UHPC shell reinforced grouting sleeve connection fabricated bridge pier and construction method

Abstract

The invention discloses a UHPC shell reinforced grouting sleeve connection fabricated bridge pier and a construction method, and belongs to the field of fabricated structures, the UHPC shell reinforced grouting sleeve connection fabricated bridge pier comprises a prefabricated module body, a post-cast UHPC area and a bearing platform which are connected in sequence; the post-pouring UHPC area is poured between the prefabricated module body and the bearing platform and wraps a connecting seam between the prefabricated module body UHPC protection layer and the bearing platform; a method for building the UHPC shell reinforced grouting sleeve connection fabricated bridge pier comprises the steps of prefabricated module body manufacturing, bearing platform construction, fabricated connection, post-pouring UHPC area construction and maintenance, in the fabricated construction process of the fabricated bridge pier, ultra-high performance concrete UHPC is adopted for conducting staggered-layer pouring connection on joints between the prefabricated module body and the bearing platform, and the prefabricated module body and the bearing platform are connected through grouting; and a discontinuous joint structure with the interior completely wrapped by UHPC is formed, chemical erosion such as external chloride ions is effectively isolated, and the strength, corrosion resistance and assembly integrity of the joints are remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the field of prefabricated structures, and particularly relates to a prefabricated bridge pier connected by a UHPC shell enhanced grouting sleeve and a construction method. Background Art

[0002] Prefabricated bridges have become an important engine for the high-quality development of transportation infrastructure. However, for prefabricated bridges mainly made of reinforced concrete, during their service life of decades or even hundreds of years, especially in high-concentration chloride ion erosion environments such as marine environments, saline-alkali areas, and industrial atmospheres, their pier bodies, especially the precast assembly connection areas, are extremely prone to corrosion damage, resulting in a significant degradation of structural performance. Compared with cast-in-situ bridges in the same environment, the operation risks are more complex. It can be seen that with the wide application of prefabricated bridges, how to ensure the long-term service safety of the structure has become an urgent problem to be solved. The effective connection between prefabricated bridge modules is the key to ensuring the mechanical performance of its structural system. At present, the connection methods of prefabricated modules mainly include sleeve grouting connection, corrugated pipe grouting connection, socket connection, etc. Among them, the sleeve grouting connection has been widely used in prefabricated bridge piers due to its reliable force transmission, convenient construction and other advantages. However, the multi-interface force transmission performance of steel sleeves, grouting materials and steel bars deteriorates due to corrosion, and is superimposed with the corrosion effects of the through-joint steel bars and the steel bars of the prefabricated module body, bringing serious hidden dangers to the safe service of prefabricated bridge piers. In particular, the seismic performance degradation problem of prefabricated bridge piers in earthquake areas after corrosion has become a challenge that cannot be ignored. Therefore, there is an urgent need for a technology in the prior art to solve the above problems. Summary of the Invention

[0003] The purpose of the present invention is to address the technical problems existing in the prior art, and propose a prefabricated bridge pier connected by a UHPC shell enhanced grouting sleeve and a construction method.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] According to the first aspect of the present invention, a precast pier connected by a UHPC shell-reinforced grouting sleeve is proposed, which includes a precast module body, a post-cast UHPC area and a bearing platform connected in sequence; the precast module body includes precast module body stirrups, precast module body longitudinal steel bars, precast module body UHPC protective layer, precast module body ordinary concrete core and grouting sleeve, and the precast module body stirrups and precast module body longitudinal steel bars are welded to form a steel bar cage; the grouting sleeve includes a grouting sleeve wall, a high-strength rubber positioning plug, a steel bar positioning pin, a grouting sleeve grouting port, a grouting sleeve slurry outlet and sleeve stirrups, the grouting sleeve grouting port and the grouting sleeve slurry outlet are opened on the side wall of the grouting sleeve, and the grouting sleeve slurry outlet is located above the grouting sleeve grouting port; the sleeve stirrups are tied outside the grouting sleeve; the precast module body ordinary concrete core is formed by casting along the steel bar cage and the grouting sleeve wall; the precast module body UHPC protective layer is formed by casting in the area without the grouting sleeve at the upper part of the precast module body; the bearing platform includes bearing platform longitudinal steel bars and a bearing platform ordinary concrete body, the bearing platform longitudinal steel bars are arranged corresponding to the grouting sleeve, and the bearing platform longitudinal steel bars exposed at the upper part of the bearing platform correspond one by one to the dimensions and positions of the grouting sleeves at the lower part of the precast module body; the post-cast UHPC area is cast between the precast module body and the bearing platform and wraps the connection seam between the precast module body UHPC protective layer and the bearing platform; wherein the high-strength rubber positioning plug and the steel bar positioning pin are used to temporarily fix the precast module body longitudinal steel bars and the bearing platform longitudinal steel bars before grouting.

[0006] Further, the high-strength rubber positioning plug is of an annular structure, the inner diameter of which matches the diameter of the precast module body longitudinal steel bars, and the outer diameter matches the inner diameter of the grouting sleeve wall.

[0007] Further, the steel bar positioning pin is a stainless steel pin, which cooperates with the high-strength rubber positioning plug to realize the radial and axial positioning of the precast module body longitudinal steel bars.

[0008] Further, the bearing platform is provided with an assembly groove at the connection with the precast module body, and the post-cast UHPC area simultaneously covers the vertical joint, the horizontal joint and the groove area to form an integral UHPC wrapping layer.

[0009] According to the second aspect of the present invention, a construction method for the precast pier connected by the UHPC shell-reinforced grouting sleeve is proposed, which includes the following steps:

[0010] Step 1: Fabrication of the precast module body:

[0011] Weld the precast module body longitudinal steel bars and the precast module body stirrups to form a steel bar cage;

[0012] Install the grouting sleeve, and temporarily fix the precast module body longitudinal steel bars through the high-strength rubber positioning plug and the steel bar positioning pin;

[0013] Cast the ordinary concrete core of the precast module body and the UHPC protective layer of the precast module body in sub - areas;

[0014] Step two: Construction of the bearing platform:

[0015] Bind the longitudinal steel bars of the bearing platform on - site and pour the ordinary concrete body of the bearing platform;

[0016] Step three: Assembly connection:

[0017] Lift the precast module body above the bearing platform, insert the longitudinal steel bars of the bearing platform into the grouting sleeves, and temporarily fix them with high - strength rubber positioning plugs and steel bar positioning pins. After temporary fixing, bind the sleeve stirrups;

[0018] Conduct pressure grouting through the grouting ports of the grouting sleeves until the grouting material overflows from the grouting outlets of the grouting sleeves;

[0019] Step four: Construction of the post - cast UHPC area:

[0020] Formwork and pour UHPC materials to wrap the joint area;

[0021] Step five: Curing:

[0022] Conduct moisture - retaining curing on the grouting material and the post - cast UHPC area.

[0023] Furthermore, the specific process of casting the ordinary concrete core of the precast module body and the UHPC protective layer of the precast module body in sub - areas is as follows:

[0024] Formwork and pour the ordinary concrete core of the precast module body: During the pouring process, formwork and pour along the longitudinal steel bars and stirrups of the precast module body at the upper part of the precast module body without grouting sleeves, and formwork and pour along the wall of the grouting sleeves at the lower part of the precast module body with grouting sleeves;

[0025] Formwork and pour the UHPC protective layer of the precast module body: During the pouring process, formwork and pour according to engineering requirements at the upper part of the precast module body without grouting sleeves, and do not pour at the lower part of the precast module body with grouting sleeves.

[0026] Furthermore, in step two, the longitudinal steel bars of the bearing platform exposed at the upper part of the bearing platform correspond one - to - one in size and position to the grouting sleeves at the lower part of the precast module body.

[0027] Furthermore, in step four, in addition to being cast between the precast module body and the bearing platform, the post - cast UHPC area is also set in the assembly grooves and on the surfaces between the UHPC protective layer of the precast module body and the bearing platform to wrap the connection seams formed by the assembly.

[0028] Compared with the prior art, through the above design solution, the present invention proposes a UHPC shell enhanced grouting sleeve connection precast bridge pier and construction method. During the assembly construction process of the precast bridge pier of the present invention, by using ultra-high performance concrete (UHPC) to carry out stepped casting connection on the joint between the precast module body and the bearing platform, a discontinuous joint structure that is completely wrapped by UHPC inside is formed, effectively isolating external chemical erosion such as chloride ions, and significantly improving the strength, corrosion resistance and assembly integrity at the joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the construction assembly structure of the UHPC shell enhanced grouting sleeve connection precast bridge pier of the present invention;

[0030] Figure 2 It is a schematic longitudinal sectional view of the precast bridge pier of the present invention;

[0031] Figure 3 It is a schematic cross-sectional view of the upper part of the precast bridge pier of the present invention where stirrups restrain longitudinal steel bars;

[0032] Figure 4 It is a schematic cross-sectional view of the sleeve connection part of the precast bridge pier of the present invention;

[0033] Figure 5 It is a schematic partial sectional view of the joint where the precast bridge pier, the post-cast UHPC area and the bearing platform of the present invention are interconnected;

[0034] Figure 6 It is a schematic diagram of the bearing platform structure of the UHPC shell enhanced grouting sleeve connection precast bridge pier of the present invention;

[0035] The reference signs in the drawings are as follows: 1 - precast module body; 2 - post-cast UHPC area; 3 - bearing platform; 4 - grouting sleeve; 5 - stirrups of precast module body; 6 - longitudinal steel bars of precast module body; 7 - longitudinal steel bars of bearing platform; 8 - UHPC protective layer of precast module body; 9 - ordinary concrete core of precast module body; 10 - grouting sleeve wall; 11 - high-strength rubber positioning plug; 12 - steel bar positioning pin; 13 - grouting port of grouting sleeve; 14 - slurry outlet of grouting sleeve; 15 - ordinary concrete body of bearing platform; 16 - grouting material; 17 - sleeve stirrups. DETAILED DESCRIPTION OF THE INVENTION

[0036] In order to explain the present invention more clearly, the present invention will be further described below with reference to the drawings. Those skilled in the art should understand that the specific content described below is illustrative rather than restrictive, and should not be used to limit the protection scope of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should have the ordinary meaning understood by those of ordinary skill in the field to which the present invention belongs.

[0037] To avoid obscuring the essence of the present invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0038] Refer to Figures 1 to 6 , the present invention proposes a precast pier connected by a UHPC shell-reinforced grouting sleeve, which includes a precast module body 1, a post-cast UHPC area 2, and a bearing platform 3. It should be noted that the ultra-high performance concrete (referred to as UHPC) material in the present invention has the advantages of dense structure, strong impermeability, slow chloride ion diffusion rate, good mechanical properties, and good bending, tensile, shear, and compressive properties. The precast module body 1, the post-cast UHPC area 2, and the bearing platform 3 are connected in sequence.

[0039] The precast module body 1 includes precast module body stirrups 5, precast module body longitudinal steel bars 6, precast module body UHPC protective layer 8, precast module body normal concrete core 9, and a grouting sleeve 4. The grouting sleeve 4 includes a grouting sleeve wall 10, a high-strength rubber positioning plug 11, a steel bar positioning pin 12, a grouting sleeve grouting port 13, a grouting sleeve slurry outlet 14, and sleeve stirrups 17; the grouting sleeve grouting port 13 and the grouting sleeve slurry outlet 14 are opened on the side wall of the grouting sleeve 4, and the grouting sleeve slurry outlet 14 is located above the grouting sleeve grouting port 13; the sleeve stirrups 17 are tied outside the grouting sleeve 4; the high-strength rubber positioning plug 11 and the steel bar positioning pin 12 are used in cooperation to position and initially fix the precast module body longitudinal steel bar 6, facilitating formwork support for casting the precast module body normal concrete core 9 and the precast module body UHPC protective layer 8. The high-strength rubber positioning plug 11 is of an annular structure, with an inner diameter matching the diameter of the precast module body longitudinal steel bar 6 and an outer diameter matching the inner diameter of the grouting sleeve wall 10. The material of the high-strength rubber positioning plug 11 is hydrogenated nitrile rubber, which has strong tear strength and tensile strength, and the tensile strength can reach 20 MPa. It should be noted that the precast module body stirrups 5 and the sleeve stirrups 17 in the present invention adopt the stirrups commonly used in existing reinforced concrete components for shear resistance and fixing the positions of longitudinal stressed steel bars.

[0040] The precast module body longitudinal steel bar 6 and the grouting sleeve 4 are positioned and fixed by the high-strength rubber positioning plug 11 and the steel bar positioning pin 12 to initially form an integral whole.

[0041] The precast module body longitudinal steel bar 6 and the precast module body stirrups 5 are initially fixed into an integral whole by welding.

[0042] The precast module body normal concrete core 9 is cast by formwork support along the precast module body longitudinal steel bar 6 and the precast module body stirrups 5 at the upper part of the precast module body 1 where there is no grouting sleeve 4, and is cast by formwork support along the grouting sleeve wall 10 at the lower part of the precast module body 1 where there is a grouting sleeve 4.

[0043] The UHPC protective layer 8 of the precast module body is cast by formwork according to engineering requirements at the upper part of the precast module body 1 where there is no grouting sleeve 4, and is not cast at the lower part of the precast module body 1 where there is a grouting sleeve 4.

[0044] After the ordinary concrete core 9 of the precast module body and the UHPC protective layer 8 of the precast module body are cast, all components in the precast module body 1 form an integral whole.

[0045] The longitudinal bearing platform steel bars 7 exposed at the upper part of the bearing platform 3 correspond one by one in size and position to the grouting sleeves 4 at the lower part of the precast module body 1.

[0046] The ordinary concrete body 15 of the bearing platform is cast from ordinary concrete, and an assembly groove is provided at the assembly connection with the precast module body 1. Ordinary concrete is the most widely used concrete in civil engineering, which is a cement concrete made with cement as the binder, sand and stone as the aggregates, and water added and mixed.

[0047] In addition to being cast between the precast module body 1 and the bearing platform 3, the post-cast UHPC area 2 is also provided in the assembly groove between the UHPC protective layer 8 of the precast module body and the bearing platform 3 and on the surface of the bearing platform 3 to wrap the connection seam formed by the assembly.

[0048] The present invention also proposes a construction method for a precast bridge pier connected by a UHPC shell enhanced grouting sleeve, which is used to manufacture the above-mentioned precast bridge pier connected by a UHPC shell enhanced grouting sleeve, and includes the following steps, which are carried out in sequence:

[0049] Step 1: Weld the longitudinal steel bars 6 and stirrups 5 of the precast module body to initially form an integral whole;

[0050] Step 2: Install the grouting sleeve 4 on the longitudinal steel bars 6 of the precast module body and position and fix it through the high-strength rubber positioning plug 11 and the steel bar positioning pin 12 to initially form an integral whole;

[0051] Step 3: Formwork and cast the ordinary concrete core 9 of the precast module body and perform initial curing; during the casting process, formwork and cast along the longitudinal steel bars 6 and stirrups 5 of the precast module body at the upper part of the precast module body 1 where there is no grouting sleeve 4, and formwork and cast along the wall 10 of the grouting sleeve at the lower part of the precast module body 1 where there is a grouting sleeve 4; in particular, ensure that the grouting port 13 and the grouting outlet 14 of the grouting sleeve are exposed after casting, so as to ensure the normal progress of subsequent grouting;

[0052] Step 4: Formwork and cast the UHPC protective layer 8 of the precast module body; during the casting process, formwork and cast according to engineering requirements at the upper part of the precast module body 1 where there is no grouting sleeve 4, and do not cast at the lower part of the precast module body 1 where there is a grouting sleeve 4;

[0053] Step 5: Cure the ordinary concrete core 9 and the UHPC protective layer 8 of the precast module body; the precast module body 1 is fabricated;

[0054] Step 6: Fabricate the bearing platform 3: Reinforce the steel bars, formwork and pour ordinary concrete on-site according to the actual requirements of the project; during the fabrication process, pay attention to the exposure of the longitudinal steel bars 7 of the upper bearing platform and make them correspond one by one to the size and position of the grouting sleeves 4 at the lower part of the precast module body 1;

[0055] Step 7: Transport the precast precast module body 1 to the site and conduct preliminary assembly with the bearing platform 3: Hoist the precast module body 1 above the bearing platform 3, combine the longitudinal steel bars 7 of the upper bearing platform that are exposed with the grouting sleeves 4 at the lower part of the precast module body 1, and position and fix them initially as a whole through the high-strength rubber positioning plugs 11 and the steel bar positioning pins 12. After preliminary fixation, tie and fix the sleeve stirrups 17;

[0056] Step 8: Grout the grouting sleeve 4: Use the existing pressure grouting method to pour the grouting material 16 through the grouting port 13 of the grouting sleeve. Stop grouting and conduct preliminary curing when it is observed that the grouting material 16 flows out from the grouting outlet 14 of the grouting sleeve;

[0057] Step 9: Formwork between the precast module body 1 and the bearing platform 3, pour and cure the post-cast UHPC area 2; Specifically: The bearing platform 3 is provided with an assembly groove at the connection with the precast module body 1. In addition to being poured and set between the precast module body 1 and the bearing platform 3, the post-cast UHPC area 2 is also provided in the assembly groove and on the surface between the UHPC protective layer 8 of the precast module body and the bearing platform 3 to wrap the connection seam formed by the assembly;

[0058] Step 10: Cure the grouting material 16 in the grouting sleeve and the cast ultra-high performance concrete (UHPC) connection layer to complete the fabrication.

[0059] In summary, during the assembly construction process of the prefabricated bridge pier of the present invention, by using ultra-high performance concrete (UHPC) to conduct stepped pouring connection on the joints between the precast module body and the bearing platform, a discontinuous joint structure that is completely wrapped by UHPC inside is formed, effectively isolating external chemical erosion such as chloride ions, and significantly improving the strength, corrosion resistance and assembly integrity at the joints.

[0060] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. An assembled pier connected by a UHPC shell-reinforced grouting sleeve, characterized in that, It includes a precast module body (1), a cast-in-place UHPC area (2), and a bearing platform (3) connected in sequence; the precast module body (1) includes precast module body stirrups (5), precast module body longitudinal steel bars (6), precast module body UHPC protective layer (8), precast module body normal concrete core (9), and grouting sleeves (4). The precast module body stirrups (5) and the precast module body longitudinal steel bars (6) are welded to form a steel bar framework; the grouting sleeve (4) includes a grouting sleeve wall (10), a high-strength rubber positioning plug (11), a steel bar positioning pin (12), a grouting sleeve grouting port (13), a grouting sleeve slurry outlet (14), and sleeve stirrups (17). The grouting sleeve grouting port (13) and the grouting sleeve slurry outlet (14) are opened on the side wall of the grouting sleeve (4), and the grouting sleeve slurry outlet (14) is located above the grouting sleeve grouting port (13); the sleeve stirrups (17) are tied outside the grouting sleeve (4); the precast module body normal concrete core (9) is poured along the steel bar framework and the grouting sleeve wall (10); the precast module body UHPC protective layer (8) is poured in the area without the grouting sleeve (4) at the upper part of the precast module body (1); the bearing platform (3) includes bearing platform longitudinal steel bars (7) and a bearing platform normal concrete body (15). The bearing platform longitudinal steel bars (7) are arranged corresponding to the grouting sleeves (4), and the bearing platform longitudinal steel bars (7) exposed at the upper part of the bearing platform (3) correspond to the sizes and positions of the grouting sleeves (4) at the lower part of the precast module body (1) one by one; the cast-in-place UHPC area (2) is poured between the precast module body (1) and the bearing platform (3) and wraps the joint between the precast module body UHPC protective layer (8) and the bearing platform (3); wherein the high-strength rubber positioning plug (11) and the steel bar positioning pin (12) are used to temporarily fix the precast module body longitudinal steel bars (6) and the bearing platform longitudinal steel bars (7) before grouting.

2. The assembled bridge pier with UHPC shell reinforced grouting sleeve connection according to claim 1, wherein The high-strength rubber positioning plug (11) is of an annular structure, with its inner diameter matching the diameter of the precast module body longitudinal steel bar (6) and its outer diameter matching the inner diameter of the grouting sleeve wall (10).

3. The prefabricated bridge pier connected by the UHPC shell reinforced grouting sleeve according to claim 1, characterized in that, The steel bar positioning pin (12) is a stainless steel pin, which cooperates with the high-strength rubber positioning plug (11) to realize the radial and axial positioning of the precast module body longitudinal steel bar (6).

4. The precast bridge pier connected by the UHPC shell reinforced grouting sleeve according to claim 1, characterized in that, The bearing platform (3) is provided with an assembly groove at the connection with the precast module body (1), and the cast-in-place UHPC area (2) simultaneously covers the vertical joint, the horizontal joint, and the groove area to form an integral UHPC wrapping layer.

5. A construction method for an assembled bridge pier connected by a UHPC shell enhanced grouting sleeve according to any one of claims 1-4, characterized in that, It includes the following steps: Step 1: Fabrication of the precast module body (1): Weld the precast module body longitudinal steel bars (6) and the precast module body stirrups (5) to form a steel bar framework; Install the grouting sleeve (4), and temporarily fix the precast module body longitudinal steel bars (6) through the high-strength rubber positioning plug (11) and the steel bar positioning pin (12); Pour the precast module body normal concrete core (9) and the precast module body UHPC protective layer (8) in different areas; Step 2: Construction of the bearing platform (3): Bind the bearing platform longitudinal steel bars (7) on-site and pour the bearing platform normal concrete body (15); Step 3: Assembly and connection: Lift the precast module body (1) above the pile cap (3), insert the longitudinal steel bars (7) of the pile cap into the grouting sleeve (4), and temporarily fix them using high-strength rubber positioning plugs (11) and steel bar positioning pins (12). After temporary fixation, tie the sleeve stirrups (17); Perform pressure grouting through the grouting port (13) of the grouting sleeve until the grouting material (16) overflows from the grouting outlet (14) of the grouting sleeve; Step 4: Construction of the post-cast UHPC area (2): Formwork and pour the UHPC material to wrap the joint area; Step 5: Curing: Perform moisture curing on the grouting material (16) and the post-cast UHPC area (2).

6. The method according to claim 5, wherein The specific process of separately casting the ordinary concrete core (9) of the precast module body and the UHPC protective layer (8) of the precast module body is as follows: Formwork and pour the ordinary concrete core (9) of the precast module body: During the pouring process, formwork and pour along the longitudinal steel bars (6) and stirrups (5) of the precast module body at the upper part of the precast module body (1) where there is no grouting sleeve (4), and formwork and pour along the wall of the grouting sleeve (10) at the lower part of the precast module body (1) where there is a grouting sleeve (4); Formwork and pour the UHPC protective layer (8) of the precast module body: During the pouring process, formwork and pour according to engineering requirements at the upper part of the precast module body (1) where there is no grouting sleeve (4), and do not pour at the lower part of the precast module body (1) where there is a grouting sleeve (4).

7. The method according to claim 5, characterized in that, In Step 2, the longitudinal steel bars (7) of the pile cap exposed above the pile cap (3) correspond one by one in size and position to the grouting sleeves (4) at the lower part of the precast module body (1).

8. The method according to claim 5, characterized in that, In Step 4, the post-cast UHPC area (2) is not only cast between the precast module body (1) and the pile cap (3), but also arranged in the assembly grooves and on the surfaces of the UHPC protective layer (8) of the precast module body and the pile cap (3) to wrap the connection seams formed by the assembly.

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