A fixing structure for the main tower support column of a cable-stayed bridge without backstays

Abstract

This invention discloses a fixing structure for the support column of a cable-stayed bridge main tower without backstays, aiming to solve the problem that the support column in the prior art easily causes cracking of the concrete beam. It includes: an upper and lower force-equalizing plate connected by anchors to increase the friction area, reducing the frictional force per unit area to resist horizontal tension, thus preventing the concrete beam's cover plate from being cracked and damaged by horizontal tension; the cable transmits the horizontal tension and resists the frictional force between the upper and lower force-equalizing plates; the support column transmits the horizontal tension to the upper force-equalizing plate through a force-transmitting fixing component, which also serves to fix the cable; and an adjustable clamping component presses the vertical support component tightly against the cover plate and the bottom plate to prevent excessive deflection of the cover plate under the vertical pressure of the support column.

Description

Technical Field

[0001] This invention relates to a support column fixing structure for the main tower of a cable-stayed bridge without backstays, belonging to the field of construction technology for the main tower of a cable-stayed bridge without backstays. Background Technology

[0002] By tilting the main tower of a conventional cable-stayed bridge and eliminating the backstays, a novel and powerful type of bridge is created: the cable-stayed bridge without backstays. This type of bridge boasts a beautiful and unique shape and outstanding landscape effects, providing a new solution for urban bridge design. The main tower of a cable-stayed bridge without backstays tilts towards the side spans. This tilt causes the center of gravity of the main tower to shift away from its base, generating an overturning moment. The main girder in the middle span undergoes vertical downward deflection under its own weight and other loads. To control this deflection, the stay cables are actively tensioned, with one end anchored to the tilted tower and the other end anchored to the main girder. This reduces the deflection of the main girder and causes the main tower to deform in the opposite direction of the tilt, achieving force balance. Therefore, the weight and stiffness of the tower itself are crucial. When the main span is limited, the concrete beams in the side spans are typically used to increase the weight on the main girder in the middle span, generating a moment in the same direction as the overturning moment of the tower, thus achieving structural balance and stability.

[0003] When constructing the inclined main tower in sections using the climbing formwork method, the tensile stress on the outer side of the inclined main tower root is relatively large due to the weight of the main tower itself, the weight of the climbing formwork, and other construction loads. This can cause tensile cracking of the root concrete, deteriorating the structural performance, posing safety risks, and even causing accidents. Therefore, cable-stayed bridges without backstays often adopt the full-span scaffolding construction method, which involves erecting densely spaced scaffolding at regular intervals to provide support. This method requires a large number of formwork supports. First, a dense network of supports is erected at the bridge site. Formwork is then installed on the supports, and the bridge concrete is poured. After the concrete reaches its strength, the formwork and supports are removed. The main tower is constructed first, followed by the mid-span main beam. However, since the main tower's own rigidity only bears a portion of the weight, the remaining weight will be transferred to the cover plate of the concrete beam in the form of concentrated force by the support. The gravitational torque causes the cover plate to deflect downward, resulting in concrete cracking at the connection between the support column and the concrete mid-span main beam. The resulting horizontal tensile force will cause the concrete beam to bear local tensile stress, resulting in cracking of the concrete beam. The cracking damage is concentrated on the cover plate that is in direct contact with the support column. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a fixing structure and construction method for the support columns of the main tower of a cable-stayed bridge without backstays to prevent damage to the concrete beam from the force of the support columns.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0006] In a first aspect, the present invention provides a fixing structure for the support column of the main tower of a cable-stayed bridge without backstays, including an upper force equalizing plate and a lower force equalizing plate, wherein the upper force equalizing plate and the lower force equalizing plate are respectively used to closely adhere to the top and bottom surfaces of the cover plate of the concrete beam, and the upper force equalizing plate is also used to fixally connect with the support column.

[0007] It also includes anchors for penetrating the cover plate, and the upper force equalizing plate and the lower force equalizing plate are connected by multiple anchors for force transmission.

[0008] It also includes a force-up fixing member provided on the upper force-equalizing plate for force transmission connection with the support column, and a lower fixing member provided on the lower force-equalizing plate. The force-up fixing member and the lower fixing member are tensioned by a cable. The force-up fixing member and the lower fixing member are arranged at an angle. When the fixing structure of the support column of the main tower of the cable-stayed bridge without backstay is connected to the support column, the force-up fixing member is closer to the support column than the lower fixing member, and the force-up fixing member is further away from the root of the main tower than the lower fixing member.

[0009] It also includes at least one vertical support member for supporting the bottom plate and the cover plate of the concrete beam, and the vertical support member is further provided with an adjustable clamping member between the bottom plate and / or the cover plate.

[0010] In some embodiments of the first aspect, the anchor includes an anchor bolt that penetrates vertically through the cover plate, with both ends of the anchor bolt fixed to the upper force equalizing plate and the lower force equalizing plate respectively by nuts.

[0011] In some embodiments of the first aspect, when the fixing structure of the main tower support column of the cable-stayed bridge without backstays is connected to the support column,

[0012] When the support column is located at the center of a single box of the concrete beam, at least two of the vertical support members are arranged symmetrically with respect to the support column.

[0013] or,

[0014] When the support column is close to the middle web / side web of a single box of the concrete beam, the distance between the vertical support and the support column is the same as the distance between the support column and the adjacent middle web / side web.

[0015] In some embodiments of the first aspect, the force-up fixing member is an upper bracket, and the lower fixing member is a lower bracket of the same specification as the upper bracket.

[0016] In some embodiments of the first aspect, one end of the vertical support member is provided with the adjustable clamping member, while the other end is connected to the base plate or the cover plate for force transmission via a support member pad.

[0017] In some embodiments of the first aspect, the vertical support includes a second column.

[0018] In some embodiments of the first aspect, the adjustable clamping member includes a bridge unloading block.

[0019] Secondly, the present invention also provides a construction method for the fixing structure of the main tower support column of the cable-stayed bridge without backstays as described in any of the first aspects.

[0020] Step A: Install vertical support components and use adjustable clamps to tighten the vertical support components inside the cover plate and base plate;

[0021] Step B: Install the upper and lower force equalizing plates, and fix the upper force equalizing plate to the support column;

[0022] Step C: Tension the cables according to the amount of concrete poured in a single section of the main tower;

[0023] Repeat step C until the entire main tower section is poured.

[0024] In some embodiments of the second aspect,

[0025] In step C, finite element analysis is performed based on the single-section pouring volume of the main tower to calculate the horizontal tension force exerted by each support column on the cover plate. The formula for calculating the cable tension force of each support column is as follows:

[0026] F=w / cosα

[0027] In the formula, F is the tension force, w is the horizontal tension force, and α is the angle between the cable and the plane of the cover plate.

[0028] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0029] The fixing structure of the main tower support column of the cable-stayed bridge without backstays provided by the present invention increases the friction area by connecting the upper and lower force-equalizing plates with anchors. The friction force per unit area to resist the horizontal tension is reduced, preventing the cover plate of the concrete beam from being cracked and damaged by the horizontal tension. The cable transmits the horizontal tension and resists the friction force generated by the horizontal tension between the upper and lower force-equalizing plates. The support column transmits the horizontal tension to the upper force-equalizing plate through the force-transmitting fixing member, which also serves to fix the cable. The adjustable top tightening member presses the vertical support member into the cover plate and the bottom plate to prevent the cover plate from being damaged by excessive deflection under the vertical pressure of the support column. Attached Figure Description

[0030] Figure 1 This is a cross-sectional structural diagram of the fixing structure of the main tower support column of the cable-stayed bridge without backstay provided in Embodiment 1 of the present invention during use;

[0031] Figure 2 yes Figure 1 A three-dimensional image;

[0032] Figure 3 yes Figure 1 A sectional view of a single support column along the axis of the support column;

[0033] Figure 4 yes Figure 3 A three-dimensional image;

[0034] Figure 5 yes Figure 1 Schematic diagram of the structure of the bridge unloading block;

[0035] Figure 6 Is using Figure 1 A schematic diagram of the main tower construction and full-span scaffolding of the fixed structure of the main tower support columns of the cable-stayed bridge without backstays.

[0036] Figure 7 Is using Figure 1 A schematic diagram of the main tower construction and full-span scaffolding of the fixed structure of the main tower support columns of the cable-stayed bridge without backstays.

[0037] Figure 8 This is a side view of the main tower of the cable-stayed bridge without backstays after construction was completed;

[0038] Figure 9 This is a flowchart of the construction method for the fixing structure of the main tower support column of the cable-stayed bridge without backstays provided in Embodiment 1 of the present invention;

[0039] In the picture:

[0040] 1-Support column;

[0041] 2.1-Upper force-bearing fastener; 2.1.1-Upper bracket; 2.2-Lower fastener; 2.2.1-Lower bracket;

[0042] 3-Cable;

[0043] 4-Anchor; 4.1-Anchor bolt; 4.2-Nut;

[0044] 6.1 - Upper force equalization plate; 6.2 - Lower force equalization plate;

[0045] 7-Concrete beam; 7.1-Cover plate; 7.2-Bottom plate; 7.3-Intermediate web plate; 7.4-Side web plate;

[0046] 8-Supporting pad;

[0047] 9-Vertical support component; 9.1-Second column;

[0048] 10-Adjustable clamping component; 10.1-Bridge unloading block; 10.1.1-Adjustable distance component; 10.1.2-Clamping wedge; 10.1.3-Clamping wedge;

[0049] 11-Main tower; 12-Cable stay; 13-Diagonal brace; 14-Mid-span main beam. Detailed Implementation

[0050] The technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solution of this application, rather than limitations thereof. In the absence of conflict, the embodiments and technical features in the embodiments can be combined with each other. Example 1

[0051] This embodiment provides a fixing structure and construction method for the support column of the main tower of a cable-stayed bridge without backstays, in order to solve the problem of easy cracking between the support column and the cover plate of the concrete beam during the construction of the main tower in the prior art.

[0052] refer to Figure 8 With construction completed, and supported by the diagonal bracing 13, the inclined main tower 11 achieves tensile balance through the stay cables 12 and the mid-span main beam 14, as referenced. Figure 6 and Figure 7 The construction of the main tower 11 predates that of the mid-span main beam 14. The horizontal tension w of the main tower 11 is applied to the concrete beam 7 through the array of distributed support columns 1, and the cover plate 7.1 of the concrete beam 7 bears the brunt of the stress.

[0053] refer to Figure 1 , Figure 2 and Figure 3 The fixing structure of the main tower support column of the cable-stayed bridge without backstay provided in this embodiment includes an upper force equalizing plate 6.1 on the top surface and a lower force equalizing plate 6.2 on the bottom surface of the cover plate 7.1 that is close to the concrete beam 7. The upper force equalizing plate 6.1 and the lower force equalizing plate 6.2 clamp the cover plate 7.1 to obtain a large friction surface. The upper force equalizing plate 6.1 and the lower force equalizing plate 6.2 are connected by multiple anchors 4 that penetrate the cover plate 7.1. Through frictional contact with the cover plate 7.1, the lower force equalizing plate 6.2 shares and resists the horizontal tensile force w with the upper force equalizing plate 6.1 through the multiple anchors 4 that penetrate the cover plate 7.1 and the anchors 4 themselves.

[0054] The base of the support column 1 is anchored within the cover plate 7.1, specifically by welding it to the reinforcing steel frame within the cover plate 7.1. The upper force-equalizing plate 6.1 is fixedly connected to the support column 1, preferably by welding. A force-transmitting fixing component 2.1 for transmitting horizontal tension w is provided at the angle between the support column 1 and the cover plate 7.1. The position of the force-transmitting fixing component 2.1 is away from the main tower 11, preferably... Figure 2The position shown is located at the angle between the support column 1 and the cover plate 7.1, away from the position through which the horizontal tension force w passes by the support column 1. The lower force-equalizing plate 6.2 has a lower fixing member 2.2 that is closer to the main tower 11 than the upper force-equalizing member 2.1. A tension cable 3 is connected between the upper force-equalizing member 2.1 and the lower fixing member 2.2. The upper force-equalizing member 2.1 assists the support column 1 in transmitting the horizontal tension force w to the cable 3 and the upper force-equalizing plate 6.1. The cable 3 transmits the horizontal tension force w between the upper force-equalizing plate 6.1 and the lower force-equalizing plate 6.2 and the frictional force resisting the horizontal tension force w. The lower fixing member 2.2 is preferably... Figure 3 As shown, at the position through which the horizontal tension force w passes, the cable 3 gradually approaches the support column 1 from bottom to top. The cable 3 is tensioned until the frictional force generated by the upper force equalizing plate 6.1 and the lower force equalizing plate 6.2 against the horizontal tension force w is close, and the resultant frictional force cancels out the horizontal tension force w of the support column 1 on the cover plate 7.1. It also makes the upper force equalizing plate 6.1 and the lower force equalizing plate 6.2 further close to the cover plate 7.1, increasing the effective friction area. The frictional force generated per unit area against the horizontal tension force w is reduced, preventing the cover plate 7.1 of the concrete beam 7 from being torn and preventing the cover plate 7.1 from being damaged by the horizontal tension force w. The upper force fixing component 2.1 can be the upper bracket 2.1.1, and the lower fixing component 2.2 can be the lower bracket 2.2.1 of the same specification as the upper bracket 2.1.1, improving the substitutability of parts.

[0055] At least one vertical support 9 is provided between the bottom plate 7.2 and the cover plate 7.1 of the concrete beam 7. An adjustable clamping member 10 is provided between the vertical support 9 and the bottom plate 7.2 and / or the cover plate 7.1. By adjusting the adjustable clamping member 10, the two ends of the vertical support 9 are clamped to the cover plate 7.1 and the bottom plate 7.2, thus transferring the weight of the support column 1 and its main tower 11 downwards and preventing excessive deflection and cracking of the cover plate 7.1. Figure 1 As shown, in this embodiment, the vertical support 9 adopts a second column 9.1, and the adjustable top clamping member 10 includes a bridge unloading block 10.1 located at the bottom of the support 9. A support pad 8 is provided between the top of the second column 9.1 away from the adjustable top clamping member 10 and the cover plate 7.1. The support pad 8 is used for force transmission connection between the second column 9.1 and the cover plate 7.1. (Reference) Figure 5The bridge unloading block 10.1 includes two clamping wedges 10.1.2 positioned at the top and bottom respectively in contact with the second column 9.1 and the base plate 7.2. Two symmetrical clamping wedges 10.1.3 are provided between the two clamping wedges 10.1.2. The wedge surface of the clamping wedge 10.1.3 can slide on the wedge surface of the clamping wedge 10.1.2. An adjusting piece 10.1.1 is provided between the two clamping wedges 10.1.3. By adjusting the distance between the two clamping wedges 10.1.3 through the adjusting piece 10.1.1, the wedge surfaces of the clamping wedges 10.1.3 and the clamping wedges 10.1.2 can slide, thereby adjusting the height of the bridge unloading block 10.1, so as to tighten or loosen the second column 9.1 within the cover plate 7.1 and the base plate 7.2.

[0056] refer to Figure 3 and Figure 4 The anchor 4 includes an anchor bolt 4.1 that vertically penetrates the cover plate 7.1. The two ends of the anchor bolt 4.1 are fixed to the upper force equalizing plate 6.1 and the lower force equalizing plate 6.2 respectively by nuts 4.2, which facilitates disassembly.

[0057] refer to Figure 1 For the support column 1 located away from the web 7.3 / side web 7.4, at least two second columns 9.1 are arranged symmetrically with the same distance between them to symmetrically distribute the vertical pressure on the support column 1. When the support column 1 is close to the web 7.3 / side web 7.4, the distance of the second column 9.1 from the support column 1 is the same as the distance of the support column 1 from the adjacent middle web 7.3 / side web 7.4. (Refer to...) Figure 1 This embodiment demonstrates a scheme in which the distance between the second column 9.1 and the support column 1 is the same as the distance between the support column 1 and the adjacent side web 7.4 when the support column 1 is close to the side web 7.4.

[0058] refer to Figure 8 and Figure 9 Construction method for the fixing structure of the main tower support column of a cable-stayed bridge without backstays:

[0059] Step A: Erect the second column 9.1, and use the bridge unloading block 10.1 to press the second column 9.1 tightly into the cover plate 7.1 and the base plate 7.2;

[0060] Step B: Install the upper force equalizing plate 6.1 and the lower force equalizing plate 6.2, and fix the upper force equalizing plate 6.1 to the support column 1;

[0061] Step C: Tension cable 3 according to the single-section pouring volume of main tower 11;

[0062] Repeat step C until the entire main tower section 11 is poured.

[0063] In step C, finite element analysis is performed based on the single-section casting volume of the main tower 11 to calculate the horizontal tension w generated by each support column 1 on the cover plate 7.1. The calculation formula for the tension of the three cables of each support column 1 is as follows:

[0064] F=w / cosα

[0065] In the formula, F is the tension force, w is the horizontal tension force, and α is the angle between the cable 3 and the plane of the cover plate 7.1.

[0066] The fixing structure and construction method of the main tower support column of the cable-stayed bridge without backstay provided in this embodiment increase the friction area between the upper force plate 6.1 and the lower force plate 6.2 connected by the anchor 4 to transmit force, thus reducing the friction force per unit area to resist the horizontal tension w, preventing the cover plate 7.1 of the concrete beam 7 from being cracked and damaged by the horizontal tension w. The cable 3 transmits the horizontal tension w and the friction force to resist the horizontal tension w between the upper force plate 6.1 and the lower force plate 6.2. The support column 1 transmits the horizontal tension to the upper force plate 6.1 through the force-transmitting fixing member 2.1, which also serves to fix the cable 3. The adjustable tightening member 10 tightens the vertical support member 9 within the cover plate 7.1 and the bottom plate 7.2 to prevent the cover plate 7.1 from being damaged due to excessive deflection under the vertical pressure of the support column 1.

[0067] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and 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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0068] 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 will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0069] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A fixing structure for the main tower support column of a cable-stayed bridge without backstays, characterized in that, It includes an upper force equalizing plate (6.1) and a lower force equalizing plate (6.2), the upper force equalizing plate (6.1) and the lower force equalizing plate (6.2) are respectively used to closely adhere to the top and bottom surfaces of the cover plate (7.1) of the concrete beam (7), and the upper force equalizing plate (6.1) is also used to fix it to the support column (1); It also includes anchors (4) for penetrating the cover plate (7.1), and the upper force equalizing plate (6.1) and the lower force equalizing plate (6.2) are connected by multiple anchors (4) for force transmission. It also includes an upper force-transmitting fixing member (2.1) provided on the upper force-equalizing plate (6.1) for force transmission connection with the support column (1), and a lower fixing member (2.2) provided on the lower force-equalizing plate (6.2). The upper force-transmitting fixing member (2.1) and the lower fixing member (2.2) are tensioned by a cable (3); the upper force-transmitting fixing member (2.1) and the lower fixing member (2.2) are arranged at an angle. When the fixing structure of the support column of the main tower of the cable-stayed bridge without backstay is connected to the support column (1), the upper force-transmitting fixing member (2.1) is closer to the support column (1) than the lower fixing member (2.2), and the upper force-transmitting fixing member (2.1) is further away from the root of the main tower (11) than the lower fixing member (2.2). It also includes at least one vertical support (9) for supporting the bottom plate (7.2) and the cover plate (7.1) of the concrete beam (7), and the vertical support (9) is further provided with an adjustable fastening member (10) between the bottom plate (7.2) and / or the cover plate (7.1).

2. The fixing structure of the main tower support column of the cable-stayed bridge without backstays according to claim 1, characterized in that, The anchor (4) includes an anchor bolt (4.1) that penetrates vertically through the cover plate (7.1). The two ends of the anchor bolt (4.1) are fixed to the upper force equalizing plate (6.1) and the lower force equalizing plate (6.2) respectively by nuts (4.2).

3. The fixing structure of the main tower support column of the cable-stayed bridge without backstays according to claim 1, characterized in that, When the fixing structure of the main tower support column of the cable-stayed bridge without backstay is connected to the support column (1), When the support column (1) is located at the center of a single box of the concrete beam (7), at least two of the vertical support members (9) are arranged symmetrically with respect to the support column (1) about the center. or, When the support column (1) is close to the middle web plate (7.3) / side web plate (7.4) of a single box of the concrete beam (7), the distance of the vertical support member (9) from the support column (1) is the same as the distance of the support column (1) from the adjacent middle web plate (7.3) / side web plate (7.4).

4. The fixing structure of the main tower support column of the cable-stayed bridge without backstays according to claim 1, characterized in that, The force-up fixing component (2.1) is the upper bracket (2.1.1), and the lower fixing component (2.2) is connected to the upper bracket (2.1.1). 2.1.1) Lower leg of the same specification (2.2.1).

5. The fixing structure of the main tower support column of the cable-stayed bridge without backstays according to claim 1, characterized in that, One end of the vertical support member (9) is provided with the adjustable top clamping member (10), while the other end is connected to the bottom plate (7.2) or the cover plate (7.1) through the support member pad (8).

6. The fixing structure of the main tower support column of the cable-stayed bridge without backstays according to claim 1, characterized in that, The vertical support (9) includes a second column (9.1).

7. The fixing structure of the main tower support column of the cable-stayed bridge without backstays according to claim 1, characterized in that, The adjustable clamping element (10) includes a bridge unloading block (10.1).

8. The construction method for the fixing structure of the main tower support column of the cable-stayed bridge without backstays as described in any one of claims 1 to 7, characterized in that, Step A: Install the vertical support (9), and use the adjustable clamping device (10) to clamp the vertical support (9) into the cover plate (7.1) and the base plate (7.2); Step B: Install the upper force equalizing plate (6.1) and the lower force equalizing plate (6.2), and fix the upper force equalizing plate (6.1) to the support column (1); Step C: Tension the cables (3) according to the single-section casting volume of the main tower (11); Repeat step C until the entire section of the main tower (11) is poured.

9. The construction method for the fixing structure of the main tower support column of the cable-stayed bridge without backstays according to claim 8, characterized in that, In step C, finite element analysis is performed based on the single-section casting volume of the main tower (11) to calculate the horizontal tension (w) generated by each support column (1) on the cover plate (7.1). The formula for calculating the tension of the cable (3) of each support column (1) is as follows: F=w / cosα In the formula, F is the tension force, w is the horizontal tension force, and α is the angle between the cable (3) and the plane of the cover plate (7.1).

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