CN115559190A - Main beam structure of double-layer four-line railway steel truss girder cable-stayed bridge - Google Patents

Abstract

The invention relates to a girder structure of a double-layer four-line railway steel truss girder cable-stayed bridge, which is characterized in that through double-layer arrangement, two railways are arranged on each layer, the transverse span of the steel truss girder can be reduced, so that only two main trusses are needed, and through connecting transverse connections between the tops of two corresponding web members of the two main trusses, the upper bridge deck system can be stably supported through the two main trusses and the top transverse connections; the first bridge deck system and the third bridge deck system of the non-ballast section corresponding to the midspan and the side pan of the bridge adopt orthogonal special-shaped plates, and the second bridge deck system and/or the fourth bridge deck system of the ballast section corresponding to the side pan of the bridge adopt a steel box, a ballast body in the steel box and a combined section form of a steel bridge deck plate, so that the ballast problem of a ballast area is solved; and then make upper and lower two-layer equally divide and set up the railway line, can reduce the purlin width of steel truss, make full use of steel truss section, the greatly reduced steel volume that uses just reduces the degree of difficulty of the work of discongesting at bridge both sides.

Description

Main girder structure of a double-deck four-track railway steel truss girder cable-stayed bridge

technical field

The invention relates to the technical field of double-layer four-track railway steel truss girders, in particular to a main girder structure of a double-layer four-line railway steel truss girder cable-stayed bridge.

Background technique

In recent years, my country's railway industry has developed rapidly, and the number of long-span bridges spanning large rivers and high-level navigable rivers is increasing day by day. Too many bridges built on large rivers will adversely affect the ecology, landscape and overall planning of the coast. For the purpose of saving channel resources across the river, multi-line railways are usually planned to be constructed using the same channel across the river.

At present, the layout of steel truss bridges for four-line railways at home and abroad mainly adopts four-line railways placed on the same floor, such as the Anqing Yangtze River Bridge on the Ning'an Railway, the Jiaojiang Super Bridge on the Hangzhou-Shaoxing-Taiwan Railway, and the East New Ganjiang Bridge on the Nanchang Junction. If the four-line railway is arranged on the same floor, if steel truss girders are used, the truss width will be wider, and some bridges will be arranged in the form of three main trusses, and the amount of steel used will be larger; if steel box girders are used, the overall vertical stiffness will be slightly less than steel trusses. In some cases, the arrangement of the same floor brings certain difficulties to the deconstruction project on both sides of the bridge. Different railway lines need to be detoured, which increases the difficulty of deconstruction; there are freight railways and passenger dedicated railways running in parallel, which reduces the efficiency of deconstruction on both sides of the bridge and increases the complexity of the project. When the steel truss girders are connected to the tunnel, the diameter of the level tunnel of the fourth-line railway is too large, and the construction risk increases sharply.

Contents of the invention

The purpose of the present invention is to: for the existing four-line railway steel truss bridge across the big rivers placed on the same floor layout, there is a wide truss width, a large amount of steel, which brings certain difficulties to the dredging project on both sides of the bridge To solve the problem, provide a main girder structure of a double-deck four-track railway steel truss girder cable-stayed bridge.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A main girder structure of a double-deck four-line railway steel truss girder cable-stayed bridge, comprising main trusses located on both lateral sides of the bridge, the main trusses comprising an upper chord, a lower chord and several vertically arranged webs, the upper chord and the lower chord are arranged along the longitudinal bridge direction, the upper end of the web is connected to the upper chord, and the lower end is connected to the lower chord, and all the webs are arranged at intervals along the longitudinal bridge;

A lower deck system is connected between the two lower chords of the two main trusses, an upper deck system is connected between the two upper chords of the two main trusses, and the lower deck system Two railways are respectively arranged above and above the upper deck system, and the two railways above the upper bridge deck system are correspondingly arranged directly above the two railway lines above the lower bridge deck system. The bridge deck system and the lower bridge deck system are evenly spaced in the longitudinal direction of the bridge deck system, and the two ends of the bridge deck system beam are correspondingly connected to the upper chord or the lower chord of the main truss on both sides;

Cross-links are connected between the tops of the two corresponding web members of the main girders on both sides, and the upper side of the cross-links is connected to the lower side of the upper deck system;

The upper deck system is divided into a first deck system and a second deck system along the longitudinal direction of the bridge. The first deck system corresponds to the non-pressure section of the middle span and side span of the bridge. The second deck system corresponds to the weight section of the side span of the bridge, and the lower deck system is divided into a third deck system and a fourth deck system along the longitudinal bridge direction, and the third deck system corresponds to the The non-pressure section of the middle span and side span of the bridge, the fourth deck system corresponds to the ballast section of the side span of the bridge, the first bridge deck system and the third bridge deck system are positive Orthogonal profiled plate, the top surface of the orthogonal profiled plate is used to set the railway; the second bridge deck system and/or the fourth bridge deck system includes a steel box, a steel bridge deck on the top of the steel box, filled in The ballast body in the steel box, the steel bridge deck is used to set the railway.

The main girder structure of the double-layer four-line railway steel truss girder cable-stayed bridge of this scheme can reduce the transverse span of the steel truss girder through double-layer arrangement and two railways on each floor, so that only the main trusses on both sides are required , and the cross-links are connected between the tops of the two corresponding web members of the main truss on both sides, that is, the cross-links are connected between the tops of the web members on both lateral sides of the steel truss girder, so that it can be passed The main trusses on both sides and the top cross-links will stably support the upper deck system; Cross-shaped slabs, light in structure, the bridge deck can transmit longitudinal force as a whole, and share the axial pressure of the main truss; the second deck system and/or the fourth deck system corresponding to the weight section of the side span of the bridge The steel box, the combined section form of the ballast in the steel box and the steel bridge deck solves the ballast problem in the ballast area, reduces the amount of steel used, and can effectively solve the negative moment area at the auxiliary pier The concrete slab is difficult to bear the force; thus, the upper and lower layers can be equally divided to set up railway lines, instead of setting up four lines on the upper level and two lines on the lower level like double-layer six-line lines, which cannot be set equally. This double-layer four-line Compared with the single-layer four-line structure, the line setting method can reduce the truss width of the steel truss girder, make full use of the steel truss girder section, greatly reduce the amount of steel used, and reduce the difficulty of deconstruction work on both sides of the bridge.

Preferably, the steel box is composed of a bottom plate, side plates on both lateral sides of the bridge and two adjacent deck beams, and the bottom plate and the side plates are arranged on two adjacent bridges. Between the surface beams, the bottom plate, the two side plates, the two deck beams and the steel bridge deck form a closed box structure, and the ballast is filled in the closed box structure Inside.

In this solution, a closed box-type structure is formed by the bottom plate, the two side plates, the corresponding two adjacent bridge deck beams and the steel bridge decks of the steel truss girders, so that the two adjacent bridge decks The space between the tie beams can be filled with ballast materials, so that the ballast area structure is combined with the steel truss beams to realize the ballast function. The ballast body can be poured with concrete, mortar and other ballast materials in the prior art; the bulk density of the ballast body and the closed box structure are designed according to the actual construction conditions, and the bottom plate and side plates are designed according to the actual construction conditions.

In this scheme, the bottom slab and the two side slabs are supported by beams on the bridge deck, so there is no need to set up small longitudinal beams separately; and the closed box structure is a large and closed ballast box, and the closed box structure is supported by steel trusses. The bridge deck system of the girder and the steel deck are formed, which simplifies the connection structure between the ballast area and the steel truss girder; and the deck system of the steel truss girder and the steel bridge deck are not only a bridge structure, but also a part of the ballast box of the ballast body , the steel utilization rate is high; and the total volume of the closed box structure is larger than that of the ballast box between two adjacent bridge deck beams in the prior art, which can reduce the bulk density of the ballast material, thereby reducing the cost, without As in the prior art, the ballast is increased by increasing the height of the bridge deck beam or by increasing the height of the bridge deck beam; the above reasons make the amount of steel used in the ballast area smaller. And because there is no need to set small longitudinal beams, only the bottom plate and side plates need to be installed between two adjacent deck beams, the construction space is larger, the construction steps are fewer, and the construction is simpler; both the bottom plate and the side plates can be installed after installation. The two adjacent bridge decks are installed in time after the beams are tied, which can improve the installation efficiency. After the closed box structure is filled with the ballast material, the ballast material can form a direct support for the steel bridge deck, which can effectively improve the fatigue characteristics of the steel bridge deck, so that the steel bridge deck at the closed box structure and the lower bridge deck system Neither post-maintenance nor maintenance is required in the entire ballast area.

Further preferably, the lower part of the ballast body is an ordinary concrete layer, and the upper part is a self-compacting cement mortar layer.

This solution adopts a closed box structure, compared with the total volume of all ballast boxes between two adjacent bridge deck beams in the prior art, which enables the use of specific gravity concrete while ensuring the same ballast Ordinary concrete and self-compacting cement mortar with a smaller bulk density are used to realize the pressure. The ordinary concrete layer in the lower part of the closed box structure has a strong bearing capacity, and the self-compacting cement mortar layer is conducive to filling the upper part of the closed box structure, while ensuring Safety and compactness, and compared with heavy concrete, the internal space of the closed box structure is filled with ordinary concrete layer and self-compacting cement mortar layer, the construction is simpler, and the cost of the material itself is also lower, which can save construction cost.

Preferably, the steel box of the second deck system is composed of a bottom plate, upper chords on both lateral sides of the bridge and two adjacent beams of the bridge deck system, and the bottom plate is arranged on two adjacent Between the bridge deck beams, the bottom plate, the upper chords on both sides, the two deck beams and the steel bridge deck form a closed box structure, and the ballast is filled in the closed box structure. within the structure;

The steel box of the fourth deck system is composed of a bottom plate, lower chords on both sides of the bridge laterally, and two adjacent beams of the bridge deck system, and the bottom plate is arranged on two adjacent bridge decks. Between the tie beams, the bottom plate, the lower chords on both sides, the two bridge deck tie beams and the steel bridge deck form a closed box structure, and the ballast is filled in the closed box structure.

In this scheme, there is no need to set up side plates separately, and the closed box structure of the second deck system can be formed by using the upper chord as the side plate, and the closed box structure of the fourth deck system can be formed by using the lower chord as the side plate. Through this setting method, no need to set side plates, the installation of the closed box structure can be facilitated, and the fourth deck system and the second deck system can be directly integrated with the corresponding chords, which has higher stability and transmission. The force can be better; and the closed box structure can be widened, the volume of the ballast body that can be set can be increased, and the ballast capacity can be enhanced.

Further preferably, the steel box is only provided on the fourth bridge deck;

or,

Both the fourth deck system and the second deck system are provided with the steel box, and the volume of the steel box of the fourth deck system is larger than that of the steel box of the second deck system volume of.

Because of the increased ballast capacity, steel boxes may not be arranged at the bottom of the second bridge deck system on the upper floor only when the fourth deck system is set to meet the double-layer ballast weight of the steel truss girder. If only the arrangement of the fourth deck system cannot satisfy the double-layer ballast weight of the steel truss girder, a large ballast weight is firstly set on the fourth deck system, and a small ballast weight is set on the second deck system, That is, the volume of the steel box of the fourth deck system is larger than the volume of the steel box of the second deck system. This arrangement makes it possible for all steel boxes or larger steel boxes to be constructed on the lower floor, making the construction more convenient. At the same time, it is possible to avoid or reduce the volume of the ballast on the upper floor as much as possible, which can avoid or reduce the pressure on the upper floor. It will affect the lower deck system and its lines.

Preferably, the ballast body includes at least two layers of shrinkage-compensating concrete layers filled in layers, which can ensure that the ballast body is filled densely, and can prevent the concrete from shrinking, so as to prevent the ballast body from detaching from the closed box structure and ensure the stability of the bridge deck system. Wholeness.

Preferably, the bottom of the steel bridge deck is distributed with several first stiffeners at intervals along the transverse bridge direction, and the first stiffeners are arranged along the longitudinal bridge direction; through the first stiffeners, the ballast body and the steel bridge deck can be better integrate;

When the lower part of the ballast body is an ordinary concrete layer, the height of the top surface of the ordinary concrete layer is not higher than the bottom of the first stiffener of the steel bridge deck. The actual height of the ordinary concrete layer is determined according to the specific weight, but the height of the top surface of the ordinary concrete layer should not be higher than the bottom of the first stiffener of the steel bridge deck, so that the steel bridge deck can be better filled with self-compacting cement mortar The corner parts such as the first stiffener of the steel pipe can improve the filling effect in the closed box structure.

Preferably, several second stiffeners are arranged above the bottom plate, and several second stiffeners are arranged along the longitudinal bridge direction, and the corners of the web of the bridge deck and the lower wing plate are vertical along the longitudinal bridge direction. A joint plate is provided, and the second stiffener is connected to the corresponding joint plate of the bridge deck beam through first high-strength bolts;

and / or;

Several shear studs are provided on the four sides of the closed box structure.

The joint plate is vertically arranged at the corner of the web of the bridge deck beam and the lower wing plate, and the second stiffener is arranged on the top surface of the bottom plate along the longitudinal direction of the bridge and corresponding to the position of the joint plate, so as to ensure the stability of the bottom plate. At the same time of sufficient reinforcement, the bottom plate and the bridge deck beam can be connected more stably through the first high-strength bolts. And the joint plate can make the combination effect of the ballast body and the bridge deck beam better, and the second stiffener can make the ballast body and the bottom plate better. In this way, not only the bridge deck beam and the bottom plate can be strengthened, but also The combination performance of the ballast body and the steel box can be strengthened, so that the overall ballast capacity of the bridge deck system in the whole ballast area is stronger, the rigidity is greater, and the train running performance is excellent.

Preferably, the transverse bridges of the transverse link are bolted to the corresponding web members on both sides, and the upper side of the transverse link is welded to the lower side of the upper deck system, so as to prevent the bolts of the upper deck system from falling The impact on the safety of the lower railway, but also to ensure the convenience of installation.

Preferably, the cross-connection includes a cross bar and several oblique bars, the upper end of the oblique bar is connected to the upper side of the cross bar, and the lower end is connected to the lower side of the upper deck system, and the cross bar, the upper deck system Together with all the oblique rods, it forms several equilateral triangle structures arranged continuously along the horizontal bridge direction. While reducing the number of rods, it can be combined with the upper deck system to improve the supporting effect on the upper bridge deck system. .

In summary, owing to adopting above-mentioned technical scheme, the beneficial effect of the present invention is:

1. The main girder structure of the double-layer four-line railway steel truss girder cable-stayed bridge of the present invention can reduce the transverse span of the steel truss girder through the double-layer arrangement and two railways on each floor, so that only the two sides are required. The main truss, and the cross-links are connected between the tops of the two corresponding webs of the main trusses on both sides, that is, the cross-links are connected between the tops of the webs on both sides of the steel truss transversely, so that The upper deck system can be stably supported by the main truss on both sides and the top cross-link; and the first deck system and the third deck system corresponding to the non-pressure section of the middle span and side span of the bridge Orthogonal special-shaped slabs are used, the structure is light, and the bridge deck can transmit longitudinal force as a whole, and share the axial pressure of the main truss; the second bridge deck system corresponding to the ballast section of the side span of the bridge and/or the fourth bridge The surface system adopts the steel box, the combined section form of the ballast body in the steel box and the steel bridge deck, which solves the ballast problem that the single-layer four-line ballast structure cannot be applied to the double-layer four-line ballast area, and also reduces The amount of steel used can effectively solve the stress problem of the concrete slab in the negative bending moment area at the auxiliary pier; thus, the upper and lower floors can be equally divided to set the railway line, instead of only setting four lines on the upper floor like the double-layer six-line , the lower layer is equipped with two lines, which cannot be equally divided. Compared with the single-layer four-line structure, this double-layer four-line structure can reduce the truss width of the steel truss girder, make full use of the steel truss section, and greatly It reduces the amount of steel used, and can reduce the detour of the railway, which can realize the diversion of passengers and goods, and reduce the difficulty of the deconstruction project on both sides of the bridge.

2. The second bridge deck system and/or the fourth bridge deck system located in the ballast area adopts a closed box structure and the overall cross-sectional form of the ballast body, so that the ballast structure and the stressed structure are combined together, so that the pressure The weight capacity of the heavy area is stronger, the structure is simple, the consumables are less, the construction is convenient, and the cost is low, which can effectively improve the fatigue characteristics of the steel bridge deck, so that the steel deck of the closed box structure and the deck system below do not need post-maintenance , the whole ballast area also requires no maintenance.

3. The closed box structure of the second deck system can be formed by using the upper chord as the side plate, and the closed box structure of the fourth deck system can be formed by using the lower chord as the side plate. The side panels are provided to facilitate the installation of the closed box structure, and enable the fourth deck system and the second deck system to be directly integrated with the corresponding chords, resulting in higher stability and better force transmission; The wide closed box structure increases the volume of the ballast body that can be set, and can enhance the ballast capacity.

4. Adopting the cross-connection structure with the top fully welded and the side bolted to the web, which avoids the influence of the bolts on the upper deck system on the safety of the lower railway and ensures the convenience of installation.

5. Compared with the flat four-line structure and the all-steel bridge deck truss structure, it has higher rigidity and excellent train driving performance.

Description of drawings

Fig. 1 is the cross-sectional schematic view of the non-pressurized section of the mid-span and side span of the double-deck four-line railway steel truss girder cable-stayed bridge girder structure of the present invention;

Fig. 2 is the cross-sectional schematic view of the ballast section of the side span of the main girder structure of the double-layer four-line railway steel truss girder cable-stayed bridge described in embodiment 1;

Fig. 3 is a schematic cross-sectional view of the fourth bridge deck system in Fig. 2;

Fig. 4 is the cross-sectional schematic view of the upper deck system or the lower deck system of the weight zone of the side span in embodiment 2;

Fig. 5 is a schematic cross-sectional view at the A-A place in Fig. 4;

Fig. 6 is a schematic cross-sectional view at the B-B place in Fig. 4;

Fig. 7 is a schematic plan view of the upper deck system or the lower deck system of the ballast area of the side span in Embodiment 2.

Icons: 1-top chord; 2-bottom chord; 3-web; 41-first deck system; 42-second deck system; 51-third bridge deck system; 52-fourth deck system; 6 -cross-connection; 7-railway; 81-first high-strength bolt; 82-second high-strength bolt; 9-side plate; 91-manhole; 10-steel bridge deck; 11-bottom plate; 12-first stiffener; 13 -Second stiffener; 131-Third stiffener; 14-Deck beam; 151-Ordinary concrete layer; 152-Self-compacting cement mortar layer; 153-Shrinkage compensation concrete layer; 1511-First layer; 1512- The second layer; 16-shear nails; 17-joint plate; 18-bridge deck longitudinal girder.

detailed description

Below in conjunction with accompanying drawing, the present invention is described in detail.

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Example 1

This embodiment provides a main girder structure of a double-layer four-line railway steel truss girder cable-stayed bridge, referring to Figures 1-3, showing the transverse direction of the bridge, including the main trusses located on both sides of the bridge, and the main trusses include upper chords 1 , the lower chord 2 and several vertically arranged webs 3, the upper chord 1 and the lower chord 2 are arranged along the longitudinal bridge direction, the upper end of the web 3 is connected to the upper chord 1, and the lower end is connected to the lower chord Rods 2, all the web rods 3 are arranged at intervals along the longitudinal bridge direction;

A lower deck system is connected between the two lower chords 2 of the two main trusses, and an upper deck system is connected between the two upper chords 1 of the two main trusses. Two railways 7 are arranged above the surface system and above the upper bridge deck system, and the two railways 7 above the upper bridge deck system correspond to the two railways 7 above the lower bridge deck system. Above, the longitudinal bridges of the upper deck system and the lower deck system are evenly spaced with bridge deck beams 14, and the two ends of the bridge deck beams 14 are correspondingly connected to the upper chords of the main trusses on both sides. Rod 1 or said lower chord 2;

Cross-links 6 are connected between the tops of the corresponding two web members 3 of the main girders on both sides, and the upper side of the cross-links 6 is connected to the lower side of the upper deck system;

As shown in Figure 1-2, the upper deck system is divided into a first deck system 41 and a second deck system 42 along the longitudinal direction of the bridge, and the first deck system 41 corresponds to the mid-span and The non-weight section of the side span, the second deck system 42 corresponds to the ballast section of the side span of the bridge, and the lower deck system is divided into the third deck system 51 and the fourth bridge deck system along the longitudinal bridge direction. The surface system 52, the third deck system 51 corresponds to the non-pressure section of the middle span and the side span of the bridge, and the fourth deck system 52 corresponds to the ballast section of the side span of the bridge. The first bridge deck system 41 and the third bridge deck system 51 are orthogonal special-shaped plates, and the top surface of the orthogonal special-shaped plate is used to set the railway 7; the second bridge deck system 42 and/or the The fourth deck system 52 includes a steel box, a steel bridge deck 10 on the top of the steel box, and ballasts filled in the steel box, and the steel bridge deck 10 is used to set the railway 7 .

The main girder structure of the double-layer four-line railway steel truss girder cable-stayed bridge adopts this scheme, as shown in Figure 1, through the upper and lower double-layer arrangement, two railways 7 are arranged on each floor, and the upper and lower railways 7 are arranged correspondingly, which can reduce the steel truss The transverse span of the beam is such that only the main girders on both sides need to be provided, and the tops of the two corresponding web members 3 of the main girders on both sides are connected with cross-links 6 , and the upper parts of the cross-links 6 are connected The bottom of the upper deck system, that is, a cross-link 6 is connected between the tops of the web members 3 on both sides of the steel truss transversely, so that the main trusses on both sides and the top cross-links 6 can be connected with the upper deck system. Combined into one, and stably support the upper deck system; and the first deck system 41 and the third deck system 51 corresponding to the non-pressure section of the middle span and side span of the bridge adopt orthogonal special-shaped plates , as shown in Figure 1, the structure is light, the bridge deck can transmit the longitudinal force as a whole, and share the axial pressure of the main truss; the second bridge deck system 42 and/or the first The four-deck system 52 adopts a steel box, the ballast body in the steel box and the combined cross-section form of the steel bridge deck 10, as shown in Figure 2. On the basis of solving the problem of ballast in the ballast area, the amount of steel used is reduced. At the same time, it can effectively solve the stress problem of the concrete slab in the negative bending moment area at the auxiliary pier; thus, the upper and lower floors can be equally divided to set up railway lines, instead of having to set up four lines on the upper floor and two lines on the lower floor like double-layer six lines. Due to the problem of stress, the double-layer four-wire setting method can reduce the truss width of the steel truss girder and make full use of the steel truss girder section, greatly The amount of steel used can be reduced, and the difficulty of deconstruction works on both sides of the bridge can be reduced.

Among them, Fig. 2 shows the cross-section of the ballast area. In Fig. 2, both the upper deck system and the lower deck system adopt the form of setting steel boxes and ballast bodies. Certainly, according to the actual situation, if the form of setting steel box and ballast body in the lower layer can meet the double-layer ballast weight, then there is no need to arrange the form of steel box and ballast body in the upper layer. In the same way, only the upper deck system can be set to have a cross-section form with ballast bodies, or only the lower deck system can be set to have a cross-section form with ballast bodies. ballast, it is necessary to set both the upper deck system and the lower deck system to have the cross-section form of the ballast body. As a preferred embodiment, the steel box is only provided on the fourth deck system 52; or, both the fourth deck system 52 and the second deck system 42 are provided with the Steel boxes, the volume of the steel boxes of the fourth deck system 52 is greater than the volume of the steel boxes of the second deck system 42 . Because of the increased ballast capacity, only when the fourth deck system 52 is set to meet the double-layer ballast weight of the steel truss girder, no steel box may be arranged at the bottom of the second deck system 42 on the upper floor. If only the installation of the fourth deck system 52 cannot satisfy the double-layer ballast weight of the steel truss girder, a large ballast weight is firstly set on the fourth deck system 52, and a small one is set on the second deck system 42. The ballast is to make the volume of the steel box of the fourth deck system 52 larger than the volume of the steel box of the second deck system 42 . This arrangement makes it possible for all steel boxes or larger steel boxes to be constructed on the lower floor, making the construction more convenient. At the same time, it is possible to avoid or reduce the volume of the ballast on the upper floor as much as possible, which can avoid or reduce the pressure on the upper floor. It will affect the lower deck system and its lines.

As shown in Figures 2-3, the steel box of the second deck system 42 is composed of a bottom plate 11, upper chords 1 on both lateral sides of the bridge, and two adjacent bridge deck beams 14. The surface beam 14 can refer to the structural form in Fig. 5, wherein, the first bridge deck system 41 and the third bridge deck system 51 in Fig. 1 are all provided with the bridge deck system beam 14 along the longitudinal bridge direction, and the first bridge deck system 41 and the bridge deck beam 14 of the third deck system 51 have a spacing of 2.5-4m to ensure the strength of the orthogonal special-shaped plates of the first deck system 41 and the third deck system 51; the second bridge in Fig. 2 The deck system 42 and the fourth deck system 52 are also provided with deck beams 14 along the longitudinal direction of the bridge, and the distance between the deck beams 14 of the second deck system 42 and the fourth deck system 52 is 3-3.5m. , so that the ballast body can be combined with the deck system, so that the ballast requirements can be met. The bottom plate 11 is arranged between two adjacent deck beams 14, and the bottom plate 11, the upper chords 1 on both sides, the two deck beams 14 and the steel bridge deck 10 enclose a A closed box structure, the ballast body is filled in the closed box structure;

The steel box of the fourth deck system 52 is composed of a bottom slab 11, the lower chords 2 on both sides of the bridge transversely and two adjacent bridge deck beams 14, and the bottom slab 11 is arranged on two adjacent Between the two deck beams 14, the bottom plate 11, the lower chords 2 on both sides, the two deck beams 14 and the steel bridge deck 10 form a closed box structure, and the ballast body Filled in the closed box structure.

In this embodiment, there is no need to separately set up the side plate 9, the closed box structure of the second bridge deck system 42 can be formed by using the upper chord 1 as the side plate 9, and the fourth bridge deck can be formed by using the lower chord 2 as the side plate 9 The closed box structure of the system 52, through this arrangement, can not need to set the side plate 9, so that the installation of the closed box structure can be convenient, and the fourth bridge deck system 52 and the second bridge deck system 42 can be directly connected with the corresponding bridge deck system. The chords are integrated, so the stability is higher, and the force transmission can be better; and the closed box structure can be widened, the volume of the ballast body that can be set can be increased, and the ballast capacity can be enhanced.

In this embodiment, the ballast body includes at least two layers of shrinkage-compensating concrete layers 153 filled in layers. It can ensure that the ballast body is filled densely, and can prevent the concrete from shrinking, so as to prevent the ballast body from detaching from the closed box structure and ensure the integrity of the bridge deck system.

As shown in Figure 3, the bottom of the steel bridge deck 10 is distributed with several first stiffeners 12 at intervals along the direction of the transverse bridge, and the first stiffeners 12 are arranged along the direction of the longitudinal bridge; The steel bridge deck 10 can be better combined, and the steel bridge deck 10 can be strengthened at the same time. The first stiffener 12 may take the form of a U-rib.

Optionally, several second stiffeners 13 are arranged above the bottom plate 11, and several second stiffeners 13 are arranged along the longitudinal bridge direction. The second stiffeners 13 can strengthen the bottom plate 11, so that the thickness of the bottom plate 11 can be reduced. , which can further reduce the use of steel materials, and the second stiffener 13 can make the combination effect of the ballast body and the bottom plate 11 better. In this embodiment, a joint plate 17 is arranged vertically along the longitudinal bridge direction at the corners of the web of the bridge deck beam 14 and the lower wing plate. Referring to FIG. 5, the second stiffener 13 is connected to the bridge. The corresponding joint plates 17 of the deck beams 14 are connected by first high-strength bolts 81; the joint plates 17 are vertically arranged at the corners of the web and the lower flange of the deck beams 14, along the longitudinal direction of the bridge and corresponding to The position of the joint plate 17 is provided with a second stiffener 13 on the top surface of the bottom plate 11. While ensuring sufficient reinforcement of the bottom plate 11, the bottom plate 11 and the bridge deck beam 14 can be more stable through the first high-strength bolts 81. connect. And the joint plate 17 can make the combination effect of the ballast body and the bridge deck beam 14 better.

Through the joint plate 17, the first stiffener 12 and the second stiffener 13, not only can the deck beam 14, the steel bridge deck 10 and the bottom plate 11 be strengthened respectively, but also the bonding performance between the ballast body and the steel box can be strengthened, so that the whole ballast The bridge deck system in the heavy area has stronger overall weight capacity, greater rigidity, and excellent train running performance.

Optionally, a number of shear studs 16 are provided on the four sides of the closed box structure to strengthen the combination performance of the ballast body and the steel box, so that the overall ballast capacity of the bridge deck system in the entire ballast area is stronger and the rigidity is stronger. Bigger, excellent train performance.

In this embodiment, as shown in Figure 1-2, the transverse bridge of the transverse link 6 is bolted to the corresponding web members 3 on both sides, and the upper side of the transverse link 6 is connected to the upper bridge deck. The underside is welded. It avoids the influence of falling bolts on the upper bridge deck on the safety of the lower railway 7, and ensures the convenience of installation. As a better option, the cross-link 6 includes a cross bar and several oblique bars, the upper end of the oblique bar is connected to the upper side of the cross bar, and the lower end is connected to the lower side of the upper deck system. The cross bar, the The upper bridge deck system and all the inclined bars together form a number of equilateral triangle structures arranged continuously along the transverse bridge direction, which can be combined with the upper deck system while reducing the number of rods, improving the alignment of the upper bridge deck. The supporting effect of the system. In addition, the catenary of the lower railway 7 can also be arranged on the bridge deck beam 14 or the cross link 6 of the upper deck, so as to avoid additional setting of the catenary fixing frame.

In this embodiment, the chords on both lateral sides of each floor in the side-span pressure zone, the top steel bridge deck 10, the two longitudinally adjacent bridge deck beams 14, and the bottom plate 11 are all closed box-type structures that are integrated. structure, and then pour shrinkage compensation concrete layer by layer by opening pouring holes in the steel bridge deck 10, and inject shrinkage compensation concrete by grouting on the top to ensure dense pouring, so that the entire section is a solid steel-concrete overall structure. It can not only realize ballast, but also support and strengthen the upper steel bridge deck 10, so that the train can run more safely and comfortably.

Example 2

This embodiment provides a main girder structure of a double-layer four-track railway steel truss girder cable-stayed bridge. The difference from Embodiment 1 is that the cross-sectional structure of the ballast area is different. See Figures 4-7. In this embodiment, A side plate 9 is arranged between the two chords, as shown in Figure 4, taking the setting between the two lower chords 2 as an example, the steel box is composed of a bottom plate 11, side plates 9 on both sides of the bridge transverse It is composed of two adjacent bridge deck beams 14, the bottom plate 11 and the side plate 9 are all arranged between the adjacent two bridge deck beams 14, the bottom plate 11, the two The side plate 9 , the two deck beams 14 and the steel bridge deck 10 enclose a closed box structure, and the ballast body is filled in the closed box structure.

In this solution, the space between the bottom plate 11, the two side plates 9, and the corresponding adjacent two bridge deck beams 14 can be filled with ballast material, so that the structure of the ballast area is consistent with the steel truss girder. Combined together, the weight function is realized. The ballast body can adopt the ballast materials such as concrete and mortar in the prior art to form;

In this solution, the bottom plate 11 and the two side plates 9 are all supported by the beams 14 of the bridge deck, so there is no need to separately set up small longitudinal beams for support; and the closed box structure is a large and closed ballast box, and the closed box structure relies on It is formed by the bridge deck system of steel truss girders and the steel bridge deck 10, which simplifies the connection structure between the ballast area and the steel truss girders; and the bridge deck system of steel truss girders and the steel bridge deck 10 are not only bridge structures, but also ballast bodies Part of the ballast box, the steel utilization rate is high; and the closed box structure has a larger total volume than the ballast box between two adjacent bridge deck beams 14 in the prior art, which can reduce the bulk density of the ballast material , and then reduce the cost, without increasing the ballast by increasing the height of the bridge deck beam 14 or by increasing the height of the bridge deck beam 14 as in the prior art; the above reasons make the amount of steel used in the ballast area smaller. And because there is no need to set small longitudinal beams, only the base plate 11 and the side plate 9 need to be installed between two adjacent deck beams 14, the construction space is larger, the construction steps are fewer, and the construction is simpler; the base plate 11 and the side plate 9 Both can be installed in time after the two adjacent deck beams 14 are installed, and the installation efficiency can be improved. After the closed box structure is filled with ballast material, the ballast material can form a direct support for the steel bridge deck 10, which can effectively improve the fatigue characteristics of the steel bridge deck 10, so that the steel bridge deck 10 and the lower part of the closed box structure The bridge deck system does not require post-maintenance, nor does the entire ballast area.

Further preferably, the lower part of the ballast body is an ordinary concrete layer 151 , and the upper part is a self-compacting cement mortar layer 152 . This solution adopts a closed box structure, compared with the total volume of all ballast boxes between two adjacent bridge deck beams 14 in the prior art, which enables the use of specific gravity while ensuring the same ballast. Ordinary concrete and self-compacting cement mortar with smaller bulk density of concrete are used to realize ballasting. The ordinary concrete layer 151 in the lower part of the closed box-type structure has a strong bearing capacity, and the self-compacting cement mortar layer 152 is conducive to filling the upper part of the closed box-type structure. At the same time, the safety and compactness are guaranteed, and compared with heavy concrete, the internal space of the closed box structure is filled with the ordinary concrete layer 151 and the self-compacting cement mortar layer 152, the construction is simpler, and the cost of the material itself is also lower , thereby saving construction costs.

In this embodiment, the bottom plate 11, the side plate 9, and the steel bridge deck 10 are all equipped with a stiffening structure, and the stiffening structure is used to strengthen the bottom plate 11, the side plate 9, and the steel bridge deck 10, so that the bottom plate 11 and the side The slab 9 bears the overall pressure of the ordinary concrete layer 151 and the self-compacting cement mortar layer 152, and the steel bridge deck 10 can better withstand the pressure of the railway 7 and the train. As shown in Figures 4, 5 and 7, a vertical joint plate 17 is provided at the corners of the web of the deck beam 14 and the lower wing plate along the longitudinal direction of the bridge, and the stiffening structure of the bottom plate 11 is a number of corresponding The second stiffener 13 arranged on the joint plate 17 is arranged along the longitudinal bridge direction, and the second stiffener 13 is connected to the corresponding joint plate 17 by first high-strength bolts 81 . Along the longitudinal direction of the bridge and corresponding to the position of the joint plate 17, a second stiffener 13 is provided on the top surface of the bottom plate 11. While ensuring sufficient reinforcement of the bottom plate 11, it can also facilitate the stability of the bottom plate 11 and the bridge deck beam 14. Connection. Moreover, the second stiffener 13 is arranged on the top surface of the bottom plate 11, so that the connection between the bottom plate 11 and the ordinary concrete layer 151 is tighter, and the integrity and stability of the structure of the ballast zone are improved.

The inner side of the side plate 9 refers to the side of the side plate 9 facing the inside of the closed box structure. As shown in Figure 6, the web of the bridge deck beam 14 has a vertically arranged web stiffener, and the longitudinal bridge of the side plate 9 corresponds to the two sides of the bridge deck beam 14 respectively. The web stiffener is connected by the second high-strength bolt 82, so that the connection between the side plate 9 and the bridge deck beam 14 is more stable. And the stiffening structure of the side plate 9 is a plurality of third stiffening ribs 131, and the third stiffening rib 131 is vertically arranged on the inner side of the side plate 9, because the vertical height of the side plate 9 is higher than that of the existing ballast box The height of the side plate 9 is higher, and the side plate 9 can be better reinforced by setting the third vertical stiffener 131 . And the third stiffener 131 is arranged on the inner side of the side plate 9, so that the side plate 9 can be connected more closely with the ordinary concrete layer 151 and the self-compacting cement mortar layer 152, and the integrity and stability of the structure of the weight zone can be improved. .

After being strengthened by the above-mentioned second stiffener 13 and the third stiffener 131, it is possible to adopt a thinner base plate 11 and side plate 9, that is, a base plate 11 with a thickness of 10-16mm can be used, and a thickness greater than or equal to The 10mm side plate 9 can further reduce the amount of steel used, save costs, and is more convenient for the hoisting of the side plate 9 and the bottom plate 11.

And the side plate 9 is provided with a manhole 91, and the top of the manhole 91 is higher than the top surface of the ordinary concrete layer 151. In this embodiment, only one side plate 9 of each closed box structure is provided with a manhole. hole 91, pouring the ordinary concrete layer 151 through the manhole 91, the construction personnel can enter the manhole 91 to pour ordinary concrete, which is convenient for pouring the ordinary concrete layer 151, and can improve the quality of pouring, and there is no need to separate it on the side plate 9 Opening redundant pouring ports for pouring the common concrete layer 151 can improve the integrity of the closed box structure. And pouring ordinary concrete layer 151 can be divided into at least two layers and pouring at one time, such as first pouring the first layer 1511 at the bottom, referring to Figure 6, and then pouring the second layer 1512 on the top of the first layer 1511, this pouring method can pour The combination of the first layer 1511 and the base plate 11 together serves as the lower formwork to bear the pouring of the second layer 1512. This method can make the thickness of the base plate 11 as thin as possible, reduce the amount of steel used, and at the same time The compactness of pouring can be higher, the weight effect and the supporting ability to the steel bridge deck 10 are better. And when pouring reaches the height of the manhole 91, the manhole 91 needs to be blocked, and the cycle operation mode of pouring while sealing can be adopted.

For example: the ordinary concrete layer 151 is divided into two layers of construction. First, the first layer 1511 is poured on the base plate 11. After the strength of the first layer 1511 reaches the standard, the second layer 1512 is poured on the first layer 1511. During the pouring process of the second floor 1512, when the height of the poured ordinary concrete is higher than the elevation of the bottom of the manhole 91, a part of the bottom of the manhole 91 is blocked first, and then the ordinary concrete is poured. When the hole 91 overflows, block a part of the manhole 91 upward again, and then pour ordinary concrete, and gradually block the manhole 91 upward to pour ordinary concrete until the second layer 1512 is poured , and then completely block the manhole 91; effectively utilize the bearing capacity of the first layer 1511 ordinary concrete, so that the thinner base plate 11 and the second stiffener 13 only need to be able to bear the weight of the first layer 1511 ordinary concrete Yes, the steel-concrete structure formed by the ordinary concrete in the first layer 1511 and the bottom plate 11 can effectively bear the total weight of the ordinary concrete in the second layer 1512 and the self-compacting cement mortar layer 152 . The ordinary concrete layer 151 is divided into two layers for construction, so that the thickness of the required base plate 11 is thinner, and the strength of the required second stiffener 13 is smaller, which can save steel materials, and at the same time make the base plate 11 and the second stiffener 13 installation is easier.

After the strength of the second layer 1512 reaches the standard, a pouring hole is opened above the steel bridge deck 10 corresponding to its U-rib and U-rib or between the U-rib and bridge deck longitudinal girder 18, and self-compacting cement mortar is poured through the pouring hole layer 152 until the closed box structure is filled. Among them, the size of the pouring hole is 4-6cm, preferably 5cm, and the exhaust pipe and pouring pipe are set, and the micro-expansion self-compacting cement mortar is used to pour with pressure to ensure that the ballast box is fully filled. Pouring the self-compacting cement mortar layer 152 through the pouring hole can fill the closed box structure more conveniently, quickly and with high quality, avoiding that the corners of the U-rib and the longitudinal girder 18 of the bridge deck cannot be completely filled. This construction method of manhole 91 combined with small pouring holes can minimize the opening of a large number of larger pouring openings for the structure of the ballast area, ensure the integrity of the structure of the ballast area, and improve the quality of the structure of the ballast area.

The section form of the ballast area of the steel truss girder cable-stayed bridge described in this embodiment has a simple structure and is easy to install. The structure of the ballast area makes better use of the main structure of the steel truss girder. It only needs to add the bottom plate 11 and the side plate 9 to connect the bridge deck beam 14, and cooperate with the steel bridge deck 10 to form an overall closed box structure as the ballast area, simplifying The connection structure between the ballast area and the steel truss girder is established, and the first high-strength bolt 81 and the second high-strength bolt 82 are used for connection, which can be installed in blocks and are convenient for construction. And its structural stress is clear, without changing the stress system and mechanical performance of the steel truss girder, and the cable force still maintains the force transmission path from the chord to the bridge deck. It has good economy and can save more than 40% of steel compared with traditional ballast boxes. Two kinds of ballast materials are used, the ordinary concrete layer 151 on the bottom layer has a strong bearing capacity, and the self-compacting cement mortar layer 152 on the top layer is convenient for pouring through small holes on the top plate to ensure compactness. Moreover, the structure of the ballast area is very safe. After the ordinary concrete layer 151 is molded, it forms an integral body with the bottom plate 11, and the first high-strength bolts 81 are connected to the deck beams 14. Even if the first high-strength bolts 81 fail, the pressure The heavy area structure can also be effectively supported on the lower wing plate of the beam 14 on the bridge deck, and will not come off. And it also has the characteristics of maintenance-free and strong durability. The closed box structure is filled with ordinary concrete and self-compacting cement mortar without maintenance; the steel bridge deck 10 is in the closed box structure, the ordinary concrete layer 151 and self- Under the support of the dense cement mortar layer 152, the stress is improved and the durability is enhanced. And the outer surface of the closed box structure is smooth and tidy, which is convenient for maintenance.

The main girder structure of the steel truss girder cable-stayed bridge for the double-layer four-track railway in the above-mentioned Embodiment 1 and Example 2, compared with the traditional steel truss girder section where the four-track railway is placed on the same floor, the double-layer four-track railway is orthogonal The main girder section of special-shaped plate steel truss girder can reduce the truss width, maximize the use of section size, and reduce the amount of steel used. And it can realize the layered form of passengers and goods, realize the diversion of passengers and goods, and reduce their mutual influence. Orthogonal special-shaped slabs are used in the non-pressure sections of the mid-span and side spans, and the steel box concrete composite bridge deck structure is used in the side-span ballast sections, which solves the problem of multi-line steel truss beams. , good economy, free from maintenance. Steel boxes can use 10-12mm thick panels and 8mm stiffeners. Compared with the traditional 16mm bridge deck + U rib + steel ballast box structure, more than 40% of steel can be saved. The steel-box-concrete composite bridge deck structure does not need to be prestressed, and the steel bridge deck 10 on the top surface resists the negative moment effect of the auxiliary piers, avoiding the problem of durability caused by cracking of the concrete bridge deck. The top surface is fully welded and the side is bolted to the cross-connection 6 structure, which avoids the influence of the upper bridge deck bolts on the safety of the lower railway 7 and ensures the convenience of installation. Compared with the flat structure and all-steel deck truss structure, it has higher rigidity and excellent train performance.

The above descriptions are only 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 principles of the present invention should be included in the protection of the present invention. within range.

Claims (10)

1. The main beam structure of the cable-stayed bridge of the double-layer four-line railway steel truss girder is characterized by comprising main trusses positioned on two transverse sides of the bridge, wherein each main truss comprises an upper chord (1), a lower chord (2) and a plurality of vertically arranged web members (3), the upper chord (1) and the lower chord (2) are arranged along the longitudinal bridge direction, the upper end of each web member (3) is connected with the upper chord (1), the lower end of each web member is connected with the lower chord (2), and all the web members (3) are arranged at intervals along the longitudinal bridge direction;

a lower bridge deck system is connected between the two lower chords (2) of the two main trusses, an upper bridge deck system is connected between the two upper chords (1) of the two main trusses, two railways (7) are respectively arranged above the lower bridge deck system and the upper bridge deck system, the two railways (7) above the upper bridge deck system are correspondingly arranged right above the two railways (7) above the lower bridge deck system, bridge deck system cross beams (14) are respectively arranged in the longitudinal direction of the upper bridge deck system and the longitudinal direction of the lower bridge deck system at intervals, and two ends of each bridge deck system cross beam (14) are correspondingly connected with the upper chords (1) or the lower chords (2) of the main trusses on two sides;

the tops of two corresponding web members (3) of the main trusses on the two sides are connected with a cross link (6), and the upper side of the cross link (6) is connected with the lower side of the upper bridge deck system;

the upper bridge deck system is divided into a first bridge deck system (41) and a second bridge deck system (42) along a longitudinal bridge direction, the first bridge deck system (41) corresponds to non-ballast sections of a middle span and an edge span of the bridge, the second bridge deck system (42) corresponds to ballast sections of the edge span of the bridge, the lower bridge deck system is divided into a third bridge deck system (51) and a fourth bridge deck system (52) along the longitudinal bridge direction, the third bridge deck system (51) corresponds to non-ballast sections of the middle span and the edge span of the bridge, the fourth bridge deck system (52) corresponds to ballast sections of the edge span of the bridge, the first bridge deck system (41) and the third bridge deck system (51) are both orthogonal profiled plates, and top surfaces of the orthogonal profiled plates are used for arranging the railway (7); the second bridge deck system (42) and/or the fourth bridge deck system (52) comprise a steel box, a steel bridge deck (10) on the top of the steel box and a ballast filled in the steel box, and the steel bridge deck (10) is used for arranging the railway (7).

2. The girder construction of a double-deck four-track railway steel truss girder cable-stayed bridge according to claim 1, wherein the steel box is composed of a bottom plate (11), side plates (9) at two lateral sides of the bridge and two adjacent bridge deck system beams (14), the bottom plate (11) and the side plates (9) are both arranged between the two adjacent bridge deck system beams (14), the bottom plate (11), the two side plates (9), the two bridge deck system beams (14) and the steel bridge deck (10) form a closed box structure, and the ballast bodies are filled in the closed box structure.

3. The main girder structure of a cable-stayed bridge with a double-deck four-track railway steel truss according to claim 2, wherein the ballast body has a lower portion formed of a common concrete layer (151) and an upper portion formed of a self-compacting cement mortar layer (152).

4. The main girder construction of a double-deck four-line railway steel truss girder cable-stayed bridge according to claim 1, wherein the steel box of the second deck system (42) is composed of a bottom plate (11), upper chords (1) at two lateral sides of the bridge and two adjacent deck system crossbeams (14), the bottom plate (11) is arranged between the two adjacent deck system crossbeams (14), the bottom plate (11), the upper chords (1) at two lateral sides, the two deck system crossbeams (14) and the steel deck slab (10) enclose a closed box structure, and the ballast bodies are filled in the closed box structure;

fourth bridge deck system (52) the steel case by bottom plate (11) the lower chord member (2) and adjacent two of the horizontal both sides of bridge the bridge deck system crossbeam (14) are constituteed, bottom plate (11) set up in adjacent two between bridge deck system crossbeam (14), bottom plate (11), the lower chord member (2) of both sides, two bridge deck system crossbeam (14) with steel decking (10) enclose into and seal box structure, ballast body pack in seal box structure.

5. The double-deck four-line railway steel truss girder cable-stayed bridge main girder configuration of claim 4, wherein the steel box is provided only at the fourth deck system (52);

or the like, or, alternatively,

the fourth bridge deck system (52) and the second bridge deck system (42) are both provided with the steel box, and the volume of the steel box of the fourth bridge deck system (52) is larger than that of the steel box of the second bridge deck system (42).

6. The double-deck four-track railway steel truss cable-stayed bridge main beam construction of claim 4, wherein the ballast body comprises at least two layers of shrinkage-compensating concrete layers (153) filled in layers.

7. The main beam structure of the cable-stayed bridge with the double-layer four-line railway steel truss girder according to any one of claims 2 to 6, wherein a plurality of first stiffening ribs (12) are distributed at intervals at the bottom of the steel bridge deck (10) along the transverse bridge direction, and the first stiffening ribs (12) are arranged along the longitudinal bridge direction;

when the lower part of the ballast body is a common concrete layer (151), the top surface of the common concrete layer (151) is not higher than the bottom of the first stiffening rib (12) of the steel bridge deck (10).

8. The girder construction of a double-deck four-line railway steel truss girder cable-stayed bridge according to any one of claims 2 to 6, wherein a plurality of second stiffening ribs (13) are provided above the bottom plate (11), the plurality of second stiffening ribs (13) are provided along a longitudinal direction of the bridge, joint plates (17) are vertically provided at corners of a web plate and a lower wing plate of the bridge deck system crossbeam (14) along the longitudinal direction of the bridge, and the second stiffening ribs (13) are connected with corresponding joint plates (17) of the bridge deck system crossbeam (14) through first high-strength bolts (81);

and/or;

a plurality of shear nails (16) are arranged on four sides of the closed box-type structure.

9. The main girder construction of a cable-stayed bridge with a double-deck four-line railway steel truss according to any one of claims 1 to 6, wherein the cross links (6) are bolted at both sides thereof to the corresponding web members (3), and the upper sides of the cross links (6) are welded to the lower side of the upper bridge deck system.

10. The main beam structure of the cable-stayed bridge with the double-deck four-line railway steel truss girder as claimed in claim 9, wherein the cross link (6) comprises a cross bar and a plurality of diagonal bars, the upper ends of the diagonal bars are connected with the upper side of the cross bar, the lower ends of the diagonal bars are connected with the lower side of the upper bridge deck system, and the cross bar, the upper bridge deck system and all the diagonal bars jointly form a plurality of equilateral triangle structures which are continuously arranged along the cross bridge direction.

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