Corrugated steel-concrete combined bridge tower and stress analysis method thereof

Abstract

The invention provides a corrugated steel-concrete combined bridge tower and a stress analysis method thereof, and belongs to the technical field of bridge towers, the combined bridge tower comprises a transverse-bridge-direction corrugated steel web, an inhaul cable, a longitudinal-bridge-direction concrete web and a longitudinal-bridge-direction concrete web outer wall wrapping steel plate, the transverse-bridge-direction corrugated steel web is arranged between the two opposite longitudinal-bridge-direction concrete webs, the two ends of the transverse-bridge-direction corrugated steel web are connected with the longitudinal-bridge-direction concrete webs, the longitudinal-bridge-direction concrete web outer wall wrapping steel plates are arranged on the outer sides of the front ends of the longitudinal-bridge-direction concrete webs, and the inhaul cables are connected with the longitudinal-bridge-direction concrete webs and are obliquely arranged. The web of the concrete bridge tower in the bridge direction is designed into the corrugated steel web, the characteristics of high tensile and shear resistance of corrugated steel can be fully played, and the problem that the web of a traditional concrete bridge tower in the bridge direction cracks is effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of bridge towers, and in particular to a corrugated steel-concrete composite bridge tower and a force analysis method thereof. Background Art

[0002] The bridge towers of cable-stayed bridges and suspension bridges are usually made of concrete structures, and their transverse concrete webs are very easy to crack under the action of the longitudinal cables. The existing technology will increase the reinforcement or apply prestress in the transverse webs to offset the force of the cables, but in actual engineering, due to the characteristics of concrete structures that are compressive but not tensile, cracking of the concrete transverse webs is difficult to avoid. Concrete cracking will affect the overall strength and durability of the bridge tower structure, and it is extremely harmful to the safety of the structure. Traditional technology has no effective method to solve the problem of cracking of the transverse webs of concrete structure bridge towers. Therefore, it is necessary to design a corrugated steel-concrete composite bridge tower and its force analysis method. Summary of the invention

[0003] The purpose of the present invention is to provide a corrugated steel-concrete composite bridge tower and a force analysis method thereof, so as to solve the technical problem that the existing concrete structure is resistant to compression but not to tension, and the concrete cross bridge has cracks towards the web which are difficult to avoid.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] A corrugated steel-concrete composite bridge tower comprises a transverse corrugated steel web, a cable, a longitudinal concrete web and a steel plate wrapped around the outer wall of the longitudinal concrete web. The transverse corrugated steel web is arranged between two oppositely arranged longitudinal concrete webs and connected to the longitudinal concrete webs at both ends. The steel plate wrapped around the outer wall of the longitudinal concrete web is arranged on the outer side of the front end of the longitudinal concrete web. The cable is connected to the longitudinal concrete web and is arranged obliquely.

[0006] Furthermore, a plurality of transverse corrugated steel webs are spaced apart on the sides of two longitudinal concrete webs, and ends of the transverse corrugated steel webs are connected to steel plates wrapped around the outer walls of the longitudinal concrete webs.

[0007] Furthermore, shear nails are provided at the corrugated steel web in the transverse direction of the bridge and the concrete web in the longitudinal direction of the bridge, and shear nails are provided at the connection between the concrete web in the longitudinal direction of the bridge and the steel plate wrapped around the outer wall of the concrete web in the longitudinal direction of the bridge.

[0008] Furthermore, two cables are arranged on one side, the two cables are arranged in parallel and spaced apart, the cables pass through the concrete web along the bridge and the steel plate wrapped around the outer wall of the concrete web along the bridge, and the head of the cable is provided with a cable anchor head.

[0009] A stress analysis method for a corrugated steel-concrete composite bridge tower, the method comprising the following steps:

[0010] Step 1: setting the cross-sectional thickness of the transverse corrugated steel web (1) to t;

[0011] Step 2: Calculate the number n of shear nails between the corrugated steel web in the transverse direction and the concrete web in the longitudinal direction within the cable force influence range;

[0012] Step 3: Calculate the bending stiffness M of the shear nails between the corrugated steel web in the transverse direction and the concrete web in the longitudinal direction within the influence range of the cable force. 剪力钉 ;

[0013] Step 4: Calculate the shear capacity of the section;

[0014] Step 5: Section bending capacity;

[0015] Step 6: Assuming there are s cables in total, design the section's compressive capacity to match the tension of the s cables.

[0016] Furthermore, in step 1, the cross-section thickness t is:

[0017] Where t is the thickness of the corrugated steel web section, T is the cable tension, α is the angle between the cable and the horizontal direction, and f y is the tensile strength of steel, d is the thickness of the concrete web along the bridge direction, θ is the stress diffusion angle of the cable tension in the concrete, and r is the width of the cable anchor head.

[0018] Furthermore, the relationship between the shear stud and the cable tension in step 2 is, nf v ≥Tcosα, where n is the number of shear nails between the corrugated steel web in the transverse direction and the concrete web in the longitudinal direction within the influence range of the cable force, and f v is the shear strength of the shear stud.

[0019] Furthermore, in step 3, the bending stiffness M 剪力钉 for:

[0020]

[0021] Where M 剪力钉 is the flexural stiffness of the shear nails between the corrugated steel web in the transverse direction and the concrete web in the longitudinal direction within the cable force influence interval, and b is the transverse section width.

[0022] Furthermore, in step 4, the cross-sectional shear capacity of the composite bridge tower is greater than the shear design value, then

[0023] S 钢 f vd钢 +S 混凝土 f vd混凝土 ≥V

[0024] Where: S 钢 is the cross-sectional area of ​​the corrugated steel web in the transverse direction of the bridge, f vd钢 is the shear strength of the corrugated steel web in the transverse direction of the bridge, S 混凝土 is the cross-sectional area of ​​the concrete web along the bridge, f vd混凝土 is the shear strength of the concrete web along the bridge direction, and V is the shear design value.

[0025] Furthermore, in step 5, since the bending stiffness of the corrugated steel web in the transverse direction is less than the set value, only the two longitudinal concrete webs are considered to be subjected to the bending moment:

[0026] ①Bending capacity along the bridge:

[0027] W 顺桥 f ct ≥M 顺桥

[0028] Where: W is the moment of resistance of the bending section along the bridge direction. For the direction along the bridge, a is the length of the cross-section along the bridge, b is the width of the cross-section along the bridge, c is the distance between the two concrete webs along the bridge, and f is the distance between the two concrete webs along the bridge. ct is the tensile strength of concrete, M is the design value of the bending moment along the bridge direction;

[0029] ② Transverse bending capacity of the bridge:

[0030] W 横桥 f ct ≥M 横桥

[0031] Where: W 横桥 The moment of resistance of the bending section in the transverse direction of the bridge is: a is the cross-sectional length in the transverse direction, b is the cross-sectional width in the transverse direction, and c is the distance between the two cross-sectional concrete webs; f ct is the tensile strength of concrete, M 横桥 is the design value of the transverse bending moment;

[0032] In step 6, since the compressive capacity of the corrugated steel web in the transverse direction is less than the set value, only the pressure of the concrete webs in the two longitudinal directions is considered:

[0033] Assume there are s cables, and the tension of each cable is F i , and the angles with the horizontal direction are α i , only considering the compressive capacity of the bottom section of the corrugated steel-concrete composite bridge tower, then

[0034]

[0035] Where: S 混凝土 is the sum of the areas of the two transverse concrete webs, f cis the compressive strength of concrete, G 混凝土 is the deadweight of the concrete part of the bridge tower, G 钢 It is the deadweight of the corrugated steel part of the bridge tower.

[0036] The present invention has the following beneficial effects due to the adoption of the above technical solution:

[0037] (1) The present invention designs the web of the concrete bridge tower along the bridge direction into a corrugated steel web, which can give full play to the characteristics of the corrugated steel with strong tensile and shear resistance, and effectively solve the problem of cracking of the web along the bridge direction of the traditional concrete bridge tower;

[0038] (2) The corrugated steel-concrete bridge tower design greatly reduces the overall deadweight of the bridge tower, which can effectively reduce the cross-sectional area of ​​the bridge tower and reduce the material cost;

[0039] (3) The corrugated steel web can be constructed using a prefabricated hoisting process, which can improve construction efficiency. The steel plate wrapped on the cable anchoring surface of the concrete web along the bridge can be used as a formwork for the cast-in-place concrete web along the bridge, which facilitates construction and enhances the durability of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the three-dimensional structure of the combined bridge tower of the present invention;

[0041] Figure 2 is a top view of the combined bridge tower of the present invention;

[0042] Figure 3 It is a schematic diagram of the cable tension structure of the present invention;

[0043] Figure 4 It is a top view of the cable tension of the present invention.

[0044] In the attached drawings, 1-corrugated steel web in transverse direction, 2-cable, 3-concrete web in longitudinal direction, 4-steel plate wrapped around the outer wall of concrete web in longitudinal direction, 5-anchor head of inclined cable, 6-shear nail. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and preferred embodiments. However, it should be noted that many details listed in the specification are only for the purpose of enabling the reader to have a thorough understanding of one or more aspects of the present invention, and these aspects of the present invention can be implemented even without these specific details.

[0046] like Figure 1-2As shown, a corrugated steel-concrete composite bridge tower comprises a transverse corrugated steel web 1, a cable 2, a longitudinal concrete web 3 and a steel plate 4 wrapped around the outer wall of the longitudinal concrete web. The transverse corrugated steel web 1 is arranged between two oppositely arranged longitudinal concrete webs 3, and both ends are connected to the longitudinal concrete webs 3. The steel plate 4 wrapped around the outer wall of the longitudinal concrete web is arranged outside the front end of the longitudinal concrete web 3. The cable 2 is connected to the longitudinal concrete web 3 and is arranged obliquely. In order to save construction cost, the corrugated steel-concrete composite bridge tower structure is only used within the influence range of the cable anchoring area, and the remaining sections still use the traditional concrete structure bridge tower. It can effectively prevent the bridge tower structure from cracking. In the traditional concrete bridge tower structure, since the cables are arranged in the longitudinal direction of the bridge, the tensile force generated is distributed along the longitudinal direction of the bridge, so the transverse bridge tower web is easily torn. Corrugated steel is a steel plate bent into a corrugated shape, which has extremely small longitudinal stiffness and good tensile and shear resistance.

[0047] like Figure 3-4 As shown in the figure, the concrete web in the transverse direction of the traditional concrete bridge tower structure is replaced with a corrugated steel web. Since the longitudinal stiffness of the corrugated steel is extremely small, it hardly bears the longitudinal vertical pressure. The longitudinal vertical pressure is mainly borne by the concrete web along the bridge direction. The corrugated steel only bears the horizontal component of the cable tension, which can give full play to the tensile and shear properties of the corrugated steel and the compressive properties of concrete.

[0048] Wrapping the cable anchorage surface of the concrete web along the bridge can serve as the outer formwork of the cast-in-place concrete web along the bridge, which can facilitate construction and enhance the durability of the structure.

[0049] In order to enhance the structural integrity, shear nails are used to connect the corrugated steel web in the transverse direction of the bridge, the outer wall wrapped steel plate and the concrete web in the longitudinal direction of the bridge.

[0050] In the embodiment of the present invention, a plurality of transverse corrugated steel webs 1 are spaced apart on the sides of two longitudinal concrete webs 3, and the ends of the transverse corrugated steel webs 1 are connected to the steel plates 4 wrapped around the outer walls of the longitudinal concrete webs.

[0051] In the embodiment of the present invention, shear nails 6 are provided on the transverse corrugated steel web 1 and the longitudinal concrete web 3, and shear nails 6 are provided at the connection between the longitudinal concrete web 3 and the steel plate 4 wrapped around the outer wall of the longitudinal concrete web.

[0052] In the embodiment of the present invention, two cables 2 are arranged on one side, and the two cables 2 are arranged in parallel and spaced apart. The cable 2 passes through the concrete web 3 along the bridge and the steel plate 4 wrapped around the outer wall of the concrete web along the bridge, and the head of the cable 2 is provided with a cable anchor head 5.

[0053] like Figure 3-4 As shown, a corrugated steel-concrete composite bridge tower and a force analysis method thereof, the method comprising the following:

[0054] Step 1: Set the cross-sectional thickness of the transverse bridge corrugated steel web (1) to t;

[0055] Step 2: Calculate the number n of shear nails between the corrugated steel web in the transverse direction and the concrete web in the longitudinal direction within the cable force influence range;

[0056] Step 3: Calculate the bending stiffness M of the shear nails between the corrugated steel web in the transverse direction and the concrete web in the longitudinal direction within the influence range of the cable force 剪力钉 ;

[0057] Step 4: Calculate the shear capacity of the section;

[0058] Step 5: Section bending capacity;

[0059] Step 6: Assuming there are s cables in total, design the compressive capacity of the section to match the tension of the s cables.

[0060] In step 1, the cross-sectional thickness of the corrugated steel web in the transverse direction of the bridge is t

[0061]

[0062] Where: t is the thickness of the corrugated steel web section, T is the cable tension, α is the angle between the cable and the horizontal direction, and f y is the tensile strength of steel, d is the thickness of the concrete web along the bridge direction, θ is the stress diffusion angle of the cable tension in the concrete, and r is the width of the cable anchor head.

[0063] In step 2, the number of shear nails between the corrugated steel web in the transverse direction and the concrete web in the longitudinal direction within the cable force influence range is n

[0064] nf v ≥Tcosα

[0065] Where: n is the number of shear nails between the corrugated steel web in the transverse direction and the concrete web in the longitudinal direction within the influence range of the cable force, f v is the shear strength of the shear stud.

[0066] In step 3, the bending stiffness M of the shear nails between the corrugated steel web in the transverse direction and the concrete web in the longitudinal direction within the influence range of the cable force is 剪力钉

[0067]

[0068] Where: M 剪力钉 is the flexural stiffness of the shear nails between the corrugated steel web in the transverse direction and the concrete web in the longitudinal direction within the cable force influence interval, and b is the transverse section width.

[0069] In step 4, the shear capacity of the section

[0070] S 钢 f vd钢 +S 混凝土 f vd混凝土 ≥V

[0071] Where:

[0072] S 钢 is the cross-sectional area of ​​the corrugated steel web in the transverse direction of the bridge, f vd钢 is the shear strength of the corrugated steel web in the transverse direction of the bridge, S 混凝土 is the cross-sectional area of ​​the concrete web along the bridge, f vd混凝土 is the shear strength of the concrete web along the bridge direction, and V is the shear design value.

[0073] In step 5, the bending capacity of the section

[0074] Since the bending stiffness of the corrugated steel web in the transverse direction of the bridge is relatively weak, only the two concrete webs in the longitudinal direction of the bridge are considered to be subjected to bending moments.

[0075] ①Bending capacity along the bridge direction

[0076] W 顺桥 f ct ≥M 顺桥

[0077] Where: W 顺桥 The moment of resistance of the bending section along the bridge direction is:

[0078] a is the length of the section in the longitudinal direction of the bridge, b is the width of the section in the transverse direction of the bridge, c is the distance between the two concrete webs in the longitudinal direction of the bridge, fct is the tensile strength of concrete, and M is the design value of the bending moment in the longitudinal direction of the bridge.

[0079] ② Transverse bending capacity

[0080] W 横桥 f ct ≥M 横桥

[0081] Where: W 横桥 The moment of resistance of the bending section in the transverse direction of the bridge is: a is the cross-sectional length in the transverse direction, b is the cross-sectional width in the transverse direction, and c is the distance between the two cross-sectional concrete webs; f ct is the tensile strength of concrete, M 横桥 is the design value of the transverse bending moment of the bridge.

[0082] In step 6, the compressive strength of the cross section

[0083] Since the compressive capacity of the corrugated steel web in the transverse direction of the bridge is relatively weak, only the concrete webs in the two longitudinal directions of the bridge are considered to bear the pressure.

[0084] Assume there are s cables, and the tension of each cable is F i , and the angles with the horizontal direction are α i , only the compressive capacity of the bottom section of the corrugated steel-concrete composite bridge tower is considered.

[0085]

[0086] Where: S 混凝土 is the sum of the areas of the two transverse concrete webs, f c is the compressive strength of concrete, G 混凝土 is the deadweight of the concrete part of the bridge tower, G 钢 It is the deadweight of the corrugated steel part of the bridge tower.

[0087] Through stress analysis, we can accurately guide the size and stress limit of each component, so that the set pressure resistance meets the requirements while saving costs.

[0088] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A corrugated steel-concrete composite bridge tower, characterized in that: The invention comprises a transverse corrugated steel web (1), a cable (2), a longitudinal concrete web (3) and a steel plate (4) wrapped around the outer wall of the longitudinal concrete web. The transverse corrugated steel web (1) is arranged between two opposite longitudinal concrete webs (3) and connected to the longitudinal concrete webs (3) at both ends. The steel plate (4) wrapped around the outer wall of the longitudinal concrete web is arranged outside the front end of the longitudinal concrete web (3). The cable (2) is connected to the longitudinal concrete web (3) and is arranged obliquely.

2. The corrugated steel-concrete composite bridge tower according to claim 1, characterized in that: A plurality of transverse corrugated steel webs (1) are arranged at intervals on the sides of two longitudinal concrete webs (3), and the ends of the transverse corrugated steel webs (1) are connected to the steel plates (4) wrapped around the outer walls of the longitudinal concrete webs.

3. The corrugated steel-concrete composite bridge tower according to claim 1, characterized in that: The transverse corrugated steel web (1) and the longitudinal concrete web (3) are provided with shear nails (6), and the longitudinal concrete web (3) and the shear nails (6) are provided at the connection between the longitudinal concrete web (3) and the steel plate (4) wrapped around the outer wall of the longitudinal concrete web.

4. The corrugated steel-concrete composite bridge tower according to claim 1, characterized in that: Two cables (2) are arranged on one side, and the two cables (2) are arranged in parallel and spaced apart. The cables (2) pass through the concrete web (3) along the bridge and the steel plate (4) wrapped around the outer wall of the concrete web along the bridge, and the head of the cables (2) is provided with an inclined cable anchor head (5).

5. A stress analysis method for a corrugated steel-concrete composite bridge tower according to any one of claims 1 to 4, characterized in that: The method comprises the following: Step 1: setting the cross-sectional thickness of the transverse corrugated steel web (1) to t; Step 2: Calculate the number n of shear nails between the corrugated steel web in the transverse direction and the concrete web in the longitudinal direction within the cable force influence range; Step 3: Calculate the bending stiffness M of the shear nails between the corrugated steel web in the transverse direction and the concrete web in the longitudinal direction within the influence range of the cable force 剪力钉 ; Step 4: Calculate the shear capacity of the section; Step 5: Section bending capacity; Step 6: Assuming there are s cables in total, design the section's compressive capacity to match the tension of the s cables.

6. The stress analysis method of a corrugated steel-concrete composite bridge tower according to claim 5, characterized in that: In step 1, the section thickness t is: Where t is the thickness of the corrugated steel web section, T is the cable tension, α is the angle between the cable and the horizontal direction, and f y is the tensile strength of steel, d is the thickness of the concrete web along the bridge direction, θ is the stress diffusion angle of the cable tension in the concrete, and r is the width of the cable anchor head.

7. The stress analysis method of a corrugated steel-concrete composite bridge tower according to claim 5, characterized in that: The relationship between the shear stud and the cable tension in step 2 is, nf v ≥Tcosα, where n is the number of shear nails between the corrugated steel web in the transverse direction and the concrete web in the longitudinal direction within the cable force influence range, f v is the shear strength of the shear stud.

8. The stress analysis method of a corrugated steel-concrete composite bridge tower according to claim 5, characterized in that: Bending stiffness M in step 3 剪力钉 for: Where M 剪力钉 is the flexural stiffness of the shear nails between the corrugated steel web in the transverse direction and the concrete web in the longitudinal direction within the cable force influence interval, and b is the transverse section width.

9. The stress analysis method of a corrugated steel-concrete composite bridge tower according to claim 5, characterized in that: In step 4, the cross-sectional shear capacity of the composite bridge tower is greater than the shear design value, then S 钢 f vd钢 +S 混凝土 f vd混凝土 ≥V Where: S 钢 is the cross-sectional area of ​​the corrugated steel web in the transverse direction of the bridge, f vd钢 is the shear strength of the corrugated steel web in the transverse direction of the bridge, S 混凝土 is the cross-sectional area of ​​the concrete web along the bridge, f vd混凝土 is the shear strength of the concrete web along the bridge direction, and V is the shear design value.

10. The stress analysis method of a corrugated steel-concrete composite bridge tower according to claim 5, characterized in that: In step 5, since the bending stiffness of the corrugated steel web in the transverse direction is less than the set value, only the two longitudinal concrete webs are considered to be subjected to the bending moment: ①Bending capacity along the bridge: W 顺桥 f ct ≥M 顺桥 Where: W is the moment of resistance of the bending section along the bridge direction. For the direction along the bridge, a is the length of the cross-section along the bridge, b is the width of the cross-section along the bridge, c is the distance between the two concrete webs along the bridge, and f is the distance between the two concrete webs along the bridge. ct is the tensile strength of concrete, M is the design value of the bending moment along the bridge direction; ② Transverse bending capacity of the bridge: W 横桥 f ct ≥M 横桥 Where: W 横桥 The moment of resistance of the bending section in the transverse direction of the bridge is: a is the cross-sectional length in the transverse direction, b is the cross-sectional width in the transverse direction, and c is the distance between the two cross-sectional concrete webs; f ct is the tensile strength of concrete, M 横桥 is the design value of the transverse bending moment; In step 6, since the compressive capacity of the corrugated steel web in the transverse direction is less than the set value, only the pressure of the concrete webs in the two longitudinal directions is considered: Assume there are s cables, and the tension of each cable is F i , and the angles with the horizontal direction are α i , only considering the compressive capacity of the bottom section of the corrugated steel-concrete composite bridge tower, then Where: S 混凝土 is the sum of the areas of the two transverse concrete webs, f c is the compressive strength of concrete, G 混凝土 is the deadweight of the concrete part of the bridge tower, G 钢 It is the deadweight of the corrugated steel part of the bridge tower.

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