T-shaped steel pipe recycled concrete prefabricated pier column-foundation socket joint and construction method

Abstract

The invention relates to a T-shaped steel pipe recycled concrete prefabricated pier column-foundation socket joint and a construction method, and belongs to the technical field of structural engineering. Comprising a prefabricated T-shaped steel tube recycled concrete pier column and a recycled concrete foundation, the prefabricated T-shaped steel tube recycled concrete pier column is composed of a pier body T-shaped steel tube and a pier body amplification foot, the recycled concrete foundation is composed of horizontal pressure-bearing angle steel, foundation longitudinal steel bars and foundation stirrups, and the pier column and the foundation form a stress whole through a vertical reinforcing device and UHPC. The pier body amplification foot and the recycled concrete foundation are connected through a vertical reinforcing device in a penetrating mode and can resist the drawing force of a joint area, and the horizontal force is jointly borne by concrete and horizontal pressure-bearing angle steel. Structural plasticity, mechanical property and environmental protection property can be greatly improved, and popularization and application of a prefabricated assembly construction technology in a complex service environment are achieved.

Description

Technical Field

[0001] The invention relates to a prefabricated assembly pier column-foundation socket joint, in particular to a T-shaped steel tube recycled concrete prefabricated assembly pier column-foundation socket joint and a construction method, belonging to the technical field of structural engineering. Background Art

[0002] Build a strong transportation country and improve comprehensive transportation hubs. With the continuous increase in transportation demand and the improvement of environmental awareness, the construction of regional bridges is in urgent need of innovation and change. The traditional on-site casting method often faces problems such as long construction period, difficult to control construction quality and environmental pollution. The prefabricated and assembled bridge node construction technology effectively improves construction efficiency by prefabricating components in the factory, which can greatly reduce the interference with the on-site environment. At the same time, combined with the design of ultra-high performance concrete (UHPC) and steel tube recycled concrete, this bridge node not only has excellent plasticity, strength and environmental protection, but also improves ductility while contributing to resource recycling and improving economy. Especially in special environments such as earthquake-prone areas, this combination of structures has both excellent force performance and high economy.

[0003] my country is located between the Pacific Rim seismic belt and the Eurasian seismic belt, with frequent seismic activities, which poses severe challenges to the construction and design of transportation bridges. In bridge design, structural nodes, as the core connection points of various components, are key areas for optimizing design, especially the connection between piers and foundations, which is often regarded as its weakest link. Therefore, in order to improve the seismic performance, it is necessary to develop pier-foundation node connection schemes and construction processes suitable for strong earthquake zones to meet the huge needs of actual bridge projects. At this stage, the seismic resistance of the proposed prefabricated structural nodes in the lower part of the bridge is still insufficient and difficult to adapt to the needs of future transportation development, especially in areas where earthquakes occur frequently. Therefore, the development of seismic design schemes and construction technologies that meet high standards will greatly enhance the overall safety and service life of bridges in strong earthquake zones, thereby safeguarding future transportation infrastructure.

[0004] The advantages of steel tube concrete such as high strength, high plasticity and convenient construction are widely used in engineering, and the socket connection is also widely used in the prefabricated pier node connection technology, reflecting its advantages such as simple connection, strong adaptability and reduced on-site construction, in order to meet the performance of bridge infrastructure in high seismic areas. At present, the traditional pier-foundation socket node structural connection has the disadvantages of large socket depth, easy damage of the node, insufficient anti-overturning, etc., which is not conducive to the safety and economy of the structure and has poor applicability. For example, CN108547216A discloses a precast concrete bridge pier and bridge foundation tooth key socket structure and construction method, which includes a precast pier and a bridge foundation, the pier including an exposed end and an embedded end of the pier, a reserved socket slot is arranged downward on the top surface of the bridge foundation, the shape of the socket slot matches the shape of the embedded end of the pier so that the embedded end of the pier can be embedded in the socket slot, an annular pier key slot is arranged along the outer wall of the embedded end of the pier, and a corresponding annular bridge foundation key slot is arranged along the inner wall of the socket slot, after the embedded end of the pier is embedded in the socket slot, a socket bottom gap is left between the bottom surface of the embedded end of the pier and the bottom surface of the socket slot, and a socket gap is left between the outer wall of the embedded end of the end column and the inner wall of the socket slot; the cast-in-place pouring material in the socket gap from the top entrance solidifies into an annular tooth key in the pier key slot and the bridge foundation key slot. CN113585053A discloses a prefabricated assembled steel tube concrete bridge pier with off-site prestressing and a construction method thereof, wherein the steel tube concrete bridge pier comprises at least two segment steel tubes and inner filling concrete respectively filled in the segment steel tubes, two adjacent segment steel tubes are fixedly connected by pier column energy-absorbing parts, and prestressed tendons are tensioned between the inner filling concrete at both ends of the pier.

[0005] Therefore, it is urgent to propose a new type of assembled T-shaped pier-foundation socket-type node structure to solve the above-mentioned problems of large socket depth, easy damage of the node, and insufficient anti-overturning. Summary of the invention

[0006] In view of the above-mentioned defects of the above-mentioned prior art, the present invention proposes a T-shaped steel tube recycled concrete prefabricated assembly pier-foundation socket node and construction method, which can well meet the seismic mechanical properties of the connection node and has the advantages of high plasticity, convenient construction, resource recycling, low socket depth and high economy, etc., providing a new solution for the prefabricated pier-foundation node connection design in the field of bridge engineering.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] The T-shaped steel tube recycled concrete prefabricated assembled pier column-foundation socket node is composed of a prefabricated T-shaped steel tube recycled concrete pier column, a recycled concrete foundation, a vertical reinforcement device and a horizontal pressure-bearing angle steel.

[0009] The prefabricated T-shaped steel tube recycled concrete pier column comprises a pier body T-shaped steel tube and an internal pier body embedded metal tube; the bottom of the pier body T-shaped steel tube is an expanded surrounding area, which together with the internal recycled concrete forms a pier body enlarged foot; the pier body enlarged foot is inserted into the socket of the recycled concrete foundation, and high-strength concrete UHPC is poured between the two;

[0010] The pier body embedded metal pipe is vertically embedded in the pier body enlarged foot, with the bottom parallel to the bottom of the pier body enlarged foot, and the top is welded parallel to the pier body T-shaped steel pipe variable cross-section steel plate;

[0011] The pier body T-shaped steel pipe comprises steel pipe reserved holes, steel pipe stiffening ribs and shear nails; the steel pipe stiffening ribs are located on the four inner walls of the pier body T-shaped steel pipe of the pier body enlargement foot and the bottom surface of the variable-section steel plate; the steel pipe reserved holes are arranged on the variable-section steel plate; the shear nails are welded to the inner and outer walls of the pier body T-shaped steel pipe where the pier body enlargement foot is located;

[0012] The recycled concrete foundation comprises a foundation embedded metal pipe and a horizontal pressure-bearing angle steel; the foundation embedded metal pipe is embedded in the foundation below the socket of the recycled concrete foundation, the top surface of which extends out of the bottom surface of the socket, and the bottom surface is flush with the bottom surface of the recycled concrete foundation; the foundation embedded metal pipe corresponds to the pier body embedded metal pipe thereon one by one;

[0013] The horizontal pressure-bearing angle steel includes an L-shaped longitudinal steel beam, an L-shaped stress-bearing steel plate, a horizontal connection steel plate, a vertical connection steel plate and an anchoring steel plate, which are buried in the corners of the reserved socket of the recycled concrete foundation, and the inner part is buried in the inner part of the foundation longitudinal steel bars and the foundation stirrups, and is connected and fixed to the foundation longitudinal steel bars and the foundation stirrups by welding, while the part extending out of the foundation socket is limited between the four sides of the pier body enlarged foot and the four sides of the foundation socket;

[0014] One end of the plurality of L-shaped longitudinal steel beams is fixed in parallel through an anchoring steel plate, and the other end is fixed in parallel through an L-shaped load-bearing steel plate. A plurality of groups of horizontal connecting steel plates and vertical connecting steel plates are welded at intervals in the middle of the L-shaped longitudinal steel beam; the L-shaped load-bearing steel plate extends out of the recycled concrete foundation and is located between the pier body enlarged foot and the socket;

[0015] The vertical reinforcement device includes a screw rod, a nut and a rod anchoring end. The screw rod passes through the pier body embedded metal pipe, the foundation embedded metal pipe and the corresponding steel pipe reserved hole, and its upper and lower ends are fixed by the nut and the rod anchoring end respectively.

[0016] Furthermore, the recycled concrete foundation also includes foundation longitudinal steel bars and foundation stirrups. The foundation stirrups are arranged around the sockets, penetrate the middle of the recycled concrete foundation and overlap with the foundation longitudinal bars.

[0017] Furthermore, the horizontal pressure-bearing angle steel is horizontally embedded in the recycled concrete foundation at a horizontal distance not less than 3-6 times of the socket depth, and the horizontal pressure-bearing angle steel located inside the recycled concrete foundation is fixed to the foundation longitudinal steel bars and foundation stirrups by welding.

[0018] Furthermore, the L-shaped load-bearing steel plate is horizontally arranged with the side wall of the pier body enlargement foot, and each side wall is correspondingly provided with at least two groups of horizontal pressure-bearing angle steels; the horizontal distance between the L-shaped load-bearing steel plate and the four sides of the pier body enlargement foot and the four sides of the socket slot is not less than 20 mm, the vertical distance with the bottom surface of the pier body enlargement foot is not less than 20 mm, and the distance between multiple groups of L-shaped load-bearing steel plates arranged side by side is not less than 20 mm.

[0019] Furthermore, the compressive strength of the high-strength concrete UHPC is not less than 120 MPa, and the tensile strength is not less than 10 MPa.

[0020] Furthermore, the socket depth of the pier body enlarged foot is not less than 0.6 times the side length of the prefabricated T-shaped steel tube recycled concrete pier column, and the expansion width of the pier body enlarged foot is not less than 0.2 times the side length of the prefabricated T-shaped steel tube recycled concrete pier column.

[0021] Furthermore, the inner diameter of the foundation embedded metal tube and the pier body embedded metal tube is at least 10 mm larger than the diameter of the screw in the vertical reinforcement device, and the thickness is not less than 2 mm, and the length of the top surface of the foundation embedded metal tube extending out of the bottom surface of the socket slot is not less than 10 mm.

[0022] Furthermore, a 10-30mm mortar layer is arranged between the bottom surface of the enlarged foot of the pier body and the bottom surface of the recycled concrete foundation socket; in addition, a steel pipe pad is placed between the nut and the reserved hole of the steel pipe, and a foundation pad is placed between the rod anchor end and the embedded metal pipe of the foundation; the internal hole diameter of the steel pipe pad and the foundation pad is at least 2mm larger than the diameter of the vertical reinforcement device.

[0023] Furthermore, the shear nails on the inner and outer walls of the pier body T-shaped steel pipe of the pier body enlarged foot are divided into long shear nails and short shear nails.

[0024] The construction method of the T-shaped steel tube recycled concrete prefabricated assembly pier column-foundation socket node comprises the following steps:

[0025] S1. Prefabricated T-shaped steel tube recycled concrete pier columns are processed in the factory. The pier body T-shaped steel tube is welded and connected at the steel tube variable section, and the steel tube reserved hole of the pier body T-shaped steel tube variable section steel plate is reserved and positioned. The top surface of the pier body embedded metal tube is welded and positioned at the lower part of the steel tube reserved hole and the axis is aligned. The steel tube stiffening rib is welded and positioned between the inner wall surface of the pier body T-shaped steel tube of the pier body enlargement foot and the corner of the bottom surface of the variable section steel plate, so that the pier body embedded metal tube and the steel tube stiffening rib are both vertically fixed inside the pier body T-shaped steel tube, and then the shear nails are welded to the inner and outer wall surfaces of the pier body T-shaped steel tube on the side of the pier body enlargement foot to form the pier body T-shaped steel tube as a whole, and recycled concrete is poured into the pier body T-shaped steel tube. The test piece is cured to complete the production of prefabricated T-shaped steel tube recycled concrete pier columns;

[0026] S2. Processing the L-shaped longitudinal steel beam, L-shaped stress-bearing steel plate, horizontal connecting steel plate, vertical connecting steel plate and anchoring steel plate components of the horizontal pressure-bearing angle steel in the factory, connecting the L-shaped longitudinal steel beams in parallel by welding the horizontal connecting steel plate and the vertical connecting steel plate in the middle of the L-shaped longitudinal steel beam body; then, welding the L-shaped stress-bearing steel plate and the anchoring steel plate to one end of the parallel L-shaped longitudinal steel beams respectively to form a horizontal local stress-bearing steel skeleton, and completing the production of the horizontal pressure-bearing angle steel;

[0027] S3. Tie the foundation longitudinal steel bars and foundation stirrups of the recycled concrete foundation on site, reserve a socket for placing the pier body enlargement foot, and horizontally place the horizontal pressure-bearing angle steels processed and manufactured in the factory on the four sides of the socket. The horizontal pressure-bearing angle steels located inside the recycled concrete foundation are connected to the foundation longitudinal steel bars and foundation stirrups by welding to fix them, so that each load-bearing steel plate is parallel to the four side surfaces of the socket, and the foundation pre-buried metal pipe is vertically placed on the bottom of the socket, the upper end of the foundation pre-buried metal pipe extends out of the bottom surface of the recycled concrete foundation socket, and the lower end of the foundation pre-buried metal pipe is flush with the recycled concrete foundation, support the formwork, pour the recycled concrete, maintain the components, remove the formwork, and complete the production of the recycled concrete foundation;

[0028] S4. Transport the prefabricated T-shaped steel tube recycled concrete pier to the construction site, lay a mortar layer on the bottom surface of the recycled concrete foundation socket, insert the L-shaped load-bearing steel plate that passes through the four sides of the pier body enlargement foot parallel to the horizontal pressure-bearing angle steel on all sides into the socket, place the foundation pad and steel pipe pad on the bottom of the foundation embedded metal pipe and the upper surface of the steel pipe reserved hole of the pier body enlargement foot respectively, pass the vertical reinforcement device through the foundation pad, the foundation embedded metal pipe, the pier body embedded metal pipe, the steel pipe reserved hole and the steel pipe pad, pre-tighten the vertical reinforcement device through the screw and nut at the upper end, and adjust the horizontality and verticality of the prefabricated T-shaped steel tube recycled concrete pier at the same time, complete the placement of the prefabricated T-shaped steel tube recycled concrete pier, pour high-strength concrete UHPC between the four sides of the pier body enlargement foot and the four sides of the recycled concrete foundation socket, so that the pier body enlargement foot and the recycled concrete foundation are connected as a whole, and the assembly of the prefabricated T-shaped steel tube recycled concrete pier and the recycled concrete foundation is completed.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The present invention processes prefabricated piers in a prefabrication plant, uses a connection node between a recycled concrete T-shaped pier and a recycled concrete foundation, and combines a combination of a T-shaped steel pipe, a vertical reinforcement device, and a horizontal pressure-bearing angle steel to ensure the stability and reliability of the component. During the construction process, both the pier and the foundation use recycled concrete, and with the application of environmental protection technology and clean energy, it significantly reduces pollution emissions, protects natural resources, and contributes to the restoration and maintenance of ecological balance. At the same time, this technology not only ensures the quality of construction and component quality, but also has the advantages of simple construction methods, clear node design, and shallow socket depth. The prefabricated assembly design effectively saves on-site workload and time, reduces labor and transportation costs, and reduces negative impacts on the environment. The use of steel tube recycled concrete piers can improve deformation capacity and reduce formwork rate, while ultra-high performance concrete (UHPC) can improve node corrosion resistance, extend service life, and reduce later maintenance costs. Recycled concrete can give full play to the advantages of green building materials in environmental protection, energy saving and renewability, thereby promoting the widespread application of green building materials.

[0031] 2. Placing most of the skeleton of the horizontal pressure-bearing angle steel inside the foundation can significantly enhance the connectivity between the recycled concrete of the foundation around the socket and the recycled concrete far from the socket of the foundation. In this way, an integrated structure can be created to resist the extension of the oblique cracks caused by the stress at the bottom of the socket to the top of the foundation, and the skeleton part located in the socket area can further enhance the anchoring capacity of the high-strength concrete (UHPC) between the pier and the foundation gap. At the same time, the horizontal resistance of the connection node can also be improved, and the bearing responsibility of the horizontal force is shared by the concrete and the horizontal pressure-bearing angle steel. The horizontal pressure-bearing angle steel is responsible for most of the horizontal force around the socket of the foundation, thereby reducing the risk of possible crushing of the cap concrete, so that the plastic hinge area will be generated preferentially at the pier above the connection node to avoid damage to the node. Under the action of the new structure, even the pier with a low socket depth can achieve a more coordinated working mechanism with the foundation, effectively improving the seismic performance of the pier-foundation connection node.

[0032] 3. The pier body enlarged foot is connected to the recycled concrete foundation through the vertical reinforcement device, and the pre-tightening force is applied to the vertical reinforcement device, which can effectively resist the pull-out force in the node area, and the presence of the pier column enlarged foot can enhance the anti-overturning ability of the connection node. This design can provide sufficient connection strength and seismic performance, while effectively reducing the difficulty and precision during prefabrication and assembly construction, further optimizing the structure of the connection node, improving the integrity of the foundation structure, reducing the project cost, simplifying the construction process, and saving construction costs.

[0033] 4. The presence of shear nails in the pier body can enhance the bonding performance between the T-shaped steel pipe and high-strength concrete (UHPC), and effectively ensure the seismic performance of the prefabricated pier-foundation connection node, ensuring the pull-out resistance under earthquake action. The presence of stiffening ribs can increase the stiffness of the T-shaped steel pipe and the seismic performance of the connection node area. While ensuring the seismic requirements of prefabricated assembled pier-foundation nodes in medium and high intensity areas, it can provide a higher bending safety reserve and ensure less damage to the plastic hinge area of ​​the pier column after the earthquake. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic elevation view of the present invention;

[0035] Figure 2 This is a partial elevation diagram of the pier body with the enlarged foot;

[0036] Figure 3 The present invention Figure 1 AA cross-sectional diagram of ;

[0037] Figure 4 The present invention Figure 1 BB cross-section diagram;

[0038] Figure 5It is a partial plan view of the pier body with the enlarged foot;

[0039] Figure 6 Schematic diagram of the horizontal pressure-bearing angle steel and its components of the present invention, wherein: (a) is a schematic diagram of the horizontal force-resisting device; (b) is a schematic diagram of the cross section of the L-shaped load-bearing steel plate; (c) is a schematic diagram of the cross section of the L-shaped longitudinal steel beam; (d) is a schematic diagram of the cross section of the middle part of the device;

[0040] Figure 7 Schematic diagram of the processing of prefabricated recycled concrete pier columns of the present invention, wherein: (a) is a schematic diagram of the processing of T-shaped steel pipes for the pier body; (b) is an overall diagram of the prefabricated T-shaped steel pipe recycled concrete pier column;

[0041] Figure 8 Schematic diagram of recycled concrete foundation processing of the present invention, wherein: (a) is a schematic diagram of steel bar skeleton binding; (b) is a schematic diagram of horizontal pressure angle steel; (c) is a diagram of the placement of pre-buried metal pipes in the foundation; (d) is a schematic diagram of the placement of horizontal pressure angle steel; (e) is an overall diagram of recycled concrete foundation;

[0042] Fig. 9 It is a three-dimensional schematic diagram of the prefabricated assembled T-type pier column-foundation of the present invention, wherein: (a) is a prefabricated T-type steel tube recycled concrete pier column; (b) is a recycled concrete foundation; (c) is an assembly diagram of the pier body enlarged foot and socket; (d) is an assembly diagram of the vertical reinforcement device placement, anchoring and pre-tightening; (e) is a schematic diagram of the socket gap grouting; (f) is an overall diagram of the assembled T-type pier column-foundation. DETAILED DESCRIPTION

[0043] The following is combined with Figure 1-9 The present invention is further described in detail with specific implementations to facilitate a clear understanding of the present invention, but they do not constitute a limitation on the present invention.

[0044] Example 1

[0045] A T-shaped steel tube recycled concrete prefabricated assembly pier column-foundation socket joint in this embodiment 1, such as Figure 1-2 As shown, it is composed of a prefabricated T-shaped steel tube recycled concrete pier column 1, a recycled concrete foundation 7, a vertical reinforcement device 11 and a horizontal pressure-bearing angle steel 16. The prefabricated T-shaped steel tube recycled concrete pier column 1 includes a pier body T-shaped steel tube 3 and an internal pier body embedded metal tube 2. The top of the pier body T-shaped steel tube 3 is a rectangular recycled steel tube concrete, as shown in FIG. Figure 3 As shown, the bottom is an enlarged surrounding area, which together with the recycled concrete inside forms the pier body enlarged foot 23, as shown in FIG. Figure 7As shown. The pier body enlarged foot 23 is inserted into the socket of the recycled concrete foundation 7, and high-strength concrete UHPC 24 is poured between the two. The recycled concrete foundation 7 also includes foundation longitudinal steel bars 8 and foundation stirrups 9. The foundation stirrups 9 are arranged around the socket, penetrate the middle of the recycled concrete foundation 7 and overlap with the foundation longitudinal bars 8.

[0046] like Figure 2 As shown, the pier body embedded metal pipe 2 is vertically embedded in the pier body enlarged foot 23, with the bottom parallel to the bottom of the pier body enlarged foot 23, and the top is welded parallel to the variable cross-section steel plate of the pier body T-shaped steel pipe 3. The pier body T-shaped steel pipe 3 includes steel pipe reserved holes 4, steel pipe stiffening ribs 5 and shear nails 22. Figure 5 As shown, the steel pipe stiffening ribs 5 are located on the four inner walls of the pier body T-shaped steel pipe 3 and the bottom surface of the variable-section steel plate of the pier body enlargement foot 23. The steel pipe reserved holes 4 are set on the variable-section steel plate. The shear nails 22 are welded on the inner and outer walls of the pier body T-shaped steel pipe 3 where the pier body enlargement foot 23 is located. The shear nails 22 on the inner and outer walls of the pier body T-shaped steel pipe 3 of the pier body enlargement foot 23 are divided into long shear nails and short shear nails.

[0047] In this embodiment, Figure 1-2 As shown, the recycled concrete foundation 7 includes a foundation embedded metal pipe 10 and a horizontal pressure-bearing angle steel 16. The foundation embedded metal pipe 10 is embedded in the foundation below the socket of the recycled concrete foundation 7, and its top surface extends out of the bottom surface of the socket, and the bottom surface is flush with the bottom surface of the recycled concrete foundation 7. The foundation embedded metal pipe 10 corresponds one-to-one to the pier body embedded metal pipe 2 thereon.

[0048] like Figure 6 As shown, the horizontal pressure angle steel 16 includes an L-shaped longitudinal steel beam 17, an L-shaped stress-bearing steel plate 20, a horizontal connecting steel plate 18, a vertical connecting steel plate 19 and an anchoring steel plate 21, which are buried in the reserved socket corner of the recycled concrete foundation 7, and the inner part is buried in the foundation longitudinal steel bar 8 and the foundation stirrup 9, and is connected and fixed to the foundation longitudinal steel bar 8 and the foundation stirrup 9 by welding, while the part extending out of the foundation socket is limited to the four sides between the pier body enlarged foot 23 and the four sides of the foundation socket. One end of multiple L-shaped longitudinal steel beams 17 is fixed in parallel by the anchoring steel plate 21, and the other end is fixed in parallel by the L-shaped stress-bearing steel plate 20. Multiple groups of horizontal connecting steel plates 18 and vertical connecting steel plates 19 are welded at intervals in the middle of the L-shaped longitudinal steel beam 17. The L-shaped stress-bearing steel plate 20 extends out of the recycled concrete foundation 7 and is located between the pier body enlarged foot 23 and the socket.

[0049] In this embodiment, Figure 2 As shown, the vertical reinforcement device 11 includes a screw rod 12, a nut 13 and a rod anchoring end 14. The screw rod 12 passes through the pier body embedded metal pipe 2, the foundation embedded metal pipe 10 and the corresponding steel pipe reserved hole 4, and its upper and lower ends are fixed by the nut 13 and the rod anchoring end 14 respectively.

[0050] In this embodiment, specifically, the horizontal pressure angle steel 16 is horizontally buried in the recycled concrete foundation 7 at a horizontal distance not less than 3-6 times the socket depth, and the horizontal pressure angle steel 16 located inside the recycled concrete foundation 7 is fixed to the foundation longitudinal steel bar 8 and the foundation stirrup 9 by welding. The L-shaped stress-bearing steel plate 20 is horizontally arranged with the side wall of the pier body enlargement foot 23, and two groups of horizontal pressure-bearing angle steels 16 are arranged correspondingly on each side wall. The horizontal distance between the L-shaped stress-bearing steel plate 20 and the four sides of the pier body enlargement foot 23 and the four sides of the socket slot is not less than 20mm, the vertical distance with the bottom surface of the pier body enlargement foot 23 is not less than 20mm, and the distance between the two groups of L-shaped stress-bearing steel plates 20 arranged side by side is not less than 20mm. The compressive strength of high-strength concrete UHPC24 is not less than 120MPa, and the tensile strength is not less than 10MPa. In addition, the socket depth of the pier body enlarged foot 23 is not less than 0.6 times the side length of the prefabricated T-shaped steel tube recycled concrete pier column 1, and the expanded width of the pier body enlarged foot 23 is not less than 0.2 times the side length of the prefabricated T-shaped steel tube recycled concrete pier column 1. The inner diameter of the foundation embedded metal pipe 10 and the pier body embedded metal pipe 2 is at least 10mm larger than the diameter of the screw 12 in the vertical reinforcement device 11, and the thickness is not less than 2mm, and the length of the top surface of the foundation embedded metal pipe 10 extending from the bottom surface of the socket slot is not less than 10mm.

[0051] In addition, if Figure 2 As shown, a 10-30 mm thick mortar layer 25 is provided between the bottom surface of the pier body enlarged foot 23 and the bottom surface of the socket of the recycled concrete foundation 7. A steel pipe pad 6 is placed between the nut 13 and the steel pipe reserved hole 4, and a foundation pad 15 is placed between the rod anchor end 14 and the foundation embedded metal pipe 10. The internal aperture of the steel pipe pad 6 and the foundation pad 15 is at least 2 mm larger than the diameter of the vertical reinforcement device 11.

[0052] Example 2

[0053] The construction method of the T-shaped steel tube recycled concrete prefabricated assembly pier column-foundation socket node of the above-mentioned embodiment 1 comprises the following steps:

[0054] S1. Process the prefabricated T-shaped steel tube recycled concrete pier 1 in the factory, weld and connect the pier body T-shaped steel tube 3 at the place where the steel tube has a variable cross-section, and reserve and position the steel tube reserved hole 4 of the variable cross-section steel plate of the pier body T-shaped steel tube 3. The top surface of the pier body embedded metal tube 2 is welded and positioned at the lower part of the steel tube reserved hole 4 and the axis is aligned. The steel tube stiffening rib 5 is welded and positioned between the inner wall surface of the pier body T-shaped steel tube 3 of the pier body enlargement foot 23 and the corner of the bottom surface of the variable cross-section steel plate, so that the pier body embedded metal tube 2 and the steel tube stiffening rib 5 are both vertically fixed inside the pier body T-shaped steel tube 3, and then the shear nails 22 are welded to the inner and outer wall surfaces of the pier body T-shaped steel tube 3 on the side of the pier body enlargement foot 23 to form the pier body T-shaped steel tube 3 as a whole, pour recycled concrete into the pier body T-shaped steel tube 3, and perform specimen curing to complete the production of the prefabricated T-shaped steel tube recycled concrete pier 1. Figure 7 shown.

[0055] S2. The L-shaped longitudinal steel beam 17, L-shaped stress-bearing steel plate 20, horizontal connecting steel plate 18, vertical connecting steel plate 19 and anchoring steel plate 21 components of the horizontal pressure-bearing angle steel 16 are processed in the factory, and the horizontal connecting steel plate 18 and the vertical connecting steel plate 19 are welded in the middle of the beam of the L-shaped longitudinal steel beam 17 to connect the L-shaped longitudinal steel beam 17 in parallel. Afterwards, the L-shaped stress-bearing steel plate 20 and the anchoring steel plate 21 are respectively welded to one end of the parallel L-shaped longitudinal steel beam 17 to form a horizontal local stress-bearing steel skeleton, and the production of the horizontal pressure-bearing angle steel 16 is completed.

[0056] S3. Tie the foundation longitudinal steel bars 8 and foundation stirrups 9 of the recycled concrete foundation 7 on site, reserve a socket for placing the pier body enlarged foot 23, and horizontally place the horizontal pressure-bearing angle steels 16 processed and manufactured in the factory on the four sides of the socket. The horizontal pressure-bearing angle steels 16 located inside the recycled concrete foundation 7 are connected to the foundation longitudinal steel bars 8 and the foundation stirrups 9 by welding to fix them, so that each load-bearing steel plate 13 is parallel to the four side surfaces of the socket, and vertically place the foundation embedded metal pipe 10 on the bottom surface of the socket, the upper end of the foundation embedded metal pipe 10 extends out of the bottom surface of the socket of the recycled concrete foundation 7, and the lower end of the foundation embedded metal pipe 10 is flush with the recycled concrete foundation 7, support the formwork, pour the recycled concrete, maintain the components, remove the formwork, and complete the production of the recycled concrete foundation 7, such as Figure 8 shown.

[0057] S4. Transport the prefabricated T-shaped steel tube recycled concrete pier 1 to the construction site, lay a mortar layer 25 on the bottom surface of the socket of the recycled concrete foundation 7, insert the L-shaped stress-bearing steel plate 20 that passes through the four sides of the pier body enlarged foot 23 in parallel through the surrounding horizontal pressure-bearing angle steels 16 into the socket, place the foundation pad 15 and the steel pipe pad 6 on the bottom of the foundation embedded metal pipe 10 and the upper surface of the steel pipe reserved hole 4 of the pier body enlarged foot 23 respectively, and pass the vertical reinforcement device 11 through the foundation pad 15, the foundation embedded metal pipe 10, the pier body embedded metal pipe 2, and the steel pipe reserved hole 4 And the steel pipe pad 6, pre-tighten the vertical reinforcement device 11 through the screw rod 12 and the nut 13 at the upper end, and adjust the horizontality and verticality of the prefabricated T-shaped steel pipe recycled concrete pier 1 at the same time, complete the placement of the prefabricated T-shaped steel pipe recycled concrete pier 1, and pour high-strength concrete UHPC24 between the four sides of the pier body enlarged foot 23 and the four sides of the socket of the recycled concrete foundation 7, so that the pier body enlarged foot 23 and the recycled concrete foundation 7 are connected as a whole, and the assembly work of the prefabricated T-shaped steel pipe recycled concrete pier 1 and the recycled concrete foundation 7 is completed, such as Fig. 9 shown.

[0058] The above is only a preferred embodiment of the present invention, and does not impose any formal limitation on the structure of the present invention. The layout type and the number of uses of the present invention are not limited to this example, and can be optimized and selected according to the actual project. Any modification, equivalent change and decoration of the above embodiment based on the technical principle of the present invention that does not deviate from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A T-shaped steel tube recycled concrete prefabricated assembly pier column-foundation socket joint, comprising a prefabricated T-shaped steel tube recycled concrete pier column (1), a recycled concrete foundation (7), a vertical reinforcement device (11) and a horizontal pressure-bearing angle steel (16), characterized in that: The prefabricated T-shaped steel tube recycled concrete pier column (1) comprises a pier body T-shaped steel tube (3) and an internal pier body embedded metal tube (2); the bottom of the pier body T-shaped steel tube (3) is an expanded surrounding area, which together with the internal recycled concrete forms a pier body enlarged foot (23); the pier body enlarged foot (23) is inserted into a socket of a recycled concrete foundation (7), and high-strength concrete UHPC (24) is poured between the two; The pier body embedded metal pipe (2) is vertically embedded in the pier body enlarged foot (23), with the bottom parallel to the bottom of the pier body enlarged foot (23), and the top is welded in parallel to the variable cross-section steel plate of the pier body T-shaped steel pipe (3); The pier body T-shaped steel pipe (3) comprises a steel pipe reserved hole (4), a steel pipe stiffening rib (5) and a shear nail (22); the steel pipe stiffening rib (5) is located on the four inner walls of the pier body T-shaped steel pipe (3) and the bottom surface of the variable-section steel plate of the pier body enlarged foot (23); the steel pipe reserved hole (4) is arranged on the variable-section steel plate; the shear nail (22) is welded to the inner wall and the outer wall of the pier body T-shaped steel pipe (3) where the pier body enlarged foot (23) is located; The recycled concrete foundation (7) comprises a foundation pre-buried metal pipe (10) and a horizontal pressure-bearing angle steel (16); the foundation pre-buried metal pipe (10) is pre-buried inside the foundation below the socket of the recycled concrete foundation (7), with its top surface extending out of the bottom surface of the socket, and its bottom surface flush with the bottom surface of the recycled concrete foundation (7); the foundation pre-buried metal pipe (10) corresponds one-to-one to the pier body pre-buried metal pipe (2) thereon; The horizontal pressure-bearing angle steel (16) comprises an L-shaped longitudinal steel beam (17), an L-shaped load-bearing steel plate (20), a horizontal connecting steel plate (18), a vertical connecting steel plate (19) and an anchoring steel plate (21), which is embedded in the corner of the reserved socket of the recycled concrete foundation (7), the inner part is embedded in the inner part of the foundation longitudinal steel bar (8) and the foundation stirrup (9), and is connected and fixed to the foundation longitudinal steel bar (8) and the foundation stirrup (9) by welding, and the part extending out of the foundation socket is limited to between the four sides of the pier body enlarged foot (23) and the four sides of the foundation socket; One end of the plurality of L-shaped longitudinal steel beams (17) is fixed in parallel via an anchoring steel plate (21), and the other end is fixed in parallel via an L-shaped load-bearing steel plate (20); a plurality of groups of horizontal connecting steel plates (18) and vertical connecting steel plates (19) are welded at intervals in the middle of the L-shaped longitudinal steel beam (17); the L-shaped load-bearing steel plate (20) extends out of the recycled concrete foundation (7) and is located between the pier body enlarged foot (23) and the socket; The vertical reinforcement device (11) comprises a screw rod (12), a nut (13) and a rod anchoring end (14); the screw rod (12) penetrates the pier body embedded metal pipe (2), the foundation embedded metal pipe (10) and the corresponding steel pipe reserved hole (4), and its upper and lower ends are fixed by the nut (13) and the rod anchoring end (14) respectively.

2. The T-shaped steel tube recycled concrete prefabricated assembly pier-foundation socket node according to claim 1 is characterized in that: The recycled concrete foundation (7) also includes foundation longitudinal reinforcement (8) and foundation stirrups (9). The foundation stirrups (9) are arranged around the sockets, penetrate the middle of the recycled concrete foundation (7) and overlap with the foundation longitudinal reinforcement (8).

3. The T-shaped steel tube recycled concrete prefabricated assembly pier-foundation socket node according to claim 2 is characterized by: The horizontal pressure-bearing angle steel (16) is horizontally embedded in the recycled concrete foundation (7) at a horizontal distance not less than 3 to 6 times the socket depth, and the horizontal pressure-bearing angle steel (16) located inside the recycled concrete foundation (7) is connected and fixed to the foundation longitudinal steel bars (8) and the foundation stirrups (9) by welding.

4. The T-shaped steel tube recycled concrete prefabricated assembly pier-foundation socket node according to claim 2 is characterized by: The L-shaped stress-bearing steel plate (20) is arranged in parallel with the side wall of the pier body enlargement foot (23), and each side wall is correspondingly provided with at least two groups of horizontal pressure-bearing angle steels (16); the horizontal distance between the L-shaped stress-bearing steel plate (20) and the four side surfaces of the pier body enlargement foot (23) and the four side surfaces of the socket slot is not less than 20 mm, and the vertical distance from the bottom surface of the pier body enlargement foot (23) is not less than 20 mm, and the distance between multiple groups of L-shaped stress-bearing steel plates (20) arranged side by side is not less than 20 mm.

5. The T-shaped steel tube recycled concrete prefabricated assembly pier column-foundation socket node according to claim 2 is characterized in that: The high-strength concrete UHPC (24) has a compressive strength of not less than 120 MPa and a tensile strength of not less than 10 MPa.

6. The T-shaped steel tube recycled concrete prefabricated assembly pier-foundation socket node according to claim 2, characterized in that: The socket depth of the pier body enlarged foot (23) is not less than 0.6 times the side length of the prefabricated T-shaped steel tube recycled concrete pier column (1), and the expansion width of the pier body enlarged foot (23) is not less than 0.2 times the side length of the prefabricated T-shaped steel tube recycled concrete pier column (1).

7. The T-shaped steel tube recycled concrete prefabricated assembly pier-foundation socket node according to claim 2 is characterized by: The inner diameters of the foundation pre-buried metal pipe (10) and the pier body pre-buried metal pipe (2) are at least 10 mm larger than the diameter of the screw rod (12) in the vertical reinforcement device (11), and the thickness is not less than 2 mm. The top surface of the foundation pre-buried metal pipe (10) protrudes from the bottom surface of the socket slot by a length of not less than 10 mm.

8. The T-shaped steel tube recycled concrete prefabricated assembly pier-foundation socket node according to claim 2 is characterized by: A 10-30 mm thick mortar layer (25) is provided between the bottom surface of the pier body enlarged foot (23) and the bottom surface of the socket of the recycled concrete foundation (7); in addition, a steel pipe pad (6) is placed between the nut (13) and the steel pipe reserved hole (4), and a foundation pad (15) is placed between the rod anchor end (14) and the foundation embedded metal pipe (10); the internal apertures of the steel pipe pad (6) and the foundation pad (15) are at least 2 mm larger than the diameter of the vertical reinforcement device (11).

9. The T-shaped steel tube recycled concrete prefabricated assembly pier-foundation socket node according to claim 2, characterized in that: The shear nails (22) on the inner and outer walls of the pier body T-shaped steel pipe (3) of the pier body enlarged foot (23) are divided into long shear nails and short shear nails.

10. A construction method for a T-shaped steel tube recycled concrete prefabricated assembly pier-foundation socket joint according to any one of claims 2 to 9, characterized in that: The following steps are involved: S1. Prefabricate the T-shaped steel tube recycled concrete pier column (1) in the factory, weld the pier body T-shaped steel tube (3) at the place where the steel tube has a variable cross-section, and reserve a steel tube reserved hole (4) for positioning the variable cross-section steel plate of the pier body T-shaped steel tube (3). The top surface of the pier body embedded metal tube (2) is welded and positioned at the lower part of the steel tube reserved hole (4) with the axis aligned. The steel tube stiffening rib (5) is welded and positioned at the inner wall surface of the pier body T-shaped steel tube (3) and the variable cross-section steel plate of the pier body enlarged foot (23). The pier body embedded metal pipe (2) and the steel pipe stiffening rib (5) are vertically fixed inside the pier body T-shaped steel pipe (3) at the corners of the bottom surface of the steel plate, and then the shear nails (22) are welded to the inner and outer wall surfaces of the pier body T-shaped steel pipe (3) on the side of the pier body enlarged foot (23) to form the pier body T-shaped steel pipe (3) as a whole, and recycled concrete is poured into the pier body T-shaped steel pipe (3), and the specimen is cured to complete the production of the prefabricated T-shaped steel pipe recycled concrete pier column (1); S2, processing the L-shaped longitudinal steel beam (17), L-shaped stress-bearing steel plate (20), horizontal connecting steel plate (18), vertical connecting steel plate (19) and anchoring steel plate (21) components of the horizontal pressure-bearing angle steel (16) in the factory, and connecting the L-shaped longitudinal steel beams (17) in parallel by welding the horizontal connecting steel plate (18) and the vertical connecting steel plate (19) in the middle of the beam body of the L-shaped longitudinal steel beam (17); then, respectively welding the L-shaped stress-bearing steel plate (20) and the anchoring steel plate (21) to one end of the parallel L-shaped longitudinal steel beams (17) to form a horizontal local stress-bearing steel skeleton, and completing the production of the horizontal pressure-bearing angle steel (16); S3, tying the foundation longitudinal steel bars (8) and foundation stirrups (9) of the recycled concrete foundation (7) on site, reserving a socket for placing the pier body enlarged foot (23), horizontal pressure-bearing angle steels (16) processed and manufactured in the factory are horizontally placed on the four sides of the socket, and the horizontal pressure-bearing angle steels (16) located inside the recycled concrete foundation (7) are connected to the foundation longitudinal steel bars (8) and the foundation stirrups (9) by welding to fix them, so that each load-bearing steel plate (13) is parallel to the four side surfaces of the socket, and a foundation embedded metal pipe (10) is vertically placed on the bottom surface of the socket, the upper end of the foundation embedded metal pipe (10) protrudes from the bottom surface of the socket of the recycled concrete foundation (7), and the lower end of the foundation embedded metal pipe (10) is flush with the recycled concrete foundation (7), supporting the formwork, pouring the recycled concrete, curing the components, removing the formwork, and completing the production of the recycled concrete foundation (7); S4, transport the prefabricated T-shaped steel tube recycled concrete pier column (1) to the construction site, lay a mortar layer (25) on the bottom surface of the socket of the recycled concrete foundation (7), insert the L-shaped load-bearing steel plate (20) parallel to the four sides of the pier body enlarged foot (23) through the surrounding horizontal pressure-bearing angle steels (16) into the socket, place the foundation pad (15) and the steel pipe pad (6) on the bottom of the foundation pre-buried metal pipe (10) and the upper surface of the steel pipe reserved hole (4) of the pier body enlarged foot (23), respectively, and pass the vertical reinforcement device (11) through the foundation pad (15), the foundation pre-buried metal pipe (10), the pier body pre-buried metal pipe (2), and the steel pipe reserved hole (4). The holes (4) and the steel pipe pad (6) are pre-tightened by the screw rod (12) and the nut (13) at the upper end of the vertical reinforcement device (11), and the horizontality and verticality of the prefabricated T-shaped steel pipe recycled concrete pier column (1) are adjusted at the same time, so that the placement of the prefabricated T-shaped steel pipe recycled concrete pier column (1) is completed, and high-strength concrete UHPC (24) is poured between the four sides of the pier body enlarged foot (23) and the four sides of the socket of the recycled concrete foundation (7), so that the pier body enlarged foot (23) and the recycled concrete foundation (7) are connected to form a whole, and the assembly work of the prefabricated T-shaped steel pipe recycled concrete pier column (1) and the recycled concrete foundation (7) is completed.

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