Lightweight combined pier column with special-shaped hole PBL connecting pieces and spiral stirrups and construction method of lightweight combined pier column

Abstract

The invention discloses a light-weight combined pier column with special-shaped hole PBL connecting pieces and spiral stirrups and a construction method of the light-weight combined pier column. The light-weight combined pier column is composed of a hollow steel pipe, the special-shaped hole PBL connecting pieces, the spiral stirrups and cast-in-place concrete. The combination column is of a hollow structure, is light in self weight and has great advantages in engineering scenes such as large-span bridge piers and ocean platform column feet. The special-shaped hole PBL connecting piece can replace a traditional stud to be used for a combined column structure, the welding amount in construction is remarkably reduced, and therefore the anti-fatigue performance of the structure is improved, and meanwhile cost and construction time are saved. Due to the fact that the special-shaped hole PBL connecting piece is of an open hole structure, the situation that the whole block of embedded concrete is cut open can be effectively avoided, and the problem that defects are likely to be introduced to the concrete through a traditional PBL connecting piece is solved. In addition, the opening hole structure adopted by the special-shaped hole PBL connecting piece can greatly reduce the difficulty of penetrating stirrups into the special-shaped hole PBL connecting piece, and construction convenience is provided.

Description

Technical Field

[0001] The invention relates to the technical field of structural engineering, and in particular to a lightweight composite bridge pier column with a special-shaped hole PBL connector and spiral stirrups and a construction method thereof. Background Art

[0002] Steel-concrete composite structures are widely used in high-rise buildings, large-span public buildings, large-span bridges, tall structures, and large heavy-load industrial plants. Common steel-concrete composite components in actual projects mainly include composite slabs, composite beams, and composite columns. Among them, steel tube concrete is a typical steel-concrete composite structure. It has the advantages of high bearing capacity, light weight, good seismic performance, and convenient construction. It has been widely used in large-span bridges, urban interchanges, high-rise and super-high-rise buildings, subway stations, offshore platforms, etc., and has achieved good economic and social benefits.

[0003] Although steel tube concrete has the advantages of high bearing capacity, large deformation capacity and good seismic performance, there are still some problems that need to be solved in actual engineering, which are mainly manifested in the following four aspects:

[0004] (1) Although the core concrete provides improved lateral support for the outer steel tube, the steel tube concrete is still prone to local buckling failure outward under the action of axial load, making it difficult for the high-strength steel tube to fully exert its material properties.

[0005] (2) The outer steel pipe of the steel tube concrete structure is in contact with the external environment and is prone to corrosion, which leads to durability problems. The cost of rust prevention and subsequent maintenance is high.

[0006] (3) When a fire occurs, especially when the ambient temperature is greater than 600°C, the yield strength and stiffness of the steel tube decrease linearly, and its restraint effect on the core concrete decreases rapidly, resulting in serious degradation of the bearing capacity and ductility of the steel tube concrete structure, which can easily cause structural damage or even collapse. Therefore, in actual projects, steel tube concrete structures need to be sprayed with fireproof materials to improve their fire resistance, and the long-term maintenance cost is high.

[0007] (4) The steel tube concrete commonly used in engineering is generally filled steel tube concrete, that is, a composite structure formed by pouring concrete into a steel tube and compacting it. This makes the steel tube concrete heavy and unsuitable for some construction scenarios that require lightweighting, such as large-span bridge piers, super-high-rise building columns, and marine engineering structure columns.

[0008] In order to solve the durability and fire resistance problems of traditional steel tube concrete structures, concrete-wrapped hollow steel tubes have been applied. Perfobond leisten (PBL) connectors can effectively constrain the buckling of steel tubes and can directly participate in longitudinal force, greatly improving the bearing capacity of concrete-wrapped hollow steel tubes. Therefore, PBL has great potential for concrete-wrapped hollow steel tubes. Traditional PBL connectors have closed holes and are mostly used in bridge deck structures. The bridge deck structure is a horizontal plate. When PBL is assembled on the bridge deck, it is generally arranged evenly, and the holes are uniformly positioned in the horizontal direction, which is convenient for the insertion of steel bars. However, when applied to bridge piers, the closed holes of PBL are not conducive to the insertion of steel bars, making construction difficult. In addition, the traditional PBL is arranged as a whole, which easily introduces initial defects along the axiality to the bridge piers, causing the bridge piers to crack prematurely and reduce the bearing capacity. Summary of the invention

[0009] Aiming at the problems existing in traditional steel tube concrete columns and PBL connectors, the present invention provides a lightweight composite pier column with a special-shaped hole PBL connector and spiral stirrups.

[0010] A lightweight composite bridge pier column with a special-shaped hole PBL connector and spiral stirrups, comprising a hollow steel pipe, a special-shaped hole PBL connector, spiral stirrups, and cast-in-place concrete:

[0011] Further preferably, the lightweight composite pier column with special-shaped hole PBL connector and spiral stirrup comprises: a hollow steel pipe; a plurality of special-shaped hole PBL connectors welded to the outer surface of the hollow steel pipe, the plurality of special-shaped hole PBL connectors are arranged along the axial direction of the hollow steel pipe, and a special-shaped hole PBL connector is provided with a plurality of special-shaped opening holes; a spiral stirrup spirally wrapped around the hollow steel pipe and passed through the special-shaped opening holes; and cast-in-place concrete poured on the special-shaped hole PBL connector and the spiral stirrup.

[0012] The composite column is a hollow structure with light weight, and has great advantages in engineering scenarios such as large-span bridge piers and offshore platform column bases. The present invention proposes a special-shaped hole PBL connector, which can replace traditional bolts for composite column structures, significantly reducing the amount of welding during construction, thereby improving the fatigue resistance of the structure, while saving costs and construction time. Since the special-shaped hole PBL connector adopts an open hole structure, it can effectively avoid cutting the entire piece of concrete in which it is embedded, thereby improving the problem that traditional PBL connectors easily introduce defects into concrete. In addition, the open hole structure adopted by the special-shaped hole PBL connector can greatly reduce the difficulty of threading stirrups to the special-shaped hole PBL connector, providing construction convenience. Due to the shear and pull-out effects of the special-shaped hole PBL connector, its application can also significantly improve the bearing capacity, stiffness, and out-of-plane stability of the composite column. In addition, the structure also has the characteristics of strong corrosion resistance and can be widely used as a pressure-bearing column in a long-term humid environment.

[0013] The lightweight composite bridge pier column is in the form of concrete hollow steel tube outsourcing, has a light weight, and has great advantages in application scenarios such as marine structures and large-span bridge structures that have strict requirements on the self-weight of the structure.

[0014] The thickness of the hollow steel pipe is 6-50 mm.

[0015] The PBL connector is a steel plate with holes, the width of the steel plate is 30mm-100mm, the length is close to the length of the hollow steel pipe, and the number of the arranged steel plate is 4-8.

[0016] The special-shaped hole PBL connector improves the closed holes in the general PBL plate into open holes, which can facilitate the installation and construction of stirrups.

[0017] The special-shaped hole PBL connector adopts an open hole structure, so that when it is buried in concrete, it can effectively avoid separating the entire concrete, thereby improving the problem of introducing defects.

[0018] The connection method of the special-shaped hole PBL connector is welding fillet welds, and each special-shaped hole PBL connector requires 2 fillet welds.

[0019] The PBL connector with a special-shaped hole is arranged in such a way that the long side of the PBL connector with a special-shaped hole is arranged along the longitudinal direction of the hollow steel pipe, and the PBL connector with a special-shaped hole is kept perpendicular to the hollow steel pipe, and is welded to the hollow steel pipe in a clockwise or counterclockwise order.

[0020] The length of the special-shaped hole PBL connector can be the same as that of the hollow steel tube concrete, or a length range of 50mm-500mm can be reserved at both ends of the hollow steel tube without welding the special-shaped hole PBL connector.

[0021] The special-shaped hole PBL connector in the present invention improves the closed hole in the traditional PBL plate into an open special-shaped hole, and the shape of the special-shaped hole includes C-shaped, U-shaped, groove-shaped, etc.

[0022] The special-shaped hole of the special-shaped hole PBL connector can be used for stirrups to pass through. The special-shaped hole has a depth of 20-80 mm and is located on the unwelded side of the PBL plate.

[0023] The PBL connector with a special-shaped hole can be obtained by cutting a rectangular steel plate when the special-shaped hole is in a groove shape. Two PBL connectors with special-shaped holes can be obtained by cutting along the middle of a rectangular steel plate in a zigzag shape.

[0024] The spiral stirrups are arranged at a spacing of 100-600mm. In the present invention, the composite column does not need to be arranged with longitudinal reinforcement, but only with spiral stirrups. During construction, the spiral stirrups need to be spirally wrapped around the special-shaped holes of the PBL plate. The spiral stirrups can not only be used as stirrups, but also have longitudinal and transverse shear resistance.

[0025] The cast-in-place concrete is the outer cladding of the composite column structure proposed in the present invention, and the construction method is on-site pouring and spraying.

[0026] The construction method of the lightweight composite bridge pier column with special-shaped hole PBL connector and spiral stirrups comprises the following steps:

[0027] (1) Cut steel plates in the factory and prefabricate PBL connectors with special-shaped holes;

[0028] (2) Transport the prefabricated PBL connectors with special-shaped holes and the formwork required for pouring concrete to the construction site;

[0029] (3) Weld the special-shaped hole PBL connector on the hollow steel pipe, and weld the non-hole side of the special-shaped hole PBL connector to the hollow steel pipe along the longitudinal direction of the hollow steel pipe. Each special-shaped hole PBL connector needs to be welded with two welds at the bottom; 4-8 special-shaped hole PBL connectors are welded on each hollow steel pipe;

[0030] (4) spiral stirrups are arranged on the outer periphery of the hollow steel pipe, and the spiral stirrups are spirally passed through the special-shaped opening holes of the special-shaped hole PBL connector from one end of the hollow steel pipe to obtain a composite column after welding and reinforcement;

[0031] (5) Support the outer formwork of the composite column after welding and reinforcement and pour concrete.

[0032] Compared with the prior art, the main advantages of the present invention are:

[0033] The lightweight composite bridge pier column with special-shaped hole PBL connector and spiral stirrups proposed in the present invention is composed of a hollow steel pipe, a special-shaped hole PBL connector, spiral stirrups, and surrounding concrete. The special-shaped hole PBL connector needs to be welded to the outer surface of the steel pipe, and the integral structure is formed by cast-in-place concrete, which has the following advantages:

[0034] (1) This structure adopts the form of hollow steel tube wrapped with concrete, which has light weight and has great advantages in application scenarios such as marine structures and large-span bridge structures that have strict requirements on the self-weight of the structure.

[0035] (2) Concrete is poured on the outer layer of the steel pipe, which not only improves the durability of the structure, but also increases the rigidity and bearing capacity of the structure.

[0036] (3) When the lightweight composite bridge pier column proposed in the present invention is used, the outer concrete can effectively prevent the steel pipe from buckling outward. At the same time, due to the function of the special-shaped hole PBL connector, the inward deformation of the steel pipe is also constrained, that is, the shear connector actually plays two roles of shear resistance and pull-out resistance. As a result, the inward and outward buckling of the steel pipe are effectively constrained. This structure can significantly improve the anti-buckling ability of the steel pipe, thereby enhancing the bearing capacity of the original structure.

[0037] (4) The PBL connector with special-shaped holes can play the role of longitudinal reinforcement in the structure. The lightweight composite bridge pier column in the present invention only needs to be equipped with stirrups, which reduces the amount of steel used. The PBL plate and stirrups cooperate with each other to effectively restrain the outer concrete in the lateral direction.

[0038] (5) This structure uses special-shaped hole PBL connectors, which do not require longitudinal reinforcement, only stirrups. It is easy to weld, has fewer welds, and is convenient and efficient in on-site construction, significantly reducing labor costs and improving construction efficiency. In addition, due to the reduction in welding parts, costs can be effectively reduced, while significantly improving the fatigue performance of the structure.

[0039] (6) The special-shaped hole PBL connector proposed in the present invention, due to the open hole structure, can greatly facilitate the arrangement of stirrups during construction, significantly reducing the complexity of construction. At the same time, it does not affect the lateral restraint and longitudinal shearing effect of the stirrups.

[0040] (7) The present invention proposes a spiral stirrup structure, which can save the on-site tying process of traditional stirrups. A steel bar can be spirally wound along the special-shaped hole of the PBL without tying. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1-1 The hole shape of the special-shaped hole PBL connector includes C-shaped, U-shaped, groove-shaped, etc.

[0042] Figure 1-2 It is a groove-shaped PBL connector;

[0043] Figure 2-1 Manufacturing steps for grooved PBL connectors 1: cutting rectangular plates;

[0044] Figure 2-2 Manufacturing step 2 for the groove-shaped PBL connector: obtain two pieces of special-shaped hole PBL connectors;

[0045] Figure 3-1 It is a lightweight composite bridge pier column with a PBL connector with a special-shaped hole; DETAILED DESCRIPTION

[0046] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. A lightweight composite bridge pier column with a special-shaped hole PBL connector and spiral stirrups includes the following components or processed parts:

[0047] Hollow steel pipe 1;

[0048] C-hole PBL connector 2;

[0049] U-shaped hole PBL connector 3;

[0050] Groove-shaped hole PBL connector 4;

[0051] Special-shaped hole 5 of special-shaped PBL connector;

[0052] Rectangular steel plate 6

[0053] Spiral stirrups 7;

[0054] Peripheral concrete 8;

[0055] like Figure 1-1 , Figure 1-2 As shown, a lightweight composite bridge pier column with a special-shaped hole PBL connector and a spiral stirrup comprises: a hollow steel pipe 1; a plurality of special-shaped hole PBL connectors welded on the outer surface of the hollow steel pipe 1 (the shape of the special-shaped opening hole is C-shaped, U-shaped or groove-shaped, and specifically one of the C-shaped hole PBL connector 2, the U-shaped hole PBL connector 3, and the groove-shaped hole PBL connector 4 can be selected), the plurality of special-shaped hole PBL connectors are arranged along the axial direction of the hollow steel pipe 1, and a special-shaped hole PBL connector is provided with a plurality of special-shaped opening holes; a spiral stirrup 7 spirally wrapped around the hollow steel pipe 1 and penetrated in the special-shaped opening hole; and a peripheral concrete 8 cast on the special-shaped hole PBL connector and the spiral stirrup 7. The opening of the special-shaped opening hole faces the outside of the hollow steel pipe. The depth of the special-shaped opening hole is 20-80 mm. The arrangement spacing of the spiral stirrup 7 is 100-600 mm.

[0056] like Figure 1-1 , Figure 1-2 As shown in the figure, a lightweight composite bridge pier column with a special-shaped hole PBL connector and spiral stirrups has the following manufacturing and construction sequence:

[0057] (1) Factory prefabricated special-shaped hole PBL connectors. For C-shaped hole PBL connector 2 and U-shaped hole PBL connector 3, steel plates are directly cut. For groove-shaped hole PBL connector 4, Figure 2-1 , cut the rectangular steel plate 6 in a zigzag shape along the middle part. Figure 2-2 , the rectangular steel plate 6 is cut to obtain the groove-shaped hole PBL connector 4;

[0058] (2) Transport the prefabricated PBL connectors with special-shaped holes and the formwork required for pouring concrete to the construction site;

[0059] (3) Welding of special-shaped hole PBL connectors. Take the groove-shaped hole PBL connector as an example. Figure 3-1As shown, the unopened side of the grooved hole PBL connector 4 is welded to the steel pipe 1 along the longitudinal direction of the hollow steel pipe 1. During welding, the adjacent grooved hole PBL connectors 4 are vertically offset to facilitate the subsequent winding of the spiral stirrups 7 to the special-shaped holes. Each special-shaped hole PBL connector needs to be welded with two welds at the bottom. It is recommended to weld 4-8 special-shaped hole PBL connectors for each composite column;

[0060] (4) Figure 3-1 As shown, spiral stirrups 7 are arranged around the outer periphery of the hollow steel pipe 1. The steel bars are spirally passed through one end of the hollow steel pipe 1. Figure 1-2 When winding the spiral stirrups, the stirrups should be staggered through the special-shaped holes of the special-shaped hole PBL connector shown in the figure. Figure 1-2 The shaped holes of the PBL board.

[0061] (5) Support the outer formwork of the composite column after welding and reinforcement and pour concrete.

Claims

1. A lightweight composite bridge pier column with a special-shaped hole PBL connector and spiral stirrups, characterized in that: include: Hollow steel pipe; A plurality of special-shaped hole PBL connectors welded on the outer surface of the hollow steel pipe, wherein the plurality of special-shaped hole PBL connectors are arranged along the axial direction of the hollow steel pipe, and a plurality of special-shaped opening holes are arranged on one special-shaped hole PBL connector; A spiral stirrup spirally wrapped around the hollow steel pipe and inserted into the special-shaped opening; Cast-in-place concrete is poured on the special-shaped hole PBL connector and the spiral stirrups.

2. The lightweight composite bridge pier according to claim 1, characterized in that: The cast-in-place concrete is in the form of outer packaging of concrete hollow steel pipes.

3. The lightweight composite bridge pier according to claim 1, characterized in that: The shape of the special-shaped opening hole is C-shaped, U-shaped or groove-shaped.

4. The lightweight composite bridge pier according to claim 3, characterized in that: The opening of the special-shaped opening hole faces the outside of the hollow steel pipe.

5. The lightweight composite bridge pier according to claim 3, characterized in that: The depth of the special-shaped opening hole is 20-80 mm.

6. The lightweight composite bridge pier according to claim 1, characterized in that: The arrangement spacing of the spiral stirrups is 100-600mm.

7. The lightweight composite bridge pier according to claim 1, characterized in that: The welding method of the special-shaped hole PBL connector is fillet weld, and each special-shaped hole PBL connector requires 2 fillet welds.

8. The construction method of a lightweight composite bridge pier column with a special-shaped hole PBL connector and spiral stirrups according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Factory cutting of steel plates and prefabrication of PBL connectors with special-shaped holes; (2) Transport the prefabricated special-shaped hole PBL connectors and the formwork required for pouring concrete to the construction site; (3) Weld the special-shaped hole PBL connector on the hollow steel pipe, and weld the non-hole side of the special-shaped hole PBL connector to the hollow steel pipe along the longitudinal direction of the hollow steel pipe. Each special-shaped hole PBL connector needs to be welded with two welds at the bottom; (4) spiral stirrups are arranged on the periphery of the hollow steel pipe, and the spiral stirrups are spirally passed through the special-shaped opening holes of the special-shaped hole PBL connector from one end of the hollow steel pipe to obtain a composite column after welding and reinforcement; (5) Support the outer formwork of the composite column after welding and reinforcement and pour concrete.

9. The construction method according to claim 8, characterized in that: In step (3), 4-8 special-shaped hole PBL connectors are welded to each hollow steel pipe.

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