An orthogonal steel-concrete composite structure inclined bridge tower

Abstract

The present application discloses an orthogonal steel-concrete composite structure inclined bridge tower, relating to the field of bridge technology. The orthogonal steel-concrete composite structure inclined bridge tower comprises: an upper tower column, which is a steel box structure; a lower tower column, which is a steel shell concrete composite structure. The lower tower column comprises a steel shell and a first partition disposed within the steel shell. The first partition divides the inner cavity of the steel shell into a mid-span compartment near the mid-span and a side-span compartment near the side span. Concrete is poured into the side span compartment. The first partition is positioned so that the concrete stress is within the allowable range of the specification. The present application fully utilizes the advantages of both concrete and steel materials, can effectively improve the bending bearing capacity of the cross-section, and simplify the force transmission structure of the main tower and the pedestal. The centroid of the cross-section of the lower tower column is offset toward the side span, reducing the inclination angle of the cross-section centroid axis, which can effectively reduce the bending moment of the inclined tower. At the same time, the outer contour of the lower tower column is consistent with that of the upper tower column, ensuring a beautiful inclined tower shape.

Description

Technical Field

[0001] The present application relates to the field of bridge technology, and in particular to an inclined bridge tower with an orthogonal steel-concrete composite structure. Background Art

[0002] Currently, cable-stayed bridges use cables to transmit the weight of the main girder and its external loads to the main tower, which then transmits the loads to the foundation. By rationally designing the side-to-midspan ratio, cable tension, and structural form of cable-stayed bridges, whether single-tower, twin-tower, or multi-tower cable-stayed bridges, the main tower can function as an axially compressed member under dead loads and as a slightly eccentrically compressed member under dead and live loads. In this case, the main tower can be constructed using reinforced concrete, steel, or a steel-concrete composite structure to meet the load-bearing requirements.

[0003] Single-tower cable-stayed bridges are elegantly designed structures that have seen widespread use in urban municipal bridges in recent years. Due to the tilted force line of the tower, it bears significant bending moments under dead loads, which are further exacerbated by dead and live loads. This bending moment is generated by the vertical component of the stay cables and the tower's deadweight, and cannot be eliminated through cable tension adjustment or other measures. When the bending moment is within a certain range, reinforced concrete, steel, or a combination of steel and concrete structures can meet the tower's load-bearing requirements. However, as the angle between the tower and the horizontal decreases, the span increases, and the deck load increases, the bending moment in the tower increases. In this case, reinforced concrete structures struggle to meet regulatory requirements for tensile stress. Steel structures require a transition to a concrete cap at the tower base, where the bending moment is greatest. This complex construction makes pure steel structures less economical. Increasing the structural load-bearing capacity simply by increasing the tower's cross-section would not only significantly impact the aesthetic appeal of this bridge type, but would also increase construction costs, limiting its widespread adoption. Summary of the Invention

[0004] In response to one of the defects in the prior art, the purpose of this application is to provide an orthogonal steel-concrete composite structure inclined bridge tower to solve the problem of large bending moment of the inclined tower in the related art.

[0005] The present application provides an orthogonal steel-concrete composite structure inclined bridge tower, which comprises, from top to bottom:

[0006] Upper tower column, which is a steel box structure;

[0007] The lower tower column is a steel shell and concrete composite structure, comprising a steel shell and a first partition disposed within the steel shell. The first partition divides the inner cavity of the steel shell into a mid-span compartment close to the mid-span and a side-span compartment close to the side span. Concrete is poured into the side-span compartment.

[0008] The position of the first diaphragm is configured so that the concrete stress is within the allowable range of the specification.

[0009] In some embodiments, a pressure plate 8 is provided between the upper tower column and the lower tower column, and the thickness of the steel shell of the lower tower column is smaller than the thickness of the steel box of the upper tower column.

[0010] In some embodiments, the inclined bridge tower further comprises a concrete tower base disposed under the lower tower column, and the steel shell of the lower tower column extends downward into the concrete tower base.

[0011] In some embodiments, the inclined bridge tower further includes a concrete cap disposed under the concrete tower base.

[0012] In some embodiments, a plurality of prestressed anchor rods are arranged in the concrete in the side span compartment, and the anchoring end of each of the prestressed anchor rods is pre-buried in the concrete pedestal. The tensioning ends of some of the prestressed anchor rods are located at the upper end surface of the concrete in the side span compartment, and the tensioning ends of some of the prestressed anchor rods are located at a preset height above the upper end surface of the concrete in the side span compartment.

[0013] In some embodiments, the steel box inner wall of the upper tower column and the steel shell inner wall of the lower tower column are respectively provided with a plurality of stiffening ribs along their circumferences, and the stiffening ribs of the steel box inner wall of the upper tower column and the stiffening ribs of the steel shell inner wall of the lower tower column are arranged correspondingly up and down.

[0014] In some embodiments, the bending moment at the junction of the upper tower column and the lower tower column is zero.

[0015] In some embodiments, at least one second partition is provided in the side span compartment. The second partition is arranged parallel to the first partition and divides the inner cavity of the side span compartment into a plurality of chambers.

[0016] In some embodiments, first shear studs are welded to the first partition plate and the second partition plate.

[0017] In some embodiments, the steel box cross section of the upper tower column perpendicular to its axis is a single-box single-chamber or single-box multi-chamber cross section.

[0018] The beneficial effects of the technical solution provided by this application include:

[0019] The orthogonal steel-concrete composite structure inclined bridge tower of the present application includes an upper tower column and a lower tower column from top to bottom. The upper tower column is a steel box structure, and the lower tower column is a steel shell concrete composite structure. The lower tower column includes a steel shell and a first partition arranged in the steel shell. Since the first partition separates the inner cavity of the steel shell into a middle span partition close to the middle span and a side span partition close to the side span, concrete is poured in the side span partition, and the position of the first partition is configured to make the concrete stress within the allowable range of the specification; therefore, the internal force distribution of the cross section of the lower tower column is that the axial pressure is mainly borne by the concrete, and the direction of the bending moment controlled in the design is that the side span is compressed and the middle span is tensile, that is, the compressive side of the bending moment is mainly borne by the concrete, and the tensile side of the bending moment is mainly borne by the steel. The advantages of both concrete and steel are fully utilized, which can effectively improve the bending bearing capacity of the cross section and simplify the force transmission structure of the main tower and the pedestal; the centroid of the combined cross section of the lower tower column is offset toward the side span, so that the inclination angle of the cross section centroid axis is reduced, which can effectively reduce the bending moment of the inclined tower. At the same time, the outer contour of the lower tower column is consistent with that of the upper tower column, ensuring a beautiful inclined tower shape. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0021] Figure 1 This is a elevational layout of an orthogonal steel-concrete composite structure inclined bridge tower in an embodiment of the present application;

[0022] Figure 2 This is a vertical layout diagram of the lower tower column in the embodiment of the present application (only some prestressed anchor rods are shown);

[0023] Figure 3 for Figure 2 Section 1-1 in the figure;

[0024] Figure 4 for Figure 2 Section 2-2 in the figure;

[0025] Figure 5 for Figure 2 Section 3-3 in the figure.

[0026] Reference numerals:

[0027] 1. Go up the tower column;

[0028] 2. Lower tower column; 21. First diaphragm; 22. Mid-span diaphragm; 23. Side-span diaphragm; 24. Second diaphragm; 25. First shear stud; 26. Second shear stud; 27. PBL shear key;

[0029] 3. Concrete tower base; 4. Concrete cap; 5. Prestressed anchor rods; 6. Stay cables; 7. Main beam; 8. Pressure plate. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0031] like Figure 1 and Figure 2 As shown, the embodiment of the present application provides an orthogonal steel-concrete composite structure inclined bridge tower, which includes an upper tower column 1 and a lower tower column 2 from top to bottom. Among them, a cable 6 is tensioned on the upper tower column 1, and the lower end of the upper tower column 1 intersects with the main beam 7.

[0032] The upper tower column 1 is a steel box structure, comprising a steel box. The upper tower column 1 utilizes a pure steel box cross-section. The light weight of the steel tower reduces bending moments generated by its own weight and provides high bending resistance. Depending on the loads being applied to the tower column, the upper tower column 1 can be designed with a single-box, single-chamber cross-section or a single-box, multi-chamber cross-section.

[0033] like Figure 3 As shown, the lower tower column 2 is a steel-shell-concrete composite structure, comprising a steel shell and a first diaphragm 21 disposed within the steel shell. The first diaphragm 21 divides the interior of the steel shell into a mid-span compartment 22 near the midspan and a side-span compartment 23 near the side spans. The side-span compartment 23 is filled with concrete, while the mid-span compartment 22 remains hollow. In this embodiment, the first diaphragm 21 is parallel to the axis of the inclined tower.

[0034] The position of the first diaphragm 21 is configured to keep the concrete stress within the permitted range of the standard. Specifically, the position of the first diaphragm 21 is determined based on the cross-sectional area occupied by the concrete, which is determined by the internal forces of the tower column. The principle is that the concrete stress is within the permitted range of the standard under the controlled design conditions.

[0035] The orthogonal steel-concrete composite inclined bridge tower of this embodiment has an upper tower column of a steel box structure and a lower tower column of a steel-shell-concrete composite structure. The lower tower column comprises a steel shell and a first diaphragm disposed within the steel shell. The first diaphragm divides the interior of the steel shell into a mid-span compartment near the midspan and a side-span compartment near the side spans. The side span compartments are filled with concrete, and the first diaphragm is positioned to keep the concrete stress within the permitted range of the specification. Therefore, the internal forces in the cross-section of the lower tower column are distributed so that the axial pressure is primarily borne by the concrete, and the bending moment direction is controlled so that the side spans are in compression and the mid-spans are in tension. That is, the compression side of the bending moment is primarily borne by the concrete, while the tension side is primarily borne by the steel. This fully utilizes the advantages of both concrete and steel, ensuring a beautiful inclined tower shape while effectively improving the cross-sectional bending bearing capacity and simplifying the force transmission structure between the main tower and the pedestal. Furthermore, the centroidal axis offset effectively reduces the bending moment of the inclined tower without increasing the cross-sectional dimensions of the main tower.

[0036] On the basis of the above embodiment, in this embodiment, the above-mentioned orthogonal steel-concrete composite structure inclined bridge tower further includes a pressure-bearing plate 8, and the above-mentioned pressure-bearing plate 8 is arranged between the upper tower column 1 and the lower tower column 2.

[0037] In this embodiment, the pressure plate 8 is a steel plate, the upper end surface of the pressure plate 8 is welded and fixed to the lower end surface of the steel box of the upper tower column 1, and the lower end surface of the pressure plate 8 is welded and fixed to the upper end surface of the steel shell of the lower tower column 2.

[0038] The thickness of the steel shell of the lower tower column 2 is smaller than the thickness of the steel box of the upper tower column 1 .

[0039] In this embodiment, when transitioning from the steel box section of the upper tower column 1 to the steel shell concrete section of the lower tower column 2 , the pressure plate 8 can ensure reliable force transmission.

[0040] Furthermore, the inclined bridge tower further includes a concrete tower base 3 , which is disposed under the lower tower column 2 , and the steel shell of the lower tower column 2 extends downward into the concrete tower base 3 .

[0041] In this embodiment, by extending the steel shell of the lower tower column 2 downward into the concrete tower base 3 and providing a PBL shear key 27 and a second shear stud 26 on the portion of the steel shell extending into the concrete tower base 3, the force of the steel shell of the lower tower column 2 can be transmitted to the lower concrete tower base structure.

[0042] Furthermore, the inclined bridge tower further includes a concrete cap 4 , which is disposed under the concrete tower base 3 .

[0043] A plurality of prestressed anchor rods 5 are arranged in the concrete in the above-mentioned side span compartment 23. The anchor end anchor beam of each of the above-mentioned prestressed anchor rods 5 is pre-buried in the concrete cap 4. The tensioning ends of some prestressed anchor rods 5 are located at the upper end surface of the concrete in the side span compartment 23 and are connected to the pressure plate. The tensioning ends of some prestressed anchor rods 5 are located at a preset height above the upper end surface of the concrete in the side span compartment 23 to ensure that the entire section of the steel-concrete bonding surface of the lower tower column 2 is under pressure.

[0044] In this embodiment, the preset height is 1m, that is, the prestressed anchor rods 5 pass through the pressure plate, and the tensioning ends are arranged in the upper tower column 1. Optionally, the wall panel of the upper tower column 1 is further provided with supporting stiffening ribs, which are connected to the pressure plate, and the tensioning ends are connected to the top surfaces of the supporting stiffening ribs.

[0045] Based on the above embodiment, in this embodiment, multiple stiffening ribs are arranged along the circumference of the steel box inner wall of the upper tower column 1 and the steel shell inner wall of the lower tower column 2. The stiffening ribs of the steel box inner wall of the upper tower column 1 and the steel shell inner wall of the lower tower column 2 are arranged in a vertically corresponding manner to facilitate internal force transmission. The stiffening ribs of the steel box inner wall of the upper tower column 1 are connected to the upper end surface of the pressure plate 8, while the stiffening ribs of the steel shell inner wall of the lower tower column 2 are connected to the lower end surface of the pressure plate 8.

[0046] Optionally, a plurality of hollow diaphragms are additionally arranged on the lower tower column 2. The stiffening ribs and hollow diaphragms ensure that the steel shell is safely stressed and its deformation does not exceed 1.5 mm when the concrete is poured inside the steel shell.

[0047] Preferably, the bending moment at the junction of the upper tower column 1 and the lower tower column 2 is zero. In this embodiment, the control bending moment of the inclined bridge tower is opposite at the tower-beam intersection and the tower bottom, and the steel box and steel shell concrete section transition can be performed at the zero bending moment.

[0048] On the basis of the above embodiment, in this embodiment, at least one second partition plate 24 is provided in the side span compartment 23. The second partition plate 24 is arranged parallel to the first partition plate 21 and divides the inner cavity of the side span compartment 23 into a plurality of chambers.

[0049] like Figure 4 and Figure 5 As shown, optionally, the lower end surface of the second partition 24 is higher than the lower end surface of the first partition 21 .

[0050] Optionally, the lower tower column 2 adopts an eccentric steel shell concrete section, which can be a single-box double-chamber or single-box multi-chamber section.

[0051] When lower tower column 2 is equipped with only first partition 21 and no second partition 24, the steel shell of lower tower column 2 is divided into two compartments. When second partition 24 is installed in side span compartment 23, the steel shell of lower tower column 2 is divided into multiple chambers by first partition 21 and second partition 24. The number and position of second partitions 24 can be designed and arranged according to the load requirements of the tower column.

[0052] Preferably, first shear studs 25 are welded to both the first and second partitions 21, 24. Welding shear studs to the concrete-filled partitions facilitates internal force transfer between the steel and concrete. In this embodiment, both the first and second partitions 21, 24 are steel plates.

[0053] In this embodiment, the poured concrete is reinforced concrete.

[0054] On the basis of the above embodiment, in this embodiment, the steel box cross section of the upper tower column 1 perpendicular to its axis is a single-box single-chamber or single-box multi-chamber cross section.

[0055] Optionally, at least one web is further provided in the steel box of the upper tower column 1 , and the web is used to divide the steel shell into multiple chambers, forming a single-box multi-chamber cross-section.

[0056] The orthogonal steel-concrete composite inclined bridge tower of this embodiment, as a main tower for a cable-stayed bridge, features a thinner steel shell. The eccentric cross-section of the lower tower column shifts the cross-sectional centroid of the lower tower column toward the side span, reducing its actual inclination angle and, in turn, the bending moment generated by vertical forces. The lower tower column's inclination angle remains consistent with that of the upper tower column, ensuring a graceful inclined tower shape. The facade transitions from pure steel to a steel-shell concrete structure. In cross-section, the compression side is supported by concrete, while the tension side is supported by steel. The structure is a steel-concrete composite structure in both vertical and transverse directions, fully utilizing the advantages of both concrete and steel. This not only effectively increases the cross-sectional bending bearing capacity and simplifies the force transmission structure between the main tower and the pier, but also effectively reduces the bending moment of the inclined tower.

[0057] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. 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 or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0058] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises", "includes" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0059] The above are merely specific embodiments of the present application to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but rather is intended to conform to the widest scope consistent with the principles and novel features of the present application.

Claims

1. An orthogonal steel-concrete composite structure inclined bridge tower, characterized in that: From top to bottom, it includes: An upper tower column (1) is a steel box structure; The lower tower column (2) is a steel shell and concrete composite structure. The lower tower column (2) includes a steel shell and a first partition (21) arranged in the steel shell. The first partition (21) divides the inner cavity of the steel shell into a middle span partition (22) close to the middle span and a side span partition (23) close to the side span. Concrete is poured into the side span partition (23). The position of the first diaphragm (21) is configured to ensure that the concrete stress is within the allowable range of the specification.

2. The orthogonal steel-concrete composite structure inclined bridge tower according to claim 1, characterized in that: A pressure plate (8) is provided between the upper tower column (1) and the lower tower column (2), and the thickness of the steel shell of the lower tower column (2) is smaller than the thickness of the steel box of the upper tower column (1).

3. The orthogonal steel-concrete composite structure inclined bridge tower according to claim 1, characterized in that: The inclined bridge tower further comprises a concrete tower base (3) arranged below the lower tower column (2), and the steel shell of the lower tower column (2) extends downward into the concrete tower base (3).

4. The orthogonal steel-concrete composite structure inclined bridge tower according to claim 1, characterized in that: The inclined bridge tower further comprises a concrete cap (4) arranged under the concrete tower base (3).

5. The orthogonal steel-concrete composite structure inclined bridge tower according to claim 4, characterized in that: A plurality of prestressed anchor rods (5) are arranged in the concrete in the side span compartment (23), the anchoring end of each prestressed anchor rod (5) is pre-buried in the concrete cap (4), the tensioning ends of some of the prestressed anchor rods (5) are located on the upper end surface of the concrete in the side span compartment (23), and the tensioning ends of some of the prestressed anchor rods (5) are located at a preset height above the upper end surface of the concrete in the side span compartment (23).

6. The orthogonal steel-concrete composite structure inclined bridge tower according to claim 1, characterized in that: The steel box inner wall of the upper tower column (1) and the steel shell inner wall of the lower tower column (2) are respectively provided with a plurality of stiffening ribs arranged along their circumferences, and the stiffening ribs of the steel box inner wall of the upper tower column (1) and the stiffening ribs of the steel shell inner wall of the lower tower column (2) are arranged correspondingly up and down.

7. The orthogonal steel-concrete composite structure inclined bridge tower according to claim 1, characterized in that: The bending moment at the junction of the upper tower column (1) and the lower tower column (2) is zero.

8. The orthogonal steel-concrete composite structure inclined bridge tower according to claim 1, characterized in that: At least one second partition plate (24) is provided in the side span compartment (23). The second partition plate (24) is arranged in parallel with the first partition plate (21) and divides the inner cavity of the side span compartment (23) into a plurality of compartments.

9. The orthogonal steel-concrete composite structure inclined bridge tower according to claim 8, characterized in that: First shear studs (25) are welded to both the first partition plate (21) and the second partition plate (24).

10. The orthogonal steel-concrete composite structure inclined bridge tower according to claim 1, characterized in that: The steel box section of the upper tower column (1) perpendicular to its axis is a single-box single-chamber or single-box multi-chamber section.

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