A design method of a curved stiffening string steel truss bridge and a steel truss bridge

Abstract

The application discloses a curved stiffening chord steel truss bridge design method and a steel truss bridge, and relates to the technical field of bridge design.The method comprises the following steps: in a vertical plane, a part of the upper chord rod system line corresponding to the stiffening chord system line is translated upwards by a set length to serve as a stiffening chord plane rotation shaft; the vertical plane is rotated by a set angle along the stiffening chord plane rotation shaft to the bridge deck side to serve as a stiffening chord plane; the stiffening chord system line is established in the stiffening chord plane, and the stiffening chord structure is established based on the stiffening chord system line.The established stiffening chord structure has no transverse deviation when being spliced with the upper chord rod, and has no secondary stress, and can adapt to different proportional longitudinal slopes on both sides of a circular curve.The method solves the problem that the existing technology brings certain splicing secondary stress to the structure when the stiffening chord is spliced, and threatens the safety of the structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bridge design, in particular to a curved stiffening chord steel truss bridge design method and a steel truss bridge. BACKGROUND

[0002] In order to meet the requirements of large-span steel truss structure stress and landscape effect, more and more steel trusses adopt the structure form with curved stiffening chords, and the planes of the stiffening chords are not in the same plane as the chord of the main beam to meet higher landscape requirements. In the traditional steel truss bridge with stiffening chords, in order to meet the overall layout requirements of the line, the longitudinal slope and the circular curve section are considered in the vertical curve line shape of the steel truss, and in special cases, different proportions of longitudinal slopes are arranged on both sides of the circular curve section to adapt to the overall layout.

[0003] In the prior art, when the bridge span has longitudinal slopes on both sides, the main beam line shape is still designed as a flat slope when designing the stiffening chord, and there is a problem that the stiffening chord assembly will bring certain splicing secondary stress to the structure, threatening the safety of the structure. SUMMARY

[0004] In view of the defects in the prior art, the purpose of the present application is to provide a curved stiffening chord steel truss bridge design method and a steel truss bridge, which can solve the problem that when the bridge span has longitudinal slopes on both sides, the main beam line shape is still designed as a flat slope when designing the stiffening chord in the prior art, and the stiffening chord assembly will bring certain splicing secondary stress to the structure, threatening the safety of the structure.

[0005] To achieve the above purpose, the technical scheme adopted by the present application is:

[0006] On the one hand, the present application provides a curved stiffening chord steel truss bridge design method, comprising:

[0007] In the vertical plane, the part of the upper chord system line corresponding to the stiffening chord system line is translated upward by a set length as a stiffening chord plane rotation axis;

[0008] The vertical plane is rotated by a set angle along the stiffening chord plane rotation axis to the bridge deck side as the stiffening chord plane;

[0009] In the stiffening chord plane, the stiffening chord system line is established, and the stiffening chord structure is established based on the stiffening chord system line.

[0010] In some optional schemes, after the stiffening chord system line is established in the stiffening chord plane and the stiffening chord structure is established based on the stiffening chord system line, the relative position of the stiffening chord structure and the upper chord top plate is determined by accurate lofting, and it is judged whether the structure meets the stress requirement, if the structure does not meet the stress requirement, the set length and the set angle are adjusted until the structure meets the stress requirement.

[0011] In some alternatives, the upper chord system line is translated upward by a set length in the vertical plane before the stiffening chord plane of rotation axis is determined:

[0012] According to the longitudinal slope gradient of the two sides of the bridge span, the upper chord system line and the lower chord system line are determined and the main girder overall structure is formed.

[0013] According to the longitudinal slope gradient of the two sides of the bridge span, the main girder vertical curve alignment is determined.

[0014] According to the main girder vertical curve alignment, the upper chord system line and the lower chord system line are determined and the main girder overall structure is formed.

[0015] According to the main girder vertical curve alignment, the main girder vertical curve alignment is determined.

[0016] According to the main girder vertical curve alignment, the upper chord system line and the lower chord system line are determined and the main girder overall structure is formed.

[0017] In some alternatives, after the upper chord system line and the lower chord system line are determined according to the main girder vertical curve alignment and the main girder overall structure is formed, the relative position of the stiffening chord system line and the upper chord system line is determined according to the upper chord system line.

[0018] In some alternatives, the set length is half of the height of the upper chord.

[0019] In some alternatives, the stiffening chord system line is established in the stiffening chord plane, and the stiffening vertical rod structure and the stiffening chord cross strut structure are designed based on the established stiffening chord structure.

[0020] In another aspect, the present application also provides a steel truss bridge, which comprises a stiffening chord designed by the above-mentioned curved stiffening chord steel truss bridge design method.

[0021] In some alternatives, the stiffening chord is provided with an upper chord below which a lower chord is arranged in parallel and at intervals, a plurality of web members are arranged between the upper chord and the lower chord in the longitudinal bridge direction, two ends of each web member are connected to the upper chord and the lower chord, the plurality of web members are connected in sequence, a plurality of stiffening chord vertical rods are arranged in parallel at intervals between the stiffening chord and the upper chord in the longitudinal bridge direction, and the connection points of the stiffening chord vertical rods and the upper chord coincide with the connection points of the upper chord and the web members.

[0022] In some alternatives, an upper bridge deck is arranged between the upper chords on both sides of the bridge axis, a lower bridge deck is arranged between the lower chords on both sides of the bridge axis, and a plurality of stiffening chord cross struts are arranged in the longitudinal bridge direction between the stiffening chords on both sides of the bridge axis.

[0023] Compared with the prior art, the application has the advantages that: in the vertical plane, the part of the chord system line corresponding to the stiffening chord system line is translated upwards by a set length as the stiffening chord plane rotation axis; the vertical plane is rotated by a set angle along the stiffening chord plane rotation axis to the bridge deck side as the stiffening chord plane; the stiffening chord system line is established in the stiffening chord plane, and the stiffening chord structure is established based on the stiffening chord system line. The established stiffening chord structure has no transverse deviation when spliced with the upper chord, and there is no secondary stress, and can adapt to different proportions of longitudinal slopes on both sides of the circular curve. The problem that the existing technology causes certain splicing secondary stress to the structure when the stiffening chord is spliced, and threatens the safety of the structure, is solved. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0025] Figure 1 The flowchart of the curve stiffening chord steel truss bridge design method in the embodiment of the present application is shown in the figure.

[0026] Figure 2 The schematic diagram of the stiffening chord plane in the embodiment of the present application is shown in the figure.

[0027] Figure 3 The schematic diagram of the bridge vertical curve in the embodiment of the present application is shown in the figure.

[0028] Figure 4 The structural schematic diagram of the curve stiffening chord steel truss bridge in the embodiment of the present application is shown in the figure.

[0029] Figure 5 The cross-sectional structural schematic diagram of the curve stiffening chord steel truss bridge in the embodiment of the present application is shown in the figure.

[0030] In the figure: 1, upper chord system line; 2, stiffening chord; 3, stiffening chord vertical rod; 4, upper chord; 5, web rod; 6, lower chord; 7, stiffening chord cross brace; 8, stiffening chord node plate; 9, stiffening chord vertical rod node plate; 10, upper bridge deck; 11, lower bridge deck; 12, stiffening chord plane rotation axis; 13, stiffening chord plane; 14, vertical plane; 15, stiffening chord system line. DETAILED DESCRIPTION

[0031] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0032] The embodiments of the present application will be further described below with reference to the drawings.

[0033] As shown in the drawings, Figure 1 In one aspect, the present application provides a design method of a curved stiffening chord steel truss bridge, comprising:

[0034] S1: in a vertical plane, the part of the upper chord system line corresponding to the stiffening chord system line is translated upward by a set length as a stiffening chord plane rotation axis.

[0035] S2: the vertical plane is rotated by a set angle along the stiffening chord plane rotation axis to the bridge deck side as a stiffening chord plane.

[0036] S3: the stiffening chord system line is established in the stiffening chord plane, and the stiffening chord structure is established based on the stiffening chord system line.

[0037] As shown in the drawings, Figure 2 In the present embodiment, the bridge structure design and lofting are both based on the BIM (Building Information Modeling) technology. The stiffening chord system line is the axis line for the design and lofting of the stiffening chord, the upper chord system line is the axis line for the design and lofting of the upper chord, and the rest of the system lines are all in the same way. The upper chord system line 1 corresponding to the stiffening chord system line 15 is translated upward by a set length to obtain the stiffening chord plane rotation axis 12. The vertical plane 14 is rotated by a set angle along the stiffening chord plane rotation axis 12 to the bridge deck side to obtain the stiffening chord plane 13. The stiffening chord system line 15 is established in the stiffening chord plane 13, and the stiffening chord structure is established based on the stiffening chord system line 15. When the established stiffening chord structure is spliced with the upper chord, there is no transverse deviation, and there is no secondary stress, which can adapt to different proportions of longitudinal slopes on both sides of the circular curve. The problem that the existing technology brings certain splicing secondary stress to the structure when the stiffening chord is spliced, which threatens the safety of the structure, is solved. In the process of bridge design, when the longitudinal slope is adjusted, the present scheme can quickly adjust the structure to adapt to the influence of the adjustment of the longitudinal slope on the structure.

[0038] In some optional embodiments, a stiffening chord system line is established in the stiffening chord plane. After the stiffening chord structure is established with the stiffening chord system line as a reference, the relative position between the stiffening chord structure and the top plate of the upper chord is determined by precise layout, and it is determined whether the structure meets the stress requirements. If the structure does not meet the stress requirements, the set length and set angle are adjusted until the structure meets the stress requirements.

[0039] In this embodiment, the initial setting angle is determined by the landscape design effect. The initial setting length is half the height of the top chord. After accurately laying out the relative position between the stiffening chord structure and the top plate of the top chord, if the structure does not meet the stress requirements, the setting angle is adjusted first. The setting angle is adjusted while ensuring the landscape effect. If the stress requirements are still not met, the setting length is adjusted so that the structure meets the stress requirements.

[0040] In some alternative embodiments, the upper chord system line is translated upward by a predetermined length in the vertical plane before serving as the axis of rotation of the stiffening chord plane:

[0041] Determine the longitudinal slope of both sides of the bridge span based on the connection conditions on both sides of the bridge span;

[0042] Based on the longitudinal slope on both sides of the bridge span, the upper chord system line and the lower chord system line are determined to form the overall structure of the main beam.

[0043] In this embodiment, the connection conditions refer to the need for the bridge to connect to the road and railway networks on both banks after crossing the river. Since the road and railway networks on both banks are generally planned earlier than the bridge itself, the longitudinal slope should be determined based on the connection conditions from the initial stages of bridge research. For example, if the bridge needs to connect to the nearby road network as soon as possible after crossing, then the longitudinal slope of the bridge should be increased to ensure that the route is implemented as quickly as possible.

[0044] In some optional embodiments, determining the upper chord system lines and lower chord system lines based on the longitudinal slopes on both sides of the bridge span and forming the overall main beam structure includes:

[0045] The vertical curve shape of the main beam is determined based on the longitudinal slope on both sides of the bridge span.

[0046] Based on the vertical curve shape of the main beam, determine the upper chord system line and the lower chord system line to form the overall structure of the main beam.

[0047] like Figure 3 As shown, in this embodiment, the upper chord system line 1 is determined based on the vertical curve of the main beam. The upper chord system line 1 includes straight segments on both sides of the longitudinal slope and circular curve segments at the longitudinal slope.

[0048] In some alternative embodiments, after the top chord system line and the bottom chord system line are determined according to the main girder vertical curve line and the main girder overall structure is formed, the relative position of the stiffening chord system line to the top chord system line is determined according to the top chord system line.

[0049] In some alternative embodiments, the stiffening chord system line is established in the stiffening chord plane, and the stiffening chord structure is established based on the stiffening chord system line. Then, the stiffening vertical rod structure and the stiffening chord cross strut structure are designed based on the established stiffening chord structure.

[0050] As shown in Figure 4 In another aspect, the present application also provides a steel truss bridge, which comprises a stiffening chord 2 designed by the above-mentioned curved stiffening chord steel truss bridge design method.

[0051] In some alternative embodiments, the stiffening chord 2 is provided with a top chord 4, and a bottom chord 6 is arranged in parallel and at intervals below the top chord 4. A plurality of web chords 5 are arranged in the longitudinal direction between the top chord 4 and the bottom chord 6, and the two ends of each web chord 5 are connected to the top chord 4 and the bottom chord 6, respectively. A plurality of stiffening chord vertical rods 3 are arranged in parallel and at intervals in the longitudinal direction between the stiffening chord 2 and the top chord 4, and the connection points of the stiffening chord vertical rods 3 to the top chord 4 coincide with the connection points of the top chord 4 to the web chords 5.

[0052] In the present embodiment, one end of the stiffening chord vertical rod 3 connected to the top chord 4 is provided with a stiffening chord vertical rod node plate 9, and the other end of the stiffening chord vertical rod 3 connected to the stiffening chord 2 is provided with a stiffening chord node plate 8. The overall stiffness of the stiffening chord 2 is improved by arranging the stiffening chord vertical rod 3.

[0053] As shown in Figure 5 In some alternative embodiments, an upper bridge deck 10 is arranged between the top chords 4 on both sides of the bridge central axis, a lower bridge deck 11 is arranged between the bottom chords 6 on both sides of the bridge central axis, and a plurality of stiffening chord cross struts 7 are arranged in the longitudinal direction between the stiffening chords 2 on both sides of the bridge central axis.

[0054] In summary, the application translates the part of the stringer system line corresponding to the upper chord stringer system line by a set length in the vertical plane, as the stiffening chord plane rotation axis; rotates the vertical plane along the stiffening chord plane rotation axis by a set angle to the bridge deck side, as the stiffening chord plane; establishes the stiffening chord system line in the stiffening chord plane, and establishes the stiffening chord structure based on the stiffening chord system line. The established stiffening chord structure has no transverse deviation when spliced with the upper chord, and there is no secondary stress, and can adapt to different proportions of longitudinal slopes on both sides of the circular curve. Both structural stress and landscape effect are considered. The problem that the existing technology brings certain splicing secondary stress to the structure when the stiffening chord is assembled, threatening the safety of the structure, is solved. The scheme can quickly position the complex stiffening chord structure in space, and can adapt to the case of asymmetric longitudinal slope of the bridge span center. At the same time, at the initial stage of the scheme determination, the influence of lofting work on the mutual spatial relationship of the structure caused by the adjustment of the longitudinal slope on both sides can be quickly adapted. The design efficiency of the structure size and modeling at the initial stage of the scheme determination is greatly increased.

[0055] In the description of the present application, it should be noted that the positions or positional relationships indicated by the terms "upper", "lower", etc. are based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular position, be constructed and operated in a particular position, and therefore cannot be understood as a limitation on the present application. Unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0056] It should be noted that in the present application, relational terms such as "first" and "second" and the like are used only to distinguish one entity or operation from another, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of additional identical elements in the process, method, article or device including the element.

[0057] The foregoing detailed description of the application has been presented for purposes of illustration and description. Various modifications and changes can be made to these embodiments without departing from the spirit and scope of the application. It is intended that the scope of the application should not be limited by the particular representative embodiments described above.

Claims

1. A design method for a curved stiffened steel truss bridge, characterized in that, include: Determine the longitudinal slope of both sides of the bridge span based on the connection conditions on both sides of the bridge span; Based on the longitudinal slopes on both sides of the bridge span, the upper chord system lines and lower chord system lines are determined to form the overall structure of the main beam, including: The vertical curve shape of the main beam is determined based on the longitudinal slope on both sides of the bridge span. Based on the vertical curve shape of the main beam, determine the upper chord system line and the lower chord system line to form the overall structure of the main beam. Based on the upper chord system line, determine the relative position of the stiffening chord system line and the upper chord system line. In the vertical plane, the part of the upper chord system line corresponding to the stiffening chord system line is translated upward by a set length, which serves as the rotation axis of the stiffening chord plane; the stiffening chord system line is the axis line when the stiffening chord is designed and laid out, and the upper chord system line is the axis line when the upper chord is designed and laid out; The vertical plane is rotated along the stiffening chord plane by a set angle along the bridge deck side, and this is taken as the stiffening chord plane. Establish the stiffening string system line in the stiffening string plane, and establish the stiffening string structure based on the stiffening string system line.

2. The design method for curved stiffened steel truss bridges as described in claim 1, characterized in that, Establish the stiffening chord system line in the stiffening chord plane. After establishing the stiffening chord structure based on the stiffening chord system line, determine the relative position of the stiffening chord structure and the top plate of the upper chord by precise layout, and determine whether the structure meets the stress requirements. If the structure does not meet the stress requirements, adjust the set length and set angle until the structure meets the stress requirements.

3. The design method for curved stiffened steel truss bridges as described in claim 1, characterized in that, The initial set length is half the height of the upper chord.

4. The design method for curved stiffened steel truss bridges as described in claim 1, characterized in that, Establish the stiffening chord system line in the stiffening chord plane. After establishing the stiffening chord structure based on the stiffening chord system line, design the stiffening vertical bar structure and the stiffening chord horizontal brace structure on the basis of the established stiffening chord structure.

5. A steel truss bridge, characterized in that, It includes a stiffening chord (2), which is designed by the curved stiffening chord steel truss bridge design method as described in claim 1.

6. The steel truss bridge as described in claim 5, characterized in that, The stiffening chord (2) is provided with an upper chord (4) at the bottom. Below the upper chord (4), there are parallel lower chords (6). Between the upper chord (4) and the lower chord (6), there are multiple web members (5) that are connected to the upper chord (4) and the lower chord (6) at their two ends respectively. The multiple web members (5) are connected end to end. Between the stiffening chord (2) and the upper chord (4), there are multiple stiffening chord vertical members (3) that are parallel and spaced apart along the longitudinal direction. The connection point between the stiffening chord vertical member (3) and the upper chord (4) coincides with the connection point between the upper chord (4) and the web members (5).

7. The steel truss bridge as described in claim 6, characterized in that, An upper bridge surface (10) is provided between the upper chord members (4) on both sides of the bridge's central axis, and a lower bridge surface (11) is provided between the lower chord members (6) on both sides of the bridge's central axis. Multiple stiffening chord cross braces (7) are provided between the stiffening chords (2) on both sides of the bridge's central axis along the longitudinal direction.

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