Ramp bridge prestress steel box concrete cover beam prestress and concrete construction device

Abstract

The utility model discloses a pre-stress and concrete construction device for a pre-stress steel box concrete cover beam of a ramp bridge. The device comprises an assembly type tensioning support, a concrete pouring grouting pipe, a grout outlet pipe and a grout stop valve. An assembly type tensioning support reverse buckling plate is arranged at the end of a bent cap, two side steel plates are arranged to act counter-force on a steel box web of the bent cap, the two tensioning plates bear the local load of a jack, bundle penetrating holes are reserved in the tensioning plates, and the two side plates provide operation space for prestress releasing and tensioning; the assembly type tensioning support can be repeatedly used, and prestress tensioning and releasing can be achieved without arranging a tensioning pedestal; a grouting pipe and a grout stop valve are arranged on the low side of the cross slope of the cover beam, a grout outlet pipe is arranged on the high side of the cross slope of the cover beam, a sky pump is adopted for grouting into the cover beam from the grouting pipe at low pressure, the grout stop valve is closed after grout is ejected outwards stably for 2-3 min from a grout outlet hole in the top of the steel box at the high position of the cover beam, and it is guaranteed that concrete in the steel box is compact. The construction method mainly solves the problems that a novel prestressed steel box concrete cover beam bridge structure does not have a matched construction method, concrete pouring in a steel box is not compact, and a fixed pedestal cannot be arranged through pre-tensioning prestress.

Description

Technical Field

[0001] This utility model relates to the field of ramp bridge cap beam construction, specifically to a prestressing and concrete construction device for prestressed steel box concrete cap beams of ramp bridges. Background Technology

[0002] When constructing ramp bridge cap beams, the ground support method, through-bar or clamp method are usually used. Therefore, there are a lot of formwork and concrete works, and the high-altitude operation of the support is very common. The construction process is complicated and the construction period is long. The design institute proposed a prestressed steel box concrete cap beam structure for ramp bridges. There is no specific matching construction method for this new structure. There are still many problems in the construction of this structure: (1) The prestressed concrete structure of the pre-tensioning method sets up a fixed tensioning platform. After the concrete is poured and reaches the required age, the tension is released. This method requires the setting up of a fixed tensioning platform and production plant, which occupies a large area and increases the lifting weight. The economic benefits are poor and the safety risks are high. (2) The concrete in the steel box is poured directly by hopper. The pouring hole needs to be opened on the top plate of the steel box. At the same time, the density of the concrete between the pouring holes cannot be guaranteed. High pressure grouting may cause the steel box to become unstable outside the surface. Utility Model Content

[0003] Therefore, to address the aforementioned shortcomings, this utility model provides a prestressing and concrete construction device for prestressed steel box concrete cap beams of ramp bridges. This application primarily solves the problems of the lack of a matching construction method for novel prestressed steel box concrete cap beam bridge structures, insufficient compaction of the concrete inside the steel box, and the inability to install a fixed support for pre-tensioning. This method designs a prefabricated tensioning support to apply and release prestress to the steel box, and uses grouting pipes, grout outlet pipes, and grout stop valves for low-pressure grouting to ensure the compactness of the concrete inside the steel box. This provides a safe, reliable, efficient, and environmentally friendly construction method for prestressed steel box concrete cap beams of ramp bridges.

[0004] This utility model is implemented as follows: a prestressed steel box concrete cap beam prestressing and concrete construction device for a ramp bridge is constructed, characterized in that: it includes an assembled tensioning support (1) and a concrete pouring grouting pipe (2), a grout outlet pipe (3), and a grout stop valve (4); the assembled tensioning support is arranged with a counter-plate at the end of the cap beam, and two side steel plates are set to apply the reaction force to the web of the cap beam steel box. The two tensioning plates bear the local load of the jacks, and the tensioning plates are reserved with pre-drilled holes. The two side plates provide operating space for prestressing release; this assembled tensioning support can be reused and prestressing tensioning and release can be realized without setting a tensioning platform; a grouting pipe (2) and a grout stop valve (4) are set on the low side of the cap beam cross slope, and a grout outlet pipe (3) is set on the high side of the cap beam cross slope. A pump is used to inject grout into the cap beam from the grouting pipe at low pressure. After the grout outlet at the top of the steel box at the high point of the cap beam stably oozes out for 2~3 minutes, the grout stop valve is closed to ensure that the concrete inside the steel box is dense.

[0005] A method for prestressing and concrete construction of prestressed steel box girder for ramp bridges, characterized by the following specific operating steps:

[0006] Step 1: Process the cap beam steel box and the steel strands inside the box in the steel plant and transport them to the construction site. Place them on the tensioning frame nearby, leaving 50cm of steel strands at both ends. Support the cap beam web on the frame.

[0007] Step 2: Install the prestressed tensioning reaction support, using a single bundle jack to tension a single symmetrical prestressed steel strand;

[0008] Step 3: Hoist the prestressed steel box as a whole to the top of the steel pipe concrete pier, use a total station to lay out the centerline of the cap beam, use a level to measure the top elevation of the cap beam, and adjust the longitudinal and transverse positions of the cap beam;

[0009] Step 4: Install the fully automatic prefabricated platform for welding the pier and cap beam. Weld the cap beam steel box and the pier steel pipe. The cap beam and the steel pipe pier are welded with bevel penetration welding. The weld is multi-layered welding using a DC welding machine with a small diameter welding rod and a low current.

[0010] Step 5: Install the tensioning support. Use a boom pump to pour concrete at a pre-reserved 80cm position on the top of the pier steel pipe. Pump self-compacting concrete into the steel box of the cap beam. Inject pressure from the grouting pipe on the lower side of the cap beam until grout continuously and stably emerges from the top of the steel box at the higher part of the cap beam for 2-3 minutes. Then close the grout stop valve until the inside is filled and compacted. Remove the bend in the grouting pipe in time. Remove the stop valve after the concrete has initially set.

[0011] Step 6: After pouring, clean the cement slurry from the surface of the cap beam in a timely manner;

[0012] Step 7: Once the concrete strength reaches 80% or more of the design strength grade, release the prestress. Remove the prestressing tensioning reaction support and then seal the tensioning end.

[0013] This utility model has the following advantages: (1) By designing a prestressed reaction support, it provides operating space for prestressing tensioning and release, which can be reused repeatedly. It does not require the setting of a fixed tensioning platform, reducing the construction area occupied. The structure is simple, economical and reliable. (2) The concrete pouring method is simple and quick, with high construction efficiency and reliable quality. It requires less personnel and reduces a large number of high-altitude operations. (3) This patent provides a safe, economical and reliable construction method for prestressed steel box concrete cap beams of ramp bridges, which has reference significance for the construction of similar structures. Attached Figure Description

[0014] Figures 1-2 This is a schematic diagram of the tensile principle;

[0015] Figure 3 Schematic diagram of steel box concrete pouring method;

[0016] Figures 4-5 This is a side view of the tensioning support;

[0017] Figures 6-7 This is a front view diagram of a tensioning support;

[0018] Figures 8-9 This is a top view of a tensioning support.

[0019] Among them: tensioning support 1, concrete pouring grouting pipe 2, grout outlet pipe 3, grout stop valve 4, and reverse buckle plate 5. Detailed Implementation

[0020] The following will be combined with the appendix Figures 1-9 This utility model will be described in detail, and the technical solutions in the embodiments of this utility model will be clearly and completely described. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0021] This utility model provides a prestressing and concrete construction device for a prestressed steel box girder of a ramp bridge. The main structure of this patent consists of a prefabricated tensioning support 1, a concrete pouring grouting pipe 2, a grout outlet pipe 3, and a grout stop valve 4. The prefabricated tensioning support has inverted plates arranged at the ends of the girder. Two side steel plates apply the reaction force to the web of the steel box girder. Two tensioning plates bear the local load of the jacks and have pre-drilled holes for prestressing. The two side plates provide operating space for prestressing release. This prefabricated tensioning support is reusable and eliminates the need for a tensioning platform, enabling prestressing tensioning and release.

[0022] A grouting pipe and a grout stop valve are installed on the low side of the cross slope of the cap beam, and a grout outlet is installed on the high side of the cross slope of the cap beam. A boom pump is used to inject grout into the cap beam at low pressure from the grouting pipe. After the grout outlet at the top of the steel box at the top of the cap beam is stably gushing out for 2-3 minutes, the grout stop valve is closed to ensure that the concrete inside the steel box is dense.

[0023] The specific operational steps for the construction method of the prestressed steel box concrete cap beam for the ramp bridge corresponding to this application are explained below:

[0024] Step 1: Process the cap beam steel box and the steel strands inside the box at the steel plant and transport them to the construction site. Place them on the tensioning frame nearby, leaving 50cm of steel strands at both ends. Support the cap beam web on the frame.

[0025] Step 2: Install the prestressed tensioning reaction support, using a single bundle jack to tension a single symmetrical prestressed steel strand.

[0026] Step 3: Hoist the prestressed steel box as a whole to the top of the steel pipe concrete pier, use a total station to lay out the centerline of the cap beam, use a level to measure the top elevation of the cap beam, and adjust the longitudinal and transverse positions of the cap beam.

[0027] Step 4: Install the fully automatic prefabricated platform for welding the pier and cap beam. Weld the cap beam steel box and the pier steel pipe. The cap beam and the steel pipe pier are welded with bevel penetration welding. The weld is multi-layered welding using a DC welding machine with a small diameter welding rod and a low current.

[0028] Step 5: Install the tensioning support. Use a boom pump to pour concrete at a pre-reserved 80cm mark on the top of the pier steel pipe. Pump self-compacting concrete into the cap beam steel box. Inject pressure from the grouting pipe on the lower side of the cap beam until grout continuously and steadily emerges from the top of the steel box at the higher part of the cap beam for 2-3 minutes. Then close the grout stop valve until the inside is filled and compacted. Remove the bend in the grouting pipe in time. Remove the stop valve after the concrete has initially set.

[0029] Step 6: After pouring, clean the cement slurry from the surface of the cap beam in a timely manner.

[0030] Step 7: Once the concrete strength reaches 80% or more of the design strength grade, release the prestress. Remove the prestressing tensioning reaction support and then seal the tensioning end.

[0031] This patent has the following advantages and beneficial effects: (1) By designing a prestressed reaction support, it provides operating space for prestressing tensioning and release, which can be reused repeatedly. It does not require the setting of a fixed tensioning platform, reducing the construction area occupied. The structure is simple, economical and reliable. (2) The concrete pouring method is simple and quick, with high construction efficiency and reliable quality. It requires less personnel and reduces a large number of high-altitude operations. (3) This patent provides a safe, economical and reliable construction method for prestressed steel box concrete cap beams of ramp bridges, which has reference significance for the construction of similar structures.

[0032] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A prestressing and concrete construction device for a prestressed steel box girder of a ramp bridge, characterized in that; It includes a prefabricated tensioning support (1) and a concrete pouring grouting pipe (2), a grout outlet pipe (3), and a grout stop valve (4); the prefabricated tensioning support is arranged at the end of the cap beam with a reverse buckle plate, and two side steel plates are set to apply the reaction force to the web of the cap beam steel box. The two tensioning plates bear the local load of the jacks, and the tensioning plates are reserved with pre-drilled holes. The two side plates provide operating space for prestressing release; the grouting pipe (2) and the grout stop valve (4) are set on the low side of the cross slope of the cap beam, and the grout outlet pipe (3) is set on the high side of the cross slope of the cap beam.

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