A long-span top-supported steel tube concrete arch bridge

Abstract

The present invention relates to a long-span top-supported steel tube concrete arch bridge. The steel tube concrete arch bridge comprises a main arch, a ventral arch, a junction pier, a bridge deck beam and a main arch upper column. The ventral arch is arranged on both sides of the main arch along the longitudinal bridge direction. On either side of the main arch, the ventral arch is divided into a first ventral arch and a second ventral arch, the first ventral arch is fixedly connected to the ventral arch seat and the junction pier, the second ventral arch is connected to the junction pier, the main arch and / or the main arch upper column, and the main arch upper column, the junction pier and the ventral arch jointly support the bridge deck beam. Through the above arrangement, the overall height of the main arch upper column is reduced, and the deadweight of the bridge body is reduced to a certain extent to meet the force requirements of the main arch, while also reducing the engineering difficulty and engineering cost, and improving the stability of the bridge body. In addition, the ventral arch forms a longitudinal connection structure between the main arch upper columns, and also improves the longitudinal bridge stability of the main arch upper columns.

Description

Technical Field

[0001] The present invention relates to the technical field of arch bridges, and particularly to a long-span deck-type concrete-filled steel tube arch bridge. Background Art

[0002] The concrete-filled steel tube arch bridge is an excellent steel-concrete composite structure bridge. In the past 30 years, the technology of concrete-filled steel tube arch bridges has developed rapidly, and more than 400 concrete-filled steel tube arch bridges have been built across the country, making outstanding contributions to China's economic development. In terms of span, the span of the First Yangtze River Bridge in Hejiang, Sichuan, which is the largest-span concrete-filled steel tube arch bridge built so far, has reached 530m. With the further development of the economy, current highway construction is extending to the mountainous areas in the west, facing more and more deep gorges and canyons. The technical economy of long-span concrete-filled steel tube arch bridges is becoming more and more significant, and the demand is also increasing accordingly.

[0003] At present, the engineering demand for concrete-filled steel tube arch bridges has entered the 750m span level. At this span level, the existing structural form of 500m-class concrete-filled steel tube arch bridges cannot meet the requirements of strength, stiffness and stability. Specifically: the larger the main arch span of the deck-type arch bridge, the higher the rise of the main arch, and accordingly the higher the height of the columns on the main arch. For a 750m-span concrete-filled steel tube arch bridge, the height of the columns on the main arch at the arch foot position of the main arch will exceed 180m, and the stability of the columns on the main arch is difficult to meet the requirements, and they are heavy in self-weight, high in cost and difficult to construct. In addition, for a 750m-span deck-type arch bridge, the self-weights of the main arch and the deck beam increase, and the self-weight of the arch bridge increases significantly. Therefore, at the connection between the columns on the main arch and the main arch, the self-weight of the arch bridge causes a large concentrated force and moment on the main arch, that is, the dead load of the main arch increases significantly, and the existing structure of the main arch cannot meet the requirements of strength, stiffness and local stability. In addition, as the span of the arch bridge increases, the width-span ratio of the whole bridge decreases, resulting in poor lateral stability of the whole bridge. Moreover, the columns on the main arch with too high height have poor stability themselves, resulting in the existing structure of the arch bridge being unable to meet the overall stability requirements of the whole bridge. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art that the existing structure of the arch bridge cannot meet the requirements of strength, stiffness and stability under a larger span, and to provide a long-span deck-type concrete-filled steel tube arch bridge.

[0005] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0006] A long-span deck-type concrete-filled steel tube arch bridge, comprising a main arch, columns on the main arch, boundary piers and spandrel arches. The columns on the main arch, boundary piers and spandrel arches support the deck beam. The spandrel arches are respectively arranged on both sides of the main arch. The spandrel arches include a first spandrel arch and a second spandrel arch.

[0007] On each side of the main arch: a first spandrel arch is provided between the intermediate pier and the abutment, and two ends of the first spandrel arch are respectively connected to the intermediate pier and the spandrel arch seat. At least two second spandrel arches are provided longitudinally along the bridge between the intermediate pier and the crown of the main arch. Two ends of the second spandrel arch closest to the abutment side are respectively connected to the intermediate pier and the corresponding upper column of the main arch. One end of the second spandrel arch closest to the crown of the main arch is connected to the main arch, and the other end is connected to the corresponding upper column of the main arch. Two ends of the remaining second spandrel arches are respectively connected to two adjacent upper columns of the main arch.

[0008] The technical solution of the present invention provides the above-mentioned long-span through concrete-filled steel tube arch bridge, and the concrete-filled steel tube arch bridge is provided with conventional structures such as a main arch and upper columns of the main arch. The main arch is the main supporting structure of the concrete-filled steel tube arch bridge. The deck beam is arranged above the main arch and connects the roads on both sides to form a complete continuous line, so as to realize the most basic traffic function of the concrete-filled steel tube arch bridge. Intermediate piers and upper columns of the main arch are provided between the deck beam and the main arch to support the deck beam, and the lower ends of the upper columns of the main arch are connected to the upper ends of the main arch to obtain support.

[0009] A plurality of spandrel arches are provided and are respectively arranged on both sides of the main arch. The spandrel arches are divided into first spandrel arches and second spandrel arches, and the installation positions of the first spandrel arches and the second spandrel arches are different. Specifically, the first spandrel arch is arranged between the intermediate pier and the abutment on the same side. The connection mode of the first spandrel arch is that one arch foot is connected to the intermediate pier and the other arch foot is connected to the spandrel arch seat.

[0010] The second spandrel arch is arranged between the intermediate pier and the crown of the main arch. On each side of the main arch, at least two second spandrel arches are provided. Among them, it is set that: two arch feet at both ends of the second spandrel arch closest to the abutment side are respectively connected to the intermediate pier and the corresponding upper column of the main arch. One arch foot at one end of the second spandrel arch closest to the crown of the main arch is connected to the main arch, and the other arch foot is connected to the corresponding upper column of the main arch. In addition, two arch feet at both ends of the remaining second spandrel arches are respectively connected to two adjacent upper columns of the main arch along the longitudinal direction of the bridge. If only two second spandrel arches are provided, then there is no second spandrel arch whose both ends are connected to the upper columns of the main arch.

[0011] The abdominal arch abutment and the main arch abutment are both arranged on the two sides of the foundation. The specific positions of the two sides of the foundation need to be confirmed in combination with the actual situation. Since the abdominal arch is an arched structure and both ends are arranged above the main arch, therefore, using part of the abdominal arch to replace the main arch columns on the arch of the main arch that were originally used to support the deck girder can reduce the overall number of the main arch columns on the arch, especially reduce the number of the main arch columns with a relatively large height at the arch feet of the main arch, thereby significantly reducing the overall height of the main arch columns on the arch. Since the self-weight of the main arch columns on the arch is very large, the self-weight of the bridge body can be reduced to a certain extent. On the other hand, the main arch columns on the arch are relatively tall, especially the main arch columns near the arch feet of the main arch, which have the largest height and self-weight and the worst stability. Using the abdominal arch to replace part of the main arch columns on the arch can also increase the overall stability of the bridge body. And a longitudinal connection structure is formed by the abdominal arch between the main arch columns on the arch, which can enhance the longitudinal stability of the connected main arch columns on the arch and improve the longitudinal stiffness of the bridge body, and can be applied to the design of concrete-filled steel tube arch bridges with an ultra-large span of more than 700m. Considering that the span of the deck girder above the abdominal arch should correspond to the span of the abdominal arch, and the positions of the first abdominal arch and the second abdominal arch are different, for the convenience of construction, the span of the second abdominal arch can be different from the span of the first abdominal arch to adapt to different terrains.

[0012] It should be noted that in this application, the connections between structures such as the main arch, the main arch columns on the arch, and the abdominal arch can adopt conventional connection methods such as welding, bolting, and composite connection according to the actual construction needs. In addition, descriptions such as "both sides of the main arch", where both sides refer to both sides of the main arch along the longitudinal direction of the bridge. In this application, unless otherwise specified, both sides or each side in other similar descriptions also refer to both sides or one side of the main arch along the longitudinal direction of the bridge.

[0013] As a preferred technical solution of the present invention, further, a pier column is provided on the abdominal arch abutment, and the pier column is used to support the deck girder. Since the horizontal distance from the abutment to the boundary pier is relatively long, therefore, in order to ensure the stability of the deck girder at this position and reduce the burden on the first abdominal arch, we can set an additional pier column at this position, and the pier column supports the deck girder above it.

[0014] As a preferred technical solution of the present invention, further, the second abdominal arch is continuously arranged between the upper columns of the main arch in the direction from the intersection pier to the crown of the main arch. The second abdominal arch is continuously arranged between the upper columns of the main arch at the springing of the main arch. Since the heights of the upper columns of the main arch gradually decrease in the direction from the intersection pier to the crown of the main arch, this arrangement means that the second abdominal arch is preferentially arranged at a higher position of the upper columns of the main arch, that is, as close as possible to the intersection pier or the springing of the main arch. The beneficial effect is that the effect of reducing the overall height of the upper columns of the main arch is more significant.

[0015] As a preferred technical solution of the present invention, further, the upper end of the abdominal arch is provided with an abdominal arch column or an abdominal arch support, and the abdominal arch supports the bridge deck beam through the abdominal arch column or the abdominal arch support. This technical solution provides a specific way for the abdominal arch to support the bridge deck beam. When the vertical distance between the top of the abdominal arch and the bridge deck beam is small, the upper end of the abdominal arch can support the bridge deck beam by setting the abdominal arch support; when the vertical distance between the top of the abdominal arch and the bridge deck beam is large, the abdominal arch column can be set to support it. The purposes of the two solutions are the same, and the difference is to select different support structures according to different application scenarios. Those skilled in the art should consider factors such as the installation position of the abdominal arch and the height of the main arch when making a selection.

[0016] As a preferred technical solution of the present invention, further, the abdominal arch is provided with a tie cable. The horizontal tension of the tie cable on the abdominal arch should consider factors such as the horizontal thrust caused by the abdominal arch on the main arch, the upper columns of the main arch or the intersection pier to which it is connected. This technical solution uses the tie cable to balance the horizontal thrust caused by the abdominal arch at its connection position, that is, reduces the horizontal thrust borne by the upper columns of the main arch, the main arch and the intersection pier.

[0017] As a preferred technical solution of the present invention, further, the abdominal arch is a concrete-filled steel tube dumbbell-shaped structure, and the bridge deck beam is a simply supported beam structure. In this technical solution, a structural selection of the abdominal arch and the bridge deck beam is given. The abdominal arch and the bridge deck beam of this structure have a light self-weight, a simple structure, and are easy to assemble. Therefore, the construction difficulty and cost are relatively low. The bridge deck beam is a simply supported beam structure, and specifically, conventional simply supported beam structures such as prestressed concrete simply supported beams and steel box girder simply supported beams can be used. Since usually, a single section of the bridge deck beam, that is, the single-span span of the bridge deck beam, adopts a standard span, so we usually arrange several sections of the bridge deck beam to be evenly arranged in the horizontal direction at the supporting positions on the upper end of the abdominal arch, which means that the single-span spans of the several sections of the bridge deck beam are the same and correspond to the span of the abdominal arch. The span of the abdominal arch should be an integer multiple of the single-span span of the bridge deck beam to facilitate assembly during actual construction. When specifically setting, the number of sections of the bridge deck beam above a single abdominal arch should be set in combination with the force. When the number of sections is more, that is, the more bridge deck beams supported above a single abdominal arch, the more obvious the reduction of the overall height of the upper columns of the main arch in this scheme. On the other hand, the more bridge deck beam sections supported above a single abdominal arch, the higher the requirement for the load-bearing capacity of the abdominal arch. Therefore, a reasonable number of bridge deck beam sections should be set through comprehensive analysis.

[0018] As a preferred technical solution of the present invention, further, the upper columns of the main arch are steel box structures, and the main arch is a concrete-filled steel tube truss structure. Under this setting, the main arch and the upper columns of the main arch have relatively high strength and a lighter overall self-weight, which can further reduce the self-weight of the bridge body of the concrete-filled steel tube arch bridge, ensure the overall strength while reducing the dead load of the main arch. The above structural selection of the upper columns of the main arch and the main arch is particularly applicable to the technical solution of setting multiple abdominal arches in this application.

[0019] As a preferred technical solution of the present invention, further, a stiffening area is provided at the arch foot position of the main arch, and stiffening steel plates are provided at the abdominal tubes of the main arch in the stiffening area. Considering that there are still a small number of upper columns of the main arch at the arch foot position of the main arch, their height is relatively high and their self-weight is relatively large, which causes a large concentrated force and bending moment on the main arch. Therefore, in this technical solution, a stiffening area is provided at the arch foot position of the main arch. The stiffening area can enhance the structural strength of the main arch in the stiffening area by welding stiffening steel plates at the abdominal tubes of the main arch.

[0020] As a preferred technical solution of the present invention, further, the web members between the upper chord member and the lower chord member corresponding to the main arch include a plurality of transverse web members and a plurality of inclined web members. The transverse web members, inclined web members, upper chord member, and lower chord member in the stiffening area enclose a plurality of closed triangular frames arranged vertically, and stiffening steel plates are welded along the inner edge of the closed triangular frames. In this technical solution, in the stiffening area, the web members of the main arch, the upper chord member, and the lower chord member enclose a plurality of closed triangular frames. The triangular frame structure is relatively stable. To strengthen this triangular frame structure, stiffening steel plates are also welded along the inner edge of the closed triangular frames in the stiffening area. Through the above arrangement, the load-bearing capacity of the main arch in the stiffening area is significantly enhanced.

[0021] As a preferred technical solution of the present invention, further, in each side of the main arch, one end of the stiffening area is located at the arch springing of the main arch, and the other end is located between any upper column of the main arch and the arch crown of the main arch. To further ensure the overall strength of the main arch, in this technical solution, the stiffening area is further defined. Specifically, since there are still one or two relatively tall upper columns of the main arch at the arch springing of the main arch, these upper columns of the main arch cause a relatively large concentrated force and bending moment on the main arch. Therefore, the stiffening area should extend from the arch springing of the main arch to between the upper column of the main arch closest to the abutment side and the arch crown on the same side to strengthen the position where the main arch is more stressed.

[0022] As a preferred technical solution of the present invention, further, the span of the abdominal arch is 80m - 120m, and the single-span span of the bridge deck beam is 40m - 60m. This technical solution aims to provide a size selection for the abdominal arch and the bridge deck beam that is convenient for construction.

[0023] This application provides a long-span deck-type concrete-filled steel tube arch bridge, which has at least the following beneficial effects:

[0024] 1. By setting the abdominal arch above the arch springing position of the main arch, the number of relatively tall upper columns of the main arch at the arch springing of the main arch can be reduced. Since the relatively tall upper columns of the main arch will generate a relatively large concentrated force and bending moment on the main arch, therefore, by setting the abdominal arch, the concentrated force and bending moment received by the main arch can be reduced. In addition, the self-weight of the upper columns of the main arch is large, and the shortening of its overall height means that the self-weight of the bridge body of the concrete-filled steel tube arch bridge can be reduced to a certain extent, that is, the dead load of the main arch is reduced;

[0025] 2. Some of the upper columns of the main arch are connected by the abdominal arch. The setting of the abdominal arch increases the longitudinal stability of the connected upper columns of the main arch and improves the longitudinal stiffness of the bridge body;

[0026] 3. The abdominal arch is a concrete-filled steel tube dumbbell-shaped structure, which has relatively low production and transportation costs, is simple to assemble, and is convenient for construction. Using the abdominal arch to replace some of the upper columns of the main arch can significantly reduce the engineering difficulty and project cost;

[0027] 4. Through the combination of the above beneficial effects, the concrete-filled steel tube arch bridge described in this application can reach a span level greater than 700m, meeting the design requirements of the current concrete-filled steel tube arch bridge with a span of 750m. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic structural diagram of the concrete-filled steel tube arch bridge described in Embodiment 1;

[0029] Figure 2 It is an enlarged schematic diagram of one side structure of the concrete-filled steel tube arch bridge described in Embodiment 1;

[0030] Figure 3 It is a schematic structural diagram of the concrete-filled steel tube arch bridge described in Embodiment 2;

[0031] Figure 4 It is an enlarged schematic diagram of one side structure of the concrete-filled steel tube arch bridge described in Embodiment 2;

[0032] Figure 5 For Figure 4 the enlarged view at A in;

[0033] Figure 6 It is a schematic structural diagram of the concrete-filled steel tube arch bridge described in Embodiment 3;

[0034] Figure 7 It is an enlarged schematic diagram of one side structure of the concrete-filled steel tube arch bridge described in Embodiment 3.

[0035] Markings in the figure:

[0036] 1 - Main arch, 11 - Main arch seat, 111 - Upper chord, 112 - Lower chord, 113 - Horizontal abdominal tube, 114 - Oblique abdominal tube, 12 - Stiffening area, 121 - Stiffening steel plate, 2 - Abdominal arch, 21 - First abdominal arch, 22 - Second abdominal arch, 23 - Abdominal arch seat, 24 - Abdominal arch column, 3 - Upper column of the main arch, 4 - Junction pier, 5 - Bridge deck beam, 6 - Pier column, 7 - Tie rod cable. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] The present invention will be further described in detail below in conjunction with the embodiments and the accompanying drawings. However, this should not be construed as limiting the scope of the subject matter of the present invention to the following embodiments. All technologies implemented based on the content of the present invention belong to the scope of the present invention.

[0038] Embodiment 1

[0039] This embodiment provides a long-span deck concrete-filled steel tube arch bridge, which is applied above a certain canyon, that is, the concrete-filled steel tube arch bridge in this embodiment is a valley-crossing bridge.

[0040] As Figure 1 and Figure 2 shown, the concrete-filled steel tube arch bridge includes a main arch 1, main arch abutments 11, spandrel arches 2, spandrel arch abutments 23, main arch columns above the arch 3, transition piers 4, and a deck beam 5.

[0041] There are two main arch abutments 11, which are respectively arranged on the foundation bases on both sides of the canyon. The main arch 1 is arranged between the two main arch abutments 11 on both sides and is supported by the main arch abutments 11. In this embodiment, taking the main arch 1 adopting a concrete-filled steel tube truss structure as an example, the deck beam 5 is arranged above the main arch 1, and the deck beam 5 connects both sides of the canyon to form a continuous passage. The upper ends of the main arch columns above the arch 3 and the transition piers 4 support and connect the deck beam 5. The deck beam 5 is supported on the main arch 1 and the foundation bases on both sides through the main arch columns above the arch 3, spandrel arches 2, and transition piers 4. Among them, the most important is the supporting effect of the main arch 1 on the deck beam 5.

[0042] In this embodiment, there are two transition piers 4, which are symmetrically arranged along the vertical central axis plane of the main arch 1 in the transverse direction of the bridge. Referring to Figure 2 , in any side of the main arch 1, there is one transition pier 4 respectively. The two transition piers 4 are located between the main arch abutment 11 and the same-side abutment, and the lower end of the transition pier 4 shares a foundation base with the main arch abutment 11.

[0043] The concrete-filled steel tube arch bridge includes several spandrel arches 2, which are respectively arranged on both sides of the main arch 1 and are symmetrically arranged along the vertical central axis plane of the main arch 1 in the transverse direction of the bridge. Specifically, the spandrel arch 2 includes a first spandrel arch 21 and a second spandrel arch 22. On each side of the main arch 1, there is one first spandrel arch 21. One end of the first spandrel arch 21 is connected to and supported by the spandrel arch abutment 23, and the other end of the first spandrel arch 21 is connected to and supported by the transition pier 4.

[0044] On each side of the main arch 1, the second abdominal arch 22 is arranged between the boundary pier 4 and the crown of the main arch 1 on the same side. There are three second abdominal arches 22 with the same span and evenly arranged on each side of the main arch 1. Among the three second abdominal arches 22, one end of the second abdominal arch 22 closest to the abutment side is connected to and supported by the boundary pier 4, and the other end is connected to the arch-column on the main arch on the same side adjacent to the boundary pier 4; one end of the second abdominal arch 22 closest to the crown of the main arch 1 is connected to and supported by the main arch 1, and the other end is connected to the corresponding adjacent arch-column on the main arch 3; the remaining second abdominal arches 22 located between the aforementioned two second abdominal arches are respectively connected to the adjacent arch-columns on the main arch 3 at both ends. In order to ensure that the second abdominal arch 22 is arranged at a relatively high position of the arch-column on the main arch, it is further defined that the second abdominal arch 22 is continuously arranged between the arch-columns 3 on the main arch in the direction from the boundary pier 4 to the crown of the main arch 1. At the same time, this continuous arrangement method is more conducive to construction and is beneficial to shortening the construction period.

[0045] In this embodiment, the arch-column 3 on the main arch is of a steel box structure. The abdominal arches 2 are all of a concrete-filled steel tube dumbbell structure. The deck girders 5 are all of a simply supported beam structure, specifically a prestressed concrete simply supported beam structure, that is, the deck is composed of multiple sections of prestressed concrete simply supported beam structures spliced end to end. At the connection positions of the deck girders 5, they are supported and connected by the arch-column 3 on the main arch, the boundary pier 4 or the abdominal arch 2.

[0046] An abdominal arch column 24 or an abdominal arch support is provided at the upper end of the abdominal arch. In this embodiment, considering the terrain and construction convenience, the span of the first abdominal arch 21 is 120 m, and an abdominal arch column 24 is provided at the upper end of the middle part thereof. The abdominal arch column 24 supports and connects the connection positions of two sections of the deck girders 5. Correspondingly, the single-span of the deck girder 5 above the first abdominal arch 21 is 60 m, that is, there are two sections of the deck girders 5 above the first abdominal arch 21. In addition, a pier column 6 is provided on each side of the two abutments. The pier column 6 is of a relatively low height and can assist in supporting the deck girder 5.

[0047] The spans of the second abdominal arches 22 are all 80 m, and an abdominal arch column 24 is provided at the upper end of the middle part of each second abdominal arch 22 and supports the connection positions of two sections of the deck girders 5. Correspondingly, the single-span of the deck girder 5 above each second abdominal arch 22 is 40 m, that is, there are also two sections of the deck girders 5 above the first abdominal arch 21.

[0048] In this embodiment, by arranging eight of the abdominal arches 2 between the main arch 1 and the bridge deck beam 5, the overall height of the columns 3 above the main arch is significantly reduced. Since the self-weight of the columns 3 above the main arch is large, the construction is difficult, the cost is high, and the stability is poor. Therefore, through the above arrangement, the self-weight of the bridge body of the concrete-filled steel tube arch bridge can be reduced, the construction difficulty can be reduced, and its stability can be improved. In particular, the abdominal arches 2 are arranged in sequence from the abutment side to the crown side of the main arch 1, which can minimize the total height of the columns 3 above the main arch.

[0049] The greater the height of the columns 3 above the main arch, the worse the stability. In this embodiment, through the arrangement of several abdominal arches 2, the adjacent columns 3 above the main arch at both ends of the abdominal arches 2 are connected, and a longitudinal connection structure is formed between the columns 3 above the main arch, strengthening the stability of the columns 3 above the main arch and improving the longitudinal stiffness of the bridge body. In addition, if a large number of columns 3 above the main arch with a large height directly connect the bridge deck beam 5 and the main arch 1, the columns 3 above the main arch will exert a large concentrated force and bending moment on the main arch 1, which is not conducive to the structural stability of the main arch 1. Therefore, this embodiment uses the abdominal arches 2 to reduce the number of columns 3 above the main arch with a large height, significantly improving the stability of the bridge body.

[0050] Through the above arrangement, the self-weight of the concrete-filled steel tube arch bridge in this embodiment is reduced, and at the same time, the number of columns 3 above the main arch with a large height is reduced, which can reduce the dead load of the main arch 1 and improve the stability of the concrete-filled steel tube arch bridge. As a substitute for some of the columns 3 above the main arch, the abdominal arches 2 adopt a concrete-filled steel tube dumbbell structure, which has a light self-weight, high strength, and is convenient for assembly and construction, and can relatively reduce the construction difficulty and project cost.

[0051] Embodiment 2

[0052] As Figure 3 、 Figure 4 and Figure 5 shown, on the basis of Embodiment 1, further, in this embodiment, a stiffening zone 12 is provided at the arch foot position of the main arch 1, and a stiffening steel plate 121 is provided at the abdominal tube of the main arch 1 in the stiffening zone 12. Specifically, the abdominal tubes between the corresponding upper chord 111 and lower chord 112 of the main arch 1 include inclined abdominal tubes 114 and transverse abdominal tubes 113. A number of vertically arranged closed triangular frames are formed between the inclined abdominal tubes 114, transverse abdominal tubes 113, upper chord 111, and lower chord 112 in the stiffening zone 12, and stiffening steel plates 121 are welded along the inner edge of the closed triangular frames. Through this arrangement, the bearing capacity of the main arch 1 in the stiffening zone 12 is significantly improved.

[0053] On both sides of the main arch 1, since the upper columns 3 on the main arch at the arch feet are higher, the upper columns 3 on the main arch in this area exert a relatively large concentrated force and bending moment on the main arch 1. Therefore, we set one end of the stiffening zone 12 at the arch feet of the main arch 1 and the other end between the upper columns 3 on the main arch and the crown of the main arch 1. Specifically, in this embodiment, the stiffening zone 12 extends from the arch feet to the position of the second upper column 3 on the main arch arranged from the abutment side towards the crown of the main arch 1, that is, from the abutment side to the crown direction of the main arch 1, and the connection positions of the two upper columns 3 on the main arch on both sides with the main arch 1 fall within the stiffening zone 12 of the main arch 1.

[0054] Through this setting, the overall lateral out-of-plane stiffness and load-bearing capacity of the main arch 1 are improved, further enhancing the strength, stiffness and stability of the concrete-filled steel tube arch bridge.

[0055] In this embodiment, the content not specifically described otherwise is the same as that in Embodiment 1.

[0056] Embodiment 3

[0057] As Figure 6 and Figure 7 shown, on the basis of Embodiment 2, further, in the concrete-filled steel tube arch bridge of this embodiment, the spandrel arch 2 is connected with tie cables 7, and the tie cables 7 are tensioned between the spandrel arches 2. Specifically, a plurality of tie cables 7 are provided and are respectively connected to the spandrel arches 2. In this embodiment, the tie cables 7 adopt conventional existing steel strand tie cables. The purpose of setting the tie cables 7 is that the spandrel arch 2 will generate a horizontal thrust on the connected upper columns 3 on the main arch, the main arch 1 or the transition pier 4. In order to eliminate the influence of this horizontal thrust, we set the tie cables 7 at the spandrel arch 2 and balance the horizontal thrust caused by the spandrel arch 2 on the connected main arch 1, the upper columns 3 on the main arch or the transition pier 4 by setting the tension magnitude of the tie cables 7.

[0058] In this embodiment, by setting the tie cables 7 to balance the horizontal thrust of the spandrel arch 2 on structures such as the main arch 1 and the upper columns 3 on the main arch, the stability of the concrete-filled steel tube arch bridge can be further improved on the basis of the concrete-filled steel tube arch bridge described in Embodiment 2.

[0059] In this embodiment, the content not specifically described otherwise is the same as that in Embodiment 2.

[0060] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A long-span top-supported steel tube concrete arch bridge, comprising a main arch (1), a main arch upper column (3), a junction pier (4) and a bridge deck beam (5), characterized in that: It also includes a ventral arch (2), the ventral arch (2) supports the bridge deck beam (5), the ventral arch (2) is arranged on both sides of the main arch (1), the ventral arch (2) includes a first ventral arch (21) and a second ventral arch (22), and on each side of the main arch (1): the first ventral arch (21) is arranged between the junction pier (4) and the abutment, the two ends of the first ventral arch (21) are respectively connected to the junction pier (4) and the ventral arch seat (23), the junction pier (4) and the arch top of the main arch (1) are connected to each other. At least two second ventral arches (22) are arranged along the longitudinal direction of the bridge, the two ends of the second ventral arch (22) closest to the abutment are respectively connected to the junction pier (4) and the corresponding main arch upper column (3), the second ventral arch (22) closest to the arch top of the main arch (1) has one end connected to the main arch (1) and the other end connected to the corresponding main arch upper column (3), and the two ends of the remaining second ventral arches (22) are respectively connected to two corresponding adjacent main arch upper columns (3); The second ventral arch (22) is continuously arranged between the upper columns (3) of the main arch in the direction from the junction pier (4) to the arch top of the main arch (1), and the upper columns (3) of the main arch are longitudinally connected by the ventral arch (2); The web arch seat (23) is provided with a pier column (6), and the pier column (6) is used to support the bridge deck beam (5).

2. The steel tube concrete arch bridge according to claim 1, characterized in that: The upper end of the ventral arch (2) is provided with a ventral arch column (24) or a ventral arch support, and the ventral arch (2) supports the bridge deck beam (5) through the ventral arch column (24) or the ventral arch support.

3. The steel tube concrete arch bridge according to claim 1, characterized in that: The belly arch (2) is connected with a tie rod cable (7).

4. The steel tube concrete arch bridge according to any one of claims 1 to 3, characterized in that: The web arch (2) is a dumbbell-shaped structure of steel tube concrete, and the bridge deck beam (5) is a simply supported beam structure.

5. The steel tube concrete arch bridge according to any one of claims 1 to 3, characterized in that: The upper column (3) of the main arch is a steel box structure, and the main arch (1) is a steel tube concrete truss structure.

6. The steel tube concrete arch bridge according to claim 5, characterized in that: A stiffening area (12) is provided at the arch foot of the main arch (1), and a stiffening steel plate (121) is provided at the main arch soffit tube of the stiffening area (12).

7. The steel tube concrete arch bridge according to claim 6, characterized in that: The web tubes between the upper chord (111) and the lower chord (112) corresponding to the main arch (1) include a plurality of transverse web tubes (113) and a plurality of oblique web tubes (114); the transverse web tubes (113), the oblique web tubes (114), the upper chord (111) and the lower chord (112) of the stiffening area (12) form a plurality of closed triangular frames arranged vertically, and the stiffening steel plates (121) are welded to the inner edges of the closed triangular frames.

8. The steel tube concrete arch bridge according to claim 6, characterized in that: On each side of the main arch (1), one end of the stiffening area (12) is located at the arch foot of the main arch (1), and the other end is located between any one of the main arch upper columns (3) and the arch top of the main arch (1).

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