A through-type arch bridge that increases the transverse stiffness of the main beam and reduces the horizontal thrust of the foundation

Abstract

The present invention discloses a bottom-supported arch bridge which increases the lateral stiffness of the main beam and reduces the horizontal thrust of the foundation. The bridge comprises arch ribs, arch seats, main beams, and slings connecting the arch ribs and the main beam. Horizontal cables are tensioned along the longitudinal direction of the bridge on both sides of the main beam. Support rods are provided between the main beam and the horizontal cables. The horizontal cables are connected to the main beam via the support rods to form a plurality of transverse limit connections at nodes. Without increasing the width of the bridge deck and the amount of main beam material, the bridge can not only increase the lateral stiffness of the main beam and reduce the lateral amplitude, but also reduce the horizontal thrust of the foundation, reduce the excavation of the arch seat foundation and the amount of material used, and has a reasonable form, high material utilization rate, and convenient and quick construction.

Description

Technical Field

[0001] The present invention relates to the field of bridge engineering, and in particular to a bottom-supported arch bridge capable of increasing the lateral rigidity of a main beam and reducing the horizontal thrust of a foundation. Background Art

[0002] Through-arch bridges are characterized by large spanning capacities and minimal clearance requirements. The main arch of a through-arch bridge has significant vertical stiffness, and the vertical support provided by the slings makes it easier for the main girder to meet vertical stiffness requirements. The main girder must also possess sufficient stiffness in the transverse direction. If the lateral stiffness of the main girder is too low, it will experience significant lateral deformation and vibration under external loads, causing discomfort and insecurity for drivers, passengers, and pedestrians on the bridge, impacting normal operation. Therefore, the lateral stiffness of the main girder must be controlled. Key indicators for evaluating the lateral stiffness of the main girder include the ratio of the main girder width to span, the lateral deflection-to-span ratio, the lateral natural frequency, and the lateral angle at the beam ends. To ensure sufficient lateral stiffness in the main girder, the typical approach is to control the ratio of the main girder width to span within a certain range. Pedestrian bridges, railway bridges, and rail bridges are characterized by narrow decks. The deck width of super-large span bridges is also determined according to actual traffic function requirements. If the method of simply increasing the ratio of the main beam width to the span is adopted to ensure the lateral stiffness of the main beam, it will increase the deadweight, reduce structural efficiency, cause material waste, and reduce economic benefits. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a bottom-supported arch bridge that increases the lateral stiffness of the main beam and reduces the horizontal thrust of the foundation. Without increasing the bridge deck width and the amount of main beam material, it can not only increase the lateral stiffness of the main beam and reduce the lateral amplitude, but also reduce the horizontal thrust of the foundation, reduce foundation excavation and material consumption, and has a reasonable form, high material utilization rate, and convenient and quick construction.

[0004] The through-type arch bridge of the present invention, which increases the transverse rigidity of the main beam and reduces the horizontal thrust of the foundation, comprises arch ribs, arch seats, main beams, and slings connecting the arch ribs and the main beams. Horizontal cables are tensioned along the longitudinal direction of the bridge on both sides of the main beams. Support rods are provided between the main beams and the horizontal cables. The horizontal cables are connected to the main beams via the support rods to form transverse limit connections at several nodes.

[0005] Furthermore, one end of the support rod is fixedly connected to the main beam, and the other end is movably connected to the horizontal cable;

[0006] Furthermore, an enlarged foundation is fixedly connected below the arch seat, and the horizontal cable is anchored to the enlarged foundation;

[0007] Furthermore, the horizontal cables are flexible cables and are arranged parallel to the main beams, and are movably connected to the support rods in a manner that allows them to move along the longitudinal direction of the bridge;

[0008] Furthermore, the support rod is provided with an annular member slidably connected to the horizontal cable, and the annular member is sleeved on the horizontal cable;

[0009] Furthermore, a sliding sleeve is provided between the annular member and the horizontal cable;

[0010] Furthermore, the sliding sleeve includes an inner sliding sleeve fixedly arranged on the inner side wall of the annular member and an outer sliding sleeve fixedly arranged on the surface of the horizontal cable and corresponding to the inner sliding sleeve, and the inner sliding sleeve and the outer sliding sleeve can slide relative to each other along the longitudinal bridge direction;

[0011] Furthermore, the support rods form a plurality of triangular support structures between the horizontal cables and the main beam in the horizontal and vertical directions, and the triangular support structures are connected in pairs in the horizontal direction;

[0012] Furthermore, the triangular support structure is composed of a side support rod I, a middle support rod II, and a side support rod III connected to the same ring member in the horizontal plane, and the connection point between the middle support rod II and the bridge deck main beam is not on the same horizontal line as the connection points between the side support rod I and the side support rod III and the bridge deck main beam;

[0013] Furthermore, there are two arch ribs, and a plurality of cross braces distributed at equal intervals are provided between the two arch ribs.

[0014] The beneficial effects of the present invention are as follows: the bottom-supported arch bridge disclosed by the present invention, which increases the lateral stiffness of the main beam and reduces the horizontal thrust of the foundation, can not only increase the lateral stiffness of the main beam and reduce the lateral amplitude, but also reduce the horizontal thrust of the foundation, reduce foundation excavation and material consumption, without increasing the bridge deck width and the main beam material consumption. It has a reasonable form, high material utilization rate, and convenient and quick construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0016] Figure 1 This is a schematic diagram of the through arch bridge structure of the present invention;

[0017] Figure 2 for Figure 1 A perspective view of the bottom end of the beam;

[0018] Figure 3 for Figure 1 Schematic diagram of the enlarged structure at A in the middle;

[0019] Figure 4 for Figure 3 Schematic diagram of the enlarged structure decomposition of . DETAILED DESCRIPTION

[0020] Figure 1 This is a schematic diagram of the through arch bridge structure of the present invention; Figure 2 for Figure 1 A perspective view of the bottom end of the beam; Figure 3 for Figure 1 Schematic diagram of the enlarged structure at A in the middle; Figure 4 for Figure 3 An enlarged structural decomposition diagram of the structure is shown. As shown in the figure, the through-arch bridge of this embodiment, which increases the lateral stiffness of the main beam and reduces the horizontal thrust of the foundation, includes arch ribs 5, abutments 7, a main beam 1, and slings 6 connecting the arch ribs 5 and the main beam 1. Horizontal cables are tensioned along the longitudinal direction of the bridge on both sides of the main beam. Support rods 3 are provided between the main beam 1 and the horizontal cables 2. The horizontal cables 2 form a transverse limit connection with the main beam 1 through the support rods 3 at several nodes. The abutments serve as a transition structure between the arch ribs and the expanded foundation below. The horizontal cables 2 and the main beam are connected transversely through several support rods 3, forming a transverse limit connection at several nodes. The tensioned horizontal cables 2 and support rods 3 provide lateral stability and restraint for the main beam, reduce lateral deformation and amplitude, and limit lateral deformation of the main beam 1. This increases the transverse bending stiffness of the main beam 1 while limiting deformation and vibration caused by the horizontal cables 2. The horizontal cables 2 on both sides of the main beam 1 have the same diameter and the same tension.

[0021] In this embodiment, one end of the support rod 3 is fixedly connected to the main beam 1, and the other end is movably connected to the horizontal cables 2. The movably connected support rod 3 and horizontal cables 2 means that the two can move relative to each other after being connected. This is a movable connection, as opposed to a fixed connection, and is the "movable" connection. When the bridge experiences large lateral deformation and amplitude under external loads, resulting in lateral displacement, the taut horizontal cables 2 provide a rebound force in the opposite direction of the main beam's displacement through the support rod 3, thereby limiting the lateral deformation of the main beam. This movable connection also prevents wear or damage caused by stress concentration between the support rod 3 and the horizontal cables 2. However, the support rod 3 and the main beam 1 must be fixedly connected to ensure sufficient structural rigidity. The support rod 3 can be fixed to the bridge deck main beam 1 using existing fixing methods, such as welding. A fixed connection between the horizontal cables 2 and the support rod 3 is acceptable, but this method may cause stress concentration and wear.

[0022] In this embodiment, the lower part of the arch seat 7 is fixedly connected to the expansion base 8.

[0023] The horizontal cables are anchored to the expanded foundation 8. The main arch is a basket arch with arch ribs 5 tilted inwards. An arch seat 7 is provided at the arch foot and is directly connected to the expanded foundation 8. The main beam 1 only bears bending moment and does not participate in the horizontal thrust generated by the arch ribs 5. The vertical stiffness of the main beam is mainly provided by the suspension cables 6. The horizontal thrust generated by the arch ribs 5 is partially borne by the expanded foundation 8, and the remaining part is borne by the longitudinal horizontal cables 2, thereby reducing the horizontal thrust of the expanded foundation 8.

[0024] In this embodiment, the horizontal cables 2 are flexible cables arranged parallel to the main beam 1 and movably connected to the support rods 3 in a manner that allows them to move in the longitudinal direction of the bridge. The horizontal cables 2 are straight, parallel to both sides of the main beam 1, and equidistant from the edges of the main beam 1. In other words, since the support rods 3 are fixedly connected to the main beam 1, their positions are fixed. Therefore, when the horizontal cables 2 are connected to the support rods 3, they can move in the longitudinal direction of the bridge. Therefore, when the main beam 1 is subjected to load and undergoes lateral deformation, relative displacement occurs between the support rods 3 fixed to the bridge and the horizontal cables 2.

[0025] In this embodiment, the support rod 3 is provided with an annular member 4 that is slidably connected to the horizontal cable 2. The annular member 4 is sleeved on the horizontal cable 2. The annular members 4 are evenly spaced along the horizontal cable 2. The annular members 4 can be detachably connected to the horizontal cable 2, such as by bolts, or can be fixed to the horizontal cable 2. The use of the annular members 4 simplifies the structure and facilitates relative displacement between the support rod 3 and the horizontal cable 2.

[0026] In this embodiment, a sliding sleeve is provided between the annular member 4 and the horizontal cable 2; the setting of the sliding sleeve facilitates the relative displacement of the annular member 4 and the horizontal cable 2 under force conditions. In order to adapt to the structure of the annular member 4, the inner sliding sleeve is generally an arc-shaped plate and adapts to the inner wall of the annular member 4.

[0027] In this embodiment, the sliding sleeve includes an inner sliding sleeve 41 fixedly mounted on the inner sidewall of the annular member 4 and an outer sliding sleeve 21 fixedly mounted on the surface of the horizontal cable 2 and corresponding to the inner sliding sleeve 41. The inner sliding sleeve 41 and the outer sliding sleeve 21 can slide relative to each other along the longitudinal direction of the bridge. The inner sliding sleeve 41 is fixed to the inner sidewall of the annular member 4, and the outer sliding sleeve 21 is fixed to the horizontal cable 2. This not only facilitates the transmission of force between the bridge deck main beam 1 and the bridge deck main beam 1, but also generates a rebound force to reduce the lateral deformation and amplitude of the bridge deck main beam 1 when the bridge deck main beam 1 is subjected to load, reduces the frictional resistance between the annular member 4 and the horizontal cable 2, and also avoids wear between the annular member 4 and the horizontal cable 2. The outer diameter of the horizontal cable 2 should be slightly smaller than the inner diameter of the annular member 4, and the outer sliding sleeve 21 is provided in the area where the horizontal cable 2 contacts the inner sliding sleeve 41 of the annular member 4.

[0028] In this embodiment, the support rods 3 form a number of triangular support structures between the horizontal cables 2 and the bridge deck main beam 1 in the horizontal and vertical directions, and the triangular support structures are connected in pairs in the horizontal direction; that is, the connection nodes between the support rods 3 and the horizontal cables 2 form a stable triangular structure, that is, there are a number of triangular structures formed by the mutual connection of the support rods 3 in the horizontal plane direction of the bridge deck main beam 1, and a triangular structure is also formed between the support rods 3 connected to the bridge deck main beam 1 and the horizontal cables 2 in the vertical direction. Such a structure is more stable and can better provide lateral stability and constraint for the bridge deck main beam 1.

[0029] In this embodiment, the triangular support structure is composed of a side support rod I 31, a middle support rod II 33, and a side support rod III 32 connected to the same ring member 4 in the horizontal plane. The connection point of the middle support rod II 33 and the bridge deck main beam 1 is not on the same horizontal line as the connection point of the side support rod I 31 and the side support rod III 32 and the bridge deck main beam 1; as shown in the figure, for the ring member 4 at A, the side support rod I 31, the middle support rod II 33, and the side support rod III 32 are connected to the triangular support structure formed by the ring member 4, and the side support rod I 31 and the side support rod III 32 are respectively connected to the side support rod I 31 and the side support rod III 32. The side length of the triangle is the same as the length of the side support rods I 31 and III 32. The connection points with the bridge deck main beam 1 are on the same horizontal line. The connection points with the middle support rod 3 II and the bridge deck main beam 1 are not on the same horizontal line as the connection points with the side support rods I 31 and III 32. The side support rods I 31 and III 32 are connected to the adjacent support rods 3 of the triangular support structure. Therefore, in the vertical direction of the bridge deck main beam 1, the side support rods I 31 and III 32 respectively form a triangular structure with the middle support rod II 33 in the vertical direction. Each ring member 4 is connected to three support rods 3, and the support rods 3 of adjacent ring members 4 are connected to each other, making this structure more stable.

[0030] In this embodiment, the horizontal cable 2 is a flexible cable, and the support rod 3 is a rigid component; the annular member 4 is connected and fixed by a nut and a screw, which has a simple structure, is convenient and practical, and has high structural strength and good stability.

[0031] In this embodiment, there are two arch ribs 5 , and a cross brace 9 is provided between the two arch ribs 5 to ensure the stability of the main arch itself.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A through arch bridge that increases the lateral stiffness of the main beam and reduces the horizontal thrust of the foundation, characterized by: It includes arch ribs, arch seats, main beams, and slings connecting the arch ribs and the main beams. Horizontal cables are arranged on both sides of the main beams for tensioning along the longitudinal direction of the bridge. Support rods are arranged between the main beams and the horizontal cables. The horizontal cables are connected to the main beams through the support rods to form transverse limit connections with several nodes. One end of the support rod is fixedly connected to the main beam, and the other end is movably connected to the horizontal cables. An expanded foundation is fixedly connected under the arch seat, and the horizontal cables are anchored to the expanded foundation.

2. The through arch bridge for increasing the lateral rigidity of the main beam and reducing the horizontal thrust of the foundation according to claim 1, characterized in that: The horizontal cables are flexible cables and are arranged parallel to the main beams, and are movably connected to the support rods in a manner that allows them to move along the longitudinal direction of the bridge.

3. The through arch bridge for increasing the lateral rigidity of the main beam and reducing the horizontal thrust of the foundation according to claim 1, characterized in that: The support rod is provided with an annular member which is slidably connected to the horizontal cable, and the annular member is sleeved on the horizontal cable.

4. The through arch bridge for increasing the lateral rigidity of the main beam and reducing the horizontal thrust of the foundation according to claim 3, characterized in that: A sliding sleeve is provided between the annular member and the horizontal cable.

5. The through arch bridge for increasing the lateral rigidity of the main beam and reducing the horizontal thrust of the foundation according to claim 4, characterized in that: The sliding sleeve comprises an inner sliding sleeve fixedly arranged on the inner side wall of the annular member and an outer sliding sleeve fixedly arranged on the surface of the horizontal cable and corresponding to the inner sliding sleeve. The inner sliding sleeve and the outer sliding sleeve can slide relative to each other along the longitudinal bridge direction.

6. The through arch bridge for increasing the lateral rigidity of the main beam and reducing the horizontal thrust of the foundation according to claim 1, characterized in that: The support rods form a plurality of triangular support structures between the horizontal cables and the main beams of the bridge deck in the horizontal and vertical directions, and the triangular support structures are connected in pairs in the horizontal direction.

7. The through arch bridge for increasing the lateral rigidity of the main beam and reducing the horizontal thrust of the foundation according to claim 6, characterized in that: The triangular support structure is composed of side support rod I, middle support rod II and side support rod III connected to the same ring member in the horizontal plane. The connection point between the middle support rod II and the main beam of the bridge deck is not on the same horizontal line as the connection points between the side support rod I and the side support rod III and the main beam of the bridge deck.

8. The through arch bridge according to claim 1, which increases the transverse rigidity of the main beam and reduces the horizontal thrust of the foundation, is characterized in that: There are two arch ribs, and a plurality of horizontal braces distributed at equal intervals are arranged between the two arch ribs.

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