 4 is connected to the middle crossbeam 3 and the right support 7.

[0074] In this embodiment, the middle crossbeam 3 is provided with steel strands 5.

[0075] In this embodiment, the thickness T of the arched crossbeam 4 is 75-85mm, preferably 80mm.

[0076] In this embodiment, the longitudinal linearity of the arched beam 4 is a catenary with a rise-to-span ratio of 1 / 3, the vertical linearity of the arched beam 4 is a quadratic curve, and the bottom edge a of the arched beam 4 is a 1.5-order curve along the transverse direction of the arched beam 4, thereby realizing the change of the height of the arched beam 4 along the transverse direction and optimizing the weight reduction of the arched beam 4.

[0077] Furthermore, the present invention also provides a method for constructing an arched force transmission device for the joint area of ​​a single-column tower, the specific steps of which are as follows:

[0078] S1. Determine the specific shape of the arched beam 4;

[0079] S2. Calculate the tension F at both ends of the central beam 3 at the two arch feet of the arched beam 4 using the principle of force balance;

[0080] S3, use tension F to configure the steel strand 5 in the crossbeam 3.

[0081] In this embodiment, step S1, which involves determining the specific shape of the arched beam 4, is as follows:

[0082] S1-1. Determine the initial rectangle: Measure the transverse width L of the middle beam and the vertical height H of the Π-shaped main beam. L and H are respectively used as the transverse span and vertical height of the arch beam 4. Set the initial rectangle with width L and height H.

[0083] S1-2, Set the lower edge of the initial rectangle obtained in step S1-1 as a 1.5-order curve along the horizontal direction;

[0084] S1-3. Discretize the initial rectangle obtained in step S1-1 into several nodes that interact with each other to obtain the arched beam 4.

[0085] In this embodiment, in steps S1-3, the arched beam 4 is shaped using equation (Ⅰ), and the initial rectangle obtained in step S1 is discretized into several points that interact with each other, thus obtaining the specific shape of the arched beam 4:

[0086]

[0087]

[0088]

[0089] In the formula:

[0090] x i —Unknown node x-coordinate;

[0091] y i —Unknown node y-coordinate;

[0092] z i —Unknown node z-coordinate;

[0093] p x-z —The external loads in the x, y, and z directions of the unknown nodes are calculated from the internal forces on the relevant cross sections of the Π-shaped main beam 2;

[0094] x1-4 —The x-coordinates of the four nodes connected to the unknown node;

[0095] y 1-4 —The y-coordinates of the four nodes connected to the unknown node;

[0096] z 1-4 —The z-coordinates of the four nodes connected to the unknown node;

[0097] q a-d —Force density value of unknown nodes connected together.

[0098] In this embodiment, the internal forces of the Π-shaped main beam section 2 are calculated by finite element software and extracted from existing software.

[0099] In this embodiment, in steps S1-3, more than 200 nodes are selected within the initial rectangle mentioned in step S1-1, and the number of nodes is specifically arranged according to the area of ​​the initial rectangle.

[0100] In this embodiment, in step S2, the tension F is calculated using equation (II):

[0101] F·h=∑F i ·d i Formula II

[0102] In the formula:

[0103] h——Longitudinal rise of the arched crossbeam 4;

[0104] F i —The arched crossbeam 4 is subjected to longitudinal forces;

[0105] d i —Arch-shaped crossbeam 4, longitudinal force F from the arch crown i The straight-line distance.

[0106] In this embodiment, in step S3, the load-bearing capacity of the steel strand 5 is 4-6 times the tensile force F.

[0107] like Figure 1 and Figure 2 As shown, the arched force transmission device used in the single-column tower joint area consists of bridge tower 1, Π-shaped main beam 2, middle crossbeam 3, and arched crossbeam 4.

[0108] like Figure 3 As shown, the central crossbeam 3 is fixed to the bridge tower 1.

[0109] like Figure 4 and Figure 5 As shown, the vertical height H of the Π-shaped main beam 2 and the horizontal width L of the middle crossbeam 3 are represented by L and H, which together form the horizontal span and vertical height of the arched crossbeam 4.

[0110] like Figure 6 As shown, an initial rectangle with width L and height H is set, and a 1.5-order curve is set on the lower edge of the initial rectangle so that the height of the initial rectangle varies laterally. The initial rectangle is discretized into nodes in space, and each node is force-connected to the others. The following equation is used to find the shape of the arched beam 4:

[0111]

[0112]

[0113]

[0114] In the formula:

[0115] x i —Unknown node x-coordinate;

[0116] y i —Unknown node y-coordinate;

[0117] z i —Unknown node z-coordinate;

[0118] p x-z —The external loads in the x, y, and z directions of the unknown nodes can be calculated from the internal forces on the relevant cross sections of the Π-shaped main beam 2 (the internal forces of the cross sections are calculated by finite element software and extracted from existing software).

[0119] x 1-4 —The x-coordinates of the four nodes connected to the unknown node;

[0120] y 1-4 —The y-coordinates of the four nodes connected to the unknown node;

[0121] z 1-4 —The z-coordinates of the four nodes connected to the unknown node;

[0122] q a-d —Force density value of unknown nodes connected together.

[0123] Figure 7-9 The shape of the arched beam 4 is shown. The longitudinal bending line is a catenary with a rise-to-span ratio of 1 / 3, and the vertical bending line is a quadratic curve.

[0124] like Figure 10 As shown, the two ends of the arched crossbeam 4 are connected to the middle crossbeam 3. The tensile force F at both ends of the prestressed middle crossbeam 3 is calculated by the principle of equilibrium. The load F is used to design the prestressed steel strands 5 in the middle crossbeam.

[0125] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. An arched force transmission device for use in the joint area of ​​a single-column tower, characterized in that, It includes bridge towers (1), Π-shaped main beams (2), central crossbeams (3) and arched crossbeams (4). The bottom end of the bridge tower (1) passes through the Π-shaped main beam (2) and the middle cross beam (3) in sequence. The bridge tower (1) is fixed to the Π-shaped main beam (2) through the middle cross beam (3). An arched cross beam (4) is provided on both sides of the bridge tower (1). The central crossbeam (3) and the arched crossbeam (4) are located below the Π-shaped main beam (2), and the two ends of the central crossbeam (3) are connected to the Π-shaped main beam (2). The two ends of the arched crossbeam (4) are respectively connected to the two ends of the middle crossbeam (3); The longitudinal linearity of the arched beam (4) is a catenary, and the rise-to-span ratio is 1 / 3. The vertical linearity of the arched beam (4) is a quadratic curve, and the bottom edge a of the arched beam (4) is a 1.5-order curve along the transverse direction of the arched beam (4).

2. The arched force transmission device for the joint area of ​​a single-column tower according to claim 1, characterized in that, The Π-shaped main beam (2) is composed of a left support (6), a right support (7) and a connecting beam (8); one end of the connecting beam (8) is connected to the left support (6) and the other end is connected to the right support (7); one end of the middle cross beam (3) is connected to the left support (6) and the other end is connected to the right support (7); the bottom end of the bridge tower (1) passes through the connecting beam (8).

3. The arched force transmission device for the joint area of ​​a single-column tower according to claim 2, characterized in that, One end of the arched crossbeam (4) is connected to the middle crossbeam (3) and the left support (6), and the other end of the arched crossbeam (4) is connected to the middle crossbeam (3) and the right support (7).

4. The arched force transmission device for the joint area of ​​a single-column tower according to claim 1, characterized in that, The middle crossbeam (3) is equipped with steel strands (5).

5. An arched force transmission device for a single-column tower junction area according to claim 1, characterized in that, The thickness T of the arched crossbeam (4) is 75~85mm.

6. A method for constructing an arched force transmission device for the joint area of ​​a single-column tower as described in any one of claims 1-5, characterized in that, The specific steps are as follows: S1. Determine the specific shape of the arched beam (4); S2. Calculate the tension F at both ends of the central beam (3) at the two arch feet of the arched beam (4) using the principle of force balance; S3, Use tension F to configure the steel strand (5) in the crossbeam (3).

7. A method for constructing an arched force transmission device for a single-column tower junction area according to claim 6, characterized in that, In step S1, the steps for determining the specific shape of the arched beam (4) are as follows: S1-1, Determine the initial rectangle: Measure the transverse width L of the middle beam and the vertical height H of the Π-shaped main beam. L and H are respectively used as the transverse span and vertical height of the arch beam (4). Set the initial rectangle with width L and height H. S1-2, Set the lower edge of the initial rectangle obtained in step S1-1 as a 1.5-order curve along the horizontal direction; S1-3. Discretize the initial rectangle obtained in step S1-1 into several nodes that interact with each other to obtain the arched beam (4).

8. A method for constructing an arched force transmission device for a single-column tower junction area according to claim 7, characterized in that, In steps S1-3, the arched beam (4) is shaped using equation I. The initial rectangle obtained in step S1 is discretized into several points that interact with each other, thus obtaining the specific shape of the arched beam (4): Formula I, In the formula: x i —— Unknown node x coordinate; y i —— Unknown node y coordinate; z i —— Unknown node z coordinate; p x-z —— Unknown node x, y, z The external load in the direction is calculated from the internal forces on the relevant cross sections of the Π-shaped main beam (2); x 1-4 —— Four nodes connected to the unknown node x coordinate; y 1-4 —— Four nodes connected to the unknown node y coordinate; z 1-4 —— Four nodes connected to the unknown node z coordinate; q a-d —— Force density values ​​connected to unknown nodes; More than 200 nodes are selected within the initial rectangle mentioned in step S1-1.

9. A method for constructing an arched force transmission device for a single-column tower junction area according to claim 6, characterized in that, In step S2, the tension F is calculated using equation II: Formula II In the formula: h—— Longitudinal rise of the arched crossbeam (4); F i —— The arched crossbeam (4) is subjected to longitudinal forces; d i —— Arched crossbeam (4) longitudinal stress from the arch crown F i The straight-line distance.

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