Anchoring system and method of designing the same

Abstract

The present application relates to the technical field of suspension bridge, and particularly relates to an anchoring system and a design method thereof, the anchoring system comprising a composite saddle and an anchorage, a main cable is connected with the anchorage through the composite saddle, a first front anchoring surface of the anchorage close to the composite saddle is in a spherical shape, the main cable is diverged into a plurality of strands through the composite saddle, and the strands are radiated from the composite saddle and connected on the first front anchoring surface. By setting the first front anchoring surface of the anchorage in a spherical shape, the stress increment of each strand is consistent when the composite saddle is displaced and slipped, and the consistency of the stress of the main cable is ensured. Further, by setting the first front anchoring surface in a spherical shape, the adjusting displacement of the composite saddle is not limited, that is, the stress level among the strands of the main cable is consistent under any displacement of the composite saddle, the stress adjusting step of the strands in the construction process is cancelled, the stress state of the main cable is ensured, and the uniform stress of the main cable is further ensured.

Description

Technical Field

[0001] This invention relates to the field of suspension bridge technology, and in particular to an anchoring system and its design method. Background Technology

[0002] With the development of bridge construction technology, towerless suspension bridges have emerged. Towerless suspension bridges are suitable for high-intensity earthquake zones because it is difficult to set up the main towers of conventional suspension bridges in mountainous valleys with steep slopes, and it is often impossible to set up side spans. This requires selecting a saddle platform at a suitable location above the elevation of the line to directly anchor the main cable into the rock mass, and the main beam directly connects to the tunnel portal. Such a structure is a towerless suspension bridge. For example, Chinese patent application CN211472118U discloses a cable-beam stiffened towerless suspension bridge, which specifically discloses: including a main cable and a main beam below it. The main beam is suspended from the main cable by vertical hangers. Vertical main beam supports are set at both ends of the main beam. The two ends of the main cable are directly anchored into the rock mass through an anchoring system.

[0003] Since the main cable saddle and the branch cable saddle of the towerless suspension bridge are no longer arranged separately, but are combined into a composite cable saddle, as disclosed in Chinese Patent Publication No. CN204455822U, a composite cable saddle for suspension bridges and a suspension bridge constructed using the composite cable saddle are disclosed. Specifically, the composite cable saddle can support, turn and diverge the main cable, thus realizing the supporting function of the main cable saddle and the diverging function of the branch cable saddle with one component.

[0004] However, the change in the composite cable saddle structure brings new problems to the anchorage system: Conventional towerless suspension bridges require the composite cable saddle to simultaneously turn and release the main cable. Compared to the release saddle of traditional suspension bridges, the main cable's turning angle is significantly increased. With this increased turning angle, when the composite cable saddle undergoes displacement (during the bridge's construction process from empty cable to completed bridge, and under live load during bridge operation), the traditional first front anchorage setting method, such as... Figures 1-2 As shown, the main cable 1 is distributed into several strands 101 via the composite saddle 6. The strands 101 are connected to the traditional front anchor face 100 of the anchor 7. The traditional front anchor face 100 is an inclined plane. When the composite saddle undergoes displacement or slippage, the different strands 101 have different amounts of expansion and contraction due to the inclined plane of the traditional front anchor face 100. This results in significant differences in stress between the strands 101, causing uneven stress distribution. The difference can reach 6% to 10%, requiring multiple adjustments during construction. Otherwise, slippage between the strands will occur, affecting the uniformity of the main cable's stress distribution, altering the main cable's alignment, and impacting the normal operation of the bridge. Summary of the Invention

[0005] The purpose of this invention is to address the problem in conventional towerless suspension bridges in the background art where displacement or slippage of the composite cable saddle occurs. Because the traditional front anchor surface is a sloping plane, the strain increments of different cable strands differ during the movement of the composite cable saddle, leading to significant differences in stress between the cable strands. This results in uneven stress distribution, requiring multiple adjustments during construction; otherwise, slippage between cable strands will occur, affecting the uniformity of the main cable's stress, altering the main cable's alignment, and impacting the normal operation of the bridge. This invention provides an anchoring system and its design method.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] An anchoring system includes a composite saddle and an anchor. The main cable is connected to the anchor via the composite saddle. The side of the anchor closest to the composite saddle is a first front anchor face, which is spherical. The main cable branches off into several strands via the composite saddle, and each strand branches off from the composite saddle in a radial pattern and connects to the first front anchor face.

[0008] The anchoring system described in this invention has a first front anchor surface on the side of the anchor near the composite cable saddle. The first front anchor surface is spherical. The main cable branches out into several strands through the composite cable saddle. The strands all radiate out from the composite cable saddle in a radial pattern and connect to the first front anchor surface. When a composite cable saddle experiences displacement or slippage, the traditional inclined front anchor surface leads to varying degrees of expansion and contraction among different strands, resulting in significant differences in stress between the strands and causing uneven stress distribution. By setting the first front anchor surface of the anchorage to a spherical shape, the stress variables of each strand are made consistent during displacement or slippage of the composite cable saddle, ensuring consistent stress distribution on the main cable. Furthermore, by setting the first front anchor surface to a spherical shape, the adjustment displacement of the composite cable saddle is unrestricted. This means that under any displacement, the stress level among the strands of the main cable remains consistent, eliminating the need for manual adjustments. This ensures the stress state of the main cable, simplifies the construction process, optimizes the stress distribution on the operating main beam, and ultimately guarantees uniform stress distribution on the bridge's main cable.

[0009] Preferably, among the plurality of cable strands, there is a central cable strand, which is divided into a main cable section cable strand and a diverging section cable strand. The intersection of the extension line of the main cable section cable strand and the extension line of the diverging section cable strand is the first intersection point A1. The point where the central cable strand is anchored on the anchor is the first anchor point B1. The extension line of the moving direction of the composite cable saddle is set as the first extension line. The first extension line is located in a vertical plane and passes through the first intersection point A1. The first front anchor surface is a sphere whose center is located on the first extension line and passes through the first intersection point A1 and the first anchor point B1.

[0010] Preferably, the end of the composite saddle furthest from the anchorage supports the main cable, while the end closest to the anchorage diverges the main cable. The composite saddle is movable along the length of the main cable. By supporting the main cable at the end furthest from the anchorage, the main cable can be turned at the composite saddle. The divergence of the main cable at the end closest to the anchorage causes it to split into several strands after passing through the composite saddle, facilitating the anchoring of these strands to the anchorage and thus securing the end of the main cable. Furthermore, during bridge construction, as the main cable is erected and the main beam is installed, changes in the bridge alignment can be addressed by the composite saddle's ability to move along the length of the main cable, releasing longitudinal constraints and enabling adaptive adjustment. The internal force of the main cable is adjusted so that the composite cable saddle can adapt to the displacement of the composite cable saddle caused by the construction process from empty cable to completed bridge and the live load during the operation of the completed bridge. Furthermore, in conjunction with the first front anchor surface of this application, the main cable can adapt to the expansion and contraction deformation of the main cable caused by the construction process from empty cable to completed bridge and the live load during the operation of the completed bridge. That is, when the main cable undergoes displacement or slippage in the composite cable saddle, the stress of the cable strands adapts to maintain the stress consistency of each cable strand, thereby ensuring that the main cable is subjected to uniform force, thus ensuring the normal operation of the bridge and avoiding artificial adjustments during construction.

[0011] Preferably, the composite cable saddle includes a saddle body and rollers, with the saddle body moving along the length of the main cable via the rollers. During construction, as the main cable is erected and the main girder is installed, the saddle body gradually moves towards the mid-span along the length of the main cable via the bottom rollers. In other words, the composite cable saddle gradually moves towards the mid-span along the longitudinal direction of the bridge. This process is adaptive and does not require additional jacking operations, allowing the composite cable saddle to move along the length of the main cable to adapt to changes in the internal forces of the main cable.

[0012] Preferably, the saddle body is provided with a saddle groove, the side of the saddle groove facing the anchor is a diverging section saddle groove, and the side of the saddle groove away from the anchor is a main cable section saddle groove. The main cable section saddle groove smoothly transitions to the diverging section saddle groove along the length direction of the main cable. The main cable section saddle groove is used to support the main cable and to turn the main cable, and the diverging section saddle groove is used to diverge the main cable.

[0013] Preferably, the anchor includes a front anchor chamber and an anchor plug, with the end of the front anchor chamber away from the composite cable saddle connected to the anchor plug, and the cable strand located in the front anchor chamber.

[0014] This application also discloses a design method for an anchoring system, which includes the following steps:

[0015] S1: Determine the first incident angle θ1 of the composite cable saddle according to the overall bridge design;

[0016] S2: Determine the first launch angle θ2 of the composite cable saddle;

[0017] S3: Calculate the main cable stress increment based on the completed bridge cable force and the unloaded cable force;

[0018] S4: Determine the length L of the central strand;

[0019] S5: Determine the spherical parameters of the first front anchor surface;

[0020] S6: Calculate the displacement of the composite saddle based on the main cable stress increment, main cable angle, and the length of the front anchor chamber, and select the composite saddle accordingly.

[0021] The present invention discloses a design method for an anchoring system. First, the first incident angle and the first exit angle of the composite cable saddle are determined. Then, the stress increment of the main cable is calculated based on the cable force of the completed bridge and the unloaded cable force. Next, the length L of the central cable strand is determined. Then, the spherical parameters of the first front anchor surface are determined. Finally, the displacement of the composite cable saddle is calculated based on the stress increment of the main cable, the angle of the main cable, and the length of the front anchor chamber. The composite cable saddle is then selected, thus completing the anchoring system design. Through the composite cable saddle in conjunction with the first front anchor surface, the main cable can adapt to the expansion and contraction deformation of the main cable caused by the bridge construction process from unloaded cable to completed bridge and the live load during bridge operation. That is, when the main cable undergoes displacement or slippage in the composite cable saddle, the stress of the cable strands is adaptively adjusted to maintain consistent stress in each strand, thereby ensuring uniform stress on the main cable and guaranteeing normal bridge operation, avoiding manual adjustments during construction.

[0022] Preferably, in S4: the length of the center strand is determined based on the main cable stress increment, geological conditions, and the required burial depth of the anchor plug.

[0023] Preferably, in S5: the point where the central strand is anchored to the anchor is the first anchor point, i.e., point B1; the intersection of the extension line of the main cable strand and the extension line of the diverging strand is the first intersection point, i.e., point A1; the first extension line intersects the sphere at the second intersection point, i.e., point C1; and the diameter A1C1 = A1B1 / cosθ2.

[0024] Preferably, the first incident angle is the angle between the main cable and the moving direction of the composite saddle;

[0025] The first emission angle is the angle between the central cable strand and the direction of movement of the composite cable saddle;

[0026] The first incident angle and the first exit angle should preferably be the same. If the angles are different, the overall tilt angle of the composite cable saddle can be adjusted so that the moving direction of the composite cable saddle is perpendicular to the bisector of the third angle between the main cable and the central cable strand.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1. The anchoring system of the present invention has a first front anchor surface on the side of the anchor near the composite cable saddle. The first front anchor surface is spherical. The main cable is branched into several strands through the composite cable saddle. The strands are all radially branched out from the composite cable saddle and connected to the first front anchor surface. When a composite cable saddle experiences displacement or slippage, the traditional inclined front anchor surface leads to varying degrees of expansion and contraction among different strands during saddle movement. This results in significant differences in stress between the strands. In towerless suspension bridges, the main cable rotation angle is relatively large, with differences reaching 6% to 10%. Uneven stress in the strands reduces the overall integrity of the main cable and can even cause relative slippage between strands. By setting the first front anchor surface of the anchorage to a spherical shape, the stress variables of each strand are consistent when the composite cable saddle experiences displacement or slippage, ensuring consistent stress on the main cable. Furthermore, by setting the first front anchor surface to a spherical shape, the adjustment displacement of the composite cable saddle is unrestricted. This means that under any displacement, the stress level between the strands of the main cable remains consistent, ensuring the stress state of the main cable, simplifying the construction process, and ultimately guaranteeing uniform stress on the main cable of the bridge.

[0029] 2. The anchoring system of this invention supports the main cable at the end of the composite saddle furthest from the anchorage, thereby enabling the main cable to turn at the composite saddle. The main cable is then branched out at the end of the composite saddle closest to the anchorage, splitting into several strands after passing through the composite saddle. This facilitates the anchoring of the strands to the anchorage, thus securing the end of the main cable. Furthermore, during bridge construction, as the main cable is erected and the main beam is installed, when the alignment of the main cable changes, the composite saddle can move along the length of the main cable, allowing it to move along the longitudinal direction of the bridge. Sliding releases longitudinal bridge constraints, enabling adaptive adjustment of the main cable's internal forces. This allows the composite cable saddle to adapt to the displacement of the composite cable saddle caused by the bridge's construction process from empty cable to completed bridge and the live load during bridge operation. Furthermore, in conjunction with the first front anchor surface of this application, the main cable can adapt to the expansion and contraction deformation of the main cable caused by the bridge's construction process from empty cable to completed bridge and the live load during bridge operation. That is, when the main cable undergoes displacement or slippage in the composite cable saddle, the stress of the cable strands adapts to maintain consistency among the strands, thereby ensuring uniform stress on the main cable and thus guaranteeing normal bridge operation, avoiding manual adjustments during construction.

[0030] 3. The present invention provides a design method for an anchoring system, which first determines the first incident angle and the first exit angle of the composite cable saddle, then calculates the main cable stress increment based on the cable force of the completed bridge and the cable force of the empty cable, then determines the length L of the central cable strand, then determines the spherical parameters of the first front anchor surface, and calculates the displacement of the composite cable saddle based on the main cable stress increment, the main cable angle, and the length of the front anchor chamber, and selects the composite cable saddle to complete the anchoring system design. The present invention provides the force mechanism and design steps of the spherical front anchor surface anchoring system, which is convenient for engineers to apply. Attached image description:

[0031] Figure 1 This is a schematic diagram of a towerless suspension bridge.

[0032] Figure 2 This is a schematic diagram of a traditional front anchor surface in the background technology.

[0033] Figure 3 This is a schematic diagram of the anchoring system described in this invention.

[0034] Figure 4 This is a schematic diagram of the combination of the central cable strand and the composite cable saddle.

[0035] Figure 5 This is a schematic diagram of the first front anchor surface of this application.

[0036] Figure 6 yes Figure 5 A magnified view of a portion at point F.

[0037] Figure 7 This is a schematic diagram of the composite cable saddle adjusting the first incident angle and the first exit angle.

[0038] Figure 8 This is a schematic diagram of the specific structure of the anchoring system of the present invention.

[0039] Figure 9 This is a front view of a composite cable saddle.

[0040] Figure 10 yes Figure 9 Detailed drawing at point C.

[0041] Figure 11 This is a top view of the composite cable saddle.

[0042] Figure 12 This is a schematic diagram of the first front anchor surface principle. Figure 1 .

[0043] Figure 13 This is a schematic diagram of the first front anchor surface principle. Figure 2 .

[0044] Figure 14 This is a schematic diagram of the first front anchor surface principle. Figure 3 .

[0045] Figure 15 This is a schematic diagram of the first front anchor surface principle. Figure 4 .

[0046] Figure 16 This is a schematic diagram of the first front anchor surface principle. Figure 5 .

[0047] The markings in the diagram are as follows: 1-Main cable, 101-Strand, 1011-Central strand, 1012-Branching strand, 1013-Main cable strand, 2-Main beam, 3-Suspension cable, 4-Abutment, 6-Composite saddle, 61-Saddle body, 62-Grid, 63-Roller, 64-Lower bearing plate, 65-Upper bearing plate, 66-Saddle groove, 661-Main cable saddle groove, 662-Branching saddle groove, 7-Anchorage, 71-First front anchor face, 72-Front anchor chamber, 73-Anchor plug, 74-Anchorage opening, 8-Pile foundation, 81-Pile foundation, 82-Pile foundation, 9-Tunnel, 10-Slope, 80-Spherical surface, 90-First extension line, 100-Traditional front anchor face. Detailed Implementation

[0048] The present invention will be further described in detail below with reference to embodiments and specific implementation methods. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0049] Example 1

[0050] like Figure 1 As shown, the current towerless suspension bridge includes a main cable 1 and a main beam 2. The end of the main cable 1 is connected to the anchorage 7 via a composite cable saddle 6. The anchorage 7 is set on the slopes 10 on both sides of the canyon. The main beam 2 is connected to the main cable 1 below via a suspension cable 3. Abutments 4 are set at both ends of the main beam 2. The abutments 4 are used to support the main beam 2. The main beam 2 is used to connect the tunnels 9 located in the mountains on both sides of the canyon.

[0051] like Figure 3 As shown, this embodiment of an anchoring system includes a composite saddle 6 and an anchor 7. The main cable 1 is connected to the anchor 7 through the composite saddle 6. The side of the anchor 7 closest to the composite saddle 6 is a first front anchor surface 71, which is spherical. The main cable 1 branches out into several strands 101 through the composite saddle 6. All strands 101 radiate out from the composite saddle 6 in a radial pattern and are connected to the first front anchor surface 71.

[0052] When the composite saddle 6 undergoes displacement or slippage, the traditional front anchor surface 100 is an inclined plane, resulting in different amounts of expansion and contraction of the different strands 101 during the movement of the composite saddle 6. This leads to significant differences in stress among the strands 101, causing uneven stress distribution and affecting the overall stress distribution of the main cable, potentially even causing slippage between the strands 101. By setting the first front anchor surface 71 of the anchor 7 to a spherical shape, the stress variables of each strand 101 are consistent when the composite saddle 6 undergoes displacement or slippage, ensuring the consistency of the stress distribution on the main cable 1. Furthermore, by setting the first front anchor surface 71 to a spherical shape, the adjustment displacement of the composite saddle 6 is unrestricted. That is, under any displacement, the stress level among the strands 101 of the main cable 1 is consistent, eliminating the need for manual adjustment. This eliminates the stress adjustment step of the strands 101 during construction, ensuring the stress state of the main cable 1, simplifying the construction process, and thus guaranteeing the uniform stress distribution on the main cable 1.

[0053] like Figure 4 , Figure 5 As shown, among the several strands 101, there is a central strand 1011, such as Figure 6 As shown, the central cable strand 1011 is divided into the main cable section strand 1013 and the diverging section strand 1012. The intersection of the extension line of the main cable section strand 1013 and the extension line of the diverging section strand 1012 is the first intersection point, i.e., point A1. The point where the central cable strand 1011 is anchored on the anchor 7 is the first anchor point, i.e., point B1. The extension line of the moving direction of the composite cable saddle 6 is set as the first extension line 90. The first extension line 90 is located in the vertical plane where the central cable strand 1011 is located and passes through the first intersection point (point A1). The first front anchor surface 71 is a spherical surface 80 whose center is located on the first extension line 90 and passes through the first intersection point (point A1) and the first anchor point (point B1).

[0054] In this embodiment, the length direction of the main cable 1 refers to the longitudinal direction of the bridge.

[0055] like Figure 5 , Figure 12 As shown, the principle is explained using the single central strand 1011 of the main cable 1 after it has been untied:

[0056] exist Figure 12 In the diagram, point A2 represents the position of point A1 after the composite saddle 6 has moved, and the direction of extension of A1A2 represents the sliding direction of the composite saddle 6.

[0057] During bridge construction, as the main cable 1 is erected and the main beam 2 is installed, when the bridge alignment changes, the composite cable saddle 6 can move along the length of the main cable 1, thereby releasing the displacement along the length of the main cable 1 to adapt to the adjustment of the internal force of the main cable 1. In this process, A1B1 is the length of the central cable strand 1011 before the movement. After the composite cable saddle 6 moves from point A1 to point A2, A2B1 is the length of the central cable strand 1011 after the movement. A point A3 is taken on A2B1, and A3B1 is made equal to A1B1.

[0058] like Figure 13 As shown, A1A2 represents the sliding distance of the composite cable saddle 6, and the direction of the line connecting A1A2 is the sliding direction of the composite cable saddle 6. In this embodiment, it faces to the right, and the right side is the direction closer to the main beam 2. θ is the angle between A1B1 and the sliding direction of the composite cable saddle 6, that is, the angle between the extension direction of the central cable strand 1011 and A1A2.

[0059] For clarity, Figure 12 For illustrative purposes only. Figure 12 The length ratios of the line segments are not actual ratios. In the actual movement of the composite saddle 6, the sliding distance A1A2 is much smaller than the length A1B1 of the central cable strand 1011 before movement. It can be assumed that the angles between A1B1 and the sliding direction of the composite saddle 6, and between A2B1 and the sliding direction of the composite saddle 6, are both θ. Connecting A1A3, since the sliding distance A1A2 is much smaller than the length A1B1 (A3B1) of the central cable strand 1011 before movement, it can be assumed that A1A3 is perpendicular to A2B1. Figure 13 ;

[0060] like Figure 13 As shown, after the composite saddle 6 moves, let the sliding distance A1A2 = dx.

[0061] dy = A2B1 - A3B1 = A2B1 - A1B1,

[0062] That is, dy is the increase in length of the central cable strand 1011 after the central cable strand 1011 moves dx in the composite cable saddle 6;

[0063] The increased length of the central strand 1011 is dy = dx·cosθ, as shown below. Figure 13 As shown, let A1B1 = L, then the stress increment of the central cable strand 1011 after sliding is dσ.

[0064] dσ=E·dε=E·(dy / L)=E·dx·cosθ / L,

[0065] Where E is the elastic modulus of a single cable strand 101, and dε is the strain increment of a single cable strand 101.

[0066] Since the material and model of each strand 101 of the main cable 1 are the same, E and dx are the same for strands 101 at different positions, while angle θ and length L are variables. If the stress increment of all strands 101 is to be consistent, then cosθ / L of different strands needs to be constant.

[0067] like Figure 14 As shown, extend line A1C1 along the moving direction of the composite saddle 6 from A1A2. Draw a circle with diameter A1C1, centering on O1, and place point B1 on the circle. Connect B1C1, as shown. Figure 15 Let the length of A1C1 be Y, and L = Y·cosθ. Substituting L = Y·cosθ into the formula dσ = E·dx·cosθ / L, we get:

[0068] dσ=E·dx / Y,

[0069] For different positions of the 101 stock, such as Figure 16 As shown, when A1B1 represents cable strands 101 at different positions, B1 is the point where cable strands 101 at different positions intersect with a circle with A1C1 as the diameter. Since E and dx have the same value, when Y is the diameter length of A1C1, that is, B1 is in a sphere with A1C1 as the diameter (considering three dimensions as a sphere, considering two dimensions as a circle), regardless of the value of the slip distance dx, the dx / Y of each cable strand 101 is the same value. The stress increment dσ of different cable strands 101 is the same, that is, it can be realized that when the composite cable saddle 6 is displaced, the stress variables of each cable strand 101 are consistent, ensuring the consistency of the force on the main cable 1.

[0070] Therefore, when B1 is on a circle with diameter A1C1, the dx / Y of each strand 101 is the same value. Furthermore, when B1 is on a sphere with diameter A1C1, the dx / Y of each strand 101 is also the same value. Therefore, when the strand 101 is anchored on a sphere with diameter A1C1, the stress variables of each strand 101 are consistent when the composite saddle 6 is displaced, thus ensuring the consistency of the force on the main cable 1.

[0071] In this application, to facilitate the identification of the sphere with diameter A1C1, and using the central cable strand 1011 as a reference, the extension line of the moving direction of the composite cable saddle 6 is designated as the first extension line 90, and the first extension line 90 passes through the first intersection point (point A1) in the vertical plane where the central cable strand 1011 is located. The first extension line 90 is A1C1. Figure 5 Therefore, it is concluded that the first front anchor surface 71 is a sphere 80 whose center is located on the first extension line 90 (i.e., A1C1) and passes through the first intersection point (point A1) and the first anchor point (point B1).

[0072] The first extension line 90 can also be understood as: the extension line of the composite saddle 6 in the vertical plane where the central cable strand 1011 is located, passing through the first intersection point (point A1), in the direction of movement.

[0073] The first forward anchor 71 is further explained below:

[0074] In actual construction, the range of movement values ​​A1A2 of the composite cable saddle 6 is first confirmed in advance, that is, the range of pre-offset values ​​of the composite cable saddle 6. During construction, the composite cable saddle is first offset towards the first front anchor surface 71 by the construction pre-offset value. As the main cable 1 is erected and the main beam 2 is installed, the cable saddle body 61 gradually moves towards the mid-span along the length direction of the main cable 1 through the bottom roller 63. After the bridge construction is completed, the cable saddle is in the theoretical design position. This process is an adaptive process and does not require the additional jacking operation in the traditional suspension bridge construction process. This allows the composite cable saddle 6 to release the displacement along the length direction of the main cable 1, and allows the composite cable saddle 6 to adaptively adjust the internal force of the main cable. Furthermore, since the first front anchor surface 71 is arranged as the spherical surface described in this implementation, the stress variables of each cable strand 101 are consistent when the composite cable saddle 6 undergoes displacement, ensuring the consistency of the force on the main cable 1.

[0075] A preferred method, such as Figures 8-9 As shown, the end of the composite saddle 6 furthest from the anchor 7 supports the main cable 1, while the end of the composite saddle 6 near the anchor 7 disperses the main cable 1. The composite saddle 6 can move along the length of the main cable 1. By supporting the main cable 1 at the end of the composite saddle 6 near the main beam 2, the main cable 1 can be turned at the composite saddle 6. By dispersing the main cable 1 at the end of the composite saddle 6 near the anchor 7, the main cable 1 disperses into several strands 101 after passing through the composite saddle 6. The dispersed strands 101 are then anchored to the anchor 7, thus fixing the end of the main cable 1. Furthermore, during bridge construction, as the main cable 1 is erected and the main beam 2 is installed, the composite saddle 6 can move along the length of the main cable 1, thereby releasing the displacement along the length of the main cable 1 and adapting to stress changes in the main cable 1.

[0076] In a preferred embodiment, as shown in the figure, the composite cable saddle 6 includes a saddle body 61 and a roller 63. The saddle body 61 moves along the length of the main cable 1 via the roller 63. During construction, as the main cable 1 is erected and the main beam 2 is installed, the saddle body 61 gradually moves towards the mid-span along the length of the main cable 1 via the bottom roller 63. This process is adaptive and does not require additional jacking operations.

[0077] A preferred method, such as Figure 9As shown, the cable saddle body 61 is provided with a saddle groove 66. The side of the saddle groove 66 facing the anchor 7 is the diverging section saddle groove 662, and the side of the saddle groove 66 facing the main beam 2 is the main cable section saddle groove 661. The main cable section saddle groove 661 smoothly transitions to the diverging section saddle groove 662 along the length direction of the main cable 1. The main cable section saddle groove 661 is used to support the main cable 1, and the diverging section saddle groove 662 is used to diverge the main cable 1.

[0078] like Figure 10 As shown, the bottom of the main cable section saddle groove 661 has multiple rope grooves, and the bottom surface of each rope groove forms a stepped surface at the bottom of the main cable section saddle groove 661. The bottom surface of each rope groove changes with the same radius of curvature from the inside to the outside along the length direction of the main cable 1. The bottom of the diverging section saddle groove 662 has multiple rope grooves, and the bottom surface of each rope groove forms a stepped surface at the bottom of the diverging section saddle groove 662. The bottom surface of each rope groove changes with a smooth decreasing radius of curvature from the inside to the outside along the length direction of the main cable 1. The rope grooves of the main cable section saddle groove 661 smoothly transition to the rope grooves of the diverging section saddle groove 662 along the length direction of the main cable 1. The two side walls of the main cable section saddle groove 661 are vertically parallel facade structures, while the two side walls of the diverging section saddle groove 662 are outwardly expanding arc structures that smoothly and gradually change from the inside to the outside.

[0079] A preferred method, such as Figure 8 As shown, the composite cable saddle 6 is installed on the pile cap foundation 8, which includes a pile cap 81 and pile foundation 82, with the pile foundation 82 located at the lower part of the pile cap 81.

[0080] In a preferred manner, if the foundation construction conditions are good, pile foundation 82 may not be required, and instead an enlarged foundation may be used, i.e., the pile cap foundation 8 adopts an enlarged foundation.

[0081] like Figure 10 As shown, the composite cable saddle 6 is installed on the bearing platform 81. A grid 62 is pre-embedded inside the bearing platform 81. Then, the lower bearing plate 64 of the composite cable saddle 6 is fixedly installed on the grid 62. Multiple rollers 63 are set between the lower bearing plate 64 and the upper bearing plate 65. The cable saddle body 61 is connected above the upper bearing plate 65, so that the cable saddle body 61 can move along the length of the main cable 1 on the bearing platform 81. This not only facilitates the installation of the composite cable saddle 6, but also facilitates the adjustment of the internal force of the main cable 1 during construction.

[0082] A preferred method, such as Figure 8As shown, the anchorage 7 includes a front anchor chamber 72, an anchor plug body 73, and an anchorage opening 74. The end of the front anchor chamber 72 near the composite cable saddle 6 is connected to the anchorage opening 74, and the end of the front anchor chamber 72 away from the composite cable saddle 6 is connected to the anchor plug body 73. Cable strands 101 are located inside the front anchor chamber 72. Both the front anchor chamber 72 and the anchorage opening 74 are hollow structures, and the anchorage opening 74 is installed on the pier foundation 8. The composite cable saddle 6 is located inside the anchorage opening 74. Several cable strands 101 radiate from the composite cable saddle 6 and pass through the hollow area of ​​the front anchor chamber 72 before being anchored to the first front anchor surface 71 of the anchor plug body 73, thereby realizing the connection between the cable strands 101 and the anchor plug body 73, and thus making the main cable 1 and the anchorage 7 securely connected.

[0083] In a preferred embodiment, the sliding and slippage of the composite saddle 6 both represent movement.

[0084] Example 2

[0085] like Figures 3-8 As shown in Example 1, this example discloses a design method for an anchoring system, which designs the anchoring system as shown in Example 1. The method includes the following steps:

[0086] S1: Determine the first incident angle θ1 of the composite cable saddle 6 according to the overall bridge design;

[0087] S2: Determine the first exit angle θ2 of the composite cable saddle 6;

[0088] S3: Calculate the stress increment of main cable 1 based on the cable force of the completed bridge and the cable force of the empty cable;

[0089] S4: Determine the length L of the center strand 1011;

[0090] S5: Determine the spherical parameters of the first front anchor surface 71;

[0091] S6: Calculate the displacement of the composite saddle 6 based on the stress increment of the main cable 1, the angle of the main cable 1, and the length of the front anchor chamber 72, and select the composite saddle 6 accordingly.

[0092] In a preferred manner, in S4, the length L of the center strand 1011 is determined based on the stress increment of the main cable 1, geological conditions, and the required burial depth of the anchor plug 73.

[0093] A preferred method, such as Figure 5As shown, in S5: the point where the central cable strand 1011 is anchored on the anchor 7 is the first anchor point, i.e., point B1. The central cable strand 1011 is divided into the main cable section strand 1013 and the diverging section strand 1012. The intersection of the extension line of the main cable section strand 1013 and the extension line of the diverging section strand 1012 is the first intersection point, i.e., point A1. The horizontal line in the vertical plane where the central cable strand 1011 is located, passing through the first intersection point (point A1), is the first extension line 90. The first extension line 90 intersects the sphere 80 at the second intersection point, i.e., point C1. The diameter A1C1 = A1B1 / cosθ2.

[0094] In a preferred manner, in S6: the longitudinal slip of the composite saddle 6 is related to the length L of the central strand 1011 and the first exit angle θ2. The larger L is and the smaller the first exit angle θ2 is, the greater the longitudinal slip of the composite saddle 6.

[0095] In a preferred manner, the first incident angle θ1 is the angle between the moving direction of the main cable 1 and the composite saddle 6;

[0096] The first exit angle θ2 is the angle between the central cable strand 1011 and the direction of movement of the composite cable saddle 6;

[0097] The first incident angle θ1 and the first exit angle θ2 should ideally be the same. If the angles are different, such as Figure 7 As shown, the overall tilt angle of the composite cable saddle 6 can be adjusted so that the direction of movement of the composite cable saddle 6 is perpendicular to the bisector of the third included angle θ3 between the main cable 1 and the central cable strand 1011.

[0098] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An anchoring system comprising a composite saddle (6) and an anchor (7), wherein a main cable (1) is connected to the anchor (7) via the composite saddle (6), characterized in that: The anchor (7) has a first front anchor surface (71) on the side near the composite cable saddle (6). The first front anchor surface (71) is spherical. The main cable (1) is branched into several strands (101) through the composite cable saddle (6). The strands (101) are all radially branched out from the composite cable saddle (6) and connected to the first front anchor surface (71). Among the several strands (101), there is a central strand (1011), which is divided into a main cable section strand (1013) and a diverging section strand (1012). The intersection of the extension line of the main cable section strand (1013) and the extension line of the diverging section strand (1012) is the first intersection point A1. The point where the central strand (1011) is anchored on the anchor (7) is the first anchor point B1. The extension line of the moving direction of the composite saddle (6) is set as the first extension line (90). The first extension line (90) is located in the vertical plane and passes through the first intersection point A1. The first front anchor surface (71) is a sphere (80) whose center is located on the first extension line (90) and passes through the first intersection point A1 and the first anchor point B1.

2. The anchoring system according to claim 1, characterized in that, The composite saddle (6) can support the main cable (1) at the end away from the anchor (7), and the composite saddle (6) can diverge the main cable (1) at the end near the anchor (7). The composite saddle (6) can move along the length of the main cable (1).

3. An anchoring system according to claim 2, characterized in that, The composite cable saddle (6) includes a cable saddle body (61) and a roller (63), and the cable saddle body (61) moves along the length of the main cable (1) via the roller (63).

4. An anchoring system according to claim 3, characterized in that, The saddle body (61) is provided with a saddle groove (66). The side of the saddle groove (66) facing the anchor (7) is a diverging section saddle groove (662). The side of the saddle groove (66) away from the anchor (7) is a main cable section saddle groove (661). The main cable section saddle groove (661) smoothly transitions to the diverging section saddle groove (662) along the length direction of the main cable (1). The main cable section saddle groove (661) is used to support the main cable (1), and the diverging section saddle groove (662) is used to diverge the main cable (1).

5. An anchoring system according to any one of claims 1-4, characterized in that, The anchor (7) includes a front anchor chamber (72) and an anchor plug (73). The front anchor chamber (72) is connected to the anchor plug (73) at one end away from the composite cable saddle (6). The cable strand (101) is located inside the front anchor chamber (72).

6. A design method for an anchoring system, characterized in that, The method of designing the anchoring system as described in claim 5 includes the following steps: S1: Determine the first incident angle θ1 of the composite cable saddle (6) according to the overall bridge design; S2: Determine the first exit angle θ2 of the composite cable saddle (6); S3: Calculate the stress increment of the main cable (1) based on the cable force of the completed bridge and the cable force of the empty cable; S4: Determine the length L of the central strand (1011); S5: Determine the spherical parameters of the first front anchor surface (71); S6: Calculate the displacement of the composite saddle (6) based on the stress increment of the main cable (1), the angle of the main cable (1), and the length of the front anchor chamber (72), and select the composite saddle (6).

7. The design method of an anchoring system according to claim 6, characterized in that, In S4: The length L of the center strand (1011) is determined based on the stress increment of the main cable (1), geological conditions and the required burial depth of the anchor plug (73).

8. The design method of an anchoring system according to claim 6, characterized in that, In S5: the point where the central strand (1011) is anchored to the anchor (7) is the first anchor point, i.e., point B1; the intersection of the extension line of the main cable strand (1013) and the extension line of the diverging strand (1012) is the first intersection point, i.e. point A1; the first extension line (90) intersects the sphere (80) at the second intersection point, i.e. point C1; and the diameter A1C1 = A1B1 / cosθ2.

9. The design method of an anchoring system according to claim 6, characterized in that, The first incident angle is the angle between the main cable (1) and the moving direction of the composite saddle (6); The first emission angle is the angle between the central cable strand (1011) and the moving direction of the composite cable saddle (6); The first incident angle and the first exit angle should be the same. If the angles are different, the overall tilt angle of the composite cable saddle (6) can be adjusted so that the moving direction of the composite cable saddle (6) is perpendicular to the bisector of the third included angle between the main cable (1) and the central cable strand (1011).

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