Double-pier two-side prestress large cantilever variable cross-section cast-in-place bent cap and construction method

Abstract

The invention provides a double-pier two-side prestress large cantilever variable cross-section cast-in-place cover beam and a construction method, and aims at construction of the double-pier two-side prestress large cantilever variable cross-section cast-in-place cover beam, a steel pipe column foundation is constructed on the ground, micro-concave connecting steel plates are pre-buried on the steel pipe column foundation and a bearing platform, and steel pipe columns are mounted on the steel pipe column foundation and the bearing platform; the steel pipe columns are fixed through inner supporting supports and inclined struts, the upper portions of the steel pipe columns are connected with section steel beams through connecting steel plates and connecting bolts, distribution beams and cover beam bottom dies are arranged on the upper portions of the section steel beams, and adjustable inclined formwork supports and section steel supports are arranged on the upper portions of the section steel beams to support inclined formworks. And a template transverse bracket is arranged on the section steel beam to transversely support the capping beam template. The invention belongs to the field of civil engineering, and relates to a construction method for a double-pier two-side prestress large cantilever variable cross-section cast-in-place cover beam structure, which effectively reduces the engineering cost, accelerates the construction speed, and can obtain better technical and economic benefits when being applied to actual engineering.

Description

Technical Field

[0001] The invention relates to the field of civil engineering, and in particular to a prestressed large cantilever variable-section cast-in-place cap beam on both sides of a double pier and a construction method. Background Art

[0002] In bridge engineering, with the optimization of design, ordinary cap beam structure can no longer meet the needs of actual engineering, so the design of large cantilever prestressed cap beam timely solves this demand. With the improvement of highway grade and usage function, the requirements for bridge deck width are constantly increasing. Large cantilever cap beam has the advantages of large span, simple shape, and saving space under the bridge, so it is widely used in urban viaducts.

[0003] The traditional cap beam support system construction has the disadvantages of low support erection efficiency and difficulty in adjusting the angle and installing the inclined templates at both ends of the cap beam. Summary of the invention

[0004] The object of the present invention is to provide a prestressed large cantilever variable-section cast-in-place cap beam on both sides of a double pier and a construction method for solving the above-mentioned technical problems.

[0005] In order to solve the above technical problems, the present invention provides a construction method of a prestressed large cantilever variable-section cast-in-place cap beam on both sides of a double pier, comprising the following steps:

[0006] Step 1: Construction of steel pipe column foundation: excavate the foundation pit of the steel pipe column foundation, install grouting steel pipes around the steel pipe column foundation, and reinforce the soil around the steel pipe column foundation to form cement slurry reinforced soil, then tie the foundation steel bars and pour concrete, and set a pre-buried micro-concave connecting steel plate between the steel pipe column foundation and the upper part of the cap;

[0007] Step 2: Installation of cap beam support: Install the steel pipe column on the steel pipe column foundation. The lower part of the steel pipe column is fixed to the pre-buried micro-concave connecting steel plate through the connecting steel plate and connecting bolts at the bottom of the steel pipe column. The upper part of the steel pipe column is connected to the steel beam through the connecting steel plate and connecting bolts. The adjacent steel pipe columns are fixed through internal support brackets and diagonal braces.

[0008] Step 3: Installation of cap beam template: Lay the distribution beam on the steel beam, and install the cap beam template on the distribution beam. The upper part of the steel beam supports the inclined template through the adjustable inclined template support and the steel support. The template transverse support is set on the steel beam to support the cap beam template transversely.

[0009] Step 4: Pre-pressing the support: The cap beam support is pre-pressed by the reverse pre-pressing of the bottom pedestal beam and the weight of the concrete block. A steel pull ring is set on the bottom pedestal beam, and a jack, a gasket and a steel strand are set on the upper part of the cap beam support;

[0010] Step 5: Cap beam construction: After the cap beam reinforcement and embedded parts are installed and the formwork is reinforced, the cap beam concrete is poured and maintained.

[0011] The beneficial effects of the present invention are:

[0012] (1) The pre-buried micro-concave connecting steel plate structure is used to connect the lower part of the steel pipe column of the cap beam support to improve the installation and construction efficiency of the steel pipe column of the cap beam support;

[0013] (2) Use grouting steel pipes and cement slurry to reinforce the soil around the steel pipe column foundation to improve the overall bearing capacity of the steel pipe column foundation;

[0014] (3) Use adjustable inclined formwork brackets to accurately adjust the installation position of the cap beam inclined formwork to improve the installation quality and efficiency of the cap beam formwork;

[0015] (4) The support pre-compression is carried out by combining the reverse tension pre-compression of the pedestal beam and the weight of the concrete block to improve the construction efficiency of the support pre-compression. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the structural diagram of the prestressed large cantilever variable-section cast-in-place cap beam on both sides of the double piers;

[0017] Figure 2 This is the structural diagram of the cap beam support pre-compression;

[0018] Figure 3 It is the structural diagram of the steel pipe column foundation;

[0019] Figure 4 This is a structural diagram of an adjustable tilting formwork support.

[0020] In the figure: 1. Capping platform; 2. Pre-buried micro-concave connecting steel plate; 3. Steel pipe column foundation; 4. Internal support bracket; 5. Pier column; 6. Distribution beam; 7. Cap beam formwork; 8. Cap beam; 9. Steel support; 10. Adjustable inclined formwork support; 11. Connecting steel plate; 12. Formwork horizontal support; 13. Steel beam; 14. Connecting bolts; 15. Diagonal brace; 16. Steel pipe column; 17. Bottom capping platform crossbeam; 18. Steel pull ring; 19 , jack; 20, gasket; 21, steel strand; 22, concrete block weight; 23, steel plate connecting the bottom of the steel pipe column; 24, anchoring steel bars; 25, grouting steel pipe; 26, cement slurry to reinforce the soil; 27, bottom cross beam of the bracket; 28, inclined formwork; 29, bracket adjustment beam; 30, adjusting support steel plate; 31, adjusting slot; 32, adjusting positioning bolts; 33, adjusting support steel plate fixing bolts; 34, cap beam bracket. DETAILED DESCRIPTION

[0021] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0022] Those skilled in the art should understand that, in the disclosure of the present invention, the orientation or position relationship indicated by the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0023] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0024] like Figure 1-Figure 4 The present invention provides a construction method for a double-pier two-side prestressed large cantilever variable-section cast-in-place cap beam, comprising the following steps:

[0025] Step 1, construction of steel pipe column foundation 3: excavate a foundation pit for the steel pipe column foundation 3 on the ground, set a grouting steel pipe 25 around the steel pipe column foundation 3, and reinforce the soil around the steel pipe column foundation 3 to form a cement slurry reinforced soil 26, then tie the foundation steel bars and pour concrete, and set a pre-buried micro-concave connecting steel plate 2 between the steel pipe column foundation 3 and the upper part of the cap 1;

[0026] Among them, Figure 3 As shown in the structural diagram of the steel pipe column foundation 3 , a pre-buried micro-dimpled connecting steel plate 2 and anchoring steel bars 24 are arranged on the upper portion of the steel pipe column foundation 3 , and a groove is arranged on the upper portion of the pre-buried micro-dimpled connecting steel plate 2 to connect with the steel pipe column 16 .

[0027] Step 2, installation of cap beam support 34: install steel pipe column 16 on steel pipe column foundation 3, the lower part of steel pipe column 16 is fixed to pre-buried micro-dimpled connecting steel plate 2 through connecting steel plate 23 at the bottom of steel pipe column and connecting bolts 14, the upper part of steel pipe column 16 is connected to profiled steel beam 13 through connecting steel plate 11 and connecting bolts 14, and adjacent steel pipe columns 16 are fixed through inner support bracket 4 and diagonal support 15;

[0028] Step 3, installation of cap beam template 7: laying distribution beam 6 on profiled steel beam 13 and installing cap beam template 7 on distribution beam 6, the upper part of profiled steel beam 13 supports inclined template 28 through adjustable inclined template support 10 and profiled steel support 9, the adjustable inclined template support 10 includes a plurality of adjustable support steel plates 30, the adjustable support steel plates 30 are provided with adjustment grooves 31, and positioning bolts 32 are provided in the adjustment grooves 31, so that when adjusting the positioning bolts 32, the height and angle of inclined template 28 can be adjusted, and template transverse support 12 is provided on profiled steel beam 13 to support cap beam template 7 transversely;

[0029] Among them, Figure 4 As shown in the structural diagram of the adjustable inclined formwork support 10, a support adjustment beam 29 is arranged on the upper part of several adjustable support steel plates 30 in the adjustable inclined formwork support 10, and the bottoms of several adjustable support steel plates 30 are connected to the support bottom cross beam 27, and the support bottom cross beam 27 and the support adjustment beam 29 are connected to the adjustable support steel plates 30 by adjusting support steel plate fixing bolts 33.

[0030] In one embodiment of the present scheme, the adjustment support steel plate 30 includes a first steel plate and a second steel plate, the first steel plate is inserted into the second steel plate, and an adjustment groove 31 is opened on the side of the second steel plate, and the side of the first steel plate is tightened and fixed by passing a positioning bolt 32 through the adjustment groove 31, and the positioning bolt 32 is threadedly matched with the adjustment groove 31.

[0031] Step 4: Pre-pressing the support: The cap beam support 34 is pre-pressed by the reverse tension pre-pressing of the bottom pedestal beam 17 and the concrete block weight 22. A steel pull ring 18 is provided on the bottom pedestal beam 17, and a jack 19, a gasket 20 and a steel strand 21 are provided on the upper part of the cap beam support 34;

[0032] like Figure 2 As shown, the cap beam support 34 is formed by overlapping the steel pipe column 16, the bottom pedestal beam 17, and the steel beam 13. The concrete block weight 22 is placed on the upper part of the cap beam support 34. At the same time, a jack 19 is arranged on the upper part of the cap beam support 34. The two ends of the steel strand 21 are respectively connected to the steel pull ring 18 and the jack 19, so that when the jack is lifted, the cap beam support 34 is pulled back through the steel strand 21.

[0033] A gasket 20 is provided at the bottom of the jack 19 to ensure the reverse pulling stability of the jack 19 .

[0034] Step 5, construction of cap beam 8: After the installation of the steel bars and embedded parts of the cap beam 8 and the reinforcement of the formwork are completed, the concrete pouring and maintenance construction of the cap beam 8 are carried out.

[0035] like Figure 1The structure diagram of the prestressed large cantilever variable cross-section cast-in-place cap beam 8 on both sides of the double piers shown mainly includes a cap 1, embedded micro-concave connecting steel plate 2, steel pipe column foundation 3, internal support bracket 4, pier column 5, cap beam formwork 7, cap beam 8, steel support 9, adjustable inclined formwork support 10, template transverse support 12, steel beam 13, steel pipe column 16, bottom cap cross beam 17, cap beam support 34. For the construction of the prestressed large cantilever variable cross-section cast-in-place cap beam 8 on both sides of the double piers, the steel pipe column foundation 3 is constructed on the ground, the steel pipe column foundation 3 and the cap 1 are installed with embedded micro-concave connecting steel plate 2, the cap 1 is provided with a pier column 5, the steel pipe column foundation 3 and the cap 1 are installed with a steel pipe column 16, and the distribution beam 6 and the cap beam 8 bottom formwork are provided on the steel beam 13.

[0036] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

Claims

1. The construction method of prestressed large cantilever variable cross-section cast-in-place cap beam on both sides of double piers is characterized by: The following steps are involved: Step 1, construction of steel pipe column foundation (3): excavating a foundation pit for the steel pipe column foundation (3), installing a grouting steel pipe (25) on the periphery of the steel pipe column foundation (3), and reinforcing the soil around the steel pipe column foundation (3) to form a cement slurry reinforced soil (26), then tying the foundation steel bars and pouring concrete, and pre-embedded micro-concave connecting steel plates (2) are arranged on the upper part of the steel pipe column foundation (3) and the cap (1); Step 2, installation of the cap beam support (34): install the steel pipe column (16) on the steel pipe column foundation (3), the lower part of the steel pipe column (16) is fixed to the pre-buried micro-concave connecting steel plate (2) through the steel pipe column bottom connecting steel plate (23) and connecting bolts (14), the upper part of the steel pipe column (16) is connected to the steel beam (13) through the connecting steel plate (11) and connecting bolts (14), and adjacent steel pipe columns (16) are fixed by internal support brackets (4) and diagonal braces (15); Step 3, installation of the cap beam template (7): laying the distribution beam (6) on the steel beam (13), and installing the cap beam template (7) on the distribution beam (6), the upper part of the steel beam (13) supports the inclined template (28) through an adjustable inclined template support (10) and a steel support (9), and a template transverse support (12) is set on the steel beam (13) to support the cap beam template (7) laterally; Step 4: Pre-stressing the support: The cap beam support (34) is pre-stressed by the reverse tension pre-stressing of the bottom pedestal cross beam (17) and the concrete block weight (22). A steel pull ring (18) is arranged on the bottom pedestal cross beam (17), and a jack (19), a gasket (20) and a steel strand (21) are arranged on the upper part of the cap beam support (34); Step 5: Construction of cap beam (8): After the installation of the steel bars and embedded parts of the cap beam (8) is completed and the formwork reinforcement is completed, the cap beam (8) concrete pouring and maintenance construction are carried out.

2. The construction method of the prestressed large cantilever variable cross-section cast-in-place cap beam on both sides of the double pier according to claim 1 is characterized by: In step one, a pre-buried micro-dimpled connecting steel plate (2) and anchoring steel bars (24) are arranged on the upper part of the steel pipe column foundation (3), and a groove is arranged on the upper part of the pre-buried micro-dimpled connecting steel plate (2) to connect with the steel pipe column (16).

3. The construction method of the prestressed large cantilever variable cross-section cast-in-place cap beam on both sides of the double pier according to claim 1 is characterized by: In step three, the adjustable inclined template support (10) includes a plurality of adjustable support steel plates (30), and an adjustment slot (31) is provided on the adjustable support steel plates (30). The adjustment slot (31) has a positioning bolt (32) therein, so that when the positioning bolt (32) is adjusted, the height and angle of the inclined template (28) can be adjusted.

4. The construction method of the prestressed large cantilever variable cross-section cast-in-place cap beam on both sides of the double piers according to claim 3 is characterized by: A support adjusting beam (29) is arranged on the upper part of a plurality of adjusting support steel plates (30) in the adjustable inclined formwork support (10); the bottoms of the plurality of adjusting support steel plates (30) are connected to a support bottom cross beam (27); the support bottom cross beam (27) and the support adjusting beam (29) are connected to the adjusting support steel plates (30) via adjusting support steel plate fixing bolts (33).

5. The construction method of the prestressed large cantilever variable cross-section cast-in-place cap beam on both sides of the double piers according to claim 3 is characterized by: The adjustment support steel plate (30) comprises a first steel plate and a second steel plate, wherein the first steel plate is inserted into the second steel plate, and an adjustment groove (31) is provided on the side of the second steel plate. The side of the first steel plate is tightened and fixed by passing a positioning bolt (32) through the adjustment groove (31).

6. The construction method of the prestressed large cantilever variable cross-section cast-in-place cap beam on both sides of the double pier according to claim 1 is characterized by: In step four, the cap beam support (34) is formed by overlapping the steel pipe column (16), the bottom pedestal beam (17), and the steel beam (13), and the concrete block weight (22) is placed on the upper part of the cap beam support (34). At the same time, a jack (19) is set on the upper part of the cap beam support (34), and the two ends of the steel strand (21) are respectively connected to the steel pull ring (18) and the jack (19), so that when the jack is lifted, the cap beam support (34) is pulled back through the steel strand (21).

7. The construction method of the prestressed large cantilever variable cross-section cast-in-place cap beam on both sides of the double piers according to claim 6 is characterized by: The bottom of the jack (19) is padded with a gasket (20).

8. The construction method of the prestressed large cantilever variable cross-section cast-in-place cap beam on both sides of the double pier according to claim 1 is characterized by: A pier column (5) is arranged on the upper part of the cap (1), a steel pipe column foundation (3) and a steel pipe column (16) are installed on the cap (1), and a distribution beam (6) and a bottom formwork of a cap beam (8) are arranged on the upper part of the steel beam (13).

9. A cast-in-place cap beam with large cantilever and variable cross-section and prestressed on both sides of double piers, characterized in that: It is obtained by the construction method of prestressed large cantilever variable-section cast-in-place cap beam on both sides of double piers according to any one of claims 1-8.

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