Self-adaptive bearing hollow pier top solid section bottom die

Abstract

The utility model relates to a self-adaptive bearing hollow pier top solid section bottom die which comprises a hollow pier body, hollow pier steel bars are reserved at the top of the hollow pier body, a concrete prefabricated slab is installed at the top end of the hollow pier body, and a prefabricated slab steel bar mesh is embedded in the concrete prefabricated slab. The periphery of the prefabricated plate reinforcing mesh is connected with hollow pier reinforcing steel bars in a binding mode, pier top bottom load-bearing reinforcing steel bars are installed on the hollow pier reinforcing steel bars, the top end of the hollow pier body and the top end of the concrete prefabricated plate are poured through concrete to form a cast-in-place pier top sealing bottom, and the periphery of the prefabricated plate reinforcing mesh and the pier top bottom load-bearing reinforcing steel bars are all embedded in the cast-in-place pier top sealing bottom. The hollow pier top solid section bottom formwork has the advantages that the problems that a traditional bottom formwork erecting construction process is tedious, the later-period dismantling difficulty is large, and the safety risk is high are solved; and concrete pouring of hollow pier top solid sections of different specifications can be borne in a self-adaptive mode by adjusting the using amount of pier top bottom stressed steel bars and the pouring height of a cast-in-place pier top sealing bottom.

Description

Technical Field

[0001] The utility model relates to the technical field of bridge pier construction, in particular to a bottom formwork for a solid section of a hollow pier top capable of adaptively bearing loads. Background Art

[0002] In high-speed rail bridges, the taller piers are often hollow piers. Hollow piers typically consist of a hollow pier body and a solid section at the top, with the top section typically 3-4 meters high. Construction of the top section typically begins after the pier body is completed. Traditional methods for constructing the top section include installing ground-based scaffolding within the pier, using pre-embedded steel brackets and steel supports on the inner wall of the pier top, or using precast concrete slabs as supports.

[0003] Since the height of the hollow piers of high-speed railway bridges is generally around 20-60m, and some piers are even higher than 60m, setting up ground scaffolding is not only large in size but also time-consuming and labor-intensive. This height of scaffolding is an extremely dangerous plan with a high construction risk.

[0004] However, the erection of steel supports for embedded corbels requires a high steel structure cost, and after the solid section is cast, it is difficult to remove the steel sections because there is no ground support at the bottom, and it may often be impossible to remove them, resulting in a large construction cost investment.

[0005] Since the solid section of the pier top is poured in one go, before the concrete forms strength and can bear the load, the formwork needs to have a large load-bearing capacity to withstand the weight of all the concrete on the top. If we follow the conventional thinking of concrete precast panels, as the size of the solid section increases, the thickness of the panel and the number of steel bars need to be continuously increased according to the load-bearing requirements. This not only increases the construction cost investment, but the increase in the weight of the precast panels also places higher demands on high-altitude lifting equipment.

[0006] Therefore, in order to solve the above problems, the present invention proposes a bottom formwork for the solid section of the top of a hollow pier, which has a simple and lightweight structure, can be prefabricated in a standardized manner, is easy to construct, and does not need to be dismantled later. Utility Model Content

[0007] The purpose of the utility model is to overcome the above problems existing in the prior art and to provide a bottom formwork for a solid section of a hollow pier top that can self-adaptively bear loads.

[0008] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0009] A bottom formwork for a solid section of a hollow pier top that is adaptively load-bearing comprises a hollow pier body, wherein the top of the hollow pier body is pre-set with hollow pier steel bars extending upward, a rectangular concrete precast panel is installed on the top of the hollow pier body, a precast panel steel mesh is pre-embedded in the concrete precast panel, and the four sides of the precast panel steel mesh are respectively exposed outside the concrete precast panel, the four sides of the precast panel steel mesh are respectively tied and connected to the hollow pier steel bars, stress-bearing steel bars at the bottom of the pier top are installed on the hollow pier steel bars, the top of the hollow pier body and the top of the concrete precast panel are poured with concrete to form a cast-in-place pier top bottom cover, and the four sides of the precast panel steel mesh and the stress-bearing steel bars at the bottom of the pier top are all embedded in the cast-in-place pier top bottom cover.

[0010] Among them, the concrete precast slab is provided with vertical shear-resistant connecting steel bars extending upward, the bottom of the vertical shear-resistant connecting steel bars is tied and connected to the precast slab steel mesh, and the bottom of the vertical shear-resistant connecting steel bars is embedded in the concrete precast slab; the upper part of the vertical shear-resistant connecting steel bars is tied and connected to the stress-bearing steel bars at the bottom of the pier top, and the upper part of the vertical shear-resistant connecting steel bars is embedded in the cast-in-place pier top bottom cover.

[0011] The spacing of the vertical shear-resistant connecting steel bars along the long side of the precast concrete slab is 1 meter, and the vertical shear-resistant connecting steel bars are arranged in two rows along the short side of the precast concrete slab.

[0012] The top of the precast concrete panel is provided with a plurality of evenly distributed grooves along its long side direction, the depth of the grooves is 1 cm, and the distance between any two adjacent grooves is 10 cm.

[0013] The top of the precast concrete panel is flush with the top of the designed height of the hollow pier body.

[0014] Wherein, the thickness of the precast concrete slab is 10 cm or 20 cm.

[0015] The precast slab steel mesh includes precast slab long side steel bars parallel to the long side of the concrete precast slab and precast slab short side steel bars parallel to the short side of the concrete precast slab. The precast slab long side steel bars and precast slab short side steel bars are cross-tied together.

[0016] Among them, the prefabricated plate steel mesh is one or two layers, and the distance between two adjacent prefabricated plate long side steel bars in the same layer of the prefabricated plate steel mesh is 10 cm, and the distance between two adjacent prefabricated plate short side steel bars in the same layer of the prefabricated plate steel mesh is 10 cm.

[0017] The height difference between the top of the cast-in-situ pier top seal and the top of the precast concrete slab is 8% of the design height of the solid section of the hollow pier top.

[0018] The beneficial effects of the present invention are as follows: a section of cast-in-place pier top bottom cover is first cast by using a precast concrete plate as a bottom supporting formwork, and then the precast concrete plate and the cast-in-place pier top bottom cover are used as a bottom formwork for casting the solid section of the hollow pier top, and stress-bearing steel bars at the bottom of the pier top are added to the cast-in-place pier top bottom cover to improve the bearing capacity of the cast-in-place pier top bottom cover. The bottom formwork for the solid section of the hollow pier top solves the problems of complicated construction process of traditional bottom formwork erection, great difficulty in later dismantling and high safety risks, and can adaptively bear the concrete pouring of the solid sections of the hollow pier tops of different specifications by adjusting the amount of stress-bearing steel bars at the bottom of the pier top and the pouring height of the cast-in-place pier top bottom cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 This is a structural schematic diagram of the solid section bottom formwork of the hollow pier top in Example 1 of the present utility model observed from the long side direction;

[0021] Figure 2 This is a structural schematic diagram of the bottom formwork of the solid section of the top of the hollow pier in the first embodiment of the present invention as viewed from the short side;

[0022] Figure 3 This is a schematic diagram of the structure of the concrete precast panel in the first embodiment of the present invention from a top view;

[0023] Figure 4 This is a schematic structural diagram of a precast concrete panel in the second embodiment of the present invention as viewed from the long side;

[0024] Explanation of the numbers in the figure: hollow pier body 100, hollow pier steel bar 101, precast concrete slab 1, groove 11, precast slab steel mesh 2, precast slab long side steel bar 21, precast slab short side steel bar 22, pier top and bottom stress-bearing steel bar 3, cast-in-place pier top and bottom seal 4, vertical shear connection steel bar 5. DETAILED DESCRIPTION

[0025] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0026] like Figures 1 to 3 The first embodiment shown is a bottom formwork for a solid section of a hollow pier top that is adaptively load-bearing, comprising a hollow pier body 100, the top of which is reserved with a hollow pier reinforcement 101 extending upward, and a rectangular precast concrete panel 1 installed at the top of the hollow pier body 100, the top of which is flush with the top of the designed height of the hollow pier body 100; in this embodiment, the thickness of the precast concrete panel 1 is 10 cm.

[0027] A precast concrete slab reinforcement mesh 2 is embedded in the slab, with its four sides exposed outside the slab. The mesh 2 includes long-side reinforcement bars 21 parallel to the long sides of the slab, and short-side reinforcement bars 22 parallel to the short sides of the slab. The long-side reinforcement bars 21 and short-side reinforcement bars 22 are cross-bound and tied together. Furthermore, the spacing between two adjacent long-side reinforcement bars 21 and short-side reinforcement bars 22 in the same layer of mesh 2 is 10 cm. Similarly, the spacing between two adjacent short-side reinforcement bars 22 in the same layer of mesh 2 is 10 cm.

[0028] The top of the hollow pier body 100 and the top of the concrete precast slab 1 are cast with concrete to form a cast-in-place pier top and bottom seal 4. The height difference between the top of the cast-in-place pier top and bottom seal 4 and the top of the concrete precast slab 1 is 8% of the designed height of the solid section of the hollow pier top.

[0029] The four sides of the prefabricated plate steel mesh 2 are respectively tied and connected with the hollow pier steel bars 101, and the pier top and bottom stress-bearing steel bars 3 are installed on the hollow pier steel bars 101. The four sides of the prefabricated plate steel mesh 2 and the pier top and bottom stress-bearing steel bars 3 are all embedded in the cast-in-place pier top bottom cover 4.

[0030] The precast concrete slab 1 is provided with upwardly extending vertical shear connecting steel bars 5, the bottom of the vertical shear connecting steel bars 5 is tied and connected to the precast slab steel mesh 2, and the bottom of the vertical shear connecting steel bars 5 is embedded in the precast concrete slab 1; the upper part of the vertical shear connecting steel bars 5 is tied and connected to the tension steel bars 3 at the bottom of the pier top, and the upper part of the vertical shear connecting steel bars 5 is embedded in the cast-in-place pier top bottom cover 4; the spacing of the vertical shear connecting steel bars 5 along the long side direction of the precast concrete slab 1 is 1 meter, and the vertical shear connecting steel bars 5 are arranged in two rows along the short side direction of the precast concrete slab 1.

[0031] As shown in the figure, the second embodiment is different from the first embodiment in that a plurality of evenly distributed grooves 11 are provided on the top of the precast concrete panel 1 along its long side direction, the depth of the grooves is 1 cm, and the distance between any two adjacent grooves is 10 cm.

[0032] Construction method:

[0033] 1. When pouring the hollow pier body 100, a height equal to the thickness of the precast slab is reserved at the top of the hollow pier body 100 and concrete is not poured temporarily. A hollow pier steel bar 101 extending upward is reserved at the top of the hollow pier body 100;

[0034] 2. Hoist the precast concrete slab 1 to the top of the hollow pier body 100, and tie and connect the four sides of the precast slab steel mesh 2 to the hollow pier steel bars 101 respectively;

[0035] 3. Install the stress-bearing steel bars 3 at the top and bottom of the pier on the hollow pier steel bars 101;

[0036] 4. Build the outer formwork of the solid section of the hollow pier top according to its outer shape, then pour concrete to form the cast-in-place pier top bottom seal 4, and embed the surrounding precast slab steel mesh 2 and the stress-bearing steel bars 3 at the bottom of the pier top in the cast-in-place pier top bottom seal 4;

[0037] 5. When the concrete strength of the cast-in-place pier top and bottom seal 4 reaches 80%-85% of the design strength, the integral pouring of the solid section of the hollow pier top is completed.

[0038] When the design height of the solid section of the hollow pier top is 3-3.5m, the thickness of the precast concrete slab 1 is 10cm; when the design height of the solid section of the hollow pier top is 3.5-4m, the thickness of the precast concrete slab 1 is 20cm.

[0039] When the height difference between the top of the cast-in-place pier top cover 4 and the top of the concrete precast slab 1 is less than or equal to 30 cm, the precast slab steel mesh 2 is one layer; when the height difference between the top of the cast-in-place pier top cover 4 and the top of the concrete precast slab 1 is greater than 30 cm, the precast slab steel mesh 2 is two layers, and the height difference between the two layers of precast slab steel mesh 2 is 10 cm.

[0040] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and improvements fall within the scope of the present invention as claimed.

Claims

1. A self-adaptive load-bearing hollow pier top solid section bottom formwork, including a hollow pier body, characterized by: The top of the hollow pier body is reserved with hollow pier steel bars extending upward, and a rectangular concrete precast panel is installed on the top of the hollow pier body. A precast panel steel mesh is embedded in the concrete precast panel, and the four sides of the precast panel steel mesh are exposed outside the concrete precast panel. The four sides of the precast panel steel mesh are respectively tied and connected with the hollow pier steel bars, and the hollow pier steel bars are installed with stress-bearing steel bars at the bottom of the pier. The top of the hollow pier body and the top of the concrete precast panel are poured with concrete to form a cast-in-place pier top and bottom cover, and the four sides of the precast panel steel mesh and the stress-bearing steel bars at the bottom of the pier top are embedded in the cast-in-place pier top and bottom cover.

2. The bottom formwork for the solid section of the hollow pier top according to claim 1, characterized in that: The concrete precast slab is provided with vertical shear-resistant connecting steel bars extending upward, the bottom of the vertical shear-resistant connecting steel bars is tied and connected to the precast slab steel mesh, and the bottom of the vertical shear-resistant connecting steel bars is embedded in the concrete precast slab; the upper part of the vertical shear-resistant connecting steel bars is tied and connected to the stress-bearing steel bars at the bottom of the pier top, and the upper part of the vertical shear-resistant connecting steel bars is embedded in the cast-in-place pier top bottom cover.

3. The bottom formwork for the solid section of the hollow pier top according to claim 2, characterized in that: The spacing of the vertical shear-resistant connecting steel bars along the long side direction of the concrete precast slab is 1 meter, and the vertical shear-resistant connecting steel bars are arranged in two rows along the short side direction of the concrete precast slab.

4. The bottom formwork for the solid section of the hollow pier top according to claim 1, characterized in that: The top of the precast concrete panel is provided with a plurality of evenly distributed grooves along the long side thereof. The depth of the grooves is 1 cm, and the distance between any two adjacent grooves is 10 cm.

5. The bottom formwork for the solid section of the hollow pier top according to claim 1, characterized in that: The top of the precast concrete slab is flush with the top of the designed height of the hollow pier body.

6. The bottom formwork for the solid section of the hollow pier top according to claim 1, characterized in that: The thickness of the precast concrete slab is 10 cm or 20 cm.

7. The bottom formwork for the solid section of the hollow pier top according to claim 1, characterized in that: The precast slab steel mesh includes precast slab long side steel bars parallel to the long sides of the concrete precast slab and precast slab short side steel bars parallel to the short sides of the concrete precast slab. The precast slab long side steel bars and the precast slab short side steel bars are cross-bound together.

8. The bottom formwork for the solid section of the hollow pier top according to claim 7, characterized in that: The prefabricated plate steel mesh is one or two layers, and the distance between two adjacent prefabricated plate long side steel bars in the same layer of the prefabricated plate steel mesh is 10 cm, and the distance between two adjacent prefabricated plate short side steel bars in the same layer of the prefabricated plate steel mesh is 10 cm.

9. The bottom formwork for the solid section of the hollow pier top according to claim 1, characterized in that: The height difference between the top of the cast-in-situ pier top bottom seal and the top of the concrete precast slab is 8% of the designed height of the solid section of the hollow pier top.

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