A saddle-shaped cable-girder composite beam for pedestrian suspension bridges, the suspension bridge itself, and its construction method.

Abstract

This invention provides a saddle-shaped cable-beam composite beam for pedestrian suspension bridges, a suspension bridge, and a construction method. The composite beam includes a bridge body, two upper main cables positioned above the bridge body, and two lower main cables positioned below the bridge body. Both the upper and lower main cables are arranged along the length of the bridge body. The two upper and two lower main cables are located on both sides of the bridge body. The two upper main cables are connected to both sides of the bridge body via suspenders in an inverted V-shape. The two lower main cables are connected to both sides of the bridge body via adjustable-length cables. Each cable includes a first cable, with its two ends connected to the lower main cable and the corresponding side of the bridge body, respectively. The first cable is also in a V-shape. This invention utilizes a saddle-shaped cable-beam composite beam to increase the lateral and vertical stiffness of the bridge body, enabling the continued application of pedestrian suspension bridges in the large-span range and continuing to leverage the advantages of large span capacity, thus achieving good economic benefits.

Description

Technical Field

[0001] This invention relates to the field of pedestrian suspension bridge technology, specifically to a saddle-shaped cable-beam composite beam for pedestrian suspension bridges, a suspension bridge, and a construction method thereof. Background Technology

[0002] Pedestrian suspension bridges are characterized by their large span capacity, ease of construction, light weight, high aesthetic appeal, and diverse designs, making them widely used in mountainous canyons, reservoirs, rivers, and tourist attractions.

[0003] Pedestrian suspension bridges are generally no more than 5 meters wide, or even narrower. To reduce investment, investors typically only allow a minimum pedestrian width of 3.5 meters. As a result, the ratio of bridge deck width to bridge span is often less than 1 / 20 of the conventional structural stability warning value in engineering. Because the width-to-span ratio is even smaller, the bridge becomes entirely dependent on structural stability.

[0004] To improve the stability of cable-stayed bridges, the moment of inertia of the main girder is typically increased by raising the cross-sectional height or width. This is because, according to the classical column stability formula... Among them, F cr The critical force is E; the elastic modulus of the material is E; and the moment of inertia of the structural cross section is I, where, for a rectangular cross section... b is the cross-sectional width, h is the cross-sectional height, μ is the constraint coefficient at both ends of the member, and l is the member length. Increasing the cross-sectional height can improve stability, but there are limits to how much the cross-sectional height or width can be increased, therefore the improvement in stability is also limited.

[0005] To increase the vertical and lateral stiffness of the main beam, there is an urgent need for an economical and easy-to-construct main beam cross-section to improve its stability. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a saddle-shaped cable-beam composite beam for pedestrian suspension bridges. This composite beam increases the lateral and vertical stiffness of the bridge structure by adding a main cable and adjustable-length tension cables under the bridge. The tension of the cables generates stiffness, which in turn tightens the main cable, generating outward horizontal force and downward vertical force. This allows pedestrian suspension bridges to continue to be used in the field of large spans, continuing to leverage the advantages of large span capacity of suspension bridges and achieving good economic benefits.

[0007] This invention provides a saddle-shaped cable-beam composite beam for a pedestrian suspension bridge, comprising a bridge body, two main upper cables positioned above the bridge body, and two main lower cables positioned below the bridge body. Both the main upper and lower cables are arranged along the length of the bridge body. The two main upper cables and two main lower cables are positioned on both sides of the bridge body. The two main upper cables are connected to both sides of the bridge body via suspenders, which are inverted V-shapes. The two main lower cables are connected to both sides of the bridge body via adjustable-length cables. Each cable includes a first cable, the two ends of which are respectively connected to the main lower cable and the corresponding side of the bridge body. The first cable is also in an inverted V-shape.

[0008] By installing inverted V-shaped suspension cables on the bridge and V-shaped first tension cables underneath, with both main cables on the bridge and both main cables underneath positioned on both sides of the bridge structure, a saddle-shaped structure is formed, comprising the main cables on the bridge, the main cables underneath, the first tension cables, the suspension cables, and the bridge structure. The suspension cables exert horizontal outward and vertical upward forces on the bridge structure, while the first tension cables exert horizontal outward and vertical downward forces. Since both the suspension cables and the first tension cables exert horizontal outward forces on the bridge structure, the horizontal stiffness of the bridge structure is improved. The suspension cables and the first tension cables exert vertical forces on the bridge structure, respectively, upward and downward. When the load on the bridge structure changes, both the suspension cables and the first tension cables can reduce the vertical sway of the bridge structure, thereby improving the vertical stiffness of the bridge structure and enhancing its lateral and vertical stability.

[0009] Furthermore, the cable includes a second cable, the two ends of which are respectively connected to the main cable under the bridge and the side of the bridge body diagonally corresponding to the main cable under the bridge, and adjacent second cables are arranged in a crisscross pattern.

[0010] By installing a second cable, multiple stable triangular structures are formed longitudinally between the first cable, the second cable, and the bridge deck beams, which can further improve the stability of the bridge.

[0011] Furthermore, the main cable of the bridge is in the shape of a spatial curve, and the horizontal distance between the main cable and the bridge body gradually decreases from both ends to the middle, and the vertical distance between the main cable and the bridge body gradually decreases from both ends to the middle.

[0012] The main cable of the bridge is in the shape of a spatial curve. The tension of the main cable will provide resistance in all three dimensions, providing horizontal and vertical resistance components to resist the lateral forces on the bridge.

[0013] Furthermore, the main cable under the bridge is in the shape of a spatial curve, and the horizontal distance between the main cable under the bridge and the bridge body gradually decreases from both ends to the middle, and the vertical distance between the main cable under the bridge and the bridge body gradually decreases from both ends to the middle.

[0014] The main cable under the bridge has a spatial curve, and the tension of the main cable under the bridge will provide resistance in all three dimensions, providing horizontal and vertical resistance components to further resist the lateral forces on the bridge body.

[0015] Furthermore, the slings and cables are arranged in a one-to-one correspondence.

[0016] This invention provides a suspension bridge, including the aforementioned saddle-shaped cable-beam composite beam for a pedestrian suspension bridge, and two foundations symmetrically arranged at both ends of the bridge body. The two ends of the bridge body are respectively fixedly connected to the two foundations. Each of the two foundations is provided with a first anchor on the side away from the bridge body. Two main towers are symmetrically arranged on the foundations along the axis of the bridge body. A saddle is provided on the top of the main tower. The two ends of the main cable on the bridge are connected to the first anchors. The main cable on the bridge is suspended above the bridge body through the saddle.

[0017] Furthermore, the foundation is provided with second anchorages on both sides symmetrically along the bridge axis, and the two ends of the main cable under the bridge are connected to the second anchorages.

[0018] Furthermore, the distance between the two main towers is greater than the width of the bridge structure.

[0019] The distance between the two main towers is set to be greater than the width of the bridge, so that the main cable on the bridge is in a spatial curve.

[0020] This invention provides a construction method for a suspension bridge, comprising:

[0021] S1. Construct the first anchor, the second anchor, and the foundation, and embed the first anchor, the second anchor, and the foundation into the ground;

[0022] S2. Construct the main tower on the foundation, and install the saddle on the top of the main tower;

[0023] S3. Anchor both ends of the main cable on the bridge to the first anchorage, and install the main cable on the saddle.

[0024] S4. Install slings on the main cable of the bridge and install the crossbeams of the bridge body at the lower end of the slings. Connect the crossbeams with longitudinal beams to form the bridge body.

[0025] S5. Anchor both ends of the main cable under the bridge to the second anchorage, and connect the bridge body to the main cable under the bridge using cables.

[0026] S6. Adjust the length of each cable from the mid-span of the suspension bridge toward the main tower to tighten the main cable under the bridge and generate a certain tension.

[0027] By first constructing the main cable on the bridge and then constructing the main cable under the bridge and adjusting the cable length, the main cable under the bridge is tightened, thereby increasing the vertical and horizontal stiffness of the bridge structure.

[0028] Furthermore, this includes: using finite element analysis to calculate the required main cable alignment, single-ear clamp position, main cable tension, and original cable length under the bridge to ensure the stability of the cable-stayed bridge after construction.

[0029] The beneficial effects of this invention are as follows: By setting inverted V-shaped suspension cables on the bridge and V-shaped first tension cables under the bridge, and with both main cables on the bridge and both main cables under the bridge located on both sides of the bridge body, the main cables on the bridge, the main cables under the bridge, the first tension cables, the suspension cables, and the bridge body form a saddle-shaped structure. The suspension cables exert horizontal outward force and vertical upward force on the bridge body, while the first tension cables exert horizontal outward force and vertical downward force on the bridge body. Since both the suspension cables and the first tension cables exert horizontal outward force on the bridge body, the horizontal stiffness of the bridge body is improved. The suspension cables and the first tension cables exert vertical forces upward and downward on the bridge body, respectively. When the load on the bridge body changes, both the suspension cables and the first tension cables can reduce the vertical sway of the bridge body, improve the vertical stiffness of the bridge body, and thus improve the lateral and vertical stability of the bridge body. Attached Figure Description

[0030] Figure 1 This is an elevation view of the cable-stayed bridge of the present invention;

[0031] Figure 2 This is a plan view of the cable-stayed bridge of the present invention;

[0032] Figure 3 This is a schematic diagram of the cable-beam composite beam structure of the present invention;

[0033] Figure 4 This is a schematic diagram of the inverted V-shaped structure of the main cable and beam combination on the bridge of the present invention;

[0034] Figure 5 This is a schematic diagram of the saddle-shaped structure formed by the main cable on the bridge, the main cable under the bridge, the first cable, the suspension cable, and the bridge body of the present invention.

[0035] Figure 6 This is a schematic diagram of the forces acting on the saddle-shaped structure of the present invention;

[0036] Reference numerals in the attached drawings: 1. First anchorage; 2. Foundation; 3. Second anchorage; 4. Main tower; 5. Saddle; 6. Main cable on the bridge; 7. Single-ear cable clamp; 8. Suspension cable; 9. Crossbeam; 10. Longitudinal beam; 11. Main cable under the bridge; 12. Double-ear cable clamp; 13. First cable; 14. Second cable; 15. Length adjustment device. Detailed Implementation

[0037] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0038] like Figure 1 As shown, a saddle-shaped cable-beam composite cable-stayed bridge for pedestrian suspension bridges includes a bridge body, foundation 2, first anchorage 1, second anchorage 3, main tower 4, under-bridge main cable 11, and over-bridge main cable 6.

[0039] like Figure 3 As shown, the bridge body includes multiple crossbeams 9 and multiple longitudinal beams 10. The crossbeams 9 are perpendicular to the length direction of the bridge body, and the longitudinal beams 10 are parallel to the length direction of the bridge body.

[0040] like Figure 2 As shown, there are two foundations 2, which are symmetrically arranged at both ends of the bridge body and integrated with the bridge body. The foundations 2 are embedded in the ground.

[0041] There are two first anchors 1. The two first anchors 1 are respectively set on the side of the two foundations 2 away from the bridge body. The first anchors 1 are used to anchor the main cable 6 on the bridge and are embedded in the ground.

[0042] Two main towers 4 are set on each foundation 2. The two main towers 4 are symmetrically arranged along the bridge axis. The distance between the two main towers 4 is greater than the width of the bridge. A saddle 5 is set on the top of the main tower 4. The saddle 5 is used to install the main cable 6 on the bridge.

[0043] There are two main cables 6 on the bridge. Both ends of the main cables 6 are fixedly connected to the two first anchorages 1. The main cables 6 are mounted on the saddles 5 at the top of the two main towers 4 and suspended above the bridge structure. Figure 3 , 4 As shown, the two main cables 6 are arranged on both sides of the bridge body. The two main cables 6 are connected to the corresponding sides of the bridge body by suspenders 8. The suspenders 8 are in the shape of an inverted V. Single ear clamps 7 are installed on the main cables 6. One end of the suspender 8 is connected to the single ear clamp 7, and the other end is connected to the ear plate on the bridge body.

[0044] The horizontal distance between the main cable 6 on the bridge and the bridge body gradually decreases from both ends to the middle, and the vertical distance between the main cable 6 on the bridge and the bridge body gradually decreases from both ends to the middle, thus making the main cable 6 on the bridge form a spatial curve. Similarly, the length of the suspension cable 8 from both ends to the middle of the bridge body gradually decreases, and the force applied to the suspension cable 8 closer to the middle is greater, ensuring the stability of the middle of the bridge body.

[0045] like Figure 2 As shown, four second anchorages 3 are provided, with two second anchorages 3 on each side of each foundation 2 symmetrically along the bridge axis. The second anchorages 3 are used to fix the main cables 11 under the bridge. Since the second anchorages 3 are located on both sides of the foundation 2, the distance between two main cables 11 under the bridge is greater than the distance between two main cables 6 on the bridge, which makes the horizontal force exerted by the main cables 11 under the bridge on the bridge body greater, and is more conducive to improving the horizontal stiffness of the bridge body.

[0046] like Figure 3 , 5 As shown, the main cable 11 is installed on both sides under the bridge body. Both ends of the main cable 11 are connected to the second anchorage 3. The main cable 11 is connected to the bridge body via adjustable-length cables. The cables and suspenders 8 are arranged in a one-to-one correspondence. The cables include a first cable 13 and a second cable 14. Double-ear cable clamps 12 are installed on the main cable 11. One end of the first cable 13 is connected to the double-ear cable clamp 12, and the other end is connected to the ear plate on the corresponding side of the bridge body. Figure 3 In the middle, the first cable 13 on the left connects to the main cable 11 under the bridge on the left and to the left side of the bridge body; the first cable 13 on the right connects to the main cable 11 under the bridge on the right and to the right side of the bridge body; one end of the second cable 14 is connected to the double-ear clamp 12, and the other end is connected to the ear plate on the opposite side of the bridge body. Figure 3 In this structure, one end of one of the second cables 14 is connected to the main cable 11 under the bridge on the left, and the other end is connected to the right side of the bridge body. One end of the other second cable 14 is connected to the main cable 11 under the bridge on the right, and the other end is connected to the left side of the bridge body, so that the two second cables 14 are arranged in a cross pattern. Both the first cable 13 and the second cable 14 are equipped with length adjustment devices 15 to adjust the preload of the cables on the bridge body, so that the bridge body remains stable.

[0047] The horizontal distance between the main cable 11 under the bridge and the bridge body gradually decreases from both ends to the middle, and the vertical distance between the main cable 11 under the bridge and the bridge body gradually decreases from both ends to the middle, thus making the main cable 11 under the bridge a spatial curve. Similarly, the length of the cable from both ends to the middle of the bridge body gradually decreases, and the force applied to the cable closer to the middle is greater, ensuring the stability of the middle of the bridge body.

[0048] The bridge is constructed with 6 main cables on the upper part, 11 main cables under the lower part, 13 first tension cable, and 8 suspension cables, forming a saddle-shaped structure.

[0049] like Figure 6 As shown, the suspension cable 8 exerts a horizontal outward force and a vertical upward force on the bridge body, while the first cable 13 exerts a horizontal outward force and a vertical downward force on the bridge body. Since both the suspension cable 8 and the first cable 13 exert a horizontal outward force on the bridge body, the horizontal stiffness of the bridge body is improved. The suspension cable 8 and the first cable 13 exert upward and downward vertical forces on the bridge body, respectively. When the load on the bridge body changes, both the suspension cable 8 and the first cable 13 can reduce the vertical sway of the bridge body and improve the vertical stiffness of the bridge body, thereby improving the lateral and vertical stability of the bridge body.

[0050] The construction method for this suspension bridge is as follows:

[0051] S1, according to Figure 1 A finite element model is established as shown, and the finite element program is used to calculate the required alignment of the main cable 6 on the bridge, the position of the single-ear cable clamp 7, the tension of the main cable 11 under the bridge, and the original length of the cable to ensure the stability of the bridge after its completion.

[0052] S2. Construct the first anchor 1, the second anchor 3, and the foundation 2, and embed the first anchor 1, the second anchor 3, and the foundation 2 into the ground.

[0053] S3. Construct the main tower 4, fix the lower end of the main tower 4 to the foundation 2, and fix the upper end to the saddle 5.

[0054] S4. The main cable 6 of the bridge passes around the saddle 5 and is suspended at the top of the main tower 4, and both ends of the main cable 6 of the bridge are anchored in the first anchorage 1;

[0055] S5. Install single-ear cable clamps 7 on the main cable 6 on the bridge according to the calculated cable clamp positions, and hold the main cable 6 on the bridge tightly.

[0056] S6. Install a suspender cable 8 on the single-ear cable clamp 7. The upper end of the suspender cable 8 is connected to the single-ear cable clamp 7, and the lower end is connected to the crossbeam 9 of the bridge body, forming an inverted V-shape. At the same time, the main cable 6 on the bridge no longer presents a parallel cable surface in space, but a spatial curved cable surface.

[0057] S7. Connect the longitudinal beam 10 to the crossbeam 9 of the bridge body to form the bridge body; install the bridge deck and railings and other auxiliary structures between the longitudinal beam 10 and the crossbeam 9.

[0058] S8. Install the main cable 11 under the bridge and anchor both ends of the main cable 11 under the bridge into the second anchorage 3.

[0059] S9. Install double-ear cable clamps 12 on the main cable 11 under the bridge according to the calculated cable clamp positions, and hold the main cable 11 under the bridge tightly.

[0060] S10. Connect the lower ends of the first cable 13 and the second cable 14 to the double-ear cable clamps 12 on the main cable 11 under the bridge, and connect the upper ends to the bridge crossbeam 9. The first cable 13 forms a figure-eight structure, the second cable 14 forms a cross structure, and the main cable 11 under the bridge has a spatial curved cable surface in space.

[0061] S11. Adjust the lengths of the first cable 13 and the second cable 14 one by one from the mid-span toward the main tower 4 to tighten the main cable 11 under the bridge and generate a certain tension.

[0062] S12. Conduct bridge completion acceptance.

[0063] This invention changes the traditional main cable 6 of the bridge from a parallel main cable to a three-dimensional spatial curved main cable; it solves the instability caused by insufficient vertical and lateral stiffness of the main beam of the long-span cable bridge; and by designing a saddle-shaped cable beam combined cross section, it has stronger stability than the traditional cable bridge with only lateral wind-resistant cables.

[0064] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A saddle-shaped cable-beam composite beam for pedestrian suspension bridges, characterized in that: The bridge includes a bridge body, two main cables (6) installed above the bridge body, and two main cables (11) installed below the bridge body. The main cables (6) and the main cables (11) are arranged along the length of the bridge body. The two main cables (6) and the two main cables (11) are installed on both sides of the bridge body. The two main cables (6) are connected to both sides of the bridge body by suspenders (8). The suspenders (8) are in the shape of an inverted V. The two main cables (11) are connected to both sides of the bridge body by adjustable length cables. The cables include a first cable (13). The two ends of the first cable (13) are respectively connected to the main cable (11) and the side of the bridge body corresponding to the main cable (11). The first cable (13) is in the shape of an inverted V. The main cable (6) on the bridge is in the shape of a spatial curve. The horizontal distance between the main cable (6) and the bridge body gradually decreases from both ends to the middle, and the vertical distance between the main cable (6) and the bridge body gradually decreases from both ends to the middle. The main cable (11) under the bridge is in the shape of a spatial curve. The horizontal distance between the main cable (11) and the bridge body gradually decreases from both ends to the middle. The vertical distance between the main cable (11) and the bridge body gradually decreases from both ends to the middle. The cable includes a second cable (14), the two ends of which are connected to the main cable (11) under the bridge and the side of the bridge body diagonally corresponding to the main cable (11) under the bridge, respectively, and adjacent second cables (14) are arranged crosswise.

2. The saddle-shaped cable-beam composite beam for a pedestrian suspension bridge according to claim 1, characterized in that: The slings (8) and cables are arranged in a one-to-one correspondence.

3. A suspension bridge, characterized in that: The bridge includes the saddle-shaped cable-beam composite beam for a pedestrian suspension bridge as described in claim 1 or 2, and further includes two foundations (2) symmetrically arranged at both ends of the bridge body. The two ends of the bridge body are respectively fixedly connected to the two foundations (2). Each of the two foundations (2) is provided with a first anchor (1) on the side away from the bridge body. Two main towers (4) are symmetrically arranged on the foundations (2) along the axis of the bridge body. A saddle (5) is provided on the top of the main tower (4). The two ends of the main cable (6) on the bridge are connected to the first anchor (1). The main cable (6) on the bridge is suspended above the bridge body through the saddle (5).

4. The suspension bridge according to claim 3, characterized in that: The foundation (2) is provided with second anchorages (3) on both sides symmetrically along the bridge axis, and the two ends of the main cable (11) under the bridge are connected to the second anchorages (3).

5. The suspension bridge according to claim 3, characterized in that: The distance between the two main towers (4) is greater than the width of the bridge body.

6. A construction method for a suspension bridge as described in any one of claims 3 to 5, characterized in that: include: S1. Construct the first anchor (1), the second anchor (3), and the foundation (2), and embed the first anchor (1), the second anchor (3), and the foundation (2) into the ground; S2, the main tower (4) is constructed on the foundation (2), and the saddle (5) is installed on the top of the main tower (4); S3. Anchor both ends of the main cable (6) on the first anchorage (1) and install the main cable (6) on the saddle (5); S4. Install slings (8) on the main cable (6) of the bridge and install the crossbeams (9) of the bridge body at the lower end of the slings (8). Connect the crossbeams (9) with the longitudinal beams (10) to form the bridge body. S5. Anchor both ends of the main cable (11) under the bridge to the second anchorage (3), and use the cable to connect the bridge body to the main cable (11) under the bridge. S6. Adjust the length of the cables one by one from the mid-span of the suspension bridge toward the main tower (4) so ​​that the main cable (11) under the bridge is taut and generates a certain tension.

7. The construction method for a suspension bridge according to claim 6, characterized in that: include: Before construction, the finite element program was used to calculate the required alignment of the main cable (6), position of the single-ear cable clamp (7), tension of the main cable (11) under the bridge, and original length of the cable to ensure the stability of the cable bridge after its completion.

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