Cast-in-place slab structure of pier top solid section and construction method of cast-in-place slab structure

Abstract

The invention discloses a cast-in-place slab structure of a pier top solid section and a construction method of the cast-in-place slab structure. The cast-in-place slab structure comprises a preformed groove, a cast-in-place slab body, cast-in-place slab steel bars and a formwork system. The whole formwork is used for reducing joints, the workload and construction difficulty of site construction are reduced, and the installation precision, rigidity and stability of the formwork are improved; a cast-in-place slab is made into a prefabricated or cast-in-place structure, the construction method can be adjusted according to the actual site situation or the influence of the construction period, if the construction period is sufficient and the site hoisting operation is difficult, a cast-in-place mode can be adopted, and if the construction period is short, a prefabricated mode can be adopted. And the cast-in-place slab is hoisted to the corresponding position for installation when the pier top is constructed, so that the construction progress is accelerated, and the construction period requirement is met.

Description

Technical Field

[0001] The invention relates to the field of cast-in-place concrete slabs, in particular to a cast-in-place slab structure of a pier top solid section and a construction method thereof. Background Art

[0002] At present, the cast-in-place slab of the solid section of the pier top in China usually adopts high-strength concrete, such as C50 or higher grade concrete, to ensure the sufficient strength and durability of the cast-in-place slab of the solid section of the pier top. At the same time, the configuration of cast-in-place slab reinforcement is also the key. The longitudinal force reinforcement, transverse structural reinforcement, shear reinforcement, stirrups and hanger reinforcement in the cast-in-place slab reinforcement need to be precisely arranged according to the design load and force requirements to ensure the integrity and stability of the structure. In addition, the connection structure between the solid section of the pier top and the pier body and the superstructure is also an important consideration in the design. A firm and reliable connection is achieved through embedded parts, steel bar welding and other methods. Although this connection structure can meet the principles of bridge structural mechanics, it has the following defects: 1. The construction of the cast-in-place slab of the solid section of the pier top requires precise template positioning and support, as well as strict concrete pouring and vibration technology. The construction is difficult and requires a high level of technical skills for the construction personnel; 2. The base surface of the template is uneven, or the support surface is insufficient and the support is loose, resulting in the tilt of the template, the deformation of the template leads to a large gap at the joint, poor sealing, and leakage when pouring concrete. Summary of the invention

[0003] The first purpose of the present invention is to provide a cast-in-place slab structure of a solid section on the pier top, which uses an integral formwork to reduce joints and improve the rigidity and stability of the formwork; at the same time, the cast-in-place slab is designed to be cast-in-place or prefabricated, and the construction can be selected according to the actual situation on site.

[0004] The second object of the present invention is to provide a construction method for a cast-in-place slab structure of a solid section on a pier top.

[0005] The first object of the present invention is achieved by: A cast-in-place slab structure of a solid section on a pier top comprises a reserved groove, a cast-in-place slab body, cast-in-place slab reinforcement and a formwork system; the cast-in-place slab body is cast by high-strength concrete, the cast-in-place slab body has a predetermined length, width and thickness, and has excellent bearing capacity and durability to meet the bearing requirements of the pier top; the cast-in-place slab reinforcement built into the cast-in-place slab body comprises longitudinal force-bearing reinforcement and transverse structural reinforcement arranged according to design requirements, and the overall stability and crack resistance of the cast-in-place slab are ensured through precise calculation and arrangement; a reserved groove for installing the cast-in-place slab body and serving as a connection is provided on the pier, and the concrete cast in the reserved groove realizes a firm connection between the cast-in-place slab and the pier, transfers the load and ensures the safety of the structure; the formwork system comprises a formwork, a pre-buried climbing cone and a distribution beam, and adopts a detachable design to support the concrete during the casting process, which is convenient for construction operation and subsequent maintenance.

[0006] Furthermore, the concrete strength grade of the cast-in-place slab body is not less than C50 to ensure sufficient bearing capacity.

[0007] Furthermore, the longitudinal reinforcements in the cast-in-place slab reinforcements are welded, and the shear reinforcements in the configured cast-in-place slab reinforcements are arranged near the reserved grooves to ensure the reliability of the connection and the continuity of force transmission.

[0008] Furthermore, concrete with the same strength as that of the pier body is poured into the reserved groove to achieve a firm connection between the cast-in-place slab body and the pier.

[0009] Furthermore, the formwork system of the cast-in-place slab of the solid section of the pier top uses a whole formwork as the base plate, and a pre-buried climbing cone is installed under the formwork to connect the transverse distribution beam as a support, and the formwork and the distribution beam are spot welded to prevent the formwork from being displaced.

[0010] The second object of the present invention is achieved by: A construction method for a cast-in-place slab structure of a solid section on a pier top, wherein all bridge piers are double-column "π"-shaped frame piers, the pier columns are hollow rectangles, the cross-sectional size of a single pier column top is 8.24m×7.1m, the wall thickness of the pier column is 0.8m, the top of the pier column is partially thickened, and the solid section thickness of the top cross beam of the pier column is 6m; the specific steps are as follows: A. Reinforcement binding: Process the cast-in-place slab steel bars into the corresponding component shape according to the size of the reinforcement drawing, and then tie and weld the cast-in-place slab steel bars according to the distribution of cast-in-place slab steel bars in the reinforcement drawing. Pay attention to setting the hanging bars to facilitate the later lifting of the cast-in-place slab to the corresponding position and complete the installation of the cast-in-place slab; B. Determine whether to cast in place or prefabricate based on the actual construction conditions on site: a. Prefabrication: (1) Cast-in-place slab production: According to the arrangement of the pier body steel bars, consider avoiding the pier body steel bars when distributing the cast-in-place slab steel bars to prevent conflicts during the subsequent hoisting and installation of the cast-in-place slab; place the tied cast-in-place slab steel bars in the formwork at the back site, and accurately check the position of the cast-in-place slab steel bars to prevent the cast-in-place slab steel bars from being offset and causing conflicts during subsequent installation after pouring. Pour concrete with the same strength as the pier body. After pouring, the concrete of the cast-in-place slab body needs to be watered and cured. When the concrete reaches the required strength, it is transported to the site for installation; (2) Installation of cast-in-place slab: The cast-in-place slab body is hoisted to the pier top. During installation, the position of the cast-in-place slab body must be carefully checked to prevent the cast-in-place slab body from being displaced. Concrete is poured in the reserved groove on the pier top. The solid section steel bars of the pier top are then tied to the cast-in-place slab body. Finally, the concrete of the solid section of the pier top is poured to obtain the cast-in-place slab of the solid section of the pier top. The cast-in-place slab is designed as a one-way slab and uses the same concrete as the pier body. The cast-in-place slab adopts a one-way reinforcement method and the shear steel bars of the cast-in-place slab steel bars are arranged near the reserved groove. b. Cast-in-place: (1) Formwork system installation: pre-embedded climbing cones are set at the corresponding position of the next section of the cast-in-place slab in advance, and the transverse distribution beams are welded. The entire formwork is placed on the distribution beams, and the distribution beams are spot welded to the formwork; (2) Pouring concrete: The steel bars of the cast-in-place slab are hoisted onto the formwork and accurately positioned and installed. At the same time, concrete is poured into the cast-in-place slab body and the reserved groove. When the concrete reaches the corresponding strength, the formwork and the distribution beam used for support below are removed through the manhole on the cast-in-place slab body to obtain the cast-in-place slab of the solid section of the pier top.

[0011] Compared with the prior art, the advantages of the present invention are: A. Use a whole template to reduce joints, reduce the workload and difficulty of on-site construction, and improve the installation accuracy, rigidity and stability of the template; B. The cast-in-place slab can be made into a prefabricated or cast-in-place structure, and the construction method can be adjusted according to the actual situation on site or affected by the construction period. If the construction period is sufficient and the on-site hoisting operation is more difficult, the cast-in-place form can be adopted. If the construction period is tight, the prefabrication form can be adopted. When constructing the pier top, the cast-in-place slab can be hoisted to the corresponding position for installation to speed up the construction progress and meet the construction period requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is the layout elevation drawing of the cast-in-place slab; Figure 2 for Figure 1 1-1 schematic diagram; Figure 3 for Figure 1 2-2 direction schematic diagram; Figure 4 This is the reinforcement elevation drawing of the cast-in-place slab; Figure 5 for Figure 4 1-1 schematic diagram; Figure 6 for Figure 4 2-2 direction schematic diagram; In the figure: reserved groove 1, cast-in-place slab body 2, cast-in-place slab reinforcement 3. DETAILED DESCRIPTION

[0013] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings.

[0014] A cast-in-place slab structure of a solid section on a pier top comprises a reserved groove 1, a cast-in-place slab body 2, cast-in-place slab reinforcement 3, and a formwork system; the cast-in-place slab body 2 is cast by high-strength concrete, and the cast-in-place slab body 2 has a predetermined length, width and thickness, and has excellent bearing capacity and durability to meet the bearing requirements of the pier top; the cast-in-place slab reinforcement 3 built into the cast-in-place slab body 2 comprises longitudinal force-bearing reinforcement and transverse structural reinforcement arranged according to design requirements, and the overall stability and crack resistance of the cast-in-place slab are ensured through precise calculation and arrangement; a reserved groove 1 for installing the cast-in-place slab body 2 and serving as a connection is provided on the pier, and the concrete cast in the reserved groove 1 realizes a firm connection between the cast-in-place slab and the pier, transfers the load, and ensures the safety of the structure; the formwork system comprises a formwork, embedded climbing cones, and a distribution beam, and adopts a detachable design to support concrete and form a desired shape during the casting process, which is convenient for construction operation and subsequent maintenance.

[0015] The concrete strength grade of the cast-in-place slab body 2 is not less than C50 to ensure sufficient bearing capacity.

[0016] The longitudinal reinforcement in the cast-in-place slab reinforcement 3 is welded to ensure the reliability of the connection and the continuity of force transmission.

[0017] Concrete with the same strength as that of the pier body is poured into the reserved groove 1 to achieve a firm connection between the cast-in-place slab body 2 and the pier.

[0018] The cast-in-place slab of the solid section of the pier top uses a whole formwork as the base plate. Pre-buried climbing cones are installed under the formwork to connect the transverse distribution beams as support, and the formwork and the distribution beams are spot welded to prevent the formwork from being displaced.

[0019] A construction method for a cast-in-place slab structure of a solid section on a pier top, wherein all bridge piers are double-column "π"-shaped frame piers, the pier columns are hollow rectangles, the cross-sectional size of a single pier column top is 8.24m×7.1m, the wall thickness of the pier column is 0.8m, the top of the pier column is partially thickened, and the solid section thickness of the top cross beam of the pier column is 6m; the specific steps are as follows: A. Binding of cast-in-place slab reinforcement 3: Process the cast-in-place slab reinforcement into the corresponding component shape according to the size of the reinforcement drawing, and then bind and weld the cast-in-place slab reinforcement according to the distribution of cast-in-place slab reinforcement in the reinforcement drawing. Pay attention to setting the hanging bars to facilitate the later hoisting of the cast-in-place slab to the corresponding position to complete the installation of the cast-in-place slab; a. Prefabrication: (1) Cast-in-place slab production: According to the arrangement of the pier body steel bars, consider distributing the cast-in-place slab steel bars 3 away from the pier body steel bars to prevent conflicts when hoisting and installing the cast-in-place slab body 2 in the later stage; place the tied cast-in-place slab steel bars 3 in the formwork at the back site, and accurately check the position of the cast-in-place slab steel bars 3 to prevent the cast-in-place slab steel bars 3 from being offset and causing conflicts in subsequent installation after pouring. Pour concrete with the same strength as the pier body. After pouring, the concrete of the cast-in-place slab needs to be watered and cured. When the concrete reaches the required strength, it is transported to the site for installation; (2) Installation of cast-in-place slab: hoist the cast-in-place slab body 2 to the pier top. During installation, carefully check the position of the cast-in-place slab body 2 to prevent the cast-in-place slab body 2 from being displaced. Pour concrete in the reserved groove 1 at the pier top. Then tie the solid section steel bars at the pier top to the cast-in-place slab body 2. Finally, pour the concrete of the solid section at the pier top to obtain the cast-in-place slab at the pier top. The cast-in-place slab is designed as a one-way slab and uses the same concrete as the pier body. The cast-in-place slab adopts one-way reinforcement. The shear steel bars in the cast-in-place slab steel bars 3 are arranged near the reserved groove. b. Cast-in-place: (1) Formwork system installation: pre-embedded climbing cones are set at the corresponding position of the next section of the cast-in-place slab in advance, and the transverse distribution beams are welded. The entire formwork is placed on the distribution beams, and the distribution beams are spot welded to the formwork; (2) Pouring concrete: The cast-in-place slab reinforcement 3 of the cast-in-place slab body 2 is hoisted onto the formwork and accurately positioned and installed. At the same time, concrete is poured on the cast-in-place slab body 2 and the reserved groove 1. After the concrete reaches the corresponding strength, the formwork and the distribution beam used for support below are removed through the manhole of the cast-in-place slab body 2 to obtain the cast-in-place slab of the solid section of the pier top.

Claims

1. A cast-in-place slab structure of a solid section on a pier top, characterized in that: It includes a reserved groove, a cast-in-place slab body, cast-in-place slab steel bars and a formwork system; the cast-in-place slab body is cast with high-strength concrete, and the cast-in-place slab body has a predetermined length, width and thickness, and has excellent bearing capacity and durability to meet the bearing requirements of the pier top; the cast-in-place slab steel bars built into the cast-in-place slab body include longitudinal force-bearing steel bars and transverse structural steel bars arranged according to design requirements, and the overall stability and crack resistance of the cast-in-place slab are ensured through precise calculation and arrangement; a reserved groove is provided on the pier for installing the cast-in-place slab body and serving as a connection, and the concrete poured in the reserved groove realizes a firm connection between the cast-in-place slab and the pier, transfers the load and ensures the safety of the structure; the formwork system includes formwork, embedded climbing cones and distribution beams, and adopts a detachable design to support the concrete during the pouring process, which is convenient for construction operations and subsequent maintenance.

2. The cast-in-place slab structure of the solid section of the pier top according to claim 1 is characterized in that: The longitudinal reinforcement in the cast-in-place slab is welded, and the shear reinforcement in the cast-in-place slab is arranged near the reserved groove to ensure the reliability of the connection and the continuity of force transmission.

3. The cast-in-place slab structure of the solid section of the pier top according to claim 1 is characterized in that: Concrete with the same strength as that of the pier body is poured into the reserved groove to achieve a firm connection between the cast-in-place slab body and the pier.

4. The cast-in-place slab structure of the solid section of the pier top according to claim 1, characterized in that: The formwork system of the cast-in-place slab of the solid section of the pier top uses a whole formwork as the base plate. Pre-buried climbing cones are installed under the formwork to connect the transverse distribution beams as support, and the formwork and the distribution beams are spot welded to prevent the formwork from deflecting.

5. The cast-in-place slab structure of the solid section of the pier top according to claim 1, characterized in that: The concrete strength grade of the cast-in-place slab body shall not be lower than C50 to ensure sufficient bearing capacity.

6. A construction method for the cast-in-place slab structure of the pier top solid section according to claim 1, characterized in that: The bridge piers are all double-column "π"-shaped frame piers. The pier columns are hollow rectangles. The cross-sectional dimensions of the top of a single pier column are 8.24m×7.1m. The wall thickness of the pier column is 0.8m. The top of the pier column is partially thickened, and the solid section thickness of the top cross beam of the pier column is 6m. The specific steps are as follows: A. Reinforcement binding: Process the cast-in-place slab steel bars into the corresponding component shape according to the size of the reinforcement drawing, and then tie and weld the cast-in-place slab steel bars according to the distribution of cast-in-place slab steel bars in the reinforcement drawing. Pay attention to setting the hanging bars to facilitate the later lifting of the cast-in-place slab to the corresponding position and complete the installation of the cast-in-place slab; B. Determine whether to cast in place or prefabricate based on the actual construction conditions on site: a. Prefabrication: (1) Cast-in-place slab production: According to the arrangement of the pier body steel bars, consider avoiding the pier body steel bars when distributing the cast-in-place slab steel bars to prevent conflicts during the subsequent hoisting and installation of the cast-in-place slab; place the tied cast-in-place slab steel bars in the formwork at the back site, and accurately check the position of the cast-in-place slab steel bars to prevent the cast-in-place slab steel bars from being offset and causing conflicts during subsequent installation after pouring. Pour concrete with the same strength as the pier body. After pouring, the concrete of the cast-in-place slab needs to be watered and cured. When the concrete reaches the required strength, it is transported to the site for installation; (2) Installation of cast-in-place slab: The cast-in-place slab body is hoisted to the pier top. During installation, the position of the cast-in-place slab body must be carefully checked to prevent the cast-in-place slab body from being displaced. Concrete is poured in the reserved groove on the pier top. The solid section steel bars of the pier top are then tied to the cast-in-place slab body. Finally, the concrete of the solid section of the pier top is poured to obtain the cast-in-place slab of the solid section of the pier top. The cast-in-place slab is designed as a one-way slab and uses the same concrete as the pier body. The cast-in-place slab adopts a one-way reinforcement method and the shear steel bars of the cast-in-place slab steel bars are arranged near the reserved groove. b. Cast-in-place: (1) Formwork system installation: pre-embedded climbing cones are set at the corresponding position of the next section of the cast-in-place slab in advance, and the transverse distribution beams are welded. The entire formwork is placed on the distribution beams, and the distribution beams are spot welded to the formwork; (2) Pouring concrete: The steel bars of the cast-in-place slab are hoisted onto the formwork and accurately positioned and installed. At the same time, concrete is poured into the cast-in-place slab body and the reserved groove. When the concrete reaches the corresponding strength, the formwork and the distribution beam used for support below are removed through the manhole on the cast-in-place slab body to obtain the cast-in-place slab of the solid section of the pier top.

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