Composite pile column pier structure with built-in steel pipe and construction method

Abstract

The application discloses a composite pile column type pier structure with a built-in steel pipe and a construction method, and relates to the technical field of bridge construction. The composite pile column type pier structure comprises a pile foundation, pile foundation reinforcing steel bars, a first-stage prefabricated reinforcing cage connected with the top end of the pile foundation reinforcing steel bars through a reinforcing steel bar joint, a UHPC shell formed by pouring concrete and the first-stage prefabricated reinforcing cage, a conical bottom end of the UHPC shell, a conical steel plate wrapped outside the bottom end of the UHPC shell, a tie beam installed at the top end of the pile foundation, a tie beam built-in steel pipe and tie beam reserved reinforcing steel bars embedded in the tie beam, a column body built-in steel pipe embedded in the center of a pier column, the tie beam built-in steel pipe inserted into the bottom of the column body built-in steel pipe, a grouting sleeve installed at the bottom of the pier column, and the tie beam reserved reinforcing steel bars inserted into the grouting sleeve. The UHPC is used at the position of the pier mainly subjected to seawater scouring and corrosion, so that the damage of seawater to the pier is reduced, and the durability of the pier is improved. Meanwhile, the connection between the pile foundation and the pier is strengthened by using the grouting sleeve connection and the steel pipe nesting connection, so that the safety of the bridge is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge construction, and in particular to a composite pile-column bridge pier structure using built-in steel pipes and a construction method thereof. Background Art

[0002] With the acceleration of urbanization and the growing demand for transportation, the construction of large-scale projects such as cross-river and cross-sea bridges has become a crucial component of infrastructure development worldwide. Pile-column piers, a common structural form in these projects, provide crucial support for the bridges. However, pile-column piers are susceptible to factors such as seawater erosion, immersion, and atmospheric corrosion, often damaging their substructures and threatening the safety and service life of the bridges.

[0003] To address this issue, prefabricated bridge pier structures emerged. Their rapid installation and controlled quality have led to their widespread use in large-scale bridge construction. Prefabricated piers, by prefabricating components in factories and then assembling them on-site, significantly shorten the construction period and improve project efficiency. This structural form is not only applicable to general bridge construction but is also widely used in specialized projects such as river and sea crossings, providing strong support for the smooth progress of projects. However, despite their numerous advantages in engineering construction, prefabricated piers still present challenges in areas of the pier that are susceptible to erosion. This is particularly true at the junction of the pile foundation and the pier column. Due to the unique nature of the structure, sudden changes in stiffness are prone to occur, leading to damage to the pier.

[0004] Therefore, a protective measure is urgently needed to improve the anti-scouring ability of the bottom structure of the pier and extend the service life of the bridge. Summary of the Invention

[0005] The purpose of the present invention is to provide a composite pile-column bridge pier structure using internal steel pipes and a construction method to solve the problems existing in the above-mentioned prior art.

[0006] To achieve the above-mentioned object, the present invention provides the following solution: The present invention provides a composite pile-column bridge pier structure using an internal steel pipe, comprising:

[0007] A pile foundation includes pile foundation reinforcement, wherein the top of the pile foundation reinforcement is connected to a first section of a prefabricated reinforcement cage via a reinforcement joint; the first section of the prefabricated reinforcement cage is formed by pouring concrete and a UHPC shell; the bottom end of the UHPC shell is prefabricated into a cone shape, and the bottom end of the UHPC shell is covered with a cone-shaped steel plate; the UHPC shell is located on the riverbed;

[0008] The tie beam is installed at the top of the pile foundation; it is cast after being supported by the tie beam steel bar formwork; the tie beam internal steel pipe and the tie beam reserved steel bar are embedded in the tie beam;

[0009] The pier column is provided with a column body built-in steel pipe in the center, the bottom end of the column body built-in steel pipe is arranged outside the tie beam built-in steel pipe, and the tie beam built-in steel pipe extends into the bottom of the column body built-in steel pipe; the pier column bottom is provided with a grouting sleeve; the tie beam reserved steel bars extend into the grouting sleeve.

[0010] The pile foundation steel bars, the first section of the prefabricated steel cage, the UHPC shell and the tapered steel plate are prefabricated by the concrete.

[0011] The steel bar joints on the pile foundation steel bars and the first section of the prefabricated steel cage are distributed in a staggered manner and have a connection length of not less than 500 mm.

[0012] The pile foundation top end is fixedly provided with a PVC pipe, which is used for chiseling the pile head part after the pile foundation concrete pouring is completed.

[0013] The tie beam reserved steel bars are arranged in a circumferential symmetrical manner and are at least two, which are arranged around the tie beam built-in steel pipe; the tie beam built-in steel pipe and the tie beam reserved steel bars are arranged on the top of the pile foundation, and the tie beam reserved steel bars are welded with the steel cage on the top of the pile foundation; the top end of the tie beam built-in steel pipe extends out of the top plane of the tie beam.

[0014] A composite pile column type bridge pier construction method using a built-in steel pipe, comprising the following steps:

[0015] The UHPC shell and the prefabricated bridge pier are prefabricated; the UHPC shell and the first section of the pile foundation steel cage are prefabricated into an integral whole; the column body built-in steel pipe and the grouting sleeve are prefabricated with the concrete layer of the bridge pier;

[0016] The steel pipe pile and the steel casing are driven on site, the pile foundation is drilled to the design pile bottom elevation, after the drilling is completed, the pile foundation steel cage is slowly lowered;

[0017] The steel sleeve cofferdam is installed and the bottom is sealed and water is pumped out, and the prefabricated UHPC shell is lowered and installed;

[0018] The pile top is provided with a PVC pipe as an extension formwork before the pile foundation concrete is poured by connecting the UHPC shell bottom reserved steel joint with the pile foundation steel bar;

[0019] After the concrete is initially cured, the concrete at the pile head part is chiseled out, the formwork is installed and the tie beam steel bars are installed, the tie beam built-in steel pipe is pre-buried, the tie beam reserved steel bars are arranged and welded with the steel bars at the lower pile top and used for connecting the upper column bottom grouting sleeve, and after the installation is completed, the tie beam concrete is poured;

[0020] After the tie beam construction is completed, the prefabricated pier column is lowered and installed, the tie beam is connected by the grouting sleeve, the column body built-in steel pipe is positioned and nested with the tie beam built-in steel pipe, the pier column concrete is poured, and the construction is completed.

[0021] The UHPC shell is constrained by installing the steel clamp and supported on the steel casing by the steel clamp to bear the weight of the UHPC shell.

[0022] The present invention discloses the following technical effects: the present invention uses UHPC in the parts of the bridge piers that are mainly affected by seawater scouring and corrosion, which can reduce the damage of seawater to the bridge piers and improve the durability of the bridge piers; to avoid the stiffness difference between the pile foundation and the bridge pier caused by the partial use of UHPC, steel pipes are used at this connection to increase the cross-sectional stiffness of the column body, thereby reducing the excessive stiffness difference at the pile-column connection caused by the use of UHPC in the scouring-prone part of the pile top; at the same time, grouting sleeve connection and steel pipe nesting connection are used to strengthen the connection between the pile foundation and the bridge pier, thereby ensuring the safety of the bridge.

[0023] In addition, by combining UHPC with reinforced concrete structures, the bearing capacity of the pile foundation can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 This is a schematic diagram of the connection between UHPC and the lower pile foundation reinforcement cage;

[0026] Figure 2 Schematic diagram of the positioning and installation of the UHPC shell;

[0027] Figure 3 It is a three-dimensional schematic diagram of the splicing of tie beams and piers;

[0028] Figure 4 This is a schematic diagram of the removal of the pile head;

[0029] Figure 5 A three-dimensional schematic diagram of the pile head removal;

[0030] Figure 6 This is a schematic diagram of the pile foundation after the pile head is chiseled off;

[0031] Figure 7 This is a three-dimensional schematic diagram of the pile foundation after the pile head is chiseled off;

[0032] Figure 8 This is a schematic diagram of the connection between pile foundation and tie beam;

[0033] Figure 9 It is a three-dimensional schematic diagram of the connection between pile foundation and tie beam;

[0034] Figure 10A schematic diagram for splicing a pier column;

[0035] Figure 11 A three-dimensional schematic diagram for splicing a pier column;

[0036] Figure 12 A Figure 10 A middle I-I cross-sectional view;

[0037] Figure 13 A Figure 10 A middle II-II cross-sectional view;

[0038] 1, UHPC shell; 2, concrete; 3, pile foundation reinforcement; 4, first precast reinforcement cage; 5, conical steel plate; 6, reinforcement joint; 7, tie beam embedded steel pipe; 8, column embedded steel pipe; 9, tie beam; 10, tie beam reinforcement; 11, grouting sleeve; 12, PVC pipe; 13, pier column; 14, pile foundation; 15, tie beam reserved reinforcement; 16, steel pipe pile; 17, steel sleeve box; 18, steel hoop. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0040] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0041] As Figures 1-13 shown, the present application provides a composite pile column type pier structure with embedded steel pipe, which comprises a pile foundation 14, a pile foundation reinforcement 3, a first precast reinforcement cage 4 connected to the top end of the pile foundation reinforcement 3 through a reinforcement joint 6, a UHPC shell 1 formed by pouring the first precast reinforcement cage 4 and the concrete 2, a conical bottom end of the UHPC shell 1, and a conical steel plate 5 wrapped outside the bottom end of the UHPC shell 1.

[0042] A tie beam 9 installed at the top end of the pile foundation 14, formed by post-pouring formwork with tie beam reinforcement 10, and having a tie beam embedded steel pipe 7 and a tie beam reserved reinforcement 15 pre-embedded inside the tie beam 9;

[0043] A pier column 13 having a column embedded steel pipe 8 pre-embedded in the center of the pier column 13, the bottom end of the column embedded steel pipe 8 arranged outside the tie beam embedded steel pipe 7, and the tie beam embedded steel pipe 7 extending into the bottom of the column embedded steel pipe 8; the pier column 13 having a grouting sleeve 11 installed at the bottom of the pier column 13; and the tie beam reserved reinforcement 15 extending into the grouting sleeve 11.

[0044] The pile foundation steel bars 3, the first section prefabricated steel cage 4, the UHPC shell 1 and the tapered steel plate 5 are prefabricated by concrete into the pile foundation 14.

[0045] The steel joints 6 on the pile foundation steel bars 3 and the first section prefabricated steel cage 4 are distributed in staggered positions and have a connection length of not less than 500 mm.

[0046] The PVC pipe 12 is fixedly installed at the top end of the pile foundation 14 and is used for chiseling the pile head part after the concrete pouring of the pile foundation 14 is completed.

[0047] The tie beam reserved steel bars 15 are arranged in a circumferential symmetry with at least two around the tie beam built-in steel pipe 7, the tie beam built-in steel pipe 7 and the tie beam reserved steel bars 15 are all arranged at the top of the pile foundation 14, the tie beam reserved steel bars 15 are all welded with the steel cage at the top of the pile foundation 14, and the top end of the tie beam built-in steel pipe 7 extends out of the top plane of the tie beam 9.

[0048] The composite pile column type bridge pier construction method with the built-in steel pipe comprises the following steps:

[0049] The UHPC shell and the bridge pier are prefabricated, the UHPC shell and the first section pile foundation steel cage are prefabricated into an integral whole, and the column built-in steel pipe and the grouting sleeve are all prefabricated with the concrete layer of the bridge pier;

[0050] The steel pipe pile and the steel casing are driven into the field, the pile foundation is drilled to the design pile bottom elevation, after the drilling is completed, the pile foundation steel cage is slowly lowered,

[0051] The steel sleeve cofferdam is installed and the bottom sealing and water pumping are performed, and the prefabricated UHPC shell is lowered and installed.

[0052] The steel joints reserved at the bottom of the UHPC shell are connected with the pile foundation steel bars, the PVC pipe is installed at the top of the pile as an extension formwork before the pile foundation concrete is poured.

[0053] After the concrete is initially cured, the concrete at the pile head part is chiseled out, the tie beam steel bars are installed, the tie beam built-in steel pipe is pre-buried, the tie beam reserved steel bars are arranged and welded with the steel bars at the lower pile top and used for connecting the upper column bottom grouting sleeve, and the tie beam concrete is poured after the installation is completed.

[0054] After the tie beam construction is completed, the prefabricated pier column is lowered and installed, the tie beam is connected by using the grouting sleeve, the column built-in steel pipe is positioned and nested with the tie beam pre-buried steel pipe, the pier column concrete is poured, and the construction is completed.

[0055] The UHPC shell 1 is constrained by the installed steel hoop 18 and supported on the steel sleeve 17 by the steel hoop 18 to bear the weight of the UHPC shell 1.

[0056] In an embodiment of the present application, the steel joints 6 are weak links when the steel bars bear force, should be arranged in staggered positions and have a connection length of not less than 500 mm.

[0057] In one embodiment of the present application, the height of the column built-in steel pipe 9 is equal to the height of the pier.

[0058] In one embodiment of the present application, the top of the tie beam built-in steel pipe 7 is higher than the top of the tie beam 9, and the diameter of the tie beam built-in steel pipe 7 is smaller than the diameter of the column built-in steel pipe 8.

[0059] In one embodiment of the present application, as shown in Figure 5 The tie beam reserved steel bars 15 can be provided with 2-8 bars, and the number of the grouting sleeves 11 is consistent with the number of the tie beam reserved steel bars 15.

[0060] In one embodiment of the present application, the conical steel plate 5 is used for pouring the pile foundation concrete, and the bottom concrete containing impurities can smoothly pass through the bottom of the UHPC shell 1, facilitating the removal of the concrete at the pile head in the later stage.

[0061] In one embodiment of the present application, the steel hoop 18 is formed by coupling the left and right half hoops, and the left and right half hoops are both in the shape of a semicircular ring, and the two ends of the semicircular ring are bent outward to form an installation ear, and the left and right half hoops are connected by bolts.

[0062] In one embodiment of the present application, the UHPC shell 1 is used as a protective layer for the easily eroded part of the pier, effectively reducing the damage of seawater erosion, soaking and atmospheric corrosion to the pier, and significantly prolonging the service life of the pier.

[0063] Further, the column built-in steel pipe 8 increases the column section stiffness without using UHPC, and the pile column is effectively connected through the nesting of the column built-in steel pipe 8 and the tie beam reserved steel pipe 7, avoiding the damage of the pile foundation and the pier connection caused by the sudden change of stiffness.

[0064] In one embodiment of the present application, during construction, the UHPC shell 1 and the pier column concrete layer are both prefabricated sections, and the rest are cast-in-place sections; the pier column concrete layer is connected with the tie beam reserved steel bars 15 through the grouting sleeves 11, and the column built-in steel pipe 8 is connected with the tie beam built-in steel pipe 7, so as to achieve the effect of effective connection of the pile column; wherein the steel sleeve box 17 cofferdam construction is adopted for the construction of the pile column connection, the UHPC shell 1 is prefabricated in the factory, the steel hoop 18 is used to constrain the UHPC shell during the installation of the UHPC shell 1, and the UHPC shell 1 is placed in the steel sleeve box 18, so as to support the weight of the prefabricated UHPC shell 1.

[0065] In the description of the present application, it needs to be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0066] The above-described embodiments are only to describe the preferred modes of the present application, and not to limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A composite pile-column bridge pier structure using built-in steel pipes, characterized in that: include: A pile foundation (14) comprises pile foundation steel bars (3), the top end of the pile foundation steel bars (3) being connected to a first section prefabricated steel cage (4) via a steel bar joint (6); the first section prefabricated steel cage (4) being formed by pouring concrete (2) and a UHPC shell (1); the bottom end of the UHPC shell (1) being prefabricated into a cone, and the bottom end of the UHPC shell (1) being covered with a cone-shaped steel plate (5); the UHPC shell (1) being located at a riverbed; A tie beam (9), the tie beam (9) being installed at the top of the pile foundation (14); being cast and formed by supporting a formwork with tie beam reinforcement bars (10); and having a tie beam built-in steel pipe (7) and tie beam reserved reinforcement bars (15) pre-embedded in the tie beam (9); A pier column (13), wherein a column body built-in steel pipe (8) is pre-buried in the center of the pier column (13), the bottom end of the column body built-in steel pipe (8) is arranged outside the tie beam built-in steel pipe (7), and the tie beam built-in steel pipe (7) extends into the bottom of the column body built-in steel pipe (8); a grouting sleeve (11) is installed at the bottom of the pier column (13); and the reserved steel bars (15) of the tie beam extend into the grouting sleeve (11); The steel bar joints (6) on the pile foundation steel bars (3) and the first section prefabricated steel bar cage (4) are staggered and have a connection length of not less than 500 mm; A PVC pipe (12) is fixedly installed on the top of the pile foundation (14), and the PVC pipe (12) is used to chisel out the pile head after the concrete pouring of the pile foundation (14) is completed.

2. The composite pile-column bridge pier structure with built-in steel pipes according to claim 1, characterized in that: The pile foundation reinforcement (3), the first section prefabricated reinforcement cage (4), the UHPC shell (1) and the conical steel plate (5) are prefabricated into the pile foundation (14) through the concrete.

3. The composite pile-column bridge pier structure with built-in steel pipes according to claim 1, characterized in that: The tie beam reserved steel bars (15) are centered on the tie beam built-in steel pipe (7), and at least two are symmetrically arranged in the circumferential direction; the tie beam built-in steel pipe (7) and the tie beam reserved steel bars (15) are both placed on the top of the pile foundation (14), and the tie beam reserved steel bars (15) are both welded to the steel cage on the top of the pile foundation (14); the top end of the tie beam built-in steel pipe (7) extends out of the top plane of the tie beam (9).

4. A construction method for a composite pile-column bridge pier using an inner steel pipe, comprising the composite pile-column bridge pier structure using an inner steel pipe according to claim 1, characterized in that: The following steps are involved: Prefabrication of the UHPC shell and piers; the UHPC shell and the first section of the pile foundation reinforcement cage are prefabricated as a whole; the steel pipes embedded in the column and the grouting sleeves are prefabricated together with the concrete layer of the pier; The steel pipe piles and steel casing are driven into the site, and the pile foundation is drilled to the designed pile bottom elevation. After the drilling is completed, the pile foundation reinforcement cage is slowly lowered; Install the steel box cofferdam, seal the bottom and pump out the water, and then lower and install the prefabricated UHPC shell; The steel bar joints reserved at the bottom of the UHPC shell are connected to the pile foundation steel bars. Before pouring the pile foundation concrete, a PVC pipe is installed on the top of the pile as an extension formwork; After the concrete has initially set, the concrete at the pile head is chiseled out, the formwork is supported and the tie beam reinforcement is installed. At the same time, the tie beam internal steel pipe is embedded, the tie beam reserved reinforcement is set and welded to the reinforcement at the lower pile top, and used to connect to the grouting sleeve at the upper column bottom. After the installation is completed, the tie beam concrete is poured; After the tie beam construction is completed, the prefabricated pier columns are lowered and installed, the tie beams are connected with grouting sleeves, the built-in steel pipes of the nested column body and the pre-buried steel pipes of the tie beam are positioned, and the pier column concrete is poured to complete the construction.

5. The construction method of composite pile-column bridge pier using internal steel pipes according to claim 4, characterized in that: The UHPC shell (1) is constrained by installing a steel hoop (18), and the steel hoop (18) is supported on the steel casing (17) to bear the weight of the UHPC shell (1).

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