A combined high-speed railway and highway continuous steel truss composite girder bridge and construction method

Abstract

The embodiment of the present application provides a combined continuous steel truss and girder bridge for high-speed railway and highway, comprising: a steel truss girder, a highway bridge deck system and a railway bridge deck system; the steel truss girder includes two main trusses and a plurality of upper cross girders, and each main truss includes an upper chord, a lower chord and web members; the upper cross girders are connected to the upper chords of the two main trusses; the highway bridge deck system includes a concrete bridge deck and a plurality of concrete cross beams; the concrete bridge deck is connected to the upper chords of the two main trusses through shear studs; the railway bridge deck system includes an orthotropic steel bridge deck and diaphragm beams, the orthotropic steel bridge deck is connected to the lower chords of the two main trusses, and a plurality of diaphragm beams are arranged on the lower side of the orthotropic steel bridge deck. The embodiment of the present application also provides a construction method for the combined continuous steel truss and girder bridge for high-speed railway and highway. The combined continuous steel truss and girder bridge for high-speed railway and highway and the construction method in the embodiment of the present application can reduce the project cost and improve the driving conditions of the road surface while increasing the structural stiffness.

Description

Technical Field

[0001] The present invention relates to the field of bridge engineering, and particularly to a continuous steel truss composite girder bridge for combined highway and railway of high-speed railway and a construction method thereof. Background Art

[0002] With the increase of China's investment in infrastructure construction, the large-scale construction of high-speed railways and passenger dedicated lines has led to a significant increase in the number of bridges built. The bridges for combined highway and railway of high-speed railway are bound to increase.

[0003] However, in the related art, the steel consumption of the combined highway and railway bridge with a designed speed of 350 km / h is relatively large, and the project cost is not economical. Moreover, the stiffness is weak, and the running conditions of the train are poor. Summary of the Invention

[0004] In view of this, the main purpose of the embodiments of the present application is to provide a continuous steel truss composite girder bridge for combined highway and railway of high-speed railway and a construction method thereof, so as to solve the technical problems that the steel consumption of the combined highway and railway bridge in the related art is relatively large, the stiffness is weak, and the running conditions of the train are poor.

[0005] To achieve the above object, the technical solution of the embodiments of the present application is realized as follows:

[0006] An embodiment of the present application provides a continuous steel truss composite girder bridge for combined highway and railway of high-speed railway, including:

[0007] A steel truss girder, the steel truss girder includes two main trusses and a plurality of upper cross girders. The main truss includes upper chord bars, lower chord bars arranged in parallel at intervals, and a plurality of web members connecting the upper chord bars and the lower chord bars; the two main trusses are arranged at intervals in the transverse direction of the bridge, the plurality of upper cross girders are arranged between the two main trusses and at intervals in the longitudinal direction of the bridge, and each upper cross girder is connected to the upper chord bars of the two main trusses;

[0008] A highway bridge deck system, the highway bridge deck system includes a concrete bridge deck and a plurality of concrete cross beams connected to the concrete bridge deck. The plurality of concrete cross beams are arranged at intervals in the longitudinal direction of the bridge; the concrete bridge deck is connected to the upper chord bars of the two main trusses through shear studs;

[0009] A railway bridge deck system, the railway bridge deck system includes an orthotropic steel bridge deck and a plurality of diaphragm beams arranged at intervals in the longitudinal direction of the bridge. The orthotropic steel bridge deck is connected to the lower chord bars of the two main trusses, and the plurality of diaphragm beams are arranged on the lower side of the orthotropic steel bridge deck and are connected to the orthotropic steel bridge deck and the lower chord bars of the two main trusses.

[0010] In some embodiments, one upper cross girder is arranged on the lower side of each concrete cross beam.

[0011] In some embodiments, the two main trusses are inclined, and the top width of the cross-section of the steel truss girder is greater than the bottom width of the cross-section of the steel truss girder.

[0012] In some embodiments, the highway bridge deck system includes a plurality of precast segments, and the plurality of precast segments are assembled on the steel truss girder to form the highway bridge deck system.

[0013] In some embodiments, the precast segment includes two post-cast strips arranged at intervals in the transverse bridge direction, and a plurality of concrete cross beams are located between the two post-cast strips;

[0014] The post-cast strip includes a post-cast trough chamber and a plurality of perfusion holes. The post-cast trough chamber is arranged at the bottom of the precast segment, and the plurality of perfusion holes pass through the concrete bridge deck from the top surface of the concrete bridge deck and communicate with the post-cast trough chamber;

[0015] After the plurality of precast segments are assembled on the steel truss girder to form the highway bridge deck system, the shear studs connecting the concrete bridge deck and the upper chord are all located in the post-cast trough chambers of the corresponding precast segments.

[0016] In some embodiments, the railway bridge deck system further includes small longitudinal beams;

[0017] A plurality of the small longitudinal beams are arranged between every two adjacent cross diaphragms, and each small longitudinal beam is connected to the orthotropic steel bridge deck and the two adjacent cross diaphragms.

[0018] In some embodiments, the high-speed railway combined highway-railway continuous steel truss composite girder bridge further includes a track system laid on the orthotropic steel bridge deck, and a plurality of the small longitudinal beams are located below the track system.

[0019] In some embodiments, the high-speed railway combined highway-railway continuous steel truss composite girder bridge further includes a plurality of middle piers. A part of the structure of the bottom surface of the upper chord projects downward to form a plurality of pier top upper chord strengthening sections arranged at intervals in the longitudinal bridge direction, and a part of the structure of the bottom surface of the lower chord projects downward to form a plurality of pier top lower chord strengthening sections arranged at intervals in the longitudinal bridge direction;

[0020] The pier top upper chord strengthening sections, the pier top lower chord strengthening sections and the middle piers correspond one by one. Each middle pier is connected to the corresponding pier top lower chord strengthening section, and each pier top upper chord strengthening section is located above the corresponding pier top lower chord strengthening section.

[0021] In some embodiments, the steel truss girder further includes a plurality of portal frames. At least one portal frame is provided on one side of the vertical center line of each intermediate pier. Each portal frame is connected to the corresponding upper cross beam, the enhanced section of the upper chord of the pier top, and the web member.

[0022] Another embodiment of the present application further provides a construction method for a high-speed railway-road combined continuous steel truss composite beam bridge for the above-mentioned high-speed railway-road combined continuous steel truss composite beam bridge. The orthotropic steel bridge deck includes a plurality of steel bridge deck units, and the steel truss girder includes a plurality of steel truss girder segments. The construction method includes:

[0023] Construct the side piers, intermediate piers and foundations;

[0024] Connect the steel bridge deck units and the diaphragm beams to the corresponding steel truss girder segments to form structural units;

[0025] Lift the structural units, splice the structural units into a continuous structure, and lift the continuous structure to a preset height at the intermediate pier;

[0026] Lift the highway bridge deck system onto the steel truss girder and pour the post-cast concrete to connect the highway bridge deck system to the steel truss girder;

[0027] Lower the jacking part of the continuous structure at the intermediate pier position back to the design position;

[0028] Tension the prestress of the concrete bridge deck;

[0029] Complete the bridge.

[0030] The embodiment of the present application provides a high-speed railway-road combined continuous steel truss composite beam bridge and a construction method. The steel truss girder and the railway bridge deck system of the high-speed railway-road combined continuous steel truss composite beam bridge are steel structures, and the highway bridge deck system is a concrete structure. At the same time, the upper chord and the lower chord in the steel truss girder are arranged in parallel, and a plurality of upper cross beams are arranged between the two main trusses and connected to the upper chords of the two main trusses. The concrete bridge deck of the highway bridge deck system is connected to the upper chords of the two main trusses through shear studs. The bridge deck in the railway bridge deck system is an orthotropic steel bridge deck. This makes the high-speed railway-road combined continuous steel truss composite beam bridge not only able to greatly improve the structural stiffness, but also able to reduce the height of the steel truss girder, saving steel consumption and reducing project cost, while also improving the driving conditions of the road surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is an elevation view of a high-speed railway-road combined continuous steel truss composite beam bridge provided by an embodiment of the present application;

[0032] Figure 2 isFigure 1 Cross-sectional views at A-A and B-B, where the right side of the center line is the half cross-section of A-A and the left side of the center line is the half cross-section of B-B;

[0033] Figure 3 is Figure 1 Cross-sectional view at C-C in;

[0034] Figure 4 is Figure 3 Schematic diagram of the connection relationship between the highway bridge deck system and the steel truss girder shown in, where the post-cast strip in the figure is in the state before concrete pouring;

[0035] Figure 5 is Figure 3 Schematic diagram of the connection relationship between the highway bridge deck system and the steel truss girder shown in, where the post-cast strip in the figure is in the state after concrete pouring;

[0036] Figure 6 Flow chart of a construction method for a high-speed railway combined highway-railway continuous steel truss composite beam bridge provided by an embodiment of the present application.

[0037] Reference numerals:

[0038] Steel truss girder 10; Main truss 11; Upper chord 111; Enhanced section of the upper chord at the pier top 111a; Lower chord 112; Enhanced section of the lower chord at the pier top 112a; Web member 113; Upper cross-tie beam 12; Bridge portal frame 13; Highway bridge deck system 20; Concrete bridge deck 21; Prefabricated segment 211; Post-cast strip 211a; Post-cast slot 211b; Pouring hole 211c; Concrete cross beam 22; Railway bridge deck system 30; Orthotropic steel bridge deck 31; Diaphragm beam 32; Small longitudinal beam 33; Shear studs 40; Middle pier 50; Side pier 60; Track system 70. Detailed implementation manners

[0039] It should be noted that, without conflict, the embodiments in the present application and the technical features in the embodiments can be combined with each other. The detailed description in the detailed implementation manners should be understood as an explanatory illustration of the purpose of the present application and should not be regarded as an improper limitation to the present application.

[0040] In the description of the present application, the "longitudinal direction of the bridge" orientation or positional relationship is based on the attached Figure 1 , and the "transverse direction of the bridge", "top", and "bottom" orientation or positional relationships are based on the attached Figure 2 shown orientation or positional relationship, where "upper" and "lower" are the top-bottom directions of the attached Figure 2 . It should be understood that these orientation terms are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application.

[0041] An embodiment of the present application provides a combined high-speed railway and highway continuous steel truss composite beam bridge. Please refer to Figures 1 to 5 , the combined high-speed railway and highway continuous steel truss composite beam bridge includes: a steel truss beam 10, a highway bridge deck system 20, and a railway bridge deck system 30. The steel truss beam 10 includes two main trusses 11 and a plurality of upper cross girders 12. The main trusses 11 include upper chord members 111, lower chord members 112 arranged in parallel at intervals, and a plurality of web members 113 connecting the upper chord members 111 and the lower chord members 112. The two main trusses 11 are arranged at intervals in the transverse direction of the bridge. The plurality of upper cross girders 12 are arranged between the two main trusses 11 and at intervals in the longitudinal direction of the bridge. Each upper cross girder 12 is connected to the upper chord members 111 of the two main trusses 11. That is to say, the steel truss beam 10 is a steel structure. One end of each upper cross girder 12 is connected to the upper chord member 111 of one of the main trusses 11, and the other end of each upper cross girder 12 is connected to the upper chord member 111 of the other main truss 11. Thus, the overall stiffness of the steel truss beam 10 can be improved.

[0042] The highway bridge deck system 20 includes a concrete bridge deck 21 and a plurality of concrete cross girders 22 connected to the concrete bridge deck 21. The plurality of concrete cross girders 22 are arranged at intervals in the longitudinal direction of the bridge. The concrete bridge deck 21 is connected to the upper chord members 111 of the two main trusses 11 through shear studs 40. That is to say, the highway bridge deck system 20 is a concrete structure, and the highway bridge deck system 20 is arranged on the upper side of the steel truss beam 10.

[0043] The railway bridge deck system 30 includes an orthotropic steel bridge deck 31 and a plurality of diaphragm beams 32 arranged at intervals in the longitudinal direction. The orthotropic steel bridge deck 31 is connected to the lower chord members 112 of the two main trusses 11. The plurality of diaphragm beams 32 are arranged on the lower side of the orthotropic steel bridge deck 31 and are connected to the orthotropic steel bridge deck 31 and the lower chord members 112 of the two main trusses 11. That is to say, the railway bridge deck system 30 is arranged on the lower side of the steel truss beam 10 and is a steel structure.

[0044] In the related art, the upper chord members and lower chord members of the combined railway and highway bridge generally adopt a variable height structure, that is, the upper chord members and lower chord members are not arranged in parallel. Moreover, for combined railway and highway bridges with a design speed of 350 km / h, a large amount of steel structures are generally used, resulting in a large amount of steel consumption and weak stiffness, and the running conditions of trains are poor.

[0045] In this embodiment, the continuous steel truss composite girder bridge for high-speed railway and highway co-construction adopts a steel truss-concrete composite girder, with the highway and railway arranged in layers. Among them, the steel truss girder 10 is a steel structure, the highway bridge deck system 20 arranged on the upper side of the steel truss girder 10 is a concrete structure, and the railway bridge deck system 30 arranged on the lower side of the steel truss girder 10 is a steel structure. The concrete highway bridge deck system 20 gives full play to the compressive performance of concrete, improves the structural stiffness, improves the driving conditions, and greatly reduces the steel consumption of the continuous steel truss composite girder bridge for high-speed railway and highway co-construction. The orthotropic steel bridge deck 31 in the railway bridge deck system 30 can reduce the self-weight of the structure. Compared with the co-construction bridge in the related technology, the continuous steel truss composite girder bridge for high-speed railway and highway co-construction in this embodiment can greatly improve the structural stiffness. Therefore, the height of the steel truss girder 10 can be reduced, saving steel consumption and reducing the project cost while improving the driving conditions on the road surface. The designed speed of the continuous steel truss composite girder bridge for high-speed railway and highway co-construction in this embodiment can reach 350 km / h.

[0046] In addition, the overall layout form of the steel truss girder 10 in this embodiment is low truss height and parallel chords. Therefore, while minimizing the height of the steel truss girder 10, the space of each part of the continuous steel truss composite girder bridge for high-speed railway and highway co-construction can be fully utilized, and the cross-section of the continuous steel truss composite girder bridge for high-speed railway and highway co-construction can be compactly arranged. Furthermore, while improving the structural integrity of the continuous steel truss composite girder bridge for high-speed railway and highway co-construction, the shape of the continuous steel truss composite girder bridge for high-speed railway and highway co-construction can be made more concise and beautiful.

[0047] Please refer to Figures 2 to 5 , in this embodiment, a upper cross beam 12 is arranged on the lower side of each concrete cross beam 22. That is to say, each concrete cross beam 22 is arranged between the concrete bridge deck 21 and the corresponding upper cross beam 12. The number of concrete cross beams 22 can be less than the number of upper cross beams 12, as long as there is an upper cross beam 12 arranged under each concrete cross beam 22. Each concrete cross beam 22 can be in contact with the corresponding upper cross beam 12 or have a gap with the corresponding upper cross beam 12. The advantage of arranging the upper cross beam 12 on the lower side of the concrete cross beam 22 is that it can improve the overall lateral stiffness of the continuous steel truss composite girder bridge for high-speed railway and highway co-construction and ensure the integrity of the structure during construction and use.

[0048] In other embodiments, the upper cross beam 12 may not be arranged on the lower side of the concrete cross beam 22.

[0049] Please refer to Figure 1, in this embodiment, the high-speed railway combined highway and railway continuous steel truss composite girder bridge further includes a plurality of intermediate piers 50. Part of the structure of the bottom surface of the upper chord 111 bulges downward to form a plurality of upper chord strengthening sections 111a of the pier top arranged at intervals along the longitudinal bridge direction. Part of the structure of the bottom surface of the lower chord 112 bulges downward to form a plurality of lower chord strengthening sections 112a of the pier top arranged at intervals along the longitudinal bridge direction. The upper chord strengthening sections 111a of the pier top, the lower chord strengthening sections 112a of the pier top and the intermediate piers 50 correspond one by one. Each intermediate pier 50 is connected to the corresponding lower chord strengthening section 112a of the pier top. Each upper chord strengthening section 111a of the pier top is located above the corresponding lower chord strengthening section 112a of the pier top. That is to say, the thickness dimension of some areas of the upper chord 111 is greater than that of other areas, and the thickness dimension of some areas of the lower chord 112 is also greater than that of other areas. Moreover, the thickened areas of the upper chord 111 and the lower chord 112 are both near the intermediate pier 50. Thus, it can play a role in strengthening the surrounding area of the intermediate pier 50.

[0050] Further, please refer to Figure 1 and Figure 3 , the steel truss girder 10 of this embodiment further includes a plurality of bridge portal frames 13. One bridge portal frame 13 is respectively arranged on both sides of the vertical center line of each intermediate pier 50. Each bridge portal frame 13 is connected to the corresponding upper cross beam 12, the upper chord strengthening section 111a of the pier top and the web member 113. Setting the bridge portal frame 13 can also play a role in further strengthening the surrounding area of the intermediate pier 50.

[0051] It can be understood that in other embodiments, the number of bridge portal frames 13 on both sides of the vertical center line of each intermediate pier 50 can be adjusted as needed. The bridge portal frame 13 can also be only arranged on one side of the vertical center line of each intermediate pier 50, that is, as long as at least one bridge portal frame 13 is arranged on one side of the vertical center line of each intermediate pier 50. In other embodiments, the bridge portal frame 13 can also not be arranged.

[0052] Please refer to Figure 2 and Figure 3 , in this embodiment, the two main trusses 11 are inclined, and the top width of the cross section of the steel truss girder 10 is greater than the bottom width of the cross section of the steel truss girder 10. That is to say, the cross section of the steel truss girder 10 can be an inclined truss structure. Thus, the width of the orthotropic steel bridge deck 31 can be reduced to further reduce the project cost.

[0053] Further, please refer to Figures 3 to 5, the top surface of the upper cross tie beam 12 in this embodiment is flush with the top surfaces of the upper chord members 111 of the two main trusses 11, and the bottom surface of the concrete cross beam 22 is flush with the bottom surface of the concrete bridge deck 21. The bottom surface of the concrete bridge deck 21 and the top surfaces of the upper chord members 111 of the two main trusses 11 are connected by shear studs 40. Thus, it is convenient to connect the concrete bridge deck 21 to the upper chord members 111.

[0054] Please refer to Figure 4 and Figure 5 , the highway bridge deck system 20 in this embodiment includes a plurality of precast segments 211, and the plurality of precast segments 211 are assembled on the steel truss beam 10 to form the highway bridge deck system 20. That is to say, the highway bridge deck system 20 in this embodiment adopts the segment precast and assembled technology. The precast segments 211 are precast in the factory and then assembled at the construction site. Thus, not only can the on-site construction period be shortened, but also the construction quality can be improved.

[0055] Furthermore, please refer to Figure 4 , the precast segment 211 in this embodiment includes two post-cast strips 211a arranged at intervals in the transverse direction of the bridge, and a plurality of concrete cross beams 22 are located between the two post-cast strips 211a. The post-cast strip 211a includes a post-cast groove chamber 211b and a plurality of perfusion holes 211c. The post-cast groove chamber 211b is arranged at the bottom of the precast segment 211, and the plurality of perfusion holes 211c penetrate through the concrete bridge deck 21 from the top surface of the concrete bridge deck 21 and communicate with the post-cast groove chamber 211b. After the plurality of precast segments 211 are assembled on the steel truss beam 10 to form the highway bridge deck system 20, the shear studs 40 connecting the concrete bridge deck 21 to the upper chord members 111 are all located in the post-cast groove chambers 211b of the corresponding precast segments 211. That is to say, the setting position of the post-cast groove chamber 211b corresponds to the setting position of the shear studs 40 on the steel truss beam 10. Please refer to Figure 5 , after the plurality of precast segments 211 are assembled on the steel truss beam 10, concrete can be poured into the post-cast groove chamber 211b through the perfusion holes 211c, so that the concrete bridge deck 21 can be connected to the upper chord members 111 of the two main trusses 11 through the shear studs 40.

[0056] Please refer to Figure 2 and Figure 3 , the railway bridge deck system 30 in this embodiment further includes small longitudinal beams 33. A plurality of small longitudinal beams 33 are arranged between every two adjacent diaphragm beams 32, and each small longitudinal beam 33 is connected to the orthotropic steel bridge deck 31 and the two adjacent diaphragm beams 32.

[0057] Arranging a plurality of small longitudinal beams 33 can improve the strength and stiffness of the railway bridge deck system 30 to improve the driving conditions.

[0058] Furthermore, please refer to Figure 2 andFigure 3 In addition, the combined continuous steel truss and girder bridge for high-speed railway and highway in this embodiment further includes an track system 70 laid on the orthotropic steel bridge deck 31, and a plurality of small longitudinal girders 33 are located below the track system 70. That is to say, the plurality of small longitudinal girders 33 can be arranged only below the track system 70, thereby improving the driving conditions.

[0059] Another embodiment of the present application further provides a construction method for a combined continuous steel truss and girder bridge for high-speed railway and highway, which is used for the combined continuous steel truss and girder bridge for high-speed railway and highway described above. Among them, the orthotropic steel bridge deck 31 includes a plurality of steel bridge deck units, and the steel truss girder 10 includes a plurality of steel truss girder segments. That is to say, the orthotropic steel bridge deck 31 is assembled by a plurality of steel bridge deck units, and the steel truss girder 10 is assembled by a plurality of steel truss girder segments. Please refer to Figure 1 and Figure 6 , the construction method mainly includes the following steps:

[0060] S701: Construct the side piers 60, middle piers 50 and foundations;

[0061] S702: Weld the steel bridge deck units and diaphragm beams 32 to the corresponding steel truss girder segments to form structural units;

[0062] Specifically, the steel truss girder segments can be fabricated in a factory, and then the steel bridge deck units and diaphragm beams 32 are installed on the corresponding steel truss girder segments. After a steel truss girder segment is connected to the corresponding steel bridge deck unit and diaphragm beam 32, a structural unit is formed, which is equivalent to the number of structural units being the same as the number of steel truss girder segments.

[0063] In addition, there is no sequence requirement between step S701 and step S702, and the two steps can be carried out synchronously.

[0064] S703: Lift the structural units, splice the structural units into a continuous structure, and lift the continuous structure to a preset height at the middle pier;

[0065] This step is also called beam jacking.

[0066] S704: Lift the highway bridge deck system 20 onto the steel truss girder 10, and pour the post-cast concrete to connect the highway bridge deck system 20 and the steel truss girder 10 to form an integral structure;

[0067] Specifically, the highway bridge deck system 20 can also include a plurality of precast segments 211. The precast segments 211 are precast in a factory, cured and stored, and then assembled on the steel truss girder 10 to form the highway bridge deck system 20.

[0068] S705: Lower the jacking part of the integral structure at the middle pier position back to the designed position;

[0069] This step is also called the beam lowering.

[0070] S706: Tension the prestress of the concrete bridge deck 21;

[0071] S707: Complete the bridge construction.

[0072] Specifically, in the actual construction process, after tensioning the prestress of the concrete bridge deck 21, the construction of the auxiliary facilities can then be completed, and finally the bridge construction is completed.

[0073] That is to say, the construction method mainly adopted for the high-speed railway-road combined continuous steel truss composite beam bridge in this embodiment is the beam jacking and lowering method. This construction method can not only improve the problem of internal force concentration in the pier top structure, eliminate the setting of the stiffening structure, improve the spanning ability of the high-speed railway-road combined continuous steel truss composite beam bridge, but also reduce the tensile stress of the concrete bridge deck 21, and thus can reduce the number of prestressed steel bars embedded in the concrete bridge deck 21.

[0074] The above is only the preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A combined highway-railway continuous steel truss composite girder bridge for high-speed railway, characterized in that, it includes: A steel truss girder, the steel truss girder includes two main trusses and a plurality of upper cross girders. The main truss includes upper chord bars, lower chord bars arranged in parallel at intervals, and a plurality of web members connecting the upper chord bars and the lower chord bars; the two main trusses are arranged at intervals in the transverse direction of the bridge, and a plurality of upper cross girders are arranged between the two main trusses and at intervals in the longitudinal direction of the bridge. Each upper cross girder is connected to the upper chord bars of the two main trusses; A highway bridge deck system, the highway bridge deck system includes a concrete bridge deck and a plurality of concrete cross beams connected to the concrete bridge deck. The plurality of concrete cross beams are arranged at intervals in the longitudinal direction of the bridge; the concrete bridge deck is connected to the upper chord bars of the two main trusses through shear studs; A railway bridge deck system, the railway bridge deck system includes an orthotropic steel bridge deck and a plurality of diaphragm beams arranged at intervals in the longitudinal direction. The orthotropic steel bridge deck is connected to the lower chord bars of the two main trusses. The plurality of diaphragm beams are arranged on the lower side of the orthotropic steel bridge deck and are connected to the orthotropic steel bridge deck and the lower chord bars of the two main trusses; A plurality of intermediate piers, a partial structure of the bottom surface of the upper chord bar bulges downward to form a plurality of enhanced sections of the upper chord bar at the pier top arranged at intervals in the longitudinal direction of the bridge. A partial structure of the bottom surface of the lower chord bar bulges downward to form a plurality of enhanced sections of the lower chord bar at the pier top arranged at intervals in the longitudinal direction of the bridge; The enhanced section of the upper chord bar at the pier top, the enhanced section of the lower chord bar at the pier top and the intermediate pier correspond one by one. Each intermediate pier is connected to the corresponding enhanced section of the lower chord bar at the pier top, and each enhanced section of the upper chord bar at the pier top is located above the corresponding enhanced section of the lower chord bar at the pier top; The thickness of the relative two ends of the enhanced section of the upper chord bar at the pier top gradually increases in the direction of approaching each other along the longitudinal direction of the bridge; the thickness of the relative two ends of the enhanced section of the lower chord bar at the pier top gradually increases in the direction of approaching each other along the longitudinal direction of the bridge.

2. The combined highway-railway continuous steel truss composite girder bridge for high-speed railway according to claim 1, characterized in that, One upper cross girder is arranged on the lower side of each concrete cross beam.

3. The combined highway-railway continuous steel truss composite girder bridge for high-speed railway according to claim 1 or 2, characterized in that, The two main trusses are inclined, and the top width of the cross section of the steel truss girder is greater than the bottom width of the cross section of the steel truss girder.

4. The combined highway-railway continuous steel truss composite girder bridge for high-speed railway according to claim 1 or 2, characterized in that, The highway bridge deck system includes a plurality of precast segments, and the plurality of precast segments are assembled on the steel truss girder to form the highway bridge deck system.

5. The combined highway-railway continuous steel truss composite girder bridge for high-speed railway according to claim 4, characterized in that, The precast segment includes two post-cast strips arranged at intervals in the transverse direction of the bridge, and a plurality of concrete cross beams are located between the two post-cast strips; The post-cast strip includes a post-cast trough chamber and a plurality of perfusion holes. The post-cast trough chamber is arranged at the bottom of the precast segment. The plurality of perfusion holes penetrate through the concrete bridge deck from the top surface of the concrete bridge deck and communicate with the post-cast trough chamber. After the plurality of precast segments are assembled on the steel truss girder to form the highway bridge deck system, the shear studs connecting the concrete bridge deck and the upper chord are all located in the post-cast trough chambers of the corresponding precast segments.

6. The high-speed railway road-rail combined continuous steel truss composite girder bridge according to claim 1 or 2, characterized in that the railway bridge deck system further includes small longitudinal girders; A plurality of the small longitudinal girders are arranged between every two adjacent cross diaphragms, and each small longitudinal girder is connected to the orthotropic steel bridge deck and two adjacent cross diaphragms.

7. The high-speed railway road-rail combined continuous steel truss composite girder bridge according to claim 6, characterized in that the high-speed railway road-rail combined continuous steel truss composite girder bridge further includes a track system laid on the orthotropic steel bridge deck, and a plurality of the small longitudinal girders are located below the track system.

8. The high-speed railway road-rail combined continuous steel truss composite girder bridge according to claim 1, characterized in that the steel truss girder further includes a plurality of bridge portal frames. At least one bridge portal frame is arranged on one side of the vertical center line of each middle pier, and each bridge portal frame is connected to the corresponding upper cross bracing, the enhanced section of the pier top upper chord and the web member.

9. A construction method of a high-speed railway road-rail combined continuous steel truss composite girder bridge, which is used for the high-speed railway road-rail combined continuous steel truss composite girder bridge according to claim 1. The orthotropic steel bridge deck includes a plurality of steel bridge deck units, and the steel truss girder includes a plurality of steel truss girder segments. The construction method includes: Constructing side piers, middle piers and foundations; Welding the steel bridge deck units and the cross diaphragms to the corresponding steel truss girder segments to form structural units; Lifting the structural units, splicing the structural units into a continuous structure, and jacking the continuous structure to a preset height at the middle pier; Lifting the highway bridge deck system onto the steel truss girder and pouring post-cast concrete to connect the highway bridge deck system and the steel truss girder to form an integral structure; Lowering the jacking part of the integral structure at the middle pier position back to the design position; Tensioning the prestress of the concrete bridge deck; Completing the bridge.

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