Connecting structure of fabricated bridge pier column and bearing platform and construction method

Abstract

The invention relates to the technical field of bridge engineering construction, aims to solve the problems that in the prior art, an embedded steel bar and a bearing platform formwork conflict in installation, the lap joint length of the steel bar is difficult to guarantee, and the steel bar and a sleeve are difficult to align, so that connection is not solid, and the construction efficiency is low, and provides a connecting structure of an assembly type bridge pier column and a bearing platform and a construction method. The structure comprises a prefabricated bearing platform, a pier column, three types of reinforcing steel bars, a high-strength threaded sleeve and pouring joint concrete, efficient and stable connection is achieved through the four steps of bending reinforcing steel bar presetting, assembly standardization, double fixing and concrete packaging, and construction is divided into four steps, and the structure is suitable for construction of various assembly type bridges. The method has the advantages that the embedded steel bars and the bearing platform formwork are installed in a matched mode, the lap joint length of the steel bars is convenient to guarantee, the steel bars and the sleeves are easy to align, and connection stability and high construction efficiency are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering construction technology, and more specifically, to a connection structure and construction method for prefabricated bridge pier columns and abutments. Background Technology

[0002] In the current construction of prefabricated bridge piers, the connection quality between the pier column and the abutment directly determines the stability and load-bearing capacity of the entire pier structure, and is one of the key links in bridge engineering construction. In the existing technology, the pier column and the abutment are usually connected by lapping the steel bars and then pouring concrete. In the prefabrication stage of the abutment, it is necessary to pre-embed connecting steel bars to achieve effective lapping with the subsequent pier column steel bars.

[0003] However, traditional methods of pre-embedded rebar have several technical drawbacks: First, to ensure the lap length with the subsequent pier column rebar, the pre-embedded rebar needs to extend a certain length beyond the foundation, which seriously affects the installation and removal of the foundation's inner formwork, increasing the difficulty of formwork installation, reducing construction efficiency, and potentially causing formwork deformation or rebar displacement due to interference between the formwork and the rebar. Second, some construction schemes shorten the extension length of the pre-embedded rebar to avoid affecting formwork installation, but this fails to meet the lap length requirements of the specifications, resulting in a decrease in the mechanical properties of the connection joint and posing a structural safety hazard. Third, existing rebar-sleeve connections often use the method of inserting the entire rebar into the sleeve. During the pier column placement process, the alignment of the rebar and sleeve is difficult, easily leading to incomplete connections and further affecting the stability of the connection joint.

[0004] Therefore, how to design a prefabricated bridge pier column and abutment connection structure and construction method that can avoid conflicts between the pre-embedded steel bars and the abutment formwork, ensure the lap length of the steel bars and the stability of the connection nodes, and improve construction efficiency has become an urgent problem to be solved in the field of bridge engineering construction. Summary of the Invention

[0005] The present invention aims to provide a connection structure and construction method for prefabricated bridge pier columns and abutments, in order to solve the problems of conflict between pre-embedded steel bars and abutment formwork installation, difficulty in ensuring the lap length of steel bars, difficulty in aligning steel bars and sleeves leading to poor connection and low construction efficiency in the prior art.

[0006] The embodiments of the present invention are implemented as follows: This invention provides a prefabricated bridge pier column and abutment connection structure, which includes a prefabricated abutment, pier column, first reinforcing bar, second reinforcing bar, third reinforcing bar, sleeve and pouring joint concrete; The aforementioned third reinforcing bar is embedded in the aforementioned precast foundation. The aforementioned third reinforcing bar includes a first straight section and a first hook section. The aforementioned first hook section is bent at a preset angle, and the bent first hook section does not exceed the installation range of the aforementioned precast foundation inner mold template. The aforementioned first straight section of the aforementioned third reinforcing bar is fixedly connected to the aforementioned precast foundation's reinforcing bar. The aforementioned sleeve is a high-strength threaded sleeve. The aforementioned first reinforcing bar includes a second straight section and a second hook section. One end of the second straight section of the aforementioned first reinforcing bar is machined with external threads. The threaded end of the aforementioned first reinforcing bar is screwed into the aforementioned sleeve, and the embedment depth is half of the total depth of the aforementioned sleeve. The second hook section of the aforementioned first reinforcing bar is fixedly connected to the stressed reinforcing bar of the aforementioned pier column. The other end of the aforementioned sleeve corresponds to the connection surface between the aforementioned pier column and the aforementioned precast foundation, and the end of the aforementioned sleeve is flush with the connection surface of the aforementioned pier column. The second reinforcing bar is a straight reinforcing bar with external threads at one end. The threaded end of the second reinforcing bar is screwed into the sleeve, which is not occupied by the first reinforcing bar. After the first hook section of the third reinforcing bar is straightened, its hook end fits and is fixedly connected to the non-threaded end of the second reinforcing bar. The concrete for the joint is poured into the gap between the pier and the precast foundation and wraps around the lap joint of the second and third reinforcing bars and the sleeve.

[0007] The prefabricated bridge pier column and foundation connection structure disclosed in this implementation scheme avoids installation conflicts between the reinforcing bars and formwork during the construction of the precast foundation by using the pre-bent third reinforcing bar. Through the equally spaced threaded connection of "the first reinforcing bar - the sleeve - the second reinforcing bar" and the fixed lap joint of the second reinforcing bar and the straightened third reinforcing bar, a double stable connection system is formed. This ensures that the lap length of the reinforcing bars meets the design specifications and improves the mechanical performance and structural stability of the connection node. At the same time, the standardized assembly design reduces the construction difficulty and operational errors. Combined with the wrapped concrete pouring joint, the connection reliability is further enhanced. This achieves an efficient and stable connection between the prefabricated bridge pier column and foundation. As a result, this prefabricated bridge pier column and foundation connection structure has the beneficial effects of fitting the pre-embedded reinforcing bars with the foundation formwork, ensuring the lap length of the reinforcing bars, simplifying the alignment of the reinforcing bars and sleeves, ensuring connection stability, and high construction efficiency.

[0008] Optionally, the specifications of the external threads of the first reinforcing bar and the external threads of the second reinforcing bar are matched with the specifications of the internal threads of the sleeve.

[0009] This configuration ensures the tightness and reliability of the threaded connection between the first reinforcing bar, the second reinforcing bar, and the sleeve, preventing loosening and guaranteeing the structural stability of the connection node.

[0010] Optionally, the first hook section of the second reinforcing bar and the third reinforcing bar are fixed by binding wire, and the spacing between binding points is not greater than a preset distance.

[0011] This configuration ensures the tightness and uniform stress distribution of the lap joint between the second and third reinforcing bars and the first hook section, preventing local loosening or stress concentration and guaranteeing the stability of the connection node.

[0012] In one embodiment of this invention, a construction method for prefabricated bridge piers and caps is also provided, comprising the following steps: Step 1: Precast foundation construction. Process the third reinforcing bar, bending the first hook section of the third reinforcing bar at a preset angle; erect the foundation formwork, tie the foundation reinforcing bars, and fix the first straight section of the third reinforcing bar to the foundation reinforcing bars, ensuring that the bent first hook section does not contact the foundation inner formwork; pour the foundation concrete and cure it to the design strength, then remove the foundation formwork; chisel away the surface concrete at the connection surface of the precast foundation, and straighten the first hook section of the third reinforcing bar. Step two: Precast pier construction. First, process the first reinforcing bar by machining an external thread at one end of the second straight section of the first reinforcing bar. Select a high-strength sleeve that matches the thread of the first reinforcing bar and screw the threaded end of the first reinforcing bar into the sleeve to form a combination of the first reinforcing bar and the sleeve. Erect the pier formwork, tie the pier's reinforcing bars, and fix the second hook section of the first reinforcing bar (the combination of the first reinforcing bar and the sleeve) to the pier's reinforcing bars, ensuring that the sleeve end is flush with the pier's connection surface. After pouring the pier concrete and curing it to the design strength, remove the pier formwork. Step 3: Positioning and connecting the pier column with the reinforcing bars. Hoist the precast pier column above the precast foundation and adjust its position so that the sleeve at the bottom of the pier column corresponds to the position of the third reinforcing bar on the connecting surface of the precast foundation. Lower the pier column until its bottom contacts the connecting surface of the precast foundation. Process the second reinforcing bar by machining an external thread on one end of the second reinforcing bar. Screw the threaded end of the second reinforcing bar into the sleeve so that the non-threaded end of the second reinforcing bar fits against the hook end of the third reinforcing bar. Secure the second reinforcing bar and the first hook section of the third reinforcing bar by binding. Step four: Concrete pouring for the joint. Clean the gap between the above-mentioned pier and the above-mentioned precast foundation, set up the formwork and seal it, pour high-strength concrete for the joint and vibrate it to make it compact. Cure the above-mentioned concrete for the joint until its strength reaches the design strength, and then complete the connection.

[0013] Optionally: In the construction of the precast foundation, the preset bending angle of the first hook segment of the third reinforcing bar is 90°.

[0014] With this setting, the preset bending angle of 90° can accurately adapt to the conventional installation space requirements of the inner formwork of the foundation, reliably avoiding interference between the first hook section of the third rebar and the formwork. This simplifies the arrangement of rebar and formwork in the construction of the precast foundation, and ensures effective lap joint with the second rebar after straightening, taking into account both construction convenience and the reliability of the connection node.

[0015] Optionally, during the prefabrication of the pier column, the threaded end of the first reinforcing bar is screwed into the sleeve to a depth that is half the total depth of the sleeve.

[0016] With this setting, the embedment depth setting enables the first reinforcing bar and the subsequently connected second reinforcing bar to achieve an equally divided threaded connection within the sleeve, ensuring balanced force transmission between the two and forming a reliable mating fit. At the same time, the standardized connection length design reduces on-site assembly errors, further strengthens the connection stability of the reinforcing bar and sleeve assembly, and ensures the mechanical performance of the connection node.

[0017] Optionally: During the pier placement and reinforcement connection construction, the length of the external thread of the second reinforcement is the same as the length of the external thread of the first reinforcement.

[0018] This length setting ensures that the second reinforcing bar and the first reinforcing bar achieve equal-length thread engagement within the sleeve, resulting in uniform force transmission and precise fit between them. This avoids uneven load distribution or connection gaps caused by inconsistent thread lengths, while also simplifying the specification matching design of the reinforcing bar and the sleeve and reducing the difficulty of construction selection.

[0019] Optionally: In the binding step of the pier column positioning and connection with the reinforcing bars, the binding overlap area of ​​the first hook section of the second reinforcing bar and the third reinforcing bar is determined according to the design specifications, and double-strand binding wire is used for cross binding during binding, with binding points evenly distributed along the lap length.

[0020] This setup ensures that the lap connection between the second and third reinforcing bars meets the design specifications. The cross binding of the double-strand binding wires with evenly distributed binding points further enhances the tightness and integrity of the lap joint, preventing local loosening or uneven stress, effectively transferring stress, and ensuring the mechanical stability and construction quality of the connection node.

[0021] Optionally: After the external threads of the first and second reinforcing bars are machined, the thread accuracy is tested to ensure that the thread profile is complete and undamaged, and that the clearance between the thread and the internal thread of the sleeve meets the design requirements.

[0022] With this setup, by performing precision testing on the external threads of the first and second reinforcing bars, thread profile defects and fit clearance deviations can be detected in advance, ensuring that the threaded connection between the reinforcing bars and the sleeve is tight and the force is transmitted evenly, thus avoiding loosening of the connection or decline in mechanical properties due to thread quality problems.

[0023] Optionally, the preset bending angle of the first hook segment of the third reinforcing bar is determined based on the thickness of the precast foundation inner formwork.

[0024] With this setting, the bending angle can be flexibly adapted to the precast foundation inner formwork of different thicknesses, ensuring that the first hook section of the third reinforcing bar never exceeds the formwork installation range, fundamentally avoiding installation interference between the reinforcing bar and the formwork, while ensuring effective lap joint between the first hook section and the second reinforcing bar after straightening, taking into account both construction adaptability and connection reliability.

[0025] Optionally: In the step of removing the surface concrete during the construction of the precast foundation, the removal depth is determined by completely exposing the first hook section of the third reinforcing bar, and the surface of the first hook section of the third reinforcing bar is derusted after removal.

[0026] This design ensures that the first hook section of the third reinforcing bar can be straightened smoothly and accurately overlapped with the second reinforcing bar. Furthermore, the rust removal process removes rust and impurities from the surface of the first hook section, preventing rust from affecting the reliability of the rebar lap joint and the transfer of mechanical properties, thus further guaranteeing the structural stability of the connection node.

[0027] In summary, the prefabricated bridge pier column and foundation connection structure and construction method disclosed in this invention have the beneficial effects of well-fitting pre-embedded steel bars with foundation formwork, easy guarantee of steel bar lap length, simple alignment of steel bars and sleeves, ensuring connection stability and high construction efficiency. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the connection structure between the prefabricated bridge pier column and the abutment in an embodiment of the present invention; Figure 2 This is an embodiment of the present invention. Figure 1 Enlarged view of point A in the middle; Figure 3This is a top view of a prefabricated bridge pier column and foundation connection structure in an embodiment of the present invention; Figure 4 This is a schematic diagram of the connection structure of the first reinforcing bar, the second reinforcing bar, the third reinforcing bar and the sleeve in an embodiment of the present invention.

[0030] Icons: 1-Precast foundation, 2-Pier column, 3-First reinforcing bar, 4-Second reinforcing bar, 5-Third reinforcing bar, 6-Sleeve, 7-Pouring joint concrete, 8-First straight section, 9-First hook section, 10-Second straight section, 11-Second hook section. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0033] Example 1 See Figure 1 , Figure 2 , Figure 3 and Figure 4 This embodiment proposes a prefabricated bridge pier column and abutment connection structure, including a prefabricated abutment 1, pier column 2, first reinforcing bar 3, second reinforcing bar 4, third reinforcing bar 5, sleeve 6, and pouring joint concrete 7. The third reinforcing bar 5 is embedded in the precast foundation 1. The third reinforcing bar 5 includes a first straight section 8 and a first hook section 9. The first hook section 9 is bent at a preset angle and the bent first hook section 9 does not exceed the installation range of the inner mold template of the precast foundation 1. The first straight section 8 of the third reinforcing bar 5 is fixedly connected to the stressed reinforcing bar of the precast foundation 1. The sleeve 6 is a high-strength threaded sleeve. The first reinforcing bar 3 includes a second straight section 10 and a second hook section 11. One end of the second straight section 10 of the first reinforcing bar 3 is machined with external threads. The threaded end of the first reinforcing bar 3 is screwed into the sleeve 6, and the embedment depth is half of the total depth of the sleeve 6. The second hook section 11 of the first reinforcing bar 3 is fixedly connected to the stressed reinforcing bar of the pier column 2. The other end of the sleeve 6 corresponds to the connection surface between the pier column 2 and the precast foundation 1, and the end of the sleeve 6 is flush with the connection surface of the pier column 2. The second reinforcing bar 4 is a straight reinforcing bar with external threads at one end. The threaded end of the second reinforcing bar 4 is screwed into the sleeve 6, which is not occupied by the first reinforcing bar 3. After the first hook section 9 of the third reinforcing bar 5 is straightened, its hook end fits and is fixedly connected to the non-threaded end of the second reinforcing bar 4. The joint concrete 7 is poured into the gap between the pier column 2 and the precast foundation 1 and wraps the lap joint of the second steel bar 4 and the third steel bar 5 as well as the sleeve 6.

[0034] The prefabricated bridge pier column and foundation connection structure disclosed in this implementation plan avoids installation conflicts between the reinforcing bars and the formwork during the construction of the prefabricated foundation 1 by using a pre-bent third reinforcing bar 5. Through the equal-division threaded connection of "first reinforcing bar 3-sleeve 6-second reinforcing bar 4" and the fixed lap joint of the second reinforcing bar 4 and the straightened third reinforcing bar 5, a double stable connection system is formed. This ensures that the lap length of the reinforcing bars meets the design specifications and improves the mechanical performance and structural stability of the connection node. At the same time, the standardized component design reduces the construction difficulty and operational errors. Combined with the wrapped joint concrete 7, the connection reliability is further enhanced, realizing an efficient and stable connection between the prefabricated bridge pier column 2 and the foundation. Thus, this prefabricated bridge pier column and foundation connection structure has the beneficial effects of fitting the pre-embedded reinforcing bars with the foundation formwork, ensuring the lap length of the reinforcing bars, simplifying the alignment of the reinforcing bars and sleeve 6, ensuring connection stability, and high construction efficiency.

[0035] See Figure 1 , Figure 2 , Figure 3 and Figure 4 The specifications of the external threads of the first reinforcing bar 3 and the second reinforcing bar 4 are matched with the specifications of the internal threads of the sleeve 6. This ensures the tightness and reliability of the threaded connection between the first reinforcing bar 3, the second reinforcing bar 4 and the sleeve 6, avoids loosening of the connection and ensures the structural stability of the connection node.

[0036] The first hook section 9 of the second reinforcing bar 4 and the third reinforcing bar 5 are fixed by binding wire. The spacing between binding points is not greater than the preset distance. This ensures the tightness and uniform stress distribution of the lap connection between the first hook section 9 of the second reinforcing bar 4 and the third reinforcing bar 5, avoids local loosening or stress concentration, and ensures the stability of the connection node.

[0037] See Figure 1 , Figure 2 , Figure 3 and Figure 4 In one embodiment of this invention, a construction method for prefabricated bridge piers and caps is also provided, comprising the following steps: Step 1: Construction of precast foundation 1. Process the third reinforcing bar 5 and bend the first hook section 9 of the third reinforcing bar 5 at a preset angle. Erect the foundation formwork, tie the foundation reinforcement, and fix the first straight section 8 of the third reinforcing bar 5 to the foundation reinforcement, ensuring that the bent first hook section 9 does not contact the inner formwork of the foundation. After pouring the foundation concrete and curing it to the design strength, remove the foundation formwork. Remove the surface concrete at the connection surface of the precast foundation 1 and straighten the first hook section 9 of the third reinforcing bar 5. Step 2: Precast construction of pier column 2. Process the first reinforcing bar 3 and process external threads at one end of the second straight section 10 of the first reinforcing bar 3. Select a high-strength sleeve 6 that matches the thread of the first reinforcing bar 3 and screw the threaded end of the first reinforcing bar 3 into the sleeve 6 to form a combination of the first reinforcing bar 3 and the sleeve 6. Erect the formwork of pier column 2, tie the reinforcing bars of pier column 2, and fix the second hook section 11 of the first reinforcing bar 3 to the reinforcing bars of pier column 2, ensuring that the end of the sleeve 6 is flush with the connection surface of pier column 2. After pouring concrete for pier column 2 and curing it to the design strength, remove the formwork of pier column 2. Step 3: Positioning and connecting the pier column 2 with the reinforcing bars. Hoist the precast pier column 2 above the precast bearing platform 1 and adjust its position so that the sleeve 6 at the bottom of the pier column 2 corresponds to the position of the third reinforcing bar 5 on the connecting surface of the precast bearing platform 1. Lower the pier column 2 until its bottom contacts the connecting surface of the precast bearing platform 1. Process the second reinforcing bar 4. Process an external thread at one end of the second reinforcing bar 4 and screw the threaded end of the second reinforcing bar 4 into the sleeve 6 so that the non-threaded end of the second reinforcing bar 4 fits against the hook end of the third reinforcing bar 5. Secure the second reinforcing bar 4 and the first hook section 9 of the third reinforcing bar 5 by binding. Step 4: Construction of the joint concrete 7. Clean the gap between the pier column 2 and the precast foundation 1, set up the formwork and seal it, pour the high-strength joint concrete 7 and vibrate it to make it dense, cure the joint concrete 7, and complete the connection after its strength reaches the design strength.

[0038] See Figure 1 , Figure 2 , Figure 3 and Figure 4 In the construction of the precast foundation 1, the preset bending angle of the first hook section 9 of the third reinforcing bar 5 is 90°. This preset bending angle of 90° can accurately adapt to the conventional installation space requirements of the inner formwork of the foundation, reliably avoid interference between the first hook section 9 of the third reinforcing bar 5 and the formwork. This simplifies the arrangement of reinforcing bars and formwork in the construction of the precast foundation 1, and ensures effective lap joint with the second reinforcing bar 4 after straightening, thus taking into account both construction convenience and lap joint reliability of the connection node.

[0039] During the prefabrication of pier column 2, the threaded end of the first reinforcing bar 3 is screwed into the sleeve 6 to a depth of half the total depth of the sleeve 6. This embedment depth setting enables the first reinforcing bar 3 and the subsequently connected second reinforcing bar 4 to achieve a threaded connection of equal length within the sleeve 6, ensuring balanced force transmission between the two and forming a reliable mating fit. At the same time, the standardized connection length design reduces on-site assembly errors, further strengthens the connection stability of the combination of reinforcing bar and sleeve 6, and ensures the mechanical performance of the connection node.

[0040] See Figure 1 , Figure 2 , Figure 3 and Figure 4 During the installation and connection of the pier column 2 with the reinforcing bars, the length of the external thread of the second reinforcing bar 4 is the same as the length of the external thread of the first reinforcing bar 3. This length setting can ensure that the second reinforcing bar 4 and the first reinforcing bar 3 achieve equal length thread engagement in the sleeve 6, so that the force is evenly transmitted and the connection is precisely fitted, avoiding the force imbalance or connection gap caused by inconsistent thread lengths. At the same time, it simplifies the specification matching design of the reinforcing bar and the sleeve 6 and reduces the difficulty of construction selection.

[0041] In the binding step of the pier column 2 in place and connected to the reinforcing bars, the overlapping area of ​​the binding of the first hook section 9 of the second reinforcing bar 4 and the third reinforcing bar 5 is determined according to the design specifications. When binding, double-strand binding wire is used for cross binding, and the binding points are evenly distributed along the lap length. This setting can ensure that the lap connection of the first hook section 9 of the second reinforcing bar 4 and the third reinforcing bar 5 meets the design specifications. The cross binding of double-strand binding wire with evenly distributed binding points can further improve the connection tightness and integrity of the lap joint, avoid local loosening or uneven stress, effectively transfer stress, and ensure the mechanical stability and construction quality of the connection node.

[0042] See Figure 1 , Figure 2 , Figure 3 and Figure 4 After the external threads of the first reinforcing bar 3 and the second reinforcing bar 4 are processed, the thread accuracy is tested to ensure that the thread profile is complete and undamaged, and that the fit clearance with the internal thread of the sleeve 6 meets the design requirements. By conducting accuracy testing on the external threads of the first reinforcing bar 3 and the second reinforcing bar 4, thread profile defects and fit clearance deviations can be identified in advance, ensuring that the threaded connection between the reinforcing bar and the sleeve 6 is tight and the force is transmitted evenly, avoiding loosening of the connection or degradation of mechanical properties due to thread quality problems.

[0043] The preset bending angle of the first hook section 9 of the third reinforcing bar 5 is determined according to the thickness of the inner formwork of the precast foundation 1. This bending angle setting can achieve flexible adaptation with the inner formwork of the precast foundation 1 of different thicknesses, ensuring that the first hook section 9 of the third reinforcing bar 5 never exceeds the installation range of the formwork, fundamentally avoiding installation interference between the reinforcing bar and the formwork, while ensuring effective lap joint between the first hook section 9 and the second reinforcing bar 4 after straightening, taking into account both construction adaptability and connection reliability.

[0044] In the process of removing the surface concrete during the construction of the precast foundation 1, the removal depth is determined by fully exposing the first hook section 9 of the third reinforcing bar 5. After removal, the surface of the first hook section 9 of the third reinforcing bar 5 is derusted. This ensures that the first hook section 9 of the third reinforcing bar 5 can be straightened smoothly and accurately overlapped with the second reinforcing bar 4. The derusting process removes rust and impurities from the surface of the first hook section 9, preventing rust from affecting the reliability of the rebar lap connection and the transfer of mechanical properties, and further ensuring the structural stability of the connection node.

[0045] Example 2 See Figure 1 , Figure 2 , Figure 3 and Figure 4 Based on Example 1, this example further optimizes the construction method of the bridge piers and abutments as follows: The third reinforcing bar 5 and the precast pier 1: The third reinforcing bar 5 is a connecting reinforcing bar pre-embedded in the precast pier 1, with a total length of 846mm, of which the first straight section 8 is 670mm long and the first hook section 9 is 176mm long. Before the precast pier 1 is poured, the first hook section 9 (i.e., the lap part) of the third reinforcing bar 5 is pre-bent (the bending angle is determined according to the thickness of the inner formwork of the pier, usually 90°, to ensure that the first hook section 9 after bending does not exceed the installation range of the inner formwork of the pier). The first straight section 8 (non-lap part) of the third reinforcing bar 5 is tied and fixed to the reinforcing bar of the precast pier 1 and poured together in the precast pier 1. Only the first hook section 9 after bending is set close to the connection surface between the pier and the pier column 2.

[0046] The first reinforcing bar 3 and sleeve 6, pier 2: Sleeve 6 is a high-strength threaded sleeve, the length of which is determined according to the threaded section length of the first reinforcing bar 3 and the second reinforcing bar 4 (ensuring that the first reinforcing bar 3 and the second reinforcing bar 4 are each embedded 1 / 2 the depth of sleeve 6); the total length of the first reinforcing bar 3 is 686mm, of which the second straight section 10 is 510mm long and the second hook section 11 is 176mm long. An external thread is machined at one end of the second straight section 10 of the first reinforcing bar 3 (the thread specification matches the internal thread of sleeve 6, and the threaded section length is...). The threaded end of the first reinforcing bar 3 is screwed into the sleeve 6, and the embedment depth is 1 / 2 of the total depth of the sleeve 6, forming the "first reinforcing bar 3-sleeve 6" assembly; during the prefabrication of the pier column 2, the second hook section 11 of the first reinforcing bar 3 of the above-mentioned "first reinforcing bar 3-sleeve 6" assembly is tied and fixed to the stressed reinforcing bar of the pier column 2, and poured together into the pier column 2. The other end of the sleeve 6 faces the connection surface between the pier column 2 and the foundation, and the end of the sleeve 6 is flush with the connection surface of the pier column 2.

[0047] The second reinforcing bar 4 and the sleeve 6, and the third reinforcing bar 5: The second reinforcing bar 4 is a straight reinforcing bar with a total length of 120mm. One end of it is machined with an external thread that matches the internal thread of the sleeve 6 (the length of the threaded section is equal to 1 / 2 the depth of the sleeve 6). After the pier column 2 is in place, the threaded end of the second reinforcing bar 4 is screwed into the sleeve 6 into the 1 / 2 depth not occupied by the first reinforcing bar 3, so that the second reinforcing bar 4 and the sleeve 6 are reliably connected. Then, the first hook section 9 of the third reinforcing bar 5, which is pre-bent, is straightened so that the hook end of the third reinforcing bar 5 is in contact with the non-threaded end of the second reinforcing bar 4. The two are tied securely with binding wire (the spacing between binding points is not greater than 200mm to ensure a stable lap. At this time, the lap length of the second reinforcing bar 4 and the third reinforcing bar 5 is guaranteed by the total length of the second reinforcing bar 4 and the length of the first hook section 9 of the third reinforcing bar 5, which meets the design specifications.

[0048] 7. After the second reinforcing bar 4 and the third reinforcing bar 5 are tied, the gap between the pier 2 and the foundation is cleaned, and then high-strength concrete 7 is poured to completely wrap the lap joint of the second reinforcing bar 4 and the third reinforcing bar 5 as well as the sleeve 6. After the concrete has cured to the design strength, the connection between the pier 2 and the foundation is completed.

[0049] See Figure 1 , Figure 2 , Figure 3 and Figure 4 In this embodiment, the specific construction steps for the bridge piers and foundations are as follows: Step 1, Construction of precast foundation 1: (1) Process the third steel bar 5 according to the design drawings, ensuring that its total length is 846mm (670mm for the first straight section + 176mm for the first hook section), and bend the first hook section 9 of the third steel bar 5 at a preset angle (90°); (2) Build the inner and outer formwork of the foundation, tie the reinforcing steel bars of the foundation inside the formwork, and tie the first straight section 8 (670mm) of the third steel bar 5 to the reinforcing steel bar to ensure that the first hook section 9 (176mm) after bending does not contact the inner formwork. (3) Pour the foundation concrete, and after curing it to the design strength, remove the inner formwork of the foundation; (4) By manually chiseling away the surface concrete at the connection surface of the foundation (the chiseling depth is based on exposing the first hook section 9 of the third steel bar 5), straighten the first hook section 9 of the third steel bar 5 so that it is in a vertical state (or in the same direction as the second steel bar 4). Step 2, Precast construction of pier 2: (1) Process the first steel bar 3 to ensure that its total length is 686mm (510mm for the second straight section + 176mm for the second hook section), and machine the external thread at one end of the second straight section 10 (the length of the thread section is determined according to the specifications of the sleeve 6, and must meet the requirement of screwing into the sleeve to a depth of 1 / 2). (2) Select a high-strength sleeve 6 that matches the thread of the first reinforcing bar 3, screw the threaded end of the first reinforcing bar 3 into the sleeve 6, and ensure that the embedment depth is 1 / 2 of the total depth of the sleeve 6 to form the "first reinforcing bar 3-sleeve" assembly. (3) Build the formwork for pier 2, tie the reinforcing bars of pier 2, and tie the second hook section 11 (176mm) of the first reinforcing bar 3 of the “first reinforcing bar 3-sleeve 6” assembly to the reinforcing bars of pier 2 to ensure that the end of sleeve 6 is flush with the connection surface of pier 2. (4) Pour concrete for pier column 2, and after curing to the design strength, remove the formwork for pier column 2; Step 3: Positioning and connecting pier 2 with the reinforcing steel: (1) Use lifting equipment to hoist the precast pier 2 to the top of the precast bearing platform 1, and adjust the position of the pier 2 so that the sleeve 6 at the bottom of the pier 2 corresponds to the position of the third steel bar 5 on the bearing platform connection surface; (2) Slowly lower the pier column 2 until the bottom of the pier column 2 contacts the connection surface of the foundation. At this time, the end of the sleeve 6 is directly opposite the first hook section 9 (176mm) after the third steel bar 5 is straightened. (3) Process the second reinforcing bar 4 to ensure that its total length is 120mm, and process an external thread at one end (the length of the threaded section is the same as that of the threaded section of the first reinforcing bar 3, which is equal to 1 / 2 the depth of the sleeve 6). Screw the threaded end of the second reinforcing bar 4 into the sleeve 6 until the non-threaded end of the second reinforcing bar 4 is in contact with the hook end of the third reinforcing bar 5. (4) Use binding wire to securely bind the second reinforcing bar 4 (120mm) and the first hook section 9 (176mm) of the third reinforcing bar 5 to ensure that the lap length meets the design specifications (the lap length is composed of the total length of the second reinforcing bar 4 and the length of the first hook section 9 of the third reinforcing bar 5, and the overlapping area of ​​binding can be adjusted according to the actual specifications). Step 4, Construction of Joint Concrete 7: (1) Clean the gap between the pier 2 and the foundation, remove debris and dust, and use a high-pressure water gun to rinse if necessary; (2) Set up formwork around the gap to ensure the formwork is sealed and prevent concrete leakage; (3) Pour high-strength joint concrete 7 (concrete strength grade not lower than that of the foundation and pier 2), and use a vibrator to compact it to avoid voids and cracks. (4) Curing of the concrete 7 in the joint shall be carried out for no less than 14 days. After the concrete strength reaches 100% of the design strength, the entire connection construction shall be completed.

[0050] Beneficial effects 1. Resolves the conflict between formwork and reinforcing bars, improving construction efficiency: By pre-bending the first hook segment 9 (176mm) of the third reinforcing bar 5 (total length 846mm), during the installation of the inner formwork of the precast foundation 1, the bent first hook segment 9 does not exceed the formwork range, completely avoiding the interference problem between traditional embedded reinforcing bars and formwork installation. This reduces the workload of formwork repair and reinforcing bar adjustment caused by the conflict between formwork and reinforcing bars, significantly improving the construction efficiency of the precast foundation 1.

[0051] 2. Ensuring the lap length of reinforcing bars and improving the stability of the connection node: In this scheme, the pre-bent third reinforcing bar 5 (total length 846mm) is only in a temporary state. After the inner formwork of the pier cap is removed, it will be straightened. The lap length of its hook section 9 (176mm) and the second reinforcing bar 4 (total length 120mm) can accurately meet the design specifications, and there is no problem of shortening the lap length due to avoiding the formwork. At the same time, the first reinforcing bar 3 (total length 686mm) is connected to the sleeve 6 at 1 / 2 depth, and the second reinforcing bar 4 (120mm) is connected to the sleeve 6 at the remaining depth, forming a double fixing structure of "threaded connection + binding connection". According to mechanical performance tests, the shear strength and bending strength of the connection node are increased by 25% to 35% compared with the traditional connection method, which meets the high strength requirements of prefabricated bridge piers for connection nodes and effectively ensures structural safety.

[0052] 3. Reduce construction difficulty and improve construction quality: The first reinforcing bar 3 (total length 686mm) and the sleeve 6 have been partially connected during the prefabrication stage of the pier column 2, forming a standardized "first reinforcing bar 3-sleeve 6" assembly, which reduces the difficulty of aligning the reinforcing bar and sleeve 6 on site; after the pier column 2 is in place, the second reinforcing bar 4 (120mm) can be quickly connected by screwing it into the sleeve 6, which is simple to operate and does not require complicated on-site processing; in addition, the binding connection of the second reinforcing bar 4 (120mm) and the first hook section 9 (176mm) of the third reinforcing bar 5 further ensures the reliability of the lap joint and reduces connection quality problems caused by on-site operation errors.

[0053] 4. High adaptability and wide application range: This scheme is not only applicable to the construction of prefabricated bridge piers for highway and railway bridges, but also allows for adjustments to the diameter of the reinforcing bars and the specifications of the sleeve 6 based on the first reinforcing bar 3 (total length 686mm), the second reinforcing bar 4 (total length 120mm), and the third reinforcing bar 5 (total length 846mm) according to the size and stress requirements of different piers, demonstrating strong adaptability. Furthermore, the construction process of this scheme seamlessly integrates with existing prefabricated bridge construction techniques, requiring no additional special equipment and easily promoted and applied within existing construction teams, resulting in significant economic and social benefits.

[0054] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A connection structure between a prefabricated bridge pier column and a foundation, characterized in that: It includes a precast foundation (1), a pier (2), a first reinforcing bar (3), a second reinforcing bar (4), a third reinforcing bar (5), a sleeve (6), and concrete for pouring joints (7); The third reinforcing bar (5) is embedded in the precast foundation (1). The third reinforcing bar (5) includes a first straight section (8) and a first hook section (9). The first hook section (9) is bent at a preset angle, and the bent first hook section (9) does not exceed the installation range of the inner mold template of the precast foundation (1). The first straight section (8) of the third reinforcing bar (5) is fixedly connected to the reinforcing bar of the precast foundation (1). The sleeve (6) is a high-strength threaded sleeve. The first reinforcing bar (3) includes a second straight section (10) and a second hook section (11). One end of the second straight section (10) of the first reinforcing bar (3) is processed with external threads. The end of the first reinforcing bar (3) with external threads is screwed into the sleeve (6) and the embedment depth is half of the total depth of the sleeve (6). The second hook section (11) of the first reinforcing bar (3) is fixedly connected to the reinforcing bar of the pier (2). The other end of the sleeve (6) corresponds to the connection surface between the pier (2) and the precast foundation (1), and the end of the sleeve (6) is flush with the connection surface of the pier (2). The second reinforcing bar (4) is a straight reinforcing bar with external threads at one end. The threaded end of the second reinforcing bar (4) is screwed into the sleeve (6) in the part not occupied by the first reinforcing bar (3). After the first hook section (9) of the third reinforcing bar (5) is straightened, its hook end is attached to and fixedly connected to the non-threaded end of the second reinforcing bar (4). The joint concrete (7) is poured into the gap between the pier (2) and the precast foundation (1) and wraps the lap portion of the second reinforcing bar (4), the third reinforcing bar (5) and the sleeve (6).

2. The prefabricated bridge pier column and foundation connection structure according to claim 1, characterized in that: The specifications of the external thread of the first reinforcing bar (3) and the external thread of the second reinforcing bar (4) are matched with the specifications of the internal thread of the sleeve (6).

3. The prefabricated bridge pier column and foundation connection structure according to claim 1, characterized in that: The second reinforcing bar (4) and the first hook section (9) of the third reinforcing bar (5) are tied together with binding wire, and the distance between the binding points is not greater than the preset distance.

4. A construction method for prefabricated bridge piers and caps, characterized in that, Includes the following steps: Step 1: Construction of the precast foundation (1), processing of the third steel bar (5), bending the first hook section (9) of the third steel bar (5) at a preset angle; building the foundation template, tying the foundation reinforcement, fixing the first straight section (8) of the third steel bar (5) to the foundation reinforcement, ensuring that the bent first hook section (9) does not contact the foundation inner template; pouring foundation concrete and curing, removing the foundation template; chiseling away the surface concrete at the connection surface of the precast foundation (1), straightening the first hook section (9) of the third steel bar (5); Step 2: Prefabrication of pier column (2) and processing of the first reinforcing bar (3). External thread is processed at one end of the second straight section (10) of the first reinforcing bar (3). A high-strength sleeve (6) matching the thread of the first reinforcing bar (3) is selected, and the threaded end of the first reinforcing bar (3) is screwed into the sleeve (6) to form a combination of the first reinforcing bar (3) and the sleeve (6). The pier column (2) template is erected, and the reinforcing bars of the pier column (2) are tied. The second hook section (11) of the first reinforcing bar (3) and the sleeve (6) combination is fixedly connected to the reinforcing bars of the pier column (2) to ensure that the end of the sleeve (6) is flush with the connection surface of the pier column (2). The pier column (2) concrete is poured and cured, and the pier column (2) template is removed. Step 3: Position the pier (2) and connect it with the reinforcing bars. Hoist the precast pier (2) above the precast bearing platform (1) and adjust its position so that the sleeve (6) at the bottom of the pier (2) corresponds to the position of the third reinforcing bar (5) on the connecting surface of the precast bearing platform (1). Lower the pier (2) until its bottom contacts the connecting surface of the precast bearing platform (1). Process the second reinforcing bar (4). Process an external thread on one end of the second reinforcing bar (4). Screw the threaded end of the second reinforcing bar (4) into the sleeve (6) so that the non-threaded end of the second reinforcing bar (4) fits against the hook end of the third reinforcing bar (5). Connect the second reinforcing bar (4) and the first hook section (9) of the third reinforcing bar (5) by binding. Step 4, pouring joint concrete (7) construction: clean the gap between the pier (2) and the precast abutment (1), set up the template and seal it, pour high-strength joint concrete (7) and vibrate it to compact it, cure the joint concrete (7) and complete the connection after its strength reaches the design strength.

5. The construction method for prefabricated bridge piers and caps according to claim 4, characterized in that: In the construction of the precast foundation (1), the preset bending angle of the first hook section (9) of the third steel bar (5) is 90°.

6. The construction method for prefabricated bridge piers and caps according to claim 4, characterized in that: In the prefabrication of the pier column (2), the first reinforcing bar (3) with external threads is screwed into the sleeve (6) to a depth that is half the total depth of the sleeve (6).

7. The construction method for prefabricated bridge piers and caps according to claim 4, characterized in that: During the installation and connection of the pier column (2), the length of the external thread of the second reinforcing bar (4) is consistent with the length of the external thread of the first reinforcing bar (3).

8. The construction method for prefabricated bridge piers and caps according to claim 4, characterized in that: In the binding step of the pier column (2) being positioned and connected to the reinforcing bars, the binding overlap area of ​​the first hook section (9) of the second reinforcing bar (4) and the third reinforcing bar (5) is determined according to the design specifications, and double-strand binding wires are used for cross binding during binding, with binding points evenly distributed along the overlap length.

9. A construction method for prefabricated bridge piers and caps according to claim 4, characterized in that: After the external threads of the first reinforcing bar (3) and the second reinforcing bar (4) are processed, the thread accuracy is tested to ensure that the thread profile is complete and undamaged, and that the fit clearance with the internal thread of the sleeve (6) meets the design requirements.

10. A construction method for prefabricated bridge piers and caps according to claim 4, characterized in that: The preset bending angle of the first hook section (9) of the third reinforcing bar (5) is determined according to the thickness of the inner mold template of the precast foundation (1).

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