A method for adjusting the linear shape of a cable-stayed suspension bridge

Abstract

The present application relates to a method for adjusting the linear shape of a cable-stayed suspension bridge system, wherein the cable length is adjusted by a cable anchoring structure provided on the bridge deck top plate to adjust the linear shape of the suspension area into a bridge; the cable anchoring structure includes a cable, an anchor cup connected to the cable, an anchor pad, a pressure plate provided opposite the anchor pad, a jack provided on the pressure plate, and a tension rod with one end passing through the pressure plate and the other end connected to the anchor cup; the cable is anchored to the anchor pad through the anchor cup; the jack is provided with a jack nut, which is connected to the tension rod; the distance from the jack nut to the end of the tension rod and the distance from the end of the tension rod to the bridge deck top plate meet the requirements of the cable length adjustment amount d; when the cable needs to be tensioned, d2>d; when the cable needs to be released, d1>d. The present invention provides a method for adjusting the linear shape of a cable-stayed suspension bridge system, wherein a cable anchoring structure capable of adjusting the cable length is provided to adjust the linear shape of the suspension area into a bridge, so as to provide sufficient cable length for adjustment.

Description

Technical Field

[0001] The present application relates to the technical field of bridge engineering, and in particular to a method for adjusting the bridge alignment of a suspension zone of a cable-stayed suspension system bridge. Background Art

[0002] A cable-stayed and cable-suspended bridge is a long-span bridge whose primary load-bearing structure is composed of stay cables and suspension cables. The alignment of the main beam in the cable-stayed area can be adjusted by tensioning the stay cables, while the alignment of the main beam in the suspension area can be adjusted by tensioning the suspension cables.

[0003] The main reason the completed alignment of a cable-stayed suspension bridge deviates from the designed alignment is the difference between the completed dead load and the theoretical dead load. Since the dead load is generally distributed uniformly along the longitudinal direction of the bridge, the difference between the completed dead load and the theoretical dead load can be considered a uniformly distributed load. The deviation range for the dead load can usually be calculated during the bridge design phase, and the required cable adjustment length can be calculated using a finite element model.

[0004] However, the calculation requires adjustment of the inclined cables and slings, which is a lot of work. In addition, if the calculated constant load deviation range is changed during the design phase, it needs to be recalculated, which makes the calculation efficiency very low.

[0005] On the other hand, in the suspension area of the cable-stayed suspension bridge system, the tensioning end of the cable is only located on the main beam, the tensioning space is limited, and the length of the anchor cup is also restricted by space. The cable anchoring structure on the main beam generally adopts a pin-connected type. Even if the finite element model is used to calculate the required adjustment length of the cable, it is relatively difficult to adjust the cable length. Summary of the Invention

[0006] The embodiment of the present application provides a method for adjusting the linear shape of a cable-stayed suspension bridge system to solve the technical problems in the related art of large amount of calculation and difficulty in adjusting the length of the suspension cables.

[0007] The embodiment of the present application provides a method for adjusting the linear shape of a cable-stayed suspension system bridge, wherein the suspension cable length is adjusted by a suspension cable anchoring structure provided on the top plate of the bridge deck to adjust the linear shape of the suspension area.

[0008] The sling anchoring structure includes a sling, an anchor cup connected to the sling, an anchor plate, a pressure plate arranged opposite to the anchor plate, a jack arranged on the pressure plate, and a tension rod with one end passing through the pressure plate and the other end connected to the anchor cup;

[0009] The sling is anchored to the anchor plate through the anchor cup;

[0010] The jack is provided with a jack nut, and the jack nut is connected to the tension rod;

[0011] The distance d1 from the jack nut to the end of the tension rod and the distance d2 from the end of the tension rod to the bridge deck top plate meet the requirements of the cable length adjustment amount;

[0012] The requirements for the sling length adjustment amount include: when the sling needs to be tensioned, d2>d; when the sling needs to be released, d1>d, d is the required sling length adjustment amount;

[0013] The calculation formula of the sling length adjustment amount d is:

[0014]

[0015] Where d is the required length adjustment of the sling, q is the weight of the main cable per meter along the longitudinal direction of the bridge, m is the weight of the main beam and slings per meter along the longitudinal direction of the bridge, dm is the dead load deviation, H is the theoretical horizontal force of the main cable without considering the dead load deviation, dH is the increment of the horizontal force of the main cable caused by the external load dm, x is the longitudinal distance between the sling and the nearest main tower, L is the span of the main bridge, and x0 is the length of the cable-stayed section.

[0016] In some embodiments, the calculation formulas for H and dH are:

[0017]

[0018]

[0019]

[0020]

[0021]

[0022] Where H is the theoretical horizontal force of the main cable without considering the dead load deviation, q is the weight of the main cable per meter along the longitudinal bridge direction, m is the weight of the main beam and suspender cable per meter along the longitudinal bridge direction, L is the main bridge span, x0 is the length of the cable-stayed section, f is the sag of the main cable, dm is the dead load deviation, dH is the horizontal force increment of the main cable caused by the external load dm, A, B, and C are all intermediate parameters, and E p is the elastic modulus of the main cable, A p The area of the main cable.

[0023] In some embodiments, the sling is provided with a sling nut, and the sling nut is threadedly connected to the anchor cup.

[0024] In some embodiments, the length of the anchor cup is adapted to the requirement of the sling length adjustment d, and the length of the anchor cup is at least greater than 2d plus the thickness of the sling nut.

[0025] In some embodiments, the jack is located between the bearing plate and the anchor plate.

[0026] In some embodiments, the jack nut is threadedly connected to the tension rod.

[0027] The beneficial effects of the technical solution provided by this application include:

[0028] The present application provides a method for adjusting the linear shape of a cable-stayed suspension system bridge, which provides a cable anchoring structure capable of adjusting the length of the cable. The cable length is adjusted to adjust the linear shape of the suspension area into a bridge, and relevant parameters are limited. It is required to control the distance d1 from the jack nut to the end of the tension rod and the distance d2 from the end of the tension rod to the bridge deck top plate in the cable anchoring structure to meet the requirements of the cable length adjustment amount. The cable length adjustment amount is calculated according to a formula to provide sufficient cable length during adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0030] Figure 1 Schematic diagram of the structure of the sling anchoring structure in one embodiment of the present invention.

[0031] Figure 2 1 is a top view of a sling anchoring structure according to an embodiment of the present invention.

[0032] Figure 3 Schematic diagram of a cable-stayed suspension bridge system according to one embodiment of the present invention.

[0033] Reference numerals:

[0034] 1. Bridge deck top plate; 2. Cable anchoring structure; 21. Cable; 211. Cable nut; 22. Anchor cup; 23. Anchor pad; 24. Pressure plate; 25. Jack; 251. Jack nut; 26. Tension rod. DETAILED DESCRIPTION

[0035] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0036] like Figure 1 and Figure 2 As shown, Figure 1 Schematic diagram of the structure of the sling anchoring structure in one embodiment of the present invention. Figure 2 1 is a top view of a sling anchoring structure according to an embodiment of the present invention.

[0037] The embodiment of the present application provides a method for adjusting the linear shape of a cable-stayed suspension system bridge, wherein the suspension cable length is adjusted by adjusting the suspension cable anchoring structure 2 provided on the bridge deck top plate 1 to adjust the linear shape of the suspension area.

[0038] The sling anchoring structure 2 includes a sling 21, an anchor cup 22 connected to the sling 21, an anchor plate 23, a pressure plate 24 arranged opposite to the anchor plate 23, a jack 25 arranged on the pressure plate 24, and a tension rod 26 with one end passing through the pressure plate 24 and the other end connected to the anchor cup 22;

[0039] The sling 21 is anchored to the anchor plate 23 through the anchor cup 22;

[0040] The jack 25 is provided with a jack nut 251, and the jack nut 251 is connected to the tension rod 26;

[0041] The distance d1 from the jack nut 251 to the end of the tension rod 26 and the distance d2 from the end of the tension rod 26 to the bridge deck top plate 1 meet the requirements of the cable length adjustment amount.

[0042] The requirements for the sling length adjustment amount include: when the sling 21 needs to be tensioned, d2>d; when the sling 21 needs to be released, d1>d, and d is the required sling length adjustment amount.

[0043] The calculation formula for the sling length adjustment d is:

[0044]

[0045] Where d is the required length adjustment of the sling, q is the weight of the main cable per meter along the longitudinal direction of the bridge, m is the weight of the main beam and slings per meter along the longitudinal direction of the bridge, dm is the dead load deviation, H is the theoretical horizontal force of the main cable without considering the dead load deviation, dH is the increment of the horizontal force of the main cable caused by the external load dm, x is the longitudinal distance between the sling and the nearest main tower, L is the span of the main bridge, and x0 is the length of the cable-stayed section.

[0046] An embodiment of the present application provides a method for adjusting the linear shape of a cable-stayed suspension system bridge, wherein a cable anchoring structure capable of adjusting the length of the cable is provided, and the suspension area is adjusted into the linear shape of the bridge by adjusting the length of the cable, and relevant parameters are limited. It is required to control the distance d1 from the jack nut to the end of the tension rod and the distance d2 from the end of the tension rod to the bridge deck top plate in the cable anchoring structure to meet the requirements of the cable length adjustment amount. The cable length adjustment amount is calculated according to the formula to facilitate providing sufficient cable length during adjustment.

[0047] In some embodiments, H and dH are calculated as follows:

[0048]

[0049]

[0050]

[0051]

[0052]

[0053] Where H is the theoretical horizontal force of the main cable without considering the dead load deviation, q is the weight of the main cable per meter along the longitudinal bridge direction, m is the weight of the main beam and suspender cable per meter along the longitudinal bridge direction, L is the main bridge span, x0 is the length of the cable-stayed section, f is the sag of the main cable, dm is the dead load deviation, dH is the horizontal force increment of the main cable caused by the external load dm, A, B, and C are all intermediate parameters, and E p is the elastic modulus of the main cable, A p The area of the main cable.

[0054] The following is the derivation process of the formula for the sling length adjustment amount d.

[0055] The required adjustment length of the sling 21 in the suspension area of the cable-stayed suspension system bridge is equivalent to calculating the deflection of the main beam under the action of the external load dm, the required adjustment length of the sling, and the deflection value of the main beam at the corresponding position without considering the stiffness of the cable and the main beam.

[0056] Due to symmetry, only half of the structure is calculated in this application.

[0057] Without considering the dead load deviation dm, the equation of the main cable is as follows:

[0058]

[0059]

[0060]

[0061] In the above formula: y1 is the main cable equation in the cable-stayed area, y2 is the main cable equation in the suspension area, q is the weight of the main cable per meter along the longitudinal direction of the bridge, m is the weight of the main beam and suspenders per meter along the longitudinal direction of the bridge, L is the main bridge span, H is the theoretical horizontal force of the main cable without considering the dead load deviation, and f is the sagittal height of the main cable.

[0062] Therefore, considering the external load dm, the equation after the main cable deformation should be:

[0063]

[0064]

[0065] In the above formula: y3 is the main cable equation in the cable-stayed area under the action of external load dm, y4 is the main cable equation in the suspension area under the action of external load dm, and dH is the horizontal force increment of the main cable caused by the external load dm.

[0066] Observe the above equation, the unknown variable is dH. Assuming that there is no tower deflection under the action of the external load dm, then the deformation of the main cables between the main towers along the longitudinal direction of the bridge is 0. This condition can be equivalent to the following equation:

[0067]

[0068] In the above formula: The angle between the main cable and the horizontal line.

[0069] Combining the above formulas, we can get:

[0070] CdH 2 +(CH-B)dH-A=0

[0071]

[0072]

[0073]

[0074] In the above formula, A, B, and C are all intermediate parameters, and E p is the elastic modulus of the main cable, A p The area of the main cable.

[0075] Solving the quadratic equation yields:

[0076]

[0077] therefore:

[0078]

[0079] In the above formula, d is the required length adjustment of the sling at a distance x from the main tower. Therefore, when the sling needs to be tensioned, d2>d, and when the sling needs to be released, d1>d.

[0080] In some embodiments, the sling 21 is provided with a sling nut 211, which is threadedly connected to the anchor cup 22. The sling 21 is supported on the anchor plate 23 by the sling nut 211. The threaded connection facilitates disassembly and installation and is easy to use.

[0081] In some embodiments, the length of the anchor cup 22 needs to adapt to the requirement of the cable length adjustment amount d. The cable 21 is connected to the bridge deck anchoring structure through the anchor cup 22 and the cable nut 211. The length of the cable 21 is adjusted by tensioning the anchor cup 22. Therefore, the length of the anchor cup 22 should be at least greater than 2×d plus the thickness of the cable nut 211.

[0082] In some embodiments, the jack 25 is located between the bearing plate 24 and the anchor plate 23. The tension rod 26 passes through the bearing plate 24 but is not connected to the bearing plate 24.

[0083] In some embodiments, the jack nut 251 is threadedly connected to the tension rod 26 and bears the pressure transmitted from the jack 25 to the pressure plate 24 .

[0084] When the jack 25 is working, the anchor cup 22 is forced to move downward through the combined action of the pressure plate 24, the jack nut 251 and the tension rod 26. When the required displacement is achieved, the sling nut 211 is moved and tightened with the anchor plate 23. After that, the tension rod 26, the pressure plate 24, the jack 25 and the jack nut 251 can be removed.

[0085] The present invention is described in detail below through a specific embodiment.

[0086] like Figure 3 As shown, Figure 3 Schematic diagram of a cable-stayed suspension bridge system according to one embodiment of the present invention.

[0087] There are 35 slings in total, with a spacing of 15m between them.

[0088] Other parameters: x0 = 239m, f = 152m, L = 988m; the area of a single main cable is 0.4915504m 2 ; Elastic modulus E of the main cable p Take 2x10 8 kn / m; the load borne by a single main cable is: q = 42.4657 kn / m; m = 400 kn / m, dm = 20 kn / m.

[0089] According to the calculation formula of this embodiment, when the bridge is completed, the horizontal force of the main cable H = 280030 kn, and the horizontal force increment of the main cable dH = 11878 kn.

[0090] If the finite element model is used for calculation, H = 279341 kn, with an error of 0.25%; dH = 11872 kn, with an error of 0.05%.

[0091] The length adjustment amount d required for the sling is calculated according to the calculation formula of this embodiment and the finite element model. The results are shown in Table 1.

[0092] Table 1 Calculation results

[0093] Sling length x(m) This application d (mm) Finite element model d(mm) error 239 80.9 82.4 1.8％ 254 96.6 97.0 0.4％ 269 111.3 111.0 -0.3％ 284 125.1 124.3 -0.6％ 299 137.9 136.9 -0.7％ 314 149.8 148.7 -0.7％ 329 160.7 159.8 -0.6％ 344 170.7 170.0 -0.4％ 359 179.7 179.4 -0.2％ 374 187.8 187.9 0.1％ 389 194.9 195.4 0.3％ 404 201.1 202.0 0.5％ 419 206.3 207.7 0.7％ 434 210.6 212.3 0.8％ 449 213.9 215.9 1.0％ 464 216.2 218.5 1.1％ 479 217.7 220.1 1.1％ 494 218.1 220.7 1.2％

[0094] Table 1 shows that when calculating the required sling length adjustment d, the maximum error between the calculation formula according to this embodiment and the finite element model calculations in related techniques is approximately 1.8%, indicating a very similar result. Consequently, using the sling anchor structure provided in this application to adjust the sling length and adjust the suspension area of a cable-stayed suspension bridge to the bridge alignment facilitates adjustment, significantly reduces computational workload, and improves computational efficiency.

[0095] In the description of this application, it should be noted that the orientation or positional relationship indicated by the terms "upper" and "lower" is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the method or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. Unless otherwise clearly specified and limited, the terms "install", "connect", and "connect" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0096] It should be noted that, in this application, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0097] The above are merely specific embodiments of the present application, which will enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but rather will conform to the widest scope consistent with the principles and novel features of the present application.

Claims

1. A method for adjusting the linear shape of a cable-stayed suspension bridge, characterized in that: The suspension cable length is adjusted by a suspension cable anchoring structure (2) provided on the bridge deck top plate (1) to adjust the suspension area into a bridge line shape; The sling anchoring structure (2) comprises a sling (21), an anchor cup (22) connected to the sling (21), an anchor pad (23), a pressure plate (24) arranged opposite to the anchor pad (23), a jack (25) arranged on the pressure plate (24), and a tension rod (26) with one end passing through the pressure plate (24) and the other end connected to the anchor cup (22); The sling (21) is anchored on the anchor plate (23) through the anchor cup (22); The jack (25) is provided with a jack nut (251), and the jack nut (251) is connected to the tension rod (26); The distance d1 from the jack nut (251) to the end of the tension rod (26) and the distance d2 from the end of the tension rod (26) to the bridge deck top plate (1) meet the requirements of the sling length adjustment amount; The requirements for the sling length adjustment amount include: when the sling needs to be tensioned, d2>d; when the sling needs to be released, d1>d, d is the required sling length adjustment amount; The calculation formula of the sling length adjustment amount d is: Where d is the required length adjustment of the sling, q is the weight of the main cable per meter along the longitudinal direction of the bridge, m is the weight of the main beam and slings per meter along the longitudinal direction of the bridge, dm is the dead load deviation, H is the theoretical horizontal force of the main cable without considering the dead load deviation, dH is the increment of the horizontal force of the main cable caused by the external load dm, x is the longitudinal distance between the sling and the nearest main tower, L is the span of the main bridge, and x0 is the length of the cable-stayed section.

2. The linear adjustment method of a cable-stayed suspension bridge according to claim 1, characterized in that: The calculation formulas for H and dH are: Where H is the theoretical horizontal force of the main cable without considering the dead load deviation, q is the weight of the main cable per meter along the longitudinal bridge direction, m is the weight of the main beam and suspender cable per meter along the longitudinal bridge direction, L is the main bridge span, x0 is the length of the cable-stayed section, f is the sag of the main cable, dm is the dead load deviation, dH is the horizontal force increment of the main cable caused by the external load dm, A, B, and C are all intermediate parameters, and E p is the elastic modulus of the main cable, A p The area of the main cable.

3. The linear adjustment method of a cable-stayed suspension bridge according to claim 1, characterized in that: The sling (21) is provided with a sling nut (211), and the sling nut (211) is threadedly connected to the anchor cup (22).

4. The linear adjustment method of a cable-stayed suspension bridge according to claim 2, characterized in that: The length of the anchor cup (22) is adapted to the requirement of the sling length adjustment amount d, and the length of the anchor cup (22) is at least greater than 2d plus the thickness of the sling nut (211).

5. The linear adjustment method of a cable-stayed suspension bridge according to claim 1, characterized in that: The jack (25) is located between the pressure plate (24) and the anchor plate (23).

6. The linear adjustment method of a cable-stayed suspension bridge according to claim 1, characterized in that: The jack nut (251) is threadedly connected to the tension rod (26).

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