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

Abstract

The invention discloses a ramp bridge prestress steel box concrete cover beam prestress and concrete construction device and method. 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] The invention relates to the field of ramp bridge cap beam construction, and in particular to a ramp bridge prestressed steel box concrete cap beam prestressed and concrete construction device and method. Background Art

[0002] When constructing ramp bridge cap beams, the ground support method, through-rod or clamp method are usually used. Therefore, there are a large number of formwork and concrete projects, and there are many high-altitude operations for the erection of support beams. The construction process is complex 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 a fixed tensioning pedestal, and the tension is released after the concrete pouring is completed and reaches the age requirement. This method requires the establishment of a fixed tensioning pedestal and a 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 pouring in the steel box adopts the hopper direct pouring, which requires the opening of pouring holes on the top plate of the steel box. At the same time, the density of the concrete between the pouring holes cannot be guaranteed. The use of high-pressure pouring may cause the steel box to be unstable outside the surface. Summary of the invention

[0003] Therefore, in order to solve the above-mentioned deficiencies, the present invention provides a prestressed steel box concrete cap beam prestressed and concrete construction device and method for ramp bridge; this application mainly solves the problems of no matching construction method for new bridge structures with prestressed steel box concrete cap beams, loose concrete pouring in the steel box, and inability to set a fixed pedestal for prestressing. This method designs an assembled tensioning bracket to apply and release prestress to the steel box, and sets a grouting pipe, a grouting pipe, and a grouting stop valve for low-pressure grouting to ensure that the concrete in the steel box is dense, providing a safe, reliable, efficient, and environmentally friendly construction method for prestressed steel box concrete cap beams for ramp bridges.

[0004] The present invention is implemented in the following way: a prestressed steel box concrete cap beam of a ramp bridge is constructed, and the prestressed steel box concrete cap beam and the prestressed concrete construction device are characterized in that: it comprises an assembled tensioning bracket (1) and a concrete pouring grouting pipe (2), a grouting pipe (3), and a grouting stop valve (4); the assembled tensioning bracket is arranged at the end of the cap beam through a buckle plate, and two side steel plates are arranged to apply reaction force to the web of the cap beam steel box, and the two tensioning plates bear the local load of the jack, and the beam holes are reserved thereon, and the two side plates provide an operating space for prestressing release; the assembled tensioning bracket can be reused, and prestressing and release can be achieved without setting a tensioning pedestal; a grouting pipe (2) and a grouting stop valve (4) are arranged on the low side of the cap beam transverse slope, and a grouting pipe (3) is arranged on the high side of the cap beam transverse slope, and a sky pump is used to inject grout from the grouting pipe at low pressure into the cap beam, and the grouting stop valve is closed after the grouting hole at the top of the steel box at the high end of the cap beam stably emits grout for 2 to 3 minutes, thereby ensuring that the concrete in the steel box is dense.

[0005] A method for prestressing and concrete construction of a prestressed steel box concrete cap beam of a ramp bridge, characterized by the following specific operating steps: Step 1: Process the cap beam steel box and the steel strands in the box in the steel plant and transport them to the construction site. Place them on the tensioning cradle nearby, leaving 50cm of steel strands at both ends, and support the web of the cap beam on the cradle; Step 2: Install the prestressed tensioning reaction support, using a single-beam jack to tension a single symmetrical prestressed steel strand; Step 3: hoist the prestressed steel box as a whole to the top of the steel tube concrete pier, use the total station to set out the center axis of the cap beam, use the level to measure the top elevation of the cap beam, and adjust the longitudinal and transverse positions of the cap beam; Step 4: Install the pier column-cap beam welding assembled fully automatic upper and lower platform, weld the cap beam steel box and the pier column steel pipe, and use groove penetration welding between the cap beam and the steel pipe pier column. The weld seam uses a smaller diameter electrode and a DC welding machine with lower current for multi-layer welding; Step 5: Install the tensioning bracket, use a sky pump to pour concrete at a reserved 80cm position on the top of the pier steel pipe, pump self-compacting concrete into the steel box of the cap beam, and inject pressure from the grouting pipe on the lower side of the cap beam until the grouting pipe on the top of the steel box at the top of the cap beam continues to steadily slurry out for 2-3 minutes, then close the stop valve until the inside is poured densely, remove the grouting pipe bend in time, and remove the stop valve after the concrete has initially set; Step 6: After pouring, clean the cement slurry on the surface of the cap beam in time; Step 7: When the concrete strength reaches more than 80% of the design strength grade, release the prestress. Remove the prestress tensioning reaction force support and then seal the tensioning end.

[0006] The present invention has the following advantages: (1) By designing a prestressed reaction force support, an operating space is provided for prestressing tensioning and releasing, which can be recycled and does not require a fixed tensioning pedestal, thereby reducing the construction area occupied, and the structure is simple, economical and reliable. (2) The concrete pouring method is simple and fast, with high construction efficiency, reliable quality, low manpower input, and a large amount of high-altitude operations reduced. (3) This patent provides a safe, economical and reliable construction method for the prestressed steel box concrete cap beam of the ramp bridge, which has reference significance for the construction of similar structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1-Figure 2 It is a schematic diagram of the tensioning principle; Figure 3 Schematic diagram of steel box concrete pouring method; Figure 4-Figure 5 is a schematic side view of a tension support; Figure 6-Figure 7 is a schematic diagram of the front view of the tension support; Figure 8-Figure 9 It is a top view schematic diagram of the tension support.

[0008] Among them: tensioning support 1, concrete pouring grouting pipe 2, grouting pipe 3, grouting stop valve 4, and buckle plate 5. DETAILED DESCRIPTION

[0009] The following will be combined with the attached Figure 1-Figure 9 The present invention is described in detail, and the technical solutions in the embodiments of the present invention are clearly and completely described. 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 without creative work are within the scope of protection of the present invention.

[0010] The present invention provides a prestressed steel box concrete cap beam prestressed and concrete construction device for a ramp bridge. The main structure of this patent is to set an assembled tensioning bracket 1 and a concrete pouring grouting pipe 2, a grouting pipe 3, and a grouting stop valve 4. The assembled tensioning bracket buckle plate is arranged 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 jack, and the beam holes are reserved on them. The two side plates provide operating space for prestressing. This assembled tensioning bracket can be reused, and prestressing and tensioning can be achieved without setting a tensioning pedestal.

[0011] A grouting pipe and a slurry-stop valve are set on the low side of the transverse slope of the cap beam, and a slurry outlet is set on the high side of the transverse slope of the cap beam. A sky pump is used to inject grout into the cap beam from the grouting pipe at low pressure. After the slurry outlet hole on the top of the steel box at the high part of the cap beam steadily emits slurry outward for 2 to 3 minutes, the slurry-stop valve is closed to ensure that the concrete in the steel box is dense.

[0012] The specific operation steps of the construction method of the prestressed steel box concrete cap beam of the ramp bridge corresponding to this application are described below: Step 1: Process the cap beam steel box and the steel strands in the box in the steel plant and transport them to the construction site. Place them on the tensioning cradle nearby, leaving 50cm of steel strands at both ends, and support the web of the cap beam on the cradle.

[0013] Step 2: Install the prestressed tensioning reaction support, using a single-beam jack to symmetrically tension a single prestressed steel strand.

[0014] Step 3: Lift the prestressed steel box as a whole to the top of the steel tube concrete pier, use a total station to lay out the center axis of the cap beam, use a level to measure the elevation of the top of the cap beam, and adjust the longitudinal and lateral positions of the cap beam.

[0015] Step 4: Install the pier-cap beam welding assembled fully automatic upper and lower platform, weld the cap beam steel box and the pier column steel pipe, use groove penetration welding between the cap beam and the steel pipe pier column, and use multi-layer welding with smaller diameter electrodes and lower current DC welding machine.

[0016] Step 5: Install the tensioning support, use a sky pump to pour concrete at a distance of 80 cm reserved on the top of the pier steel pipe, pump self-compacting concrete into the steel box of the cap beam, and inject pressure from the grouting pipe on the lower side of the cap beam. When the grouting pipe on the top of the steel box at the high part of the cap beam continues to steadily emit grout for 2 to 3 minutes, close the grouting stop valve until the inside is filled densely, remove the grouting pipe bend in time, and remove the stop valve after the concrete has initially set.

[0017] Step 6: After pouring, clean the cement slurry on the surface of the cap beam in time.

[0018] Step 7: When the concrete strength reaches more than 80% of the design strength grade, release the prestress. Remove the prestress tensioning reaction force support and then close the tensioning end.

[0019] This patent has the following advantages and beneficial effects: (1) By designing a prestressed reaction support, an operating space is provided for prestressing tensioning and releasing, which can be recycled and does not require a fixed tensioning pedestal, thus reducing the construction area occupied. The structure is simple, economical and reliable. (2) The concrete pouring method is simple and fast, with high construction efficiency and reliable quality, less manpower input, and a large number of high-altitude operations are reduced. (3) This patent provides a safe, economical and reliable construction method for the prestressed steel box concrete cap beam of the ramp bridge, which has reference significance for the construction of similar structures.

[0020] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one 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 will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A prestressed steel box concrete cap beam prestressed and concrete construction device for a ramp bridge, characterized in that; The invention comprises an assembled tensioning support (1) and a concrete pouring grouting pipe (2), a grouting pipe (3), and a grouting stop valve (4); the assembled tensioning support is arranged at the end of the cap beam through the buckle plate, and two side steel plates are arranged to apply reaction force to the web of the steel box of the cap beam; the two tensioning plates bear the local load of the jack, and the beam holes are reserved on the plates; the two side plates provide operation space for prestressing release; the assembled tensioning support can be reused, and prestressing and release can be achieved without setting a tensioning pedestal; a grouting pipe (2) and a grouting stop valve (4) are arranged on the low side of the transverse slope of the cap beam, and a grouting pipe (3) is arranged on the high side of the transverse slope of the cap beam, and a sky pump is used to inject grout from the grouting pipe at low pressure into the cap beam, and the grouting stop valve is closed after the grouting hole at the top of the steel box at the high end of the cap beam stably emits grout for 2 to 3 minutes, thereby ensuring that the concrete in the steel box is dense.

2. A method for prestressing and concrete construction of a prestressed steel box concrete cap beam of a ramp bridge, characterized in that: Specific steps: Step 1: Process the cap beam steel box and the steel strands in the box in the steel plant and transport them to the construction site. Place them on the tensioning cradle nearby, leaving 50cm of steel strands at both ends, and support the web of the cap beam on the cradle; Step 2: Install the prestressed tensioning reaction support, using a single-beam jack to tension a single symmetrical prestressed steel strand; Step 3: hoist the prestressed steel box as a whole to the top of the steel tube concrete pier, use the total station to set out the center axis of the cap beam, use the level to measure the top elevation of the cap beam, and adjust the longitudinal and transverse positions of the cap beam; Step 4: Install the pier column-cap beam welding assembled fully automatic upper and lower platform, weld the cap beam steel box and the pier column steel pipe, and use groove penetration welding between the cap beam and the steel pipe pier column. The weld seam uses a smaller diameter electrode and a DC welding machine with lower current for multi-layer welding; Step 5: Install the tensioning bracket, use a sky pump to pour concrete at a reserved 80cm position on the top of the pier steel pipe, pump self-compacting concrete into the steel box of the cap beam, and inject pressure from the grouting pipe on the lower side of the cap beam until the grouting pipe on the top of the steel box at the top of the cap beam continues to steadily slurry out for 2-3 minutes, then close the stop valve until the inside is poured densely, remove the grouting pipe bend in time, and remove the stop valve after the concrete has initially set; Step 6: After pouring, clean the cement slurry on the surface of the cap beam in time; Step 7: When the concrete strength reaches more than 80% of the design strength grade, release the prestress; Remove the prestressed tensioning reaction support and then close the tensioning end.

Images