Cable-stayed bridge with high and low towers

Abstract

A main bridge of the cable-stayed bridge structure comprises a low tower, a high tower, a main beam and a stay cable, the low tower and the high tower are arranged in the longitudinal direction of the bridge, the main bridge is divided into a first side span, a middle span and a second side span which are sequentially arranged, the main beam is supported on the low tower and the high tower, and the stay cable is supported on the middle span. The main beam is arranged between the low tower and the high tower and is divided into a main beam weight area located in a side span and a main beam standard section located in a main span by the low tower and the high tower, a vertical support is arranged between the low tower and the main beam, and the high tower and the main beam are fixedly connected through tower beam piers, so that the main bridge forms a'consolidation + semi-floating 'structural system; the low tower and the high tower adopt single-column type bridge towers in the transverse bridge direction, the vertical surface of the appearance is in a swan neck shape, a lower tower column adopts a variable cross-section straight line form, an upper tower column adopts a uniform cross-section section, and the uniform cross-section section of the upper tower column in the bridge direction adopts a circular curve shape in the vertical direction. According to the scheme, the structure is attractive, the structure is reasonable, and design and construction are convenient.

Description

Technical Field

[0001] The invention relates to the field of cable-stayed bridges, and in particular to a high-low tower cable-stayed bridge. Background Art

[0002] The main structure of a cable-stayed bridge is a combined structural system consisting of three basic components: towers, beams, and cables. The role of the cables is equivalent to adding a number of elastic supports within the span of the main beam, thereby greatly reducing the bending moment within the beam and the size of the beam, significantly increasing the span capacity of the bridge.

[0003] With the development of economy and society, the landscape requirements of bridge construction are constantly improving. Special-shaped cable-stayed bridges with good landscape are gradually being used. In addition, for certain suitable terrain, geology, navigation and other conditions, high-low tower cable-stayed bridges have better adaptability. According to different construction conditions and construction needs, the options for special-shaped cable-stayed bridges are diverse and are a process of continuous iterative optimization. For this type of structure, due to the asymmetry of the bridge tower and the special shape of the structure, the force on the structure is more complex than that of a conventional cable-stayed bridge. If the structural system, main structure and details are not handled properly, it will bring great difficulties to the design and construction, affecting the effect of the project.

[0004] In view of this, it is necessary to optimize and improve the structure of special-shaped cable-stayed bridges to facilitate design and construction and improve the rationality and aesthetics of the bridge system. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a high-low tower cable-stayed bridge structure with beautiful shape and reasonable structure.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A high-low tower cable-stayed bridge structure, comprising a low tower, a high tower, a main beam, and a cable, wherein the low tower and the high tower are arranged along the longitudinal direction of the bridge, and the main bridge is divided into a first side span, a middle span, and a second side span which are arranged in sequence, the main beam is supported on the low tower and the high tower, and is divided by the low tower and the high tower into a main beam weight area located in the side span and a main beam standard section located in the main span, and a vertical support is arranged between the low tower and the main beam, and a tower-beam pier is used to consolidate the high tower and the main beam, so that the main bridge forms a "consolidation + semi-floating" structural system;

[0008] The low tower and the high tower are single-column bridge towers in the horizontal direction of the bridge, and the facade is in the shape of a swan neck. The lower tower column is in the form of a variable-section straight line, and the upper tower column is in the form of a uniform section segment. The uniform section segment of the upper tower column along the bridge direction is in the shape of a circular curve vertically.

[0009] The scheme of the present invention has beautiful shape and reasonable structure, and realizes the unity of mechanics and aesthetics while facilitating design and construction.

[0010] Preferably, the vertical support includes a corbel symmetrically arranged on the low tower and a vertical supporting horizontal movable bearing arranged between the main beam and the corbel.

[0011] Preferably, the vertical supporting horizontal movable bearing includes a bidirectional movable bearing and a unidirectional movable bearing.

[0012] Preferably, a transverse wind-resistant support is also provided between the low tower and the main beam.

[0013] Preferably, the main towers of the low tower and the high tower are made of reinforced concrete, and the tower crowns are made of steel.

[0014] Preferably, with the longitudinal bridge upward, the middle span side of the tower crown continues the circular curve shape of the upper tower column to the tower top, and the side span side adopts a three-stage straight line change; with the transverse bridge upward, the tower crown adopts a straight line-circular arc line-straight line transition.

[0015] Preferably, in terms of structure, the tower crowns of the low tower and the high tower adopt a single-box welded steel structure section, a pressure plate is arranged at the bottom to be connected to the reinforced concrete main tower, and the tower crown and the main tower are connected by shear nails + anchor bolts.

[0016] Preferably, both ends of the main beam are also provided with vertical supporting horizontal movable bearings.

[0017] Preferably, the main beam is a prestressed concrete structure, adopts an inclined web single-box five-chamber cross-section structure, and the standard segment length of the main beam on the low tower side is smaller than the standard segment length of the main beam on the high tower side.

[0018] Preferably, solid cross beams are provided at both ends of the main beam, and ballast weights are provided in the box chambers of the side span sections of the main beam.

[0019] The bridge type scheme of the bridge of the present invention is a high-low tower central double-cable-plane cable-stayed bridge, the overall shape highlights the "swan" theme, and the bridge towers (low tower and high tower) are curved towers.

[0020] In terms of structural system selection, since the overall structure of the bridge of the present invention is a special-shaped cable-stayed bridge with high and low curved towers, the effects under constant load on both sides are asymmetric, and longitudinal fixed constraints need to be set, considering the poor suitability of floating systems and semi-floating systems; the rigid frame system has the advantages of not requiring the setting of supports and temporary consolidation during construction, but it is only suitable for flexible piers with higher lower towers, otherwise it will bring about greater temperature and shrinkage creep effects; the tower-beam consolidation (tower-pier separation) system requires large-tonnage supports, has low overall stiffness, and is not suitable for large-span structures; therefore, after research and comparison, the inventor adopted a high-tower consolidation and low-tower semi-floating system structure in the scheme of the present invention, and opened a main beam at the low tower to pass through the tower column, and set corbels and supports on both sides of the bridge tower to provide vertical support for the main beam.

[0021] The main structure of the bridge tower adopts reinforced concrete structure. The lower tower adopts a variable cross-section straight line form, which is conducive to structural stress. The vertical section of the upper tower column and other cross-section sections along the bridge direction adopts a circular curve shape, which is convenient for design and construction, and the cable force is adjusted to optimize the structural stress of the curved bridge tower. The tower crown adopts a simplified swan head shape and is prefabricated and installed with steel structure. The annular prestressing of the cable anchoring section adopts the U-shaped steel bundle tensioning method, and the top of the tower column is equipped with a vertical prestressed steel strand bundle to improve the local stress at the top of the tower.

[0022] The tower crown of the cable-stayed bridge tower adopts a simplified swan head shape, and the structure adopts a single-box welded steel structure section. The lower part is equipped with a pressure plate connected to the concrete bridge tower, and the steel tower crown and the lower concrete tower column are connected by shear nails + anchor bolts. Considering the construction and hoisting conditions, the tower crown steel structure is made in sections, and installed by hoisting section by section, and the sections are connected by welding.

[0023] To facilitate construction, the main beam of the cable-stayed bridge is a prestressed concrete structure with cantilever construction, and the cross section adopts a single-box five-chamber cross section with inclined webs. The main beam is designed as a three-way prestressed system, and the longitudinal prestressing of the main beam is divided into the pre-construction beam and the joint beam of the main beam cantilever pouring construction. To improve the structural stress, ballast weights are set in the box chambers at the side span section of the main beam. The ballast weights are made of prefabricated iron sand concrete blocks, and the ballast weights of each box chamber are arranged according to calculation requirements. In order to meet the lateral stress and structural counterweight, solid cross beams are set at both ends of the main beam, and the bottom of the end cross beam is heightened.

[0024] In order to meet the needs of aesthetics and structural stress, the cable-stayed cable adopts a central double-cable fan-shaped arrangement. The cable-stayed cable is tensioned at one end, with the tower as the anchor end; a concrete anchor block is set at the anchor position of the cable-stayed cable on the beam as the tension end. The cable body is composed of multiple strands of unbonded high-strength parallel galvanized steel strands, with an HDPE sheath pipe on the outer layer, which can achieve single-strand tensioning during construction and operation and maintenance.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1) The present invention adopts a "consolidated + semi-floating" cable-stayed bridge structural system, which reduces shrinkage creep and temperature effects while ensuring structural stiffness;

[0027] 2) The bridge tower of the present invention adopts a simple swan-shaped curved tower and adopts a combination of a concrete main body and a steel structure tower crown, which takes into account both mechanics and aesthetics and is convenient for construction;

[0028] 3) The main beam of the present invention adopts a weight-bearing and cross beam counterweight method, combined with cable force optimization and adjustment, to achieve a reasonable overall structure and reliable construction;

[0029] 4) The solution of the present invention has good scalability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A schematic diagram of the overall layout structure of a bridge provided by an embodiment of the present invention;

[0032] Figure 2 A schematic diagram of a bridge structure system provided by an embodiment of the present invention, wherein a is an elevation view, b is a top view, SX represents a bidirectional movable bearing, and DX represents a unidirectional movable bearing;

[0033] Figure 3 It is a schematic diagram of the vertical bridge elevation of the general structure of the low tower of the present invention;

[0034] Figure 4 It is a schematic diagram of the cross-bridge elevation of the general structure of the low tower of the present invention;

[0035] Figure 5 It is a schematic diagram of the vertical bridge elevation of the general structure of the high tower of the present invention;

[0036] Figure 6 It is a schematic diagram of the vertical bridge elevation of the general structure of the tower crown of the high tower or low tower of the present invention;

[0037] Figure 7 It is a cross-sectional schematic diagram of a reinforced concrete bridge tower of the present invention;

[0038] Figure 8 This is a schematic diagram of the vertical prestressing of the tower top of the present invention;

[0039] Fig. 9 Schematic diagram of a standard cross section of the main beam of the present invention;

[0040] Fig.10 This is a schematic diagram of the side end cross beam of the approach bridge of the present invention;

[0041] Fig.11 This is a schematic diagram of the cross beam at the side end of the abutment of the present invention;

[0042] Fig.12 It is a schematic diagram of the main beam side span counterweight of the present invention.

[0043] Fig.13 It is a schematic diagram of the three-dimensional structure of the bridge of the present invention.

[0044] In the figure:

[0045] 1 – low tower;

[0046] 2 – low tower crown;

[0047] 3 – Tower;

[0048] 4 – The crown of the tower;

[0049] 5 – cow leg;

[0050] 6——Standard section of main beam;

[0051] 7——Main beam weight area;

[0052] 8——cross beam at the side end of the approach bridge;

[0053] 9——cross beam at the side end of abutment;

[0054] 10 – stay cables;

[0055] 11——Vertical support horizontal movable bearing;

[0056] 12——Horizontal wind-resistant support;

[0057] 13 - consolidation of tower beam piers;

[0058] 14 – lower tower column;

[0059] 15 – Upper tower column;

[0060] 16——Weight. DETAILED DESCRIPTION

[0061] The present invention is further described below in conjunction with specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0062] In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention 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 limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0063] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] like Figure 1 As shown, the main bridge structure of an embodiment of a high-low tower cable-stayed bridge structure of the present invention comprises a low tower 1, a high tower 3, a main beam, and a cable-stayed cable 10. The low tower 1 and the high tower 3 are sequentially arranged in the middle of the bridge along the longitudinal direction of the bridge. The main beam is placed on the low tower 1 and the high tower 3, and the cable-stayed cables 10 are respectively installed on both sides of the low tower 1 and the high tower 3 to connect with the main beam. The main beam is divided by the low tower 1 and the high tower 3 into a main beam standard section 6 located in the middle span B, and a main beam weight-bearing area 7 located in the first side span A and the second side span C. The spans of the first side span A, the middle span B, and the second side span C are 70m, 192m, and 110m, respectively.

[0065] The main bridge adopts a "consolidation + semi-floating" structural system, that is, the tower beam pier consolidation 13 is adopted at the high tower 3, and a vertical support is set at the low tower 1. In terms of support arrangement, a vertical support horizontal movable support 11 is set on the bracket 5 at the low tower 1, and a transverse wind-resistant support 12 is set at the low tower to resist the lateral effect of the main beam under wind load and earthquake load. Vertical support horizontal movable supports 11 are also set at the ends of both sides of the main beam, such as Figure 2 SX represents a bidirectional movable bearing, and DX represents a unidirectional movable bearing.

[0066] like Figure 3 - Figure 8 As shown, the main tower (including the low tower 1 and the high tower 3) adopts a single-column bridge tower in the transverse direction of the bridge, and the exterior facade is in the shape of a swan neck. The lower tower column 14 adopts a variable-section straight line form, and the uniform-section section of the upper tower column 15 adopts a circular curve shape along the bridge direction. The total height of the low tower 1 is 83.0m (excluding the tower base), and the total height of the high tower 3 is 102.59m (excluding the tower base). The main structure of the main tower is made of C50 reinforced concrete, and the low tower crown 2 and the high tower crown 4 are made of Q235B steel respectively.

[0067] The standard cross section of the upper tower column of low tower 1 is a 440cm×350cm rectangle, and a corbel 5 and a vertical support horizontal movable support 11 for supporting the main beam are set at the bottom of the beam. The standard cross section of the upper tower column of high tower 3 is a 500cm×380cm rectangle. The crown 2 of the low tower and the crown 4 of the high tower adopt simplified swan head shapes. The shape concept of crown 2: in the longitudinal direction of the bridge, the middle span side continues the circular curve to the top of the tower, and the side span side adopts a three-stage straight line change; in the transverse direction of the bridge, a straight line-circular arc-straight line is used for transition. In terms of structure, crown 2 adopts a single-box welded steel structure section with a total height of 12m. The lower part is equipped with a pressure plate connected to the reinforced concrete main tower, and the crown and the lower concrete main tower are connected by shear nails + anchor bolts. Considering the construction and hoisting conditions, the steel structure of the crown is made in sections, installed by hoisting section by section, and the sections are connected by welding.

[0068] The annular prestressing of the anchor section of the inclined cable adopts the U-shaped steel bundle pulling method. 15 φs15.2 steel strands are arranged in each hole. The deep-buried anchor technology is adopted, and the YM15-15 DHS low-retraction anchor is matched. During construction, the round tower-shaped anchor pad and steel sleeve are pre-buried. The top of the tower column is equipped with 12φs15.2mm vertical prestressed bundles and YM15-12 anchors.

[0069] like Fig. 9 As shown, the main beam is a prestressed concrete structure, using C55 concrete, and a single-box five-chamber section of the inclined web. The beam height is 2.6m, and the cable area is raised to 2.85m to improve local stress. The main beam is constructed by cantilever casting. In order to coordinate the structural stress and progress, the standard segment length on the low tower side is 6m, and the standard segment length on the high tower side is 8m. The main beam is cast-in-place on the tower side using pier-side brackets. At the low tower position, the main tower passes through the top and bottom plates of the main beam, and temporary pier-side brackets are required. The side span is set with a 15m bracket cast-in-place section. During construction, the side span is closed first and then the middle span.

[0070] like Figure 1 and Fig.10 , Fig.11 As shown in the figure, in order to meet the needs of lateral force and increase the side span counterweight, solid beams are set at both ends of the main beam, such as Figure 1 The end cross beam 8 of the approach bridge and the end cross beam 9 of the abutment are installed, and the bottom of the end cross beam 8 of the approach bridge and the end cross beam 9 of the abutment are raised. The bottom of the end cross beam is widened from the bottom width of the original box beam to facilitate the placement of the support and enhance the lateral torsion resistance. At the same time, space is reserved for the prestressed anchoring of the cross beam; prestress is configured in the cross beam, and φs15.2mm type steel strands are configured according to calculations.

[0071] like Fig.12 As shown, a weight 16 is set in the box of the side span section of the main beam. The weight 16 adopts a 0.3×0.3×0.3m iron sand concrete prefabricated block with a design bulk density of 40kN / m3. The box is weighted according to calculation requirements.

[0072] The present invention is applicable to a high-low tower special-shaped cable-stayed bridge structure. According to the scheme provided by the present invention, it can also be extended to a similar curved bridge tower cable-stayed bridge structure.

[0073] The above is only a specific implementation scheme of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the art can make many possible changes and modifications to the technical scheme of the present invention by using the technical content disclosed above without departing from the scope of the technical scheme of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical scheme of the present invention should fall within the protection scope of the technical scheme of the present invention.

Claims

1. A high-low tower cable-stayed bridge structure, comprising a low tower, a high tower, a main beam, and a cable-stayed cable, characterized in that: The low tower and the high tower are arranged along the longitudinal direction of the bridge, and the main bridge is divided into a first side span, a middle span and a second side span arranged in sequence. The main beam is supported on the low tower and the high tower, and is divided by the low tower and the high tower into a main beam weight area located in the side span and a main beam standard section located in the main span. A vertical support is arranged between the low tower and the main beam, and a tower-beam pier is used to consolidate the high tower and the main beam, so that the main bridge forms a "consolidation + semi-floating" structural system. The low tower and the high tower are single-column bridge towers in the horizontal direction of the bridge, and the facade is in the shape of a swan neck. The lower tower column is in the form of a variable-section straight line, and the upper tower column is in the form of a uniform section segment. The uniform section segment of the upper tower column along the bridge direction is in the shape of a circular curve vertically.

2. The high-low tower cable-stayed bridge structure according to claim 1, characterized in that: The vertical support comprises a corbel symmetrically arranged on the low tower and a vertical supporting horizontal movable bearing arranged between the main beam and the corbel.

3. The high-low tower cable-stayed bridge structure according to claim 2, characterized in that: The vertical support horizontal movable bearing includes a bidirectional movable bearing and a unidirectional movable bearing.

4. The high-low tower cable-stayed bridge structure according to claim 1, characterized in that: A transverse wind-resistant support is also provided between the low tower and the main beam.

5. The high-low tower cable-stayed bridge structure according to claim 1, characterized in that: The main towers of the low tower and the high tower are made of reinforced concrete, and the tower crowns are made of steel.

6. The high-low tower cable-stayed bridge structure according to claim 5, characterized in that: With the longitudinal bridge pointing upward, the middle span side of the tower crown continues the circular curve shape of the upper tower column to the tower top, and the side span side adopts a three-stage straight line change; with the transverse bridge pointing upward, the tower crown adopts a straight line-circular arc-straight line transition.

7. The high-low tower cable-stayed bridge structure according to claim 5, characterized in that: In terms of structure, the tower crowns of the low tower and the high tower adopt a single-box welded steel structure section, a pressure plate is arranged at the bottom to be connected with the reinforced concrete main tower, and the tower crown and the main tower are connected with shear nails + anchor bolts.

8. The high-low tower cable-stayed bridge structure according to claim 2, characterized in that: Both ends of the main beam are also provided with vertical supporting horizontal movable bearings.

9. The high-low tower cable-stayed bridge structure according to claim 1, characterized in that: The main beam is a prestressed concrete structure, adopts an inclined web single-box five-chamber cross-section structure, and the standard segment length of the main beam on the low tower side is smaller than the standard segment length of the main beam on the high tower side.

10. The high-low tower cable-stayed bridge structure according to claim 1, characterized in that: Solid cross beams are arranged at both ends of the main beam, and ballast weights are arranged in the box chambers of the side span sections of the main beam.

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