Construction method of a double-wall corrugated steel pipe concrete bridge pier of a superimposed assembly type

Abstract

The application provides a construction method of a double-wall corrugated steel pipe concrete bridge pier, and belongs to the field of bridge structure members. The column body of the bridge pier is internally provided with a column internal steel pipe, a sandwich concrete and an outer galvanized corrugated steel pipe, a cap beam connecting piece with bolt holes and a pile cap connecting piece are used at the joint, the column internal steel pipe is fastened through single-side bolts, and a corrugated steel plate core mold is built-in a cup opening and is free of disassembly. During construction, the cap beam and the column single section are prefabricated in a factory, and the pile cap is cast in situ; the column is lengthened through single-side bolt splicing of the superposed sleeve pipe, is connected with the pile cap and the cap beam through single-side bolts after hoisting, and then the baffle and the column connecting piece are installed, and the whole is formed through grouting. The application has the characteristics of high assembly efficiency, reliable joint connection and excellent corrosion resistance, the corrugated steel pipe restrains the concrete in a three-way compression state, and the mechanical properties are improved; the free-of-disassembly mold design simplifies construction, can adapt to different working conditions, and is applicable to various corrosion environments and seismic fortification regions.

Description

Technical Field

[0001] This invention belongs to the field of bridge structural components, and specifically relates to a construction method for a composite prefabricated double-walled corrugated steel pipe concrete bridge pier. Background Technology

[0002] Most bridge piers currently use cast-in-place reinforced concrete solid structures, which require a large amount of formwork and supports during construction, resulting in long construction cycles, high labor costs, difficulty in ensuring construction quality, and significant impact on the surrounding environment. Furthermore, when the slenderness ratio or load eccentricity of the component is large, the concrete at the centroid of the component section does not play a role, but increases the self-weight of the structure, making transportation and installation difficult.

[0003] Hollow reinforced concrete piers and double-walled steel-tube concrete members can solve the above problems, but traditional hollow reinforced concrete members and double-walled steel-tube concrete members have prominent durability issues in corrosive environments such as open air, lakes, and oceans. Pier structures are often corroded and damaged by air and water corrosive substances and silt impacts. Moreover, due to the complexity of construction sites, the anti-corrosion maintenance of piers is often difficult and costly. On the other hand, in order to improve construction efficiency and speed up construction, prefabricated piers are an inevitable trend. However, the connection of existing prefabricated reinforced concrete piers and their joints is difficult to guarantee. The splicing structure of the longitudinal reinforcement in the joint area is complex, and the column embedment depth requirement is high. Furthermore, under seismic action, the surface concrete is prone to cracking and spalling, and the joint area bearing high stress is prone to failure, resulting in relatively weak overall seismic performance of the components. Summary of the Invention

[0004] In view of this, in order to improve the corrosion resistance of existing bridge piers, shorten the construction period of existing cast-in-place reinforced concrete bridge piers, improve the reliability of existing prefabricated bridge pier node connections and reduce the complexity of their connections, optimize the cross-sectional form of existing bridge piers, and improve the seismic performance of existing bridge piers, the present invention provides a construction method for composite prefabricated double-wall corrugated steel pipe concrete bridge piers.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a construction method for a composite prefabricated double-walled corrugated steel pipe concrete bridge pier, specifically including the following construction steps: Step 1: Precast double-walled corrugated steel pipe concrete column in the middle: Roll out corrugated steel pipes according to the design dimensions as templates, select internal steel pipes for the column and place them inside the corrugated steel pipes, weld round steel plates inside the internal steel pipes to prevent grout leakage during subsequent grouting, weld shear keys to the outside of the internal steel pipes, and weld sealing plates with pouring holes to the column ends. After pouring and curing to the design strength, remove the sealing plates. Step 2: Fabrication of connectors: Connectors include cap beam connectors, foundation connectors, baffle connectors, and column connectors; Step 3: Precast top cap beam: According to the design, the cap beam connectors and bolts are pre-embedded in the top cap beam. The top cap beam has a reserved cup opening. The bottom longitudinal reinforcement of the cap beam is cut at the reserved cup opening and then bent into a U-shape and extended into the reserved cup opening. Corrugated steel plates are cut at the reserved cup opening of the cap beam as the core mold of the cap beam. After pouring, it is cured to the design strength. The core mold of the cap beam is not removed. Step 4: Lower foundation pouring: During on-site construction, the lower foundation is poured according to the design. The foundation connectors are pre-embedded in the lower foundation. The lower foundation has a reserved cup opening. Corrugated steel plates are cut at the reserved cup opening as the foundation core mold. After pouring, it is cured to the design strength. The foundation core mold is not removed. Step 5: Node Connection: Transport the precast double-walled corrugated steel pipe concrete column to the construction site, splice the column to the designed length, insert the internal steel pipe of the column into the bearing cap connector and align it, then connect it with single-sided bolts and carry out post-pouring construction. Subsequently, hoist the top cap beam, insert the cap beam connector into the internal steel pipe of the column and align it, then connect it with single-sided bolts and carry out grouting construction. Step Six: Post-pouring grouting: Insert the reinforcing cage into the reserved cup opening of the lower foundation and carry out post-pouring concrete construction. After the column connectors and baffle connectors are installed, grouting construction is carried out.

[0006] A composite prefabricated double-wall corrugated steel tube concrete bridge pier includes a top cap beam, a middle double-wall corrugated steel tube concrete column, and a lower pier cap. The top cap beam, the middle double-wall corrugated steel tube concrete column, and the lower pier cap are arranged sequentially from top to bottom. The top cap beam includes top longitudinal reinforcement, cap beam connectors, cap beam core mold, bottom longitudinal reinforcement, cap beam reserved cup opening, and baffle. The top of the cap beam body is provided with top longitudinal reinforcement, the bottom of the cap beam body is provided with bottom longitudinal reinforcement, and the middle of the cap beam core mold is provided. The cap beam body body is also provided with cap beam connectors, cap beam reserved cup opening, and baffle. The baffle is located on the outer periphery of the column. The central double-walled corrugated steel pipe concrete column is extended by splicing single columns. Each single column includes an internal steel pipe, a sandwich concrete layer, and an external corrugated steel pipe. The internal steel pipe, sandwich concrete layer, and corrugated steel pipe are arranged sequentially from the inside to the outside. Adjacent single columns are connected by an inner layer overlapping sleeve and an external column connector. The lower support includes a support reserved cup, a reinforcing cage and a support connector. The support body is provided with the support reserved cup and the support connector. The support connector is connected to the steel pipe inside the column. The reinforcing cage is provided inside the support reserved cup.

[0007] Furthermore, the top longitudinal reinforcement of the cap beam is attached to the top plate of the cap beam connector and connected by spot welding; the pre-embedded screws are evenly distributed around the pre-reserved cup opening of the cap beam for subsequent connection of the baffle.

[0008] Furthermore, the cap beam connector includes a cross-shaped cap beam connector top plate and a cap beam connector connecting steel pipe, the pier cap connector includes a pier cap connector connecting steel pipe and a pier cap connector bottom plate, the cap beam connector connecting steel pipe and the pier cap connector connecting steel pipe are provided with bolt holes, and the internal steel pipe of the column is provided with internal steel pipe reserved bolt holes.

[0009] Furthermore, the outer diameter of the connecting steel pipe of the foundation connector is slightly smaller than the inner diameter of the internal steel pipe of the column. Before connection, the internal steel pipe of the column is inserted into the connecting steel pipe of the foundation connector. After the reserved bolt holes of the connecting steel pipe of the foundation connector above the concrete pouring interface are aligned with the reserved bolt holes of the internal steel pipe, they are fastened with single-sided bolts.

[0010] Furthermore, the internal steel pipes of the central double-wall corrugated steel pipe concrete column are connected by overlapping sleeves. The inner diameter of the overlapping sleeve is slightly larger than the outer diameter of the internal steel pipe. After the reserved bolt holes of the internal steel pipe and the reserved bolt holes of the overlapping sleeve are aligned, they are fastened by single-sided bolts.

[0011] Furthermore, the ends of the steel pipes inside the column are welded with round steel plates to prevent grout from leaking into the steel pipes during subsequent grouting or concrete pouring.

[0012] Furthermore, the steel pipes and corrugated steel pipes inside the column can be arranged coaxially or non-coaxially as needed.

[0013] Furthermore, the exposed portion of the internal steel pipe of the column extends into the reserved cup opening of the cap beam by a length of not less than D, the corrugated steel pipe extends into the reserved cup opening of the cap beam by a length of not less than 0.25D, the exposed portion of the internal steel pipe of the column extends into the reserved cup opening of the foundation by a length of not less than 2D, and the corrugated steel pipe extends into the reserved cup opening of the foundation by a length of not less than 0.5D, where D is the outer diameter of the central double-walled corrugated steel pipe concrete column.

[0014] Furthermore, the column connector includes two semi-circular corrugated plates, with column connector connecting plates at both ends of the semi-circular corrugated plates, and column connector grouting holes provided on the semi-circular corrugated plates.

[0015] Compared with the prior art, the beneficial effects of the construction method for a composite prefabricated double-walled corrugated steel pipe concrete bridge pier described in this invention are: (1) This invention adopts factory prefabrication, on-site hoisting, and bolt splicing. Compared with traditional cast-in-place reinforced concrete bridge piers, it has a faster construction speed, shorter construction cycle, less construction workload, and better construction quality. Compared with traditional prefabricated reinforced concrete bridge piers, it eliminates the process of steel sleeves and prestressed steel reinforcement arrangement, making node connection more convenient. The safety of key connection points is ensured by the overlapping and splicing of steel pipes inside the column, corrugated steel side plate restraint, baffle bending resistance, and U-shaped bending of longitudinal reinforcement of cap beam. Compared with traditional solid structure, it effectively reduces the self-weight of components, reduces unnecessary material waste, and reduces construction difficulty.

[0016] (2) This invention uses galvanized corrugated steel pipes to encase the bridge piers. The galvanized corrugated steel pipes provide circumferential constraints for the internal steel pipes and the sandwiched concrete, placing the sandwiched concrete inside the column under triaxial compression. Simultaneously, due to the presence of the internal steel pipes, the sandwiched concrete fully utilizes its mechanical properties under the constraint of the external corrugated steel pipes, thus giving the bridge piers better mechanical properties compared to existing bridge pier structures. The corrugated steel plate core mold at the reserved cup-shaped opening of the pier cap and cap beam provides lateral constraint for the concrete in the cup-shaped opening area, enhancing the bending bearing capacity of the connection node and improving its seismic performance. At the same time, the presence of the corrugated steel plate further strengthens the shear resistance of the joint in the cup-shaped opening area.

[0017] (3) The present invention uses galvanized corrugated steel pipes to encase the bridge piers, which fully protects the internal steel pipes and the sandwiched concrete from direct contact with the external environment. Due to the good corrosion resistance of galvanized corrugated steel pipes, the components have better corrosion resistance. The corrugated steel plate core mold wraps the cup-mouth area of ​​the connection node, which makes the key area of ​​the cup mouth have better corrosion resistance.

[0018] (4) The galvanized corrugated steel pipe and the inner steel pipe of the present invention can be used as casting templates when precast columns, eliminating the need for formwork operation and also eliminating the need for the configuration of stirrups inside the column. The reserved cup openings of the cap beam and the foundation are cast using galvanized corrugated steel plates as core molds. After casting, no formwork removal operation is required, reducing the amount of construction work.

[0019] (5) After the steel pipe inside the column is bolted to the lower foundation on one side, the steel cage is placed and concrete is poured afterward, making the connection more convenient and reliable. After the upper cap beam is bolted to the upper cap beam on one side, the cup-shaped part is reinforced by grouting. The addition of U-shaped bent longitudinal bars and pre-embedded bolt connecting baffles enhances the integrity of the beam-column connection node and effectively improves the seismic performance and corrosion resistance of the node area.

[0020] (6) Before grouting the reserved cup opening of the cap beam of the present invention, a baffle needs to be installed. The baffle is connected to the bottom of the cap beam by a pre-embedded screw and to the column by two semi-circular arc-shaped corrugated plates, which increases the integrity of the cap beam and the column and improves the seismic performance of the cap beam-column joint.

[0021] (7) In this invention, the splicing and lengthening of the double-walled corrugated steel pipe concrete column adopts a single-sided bolt overlapping sleeve connection followed by grouting to ensure the continuity of the internal steel pipe and the overall strength of the column. The double-walled corrugated steel pipe concrete column and the foundation adopt an overlapping connection. By increasing the bottom plate area of ​​the pre-embedded connector, the integrity of the column and the foundation can be increased, thereby strengthening the seismic performance of the pier. It can also reduce the length of the insertion cup of the traditional insert-type pier, so that this type of pier can be applied to special working conditions such as the thinner foundation.

[0022] (8) The internal steel pipe of the present invention can be used as a stress point during the hoisting operation of precast columns, and can also be used as a positioning template during the installation operation of precast columns, thus eliminating the construction process of installing positioning templates.

[0023] (9) The inner steel pipe of the present invention is welded with shear keys on the outer surface, which makes it more integrated with the sandwich concrete and the outer galvanized corrugated steel pipe, and the combination effect of concrete and steel is better. At the same time, the inner steel pipe and the outer galvanized corrugated steel pipe can be set coaxially or non-coaxially as needed (when subjected to eccentric force or with obvious bending moment, the inner steel pipe can be placed in the tension zone).

[0024] (10) The concrete in the interlayer of the present invention can be selected from ordinary concrete, reinforced concrete, recycled concrete or sea sand concrete as needed. At the same time, the steel pipe inside the column can be filled with concrete to transform it into a solid corrugated steel pipe concrete column according to the design requirements, thus expanding the scope of application. Attached Figure Description

[0025] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is an overall schematic diagram of the present invention; Figure 2 This is a schematic diagram of the pre-embedded parts for the cap beam of the present invention; Figure 3 This is a schematic diagram of the embedded parts of the foundation of the present invention; Figure 4 This is a schematic diagram of the splicing of the steel pipe at the cup-mouth node of the present invention; Figure 5 This is a schematic diagram of the steel pipe splicing of the double-wall corrugated steel pipe concrete column of the present invention; Figure 6 This is a schematic diagram of the post-cast grouting of the present invention; Figure 7 This is a schematic diagram of the welding of the circular steel plate at the end of the internal steel pipe of the present invention; Figure 8 This is a schematic diagram of the cross-section of the coaxial double-walled corrugated steel tube concrete column of the present invention; Figure 9 This is a schematic diagram of the cross-section of the non-coaxial, centrally double-walled corrugated steel tube concrete column of the present invention.

[0026] Among them: 1-1 is the top cap beam, 1-2 is the middle double-wall corrugated steel pipe concrete column, and 1-3 is the lower foundation; 2-1 is the top longitudinal reinforcement of the cap beam, 2-2 is the cap beam connector, 2-3 is the corrugated steel plate core mold of the cap beam, 2-4 is the bottom longitudinal reinforcement of the cap beam, and 2-5 is the embedded bolt. 3-1 is the corrugated steel plate core mold for the foundation; 3-2 is the foundation connector. 4-1 is the interlayer concrete, 4-2 is the corrugated steel pipe, 4-3 is the internal steel pipe of the column, 4-4 is the reserved bolt hole of the internal steel pipe of the column, 4-5 is the connecting steel pipe of the foundation connector, 4-6 is the reserved bolt hole of the connecting steel pipe of the foundation embedded connector, 4-7 is the concrete pouring interface, 4-8 is the base plate of the foundation embedded connector, and 4-9 is the single-sided bolt. 5-1 is the composite sleeve, and 5-2 is the pre-drilled bolt hole for the composite sleeve; 6-1 is the reserved cup opening for the cap beam; 6-2 is the baffle; 6-3 is the grouting hole for the baffle; 6-4 is the semi-circular corrugated steel pipe connecting plate; 6-5 is the reserved screw hole for the baffle; 6-6 is the semi-circular corrugated steel pipe; 6-7 is the column connector; 6-8 is the column connector connecting plate; 6-9 is the column connector grouting hole; 6-10 is the reserved cup opening for the foundation; 6-11 is the reinforcing cage. 7-1 is a round steel plate lifting ring, 7-2 is a round steel plate, 7-3 is a support, and 7-4 is a shear key. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments.

[0028] See Figures 1-9This embodiment describes a composite prefabricated double-walled corrugated steel pipe concrete bridge pier, which mainly includes an upper top cap beam 1-1, a middle double-walled corrugated steel pipe concrete column 1-2, a lower pier cap 1-3, and some connecting parts and post-cast concrete. The top cap beam 1-1, the middle double-walled corrugated steel pipe concrete column 1-2, and the lower pier cap 1-3 are arranged sequentially from top to bottom. The top cap beam 1-1 includes a top longitudinal reinforcement 2-1, a cap beam connector 2-2, a cap beam core mold 2-3, a bottom longitudinal reinforcement 2-4, a cap beam reserved cup 6-1, and a baffle 6-2. The top of the cap beam body is provided with the top longitudinal reinforcement 2-1, the bottom of the cap beam is provided with the bottom longitudinal reinforcement 2-4, and the middle of the cap beam core mold 2-3 is provided. The cap beam body body is also provided with the cap beam connector 2-2, the cap beam reserved cup 6-1, and the baffle 6-2. The baffle 6-2 is arranged on the outer periphery of the column body. The central double-walled corrugated steel tube concrete column 1-2 is extended by splicing single columns. Each single column includes an internal steel tube 4-3, a sandwich concrete 4-1, and an external corrugated steel tube 4-2. The internal steel tube 4-3, the sandwich concrete 4-1, and the corrugated steel tube 4-2 are arranged sequentially from the inside to the outside. Adjacent single columns are connected by an inner layer overlapping sleeve 5-1 and an external column connector 6-7. The lower support 1-3 includes a support reserved cup 6-10, a reinforcing cage 6-11, and a support connector 3-2. The support body is provided with the support reserved cup 6-10 and the support connector 3-2. The support connector 3-2 is connected to the steel pipe 4-3 inside the column. The reinforcing cage 6-11 is provided inside the support reserved cup 6-10.

[0029] The top cap beam 1-1 and the double-walled corrugated steel pipe concrete column are prefabricated in the factory, the middle double-walled corrugated steel pipe concrete column 1-2 can be spliced ​​and lengthened, and the lower foundation 1-3 is cast on site.

[0030] Specific Implementation Method Two: Combining Figure 2 , Figure 6 As shown, the connectors need to be pre-embedded during the prefabrication of the top cap beam 1-1. The top longitudinal reinforcement 2-1 of the cap beam is attached to the top plate of the cap beam connector 2-2 and connected by spot welding; the pre-embedded screws 2-5 are evenly distributed around the reserved cup opening 6-1 of the cap beam for subsequent connection of the baffle 6-2.

[0031] Specific implementation method five: such as Figure 4 As shown, the central double-walled corrugated steel pipe concrete column 1-2 mainly includes an internal steel pipe 4-3, a sandwich concrete layer 4-1, and an external galvanized corrugated steel pipe 4-2. Its strength grade, size, and form are designed according to the actual situation. The internal steel pipe 4-3 is provided with pre-embedded connectors for connecting steel pipes and reserved bolt holes 4-6 and 4-4. The size and number of these holes are determined according to actual needs.

[0032] Specific implementation method six: such as Figure 4 As shown, the connector and the internal steel pipe 4-3 of the column are connected using single-sided bolts 4-9. Taking the connection between the foundation connector 3-2 and the internal steel pipe 4-3 of the column as an example, the outer diameter of the connecting steel pipe 4-5 of the foundation connector is slightly smaller than the inner diameter of the internal steel pipe 4-3. Before connection, the internal steel pipe 4-3 of the column is inserted into the connecting steel pipe 4-5 of the foundation connector. The pre-drilled bolt holes 4-6 of the connecting steel pipe 4-5 exposed above the concrete pouring interface 4-7 are aligned with the pre-drilled bolt holes 4-4 of the internal steel pipe, and then connected and tightened using single-sided bolts 4-9.

[0033] Specific implementation method seven: such as Figure 5 As shown, the central double-walled corrugated steel pipe concrete column 1-2 can be extended by splicing. The internal steel pipe 4-3 of the column is connected by a composite sleeve 5-1. The inner diameter of the composite sleeve is slightly larger than the outer diameter of the internal steel pipe of the column. After aligning the pre-drilled bolt holes 4-4 in the internal steel pipe of the column and the pre-drilled bolt holes 5-2 in the composite sleeve, they are connected and tightened using single-sided bolts 4-9.

[0034] Specific implementation method eight: Combination Figure 4 , Figure 6 As shown, the steel pipe 4-3 inside the column is connected to the cap beam and foundation connecting pipe using single-sided bolts 4-9. After this connection, concrete pouring and grouting are carried out. For visual effect, some components are not shown. After the foundation's reserved cup opening 6-10 node is spliced, the reinforcing cage 6-11 is placed inside, followed by concrete pouring. After the cap beam's reserved cup opening 6-1 node is spliced, the baffle 6-2 is installed and connected to the top cap beam 1-1 via embedded bolts 2-5. The semi-circular corrugated steel pipe connecting plate 6-4 is connected using bolts, so that the semi-circular corrugated steel pipe 6-6 wraps around the corrugated steel pipe 4-2. Sealing is then applied to prevent grout leakage, and grouting is performed through the baffle's grouting hole 6-3.

[0035] Specific Implementation Method Nine: Combining Figure 5 , Figure 6 As shown, when the middle double-walled corrugated steel pipe concrete column 1-2 is spliced ​​and extended, after the internal steel pipe 4-3 of the column is spliced, adjacent single columns are connected by column connectors 6-7, and grouting is completed using column connectors 6-7 as templates. The column connectors 6-7 are installed on the outer periphery of the corrugated steel pipe 4-2. Each column connector 6-7 includes two semi-circular corrugated plates, with column connector connecting plates 6-8 at both ends. Grouting holes 6-9 are provided on the semi-circular corrugated plates. After the column connector connecting plates 6-8 are tightened with bolts, the column connector 6-7 wraps around the corrugated steel pipe 4-2, and is sealed with sealant to prevent grout leakage. Grouting is then performed through the grouting holes 6-9.

[0036] Specific implementation method ten: as follows Figure 7As shown, when welding the round steel plate 7-2 at the end of the internal steel pipe 4-3 of the column, first weld three supports 7-3 on the inner wall of the internal steel pipe 4-3, and then use the round steel plate lifting ring 7-1 to put the round steel plate 7-2 into the steel pipe before welding, so as to avoid the grout leaking into the steel pipe during subsequent grouting or concrete pouring.

[0037] Specific implementation method eleven: as follows Figure 8-9 As shown, the internal steel pipe 4-3 and the external galvanized corrugated steel pipe 4-2 of the column can be coaxially or non-coaxially arranged as needed.

[0038] Specific Implementation Method Twelve: During the prefabrication of the central double-walled corrugated steel tube concrete column 1-2, the concrete 4-1 in the interlayer needs to be ordinary concrete, reinforced concrete, recycled concrete, or sea sand concrete. During construction, the grout required for pouring and the subsequent concrete must have characteristics such as early strength, self-compacting, and micro-expansion. After the steel tubes 4-3 inside the column are spliced, the concrete for the subsequent pouring is placed inside.

[0039] Specific implementation method thirteen: When splicing the internal steel pipe 4-3 of the column with the connecting parts, the wall thickness of the connecting steel pipe shall not be less than the wall thickness of the internal steel pipe 4-3 of the column. At the same time, the number of single-sided bolts 4-9 used for splicing shall be calculated and configured according to the design requirements.

[0040] Specific Implementation Method Fourteen: Combining Figures 1 to 5 As shown, the corrugated steel pipe 4-2 in this embodiment is a galvanized corrugated steel pipe with a zinc protective layer electroplated on its surface. When the anti-corrosion requirements are high, it can also be used in conjunction with anti-corrosion coatings. The specific dimensions are determined according to actual needs.

[0041] Specific implementation method 15: The length of the reserved cup opening 6-1 of the top cap beam 1-1 must meet the operating space for tightening the bolts 4-9 on one side, and should not be less than D+400mm (D is the outer diameter of the middle double-wall corrugated steel pipe concrete column 1-2). The exposed part of the steel pipe 4-3 inside the column extends into the reserved cup opening 6-1 of the cap beam for a length not less than D, and the length of the corrugated steel pipe 4-3 extending into the reserved cup opening 6-1 of the cap beam for a length not less than 0.25D.

[0042] Specific implementation method sixteen: The baffle 6-2 is provided with grouting holes. The diameter of the semi-circular corrugated steel pipe 6-6 is the same as the diameter of the steel pipe 4-3 inside the column. The crests and troughs interlock with each other. The overlap length between the semi-circular corrugated steel pipe 6-6 and the lower column is not less than 0.5D. After being fastened with bolts, the interface with the cap beam and the column is sealed with glue to prevent grout leakage.

[0043] Specific Implementation Method Seventeen: The radius of the column connector 6-7 used for splicing the double-walled corrugated steel pipe concrete columns 1-2 in the middle is the same as the diameter of the column. The crests and troughs interlock with each other. The overlap length between the column connector 6-7 and the upper and lower columns is not less than 0.5D. After fastening with bolts, the interface with the column is sealed with glue to prevent grout leakage.

[0044] Specific implementation method 18: The exposed part of the steel pipe 4-3 inside the column extends into the reserved cup opening 6-10 of the foundation with a length of not less than 2D, and the corrugated steel pipe 4-2 extends into the reserved cup opening 6-10 of the foundation with a length of not less than 0.5D.

[0045] Specific Implementation Method Nineteen: Corrugated steel plates are used as core molds for the reserved cup opening 6-10 of the foundation. After pouring, the corrugated steel plates are not removed. The configuration of the internal reinforcement cage 6-11 of the reserved cup opening 6-10 of the foundation is determined by calculation based on the design values ​​of bending moment and shear force at the bottom of the column base. The stirrups of the reserved cup opening 6-10 of the foundation are densely configured at the concrete end interface area of ​​the double-walled corrugated steel pipe concrete column 1-2 in the middle.

[0046] Specific implementation method 20: The dimensions of the galvanized corrugated steel pipe 4-2 and the internal steel pipe 4-3 of the column are calculated and configured according to the design requirements.

[0047] Specific implementation method twenty-one: The internal steel pipe 4-3 of the column can be filled with concrete to transform it into a solid corrugated steel pipe concrete column according to design requirements.

[0048] A construction method for a composite prefabricated double-walled corrugated steel pipe concrete bridge pier includes the following construction steps: Step 1: Precast the middle double-wall corrugated steel pipe concrete column 1-2: Roll out the corrugated steel pipe 4-2 according to the design dimensions as a template, select the internal steel pipe 4-3 of the column according to the design requirements and place it inside the corrugated steel pipe 4-2. Weld the round steel plate 7-2 inside the internal steel pipe 4-3 of the column to prevent grout leakage during subsequent grouting. Weld the shear key 7-4 to the outside of the internal steel pipe 4-3 of the column. Weld the sealing plate with the pouring hole to the column end. Remove the sealing plate after the pouring is completed and cured to the design strength. Step Two: Fabrication of Connectors: Connectors include cap beam connector 2-2, foundation connector 3-2, baffle connector, composite sleeve 5-1, and column connector 6-7; fabricate several steel plates and steel pipes according to the design dimensions, and weld the steel plates to the steel pipes to complete the fabrication of top cap beam connector 2-2 and foundation connector 3-2; drill bolt holes in the steel pipes according to the design requirements to complete the fabrication of column composite sleeve 5-1; cut corrugated steel pipes according to the design dimensions and weld them to the baffle, weld side connecting plates to the semi-circular corrugated steel pipes, and reserve grouting holes in the baffle to complete the fabrication of baffle connectors; weld side connecting plates to the semi-circular corrugated steel pipes and reserve grouting holes to complete the fabrication of column connector 6-7.

[0049] Step 3: As Figure 2 As shown, the precast top cap beam 1-1: According to the design, the cap beam connector 2-2 and bolt 2-5 are pre-embedded in the top cap beam 1-1. A cup-shaped opening 6-1 is reserved in the top cap beam 1-1. The bottom longitudinal reinforcement 2-4 of the cap beam is cut at the reserved cup-shaped opening 6-1, then bent in a U-shape and extended into the cup-shaped opening. A corrugated steel plate is cut at the reserved cup-shaped opening 6-1 to serve as the cap beam core mold 2-3. After casting, it is cured to the design strength. After casting, the corrugated steel plate is not demolded; it serves as a shear-resistant component in the cup-shaped opening area. The top plate of the cap beam connector 2-2 is spot-welded to the top longitudinal reinforcement 2-4 of the cap beam.

[0050] Step Four: As Figure 3 As shown, the lower foundation 1-3 is poured as follows: During on-site construction, the lower foundation 1-3 is poured according to the design. The foundation connector 3-2 is pre-embedded in the lower foundation 1-3. The lower foundation 1-3 has a reserved cup opening 6-10. Corrugated steel plates are cut at the reserved cup opening 6-10 as the foundation core mold 3-1. After pouring, it is cured to the design strength. The foundation core mold 3-1 is not removed. After pouring, the corrugated steel plate is not demolded. The corrugated steel plate exists as a shear-resistant component in the reserved cup opening 6-10 area of ​​the foundation.

[0051] Step 5: Node Connection: Transport the precast central double-wall corrugated steel pipe concrete column 1-2 to the construction site, splice the column to the designed length, insert the internal steel pipe into the foundation connector 3-2 and align it, then connect it with single-sided bolts 4-9 and carry out post-pouring construction. Subsequently, hoist the top cap beam 1-1, insert the cap beam connector 2-2 into the internal steel pipe 4-3 and align it, then connect it with single-sided bolts 4-9 and carry out grouting construction. Step 6: Post-pouring grouting: Insert the steel cage 6-11 into the reserved cup opening 6-10 of the lower foundation 1-3 and carry out post-pouring concrete construction. After the column connector 6-7 and the baffle connector are installed, grouting construction is carried out.

[0052] The top cap beam 1-1 is prefabricated. During factory prefabrication, the cap beam connector 2-2 and the pre-embedded bolt 2-5 are embedded into the top cap beam 1-1. A square cap beam retaining cup 6-1 is reserved at the bottom of the top cap beam 1-1. The longitudinal reinforcement 2-4 at the bottom of the cap beam is cut at the retaining cup 6-1, bent in a U-shape, and then extends into the retaining cup 6-1. The middle double-walled corrugated steel pipe concrete column 1-2 is prefabricated. Shear keys 8-1 are welded to the outer surface of the internal steel pipe 4-2 of the column, and round steel plates 7-2 are welded to the ends for sealing. It can be extended by splicing using overlapping sleeves. The internal steel pipe 4-2 and the external corrugated steel pipe 4-3 of the column can be set coaxially or non-coaxially.

[0053] The lower foundation 1-3 is cast in place, the foundation connector 3-2 is pre-embedded, and a square foundation socket 6-10 is reserved at the top of the foundation. During on-site construction, the steel pipe 4-2 inside the middle double-wall corrugated steel pipe concrete column 1-2 is inserted into the pre-reserved connecting steel pipe at the foundation socket 6-10 and then connected with a single-sided bolt 4-9. After the splicing is completed, a reinforcing cage 6-11 is placed in the foundation socket 6-10, and then the concrete pouring for the foundation socket 6-10 is completed.

[0054] Then, the middle double-wall corrugated steel pipe concrete column 1-2 is connected to the top cap beam 1-1. Similarly, the steel pipe 4-3 inside the column of the middle double-wall corrugated steel pipe concrete column 1-2 is inserted into the reserved connecting steel pipe of the reserved cup opening 6-1 of the cap beam and then connected with single-sided bolts 4-9. After the splicing is completed, the baffle 6-2 is installed for grouting reinforcement.

[0055] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A construction method for a composite prefabricated double-walled corrugated steel pipe concrete bridge pier, characterized in that: Specifically, the construction steps include the following: Step 1: Precast the middle double-wall corrugated steel pipe concrete column (1-2): Roll out the corrugated steel pipe (4-2) according to the design dimensions as a template, select the internal steel pipe (4-3) of the column and place it inside the corrugated steel pipe (4-2). Weld the round steel plate (7-2) inside the internal steel pipe (4-3) of the column to prevent grout leakage during subsequent grouting. Weld the shear key (7-4) to the outside of the internal steel pipe (4-3) of the column. Weld the sealing plate with the pouring hole to the column end. Remove the sealing plate after the pouring is completed and cured to the design strength. Step 2: Fabrication of connectors: Connectors include cap beam connector (2-2), foundation connector (3-2), baffle connector, and column connector (6-7). Step 3: Precast top cap beam (1-1): According to the design, embed the cap beam connector (2-2) and screw (2-5) into the top cap beam (1-1). The top cap beam (1-1) has a reserved cup opening (6-1). The bottom longitudinal reinforcement (2-4) of the cap beam is cut off at the reserved cup opening (6-1) and then bent into a U-shape and extended into the reserved cup opening (6-1). Corrugated steel plate is cut at the reserved cup opening (6-1) of the cap beam as the core mold (2-3). After pouring, it is cured to the design strength. The core mold (2-3) of the cap beam is not removed. Step 4: Casting of the lower foundation (1-3): During on-site construction, the lower foundation (1-3) is cast according to the design. The foundation connector (3-2) is pre-embedded in the lower foundation (1-3). The lower foundation (1-3) has a reserved cup opening (6-10). Corrugated steel plates are cut at the reserved cup opening (6-10) of the foundation as the foundation core mold (3-1). After casting, it is cured to the design strength. The foundation core mold (3-1) is not removed. Step 5: Node Connection: Transport the precast central double-wall corrugated steel pipe concrete column (1-2) to the construction site, splice the column to the designed length, insert the internal steel pipe (4-3) of the column into the foundation connector (3-2) and align them, then connect them with single-sided bolts (4-9) and carry out post-pouring construction. Subsequently, hoist the top cap beam (1-1), insert the cap beam connector (2-2) into the internal steel pipe (4-3) of the column and align them, then connect them with single-sided bolts (4-9) and carry out grouting construction. Step 6: Post-pouring grouting: Insert the steel cage (6-11) into the reserved cup opening (6-10) of the lower foundation (1-3) and carry out post-pouring concrete construction. After the column connector (6-7) and baffle connector are completed, install them and carry out grouting construction.

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