JP3171676B2 - Construction method of cast-in-place concrete horizontal member - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a cast-in-place reinforced concrete beam in a place where there is an obstacle or difficulty in installing a shoring below a erection point, such as a transportation facility at a high place, above and below the water surface. The present invention relates to a method for erection of a horizontal member such as a girder.

[0002]

2. Description of the Related Art As a conventional method of erection of a concrete girder or a beam, a method of preparing a concrete girder near a site in advance and erection of this precast girder is generally known. -The weight and size of the girder were determined due to restrictions on lifting equipment and machinery, making it difficult to erection at extremely high places.

On the other hand, conventionally, in the method of erection of cast-in-place reinforced concrete girder or beam, in the case of erection at a high place, a high shoring is assembled and the formwork is carried out. In addition, the range of conditions that can be applied is narrow due to the large construction cost and construction period.Moreover, the load gradually increases during concrete casting, and bending occurs. There is a problem in that a load is applied to the concrete and the concrete that has set is deformed.

Conventionally, there is also known an overhanging method in which concrete girders are successively formed and overhanging the erection section. However, this method has few place restrictions and can control the amount of flexure. Although it is easy to apply, when the span is short, such as a horizontal beam or an overhanging girder of a pier, there is a problem that the setup and facilities only become large.

Therefore, in recent years, as a method of solving the above-mentioned problems, a method of applying a constant upward moment to a support for erection supporting a formwork of a girder or a beam and placing concrete in this state has been carried out. Have been done.

[0006]

In the above-mentioned conventional method of applying a moment, the final bending amount can be reduced, but when the scale becomes large, the concrete weight becomes large, and the concrete placing time becomes long, There is a problem in that a load is applied to the concrete that is about to set and deforms the concrete that is about to set.

[0007]

For SUMMARY OF THE INVENTION The present invention to solve the conventional problem above, using 支保 digits erection supporting the formwork of horizontal members, such as digits and beams for construction, upward to the erection支保 digit A PC line for applying a force is arranged, and while the concrete is being driven into the formwork , the same amount of reverse bending is generated in response to the bending caused by the driving. Erection support
Nervous coercive digit PC line, is to propose a construction method of place concrete horizontal member so as to stress.

[0008]

[Function] While concrete is being poured into a formwork, the PC line of the erection support girder is tensioned so that the same amount of bending in the opposite direction is generated immediately in response to the actual amount of bending caused by the casting. Then, since the stress is applied to the formwork via the erection support girders, no deformation occurs during the solidification of the concrete poured into the formwork.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a first embodiment in which the present invention is applied to a horizontal connecting beam (horizontal member) of a suspension bridge pier shown in FIGS.

The suspension bridge pier 1 comprises left and right towers 2 and 2
It is composed of three lower horizontal beams 3 and one upper horizontal beam 4.

Since the horizontal beams 3 and 4 are both constructed by the same construction method, the construction method of the horizontal beam 3 will be described here.

First, a cavity 5 is provided at the position where the horizontal beams are installed on the towers 2 and 2.
Is formed in the cavity 5, and a steel girder 7 made of a steel material such as a shape steel is erected on the left and right pedestals 6 and 6.

As shown in FIG. 4 , the steel girder 7 has a sheath 9 through which a PC wire 8 passes, and is provided between the fixing hardwares 10 at both ends in a form curved in an arc shape with a center hanging down. Reinforcing materials 11 and 12 on top and bottom and right and left as needed
Is attached.

In the illustrated embodiment, the steel girder 7 is made of a steel material having an I-shaped cross section, but this material type may be a box type or another type. It can be set appropriately according to the situation.

As shown in FIG. 5 , the steel girder 7 is provided with a suspended scaffold girder 14 whose required part is suspended and supported by a plurality of suspending members 13 and a scaffold plate 15 thereon.
The frame scaffold 16, the formwork 17 of the horizontal beam 3, and the formwork supporter 18 are integrally assembled on the above.

The formwork 17, 17 is fixed by a binding material 19 for binding the formwork panels facing each other, and is made to withstand the pressure and load of the concrete 20 cast into the formwork 17, It is integrated with the steel girder 7.

In the above configuration, the form 17 of the horizontal beam 3
Concretely, the PC wire 8 is tensioned by the tension jack 21 in accordance with the amount of bending of the formwork 17 caused by the casting weight during the casting. Stress is introduced so as to simultaneously generate the same amount of bending in the opposite direction as bending, and such operations are sequentially and similarly continued as the concrete placing progresses.

Next, a second embodiment in which the present invention is applied to an overhang-type pier shown in FIGS. 6 and 7 will be described.

As shown in FIG. 6 , the overhanging pier 31 is composed of a pillar portion 32 constructed by a normal construction method and an overhang portion 33 which is a horizontal member constructed by the construction method of the present invention.

FIG. 7 shows the construction of the overhang 33.
As shown in (1), a receiving beam 35 is assembled on a receiving stand 34 embedded in the column 32, a pair of left and right receiving trusses 36 and a floor girder 37 are installed between the lower surfaces thereof, and further on this floor girder 37. A scaffold girder 38 and a scaffold plate 39 are installed, and a formwork 40 and a formwork supporter 41 are integrally assembled on the scaffold plate 39.

A PC wire 43 is stretched between fixing hardware 42, 42 provided at both ends of an upper end portion of the receiving truss 36, and one end thereof is connected to a tension jack 44.

In the above configuration, concrete is cast into the formwork 40 of the overhanging portion 33, and the PC wire 43 is formed according to the amount of bending of the formwork 40 caused by the weight of the workplace during the placement. Tension is applied by the tension jacks 44, and stress is introduced into the receiving truss 36 and its floor girder 37 so as to simultaneously generate the same amount of bending in the opposite direction as the bending of the formwork 40. In the same manner.

Furthermore the present invention the third embodiment applied to a floor plate girder is a horizontal member shown in FIG. 8 will be described.

The deck slab 51 is erected on adjacent piers 52, 52.
An installation floor slab girder 54 is erected on the girder receivers 53, 53 provided opposite to the upper portions of the slabs 2, 52, and the formwork 55 of the slab girder 51 is placed thereon.
And the form support 56 is integrally installed.

A PC wire 58 is stretched between fixing hardware 57 provided at both ends of a lower end of the erected floor slab 54, and a tension jack 59 is connected to one end thereof.

In the above configuration, the form 5 of the floor slab 51
Concrete is cast into the concrete wire 5 and the PC wire 5 is set in accordance with the amount of bending of the mold 55 caused by the weight of the cast during the casting.
8 is tensioned by a tension jack 59, and
A stress is introduced so as to simultaneously generate the same amount of bending in the opposite direction as the bending of the mold frame 55, and such operations are sequentially and similarly continued as the concrete placing progresses.

[0027]

As described above, according to the present invention, concrete is poured into the formwork of the horizontal member to be erected, while the concrete is immediately adjusted to the same amount as the actual amount of flexure caused by the casting. PC of the support girder so as to cause bending in the opposite direction
The wire is tensioned and stress is applied to the formwork via the erection girder. A cast-in-place concrete horizontal member that has been normally consolidated can be erected.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a suspension bridge pier of a first embodiment to which the present invention is applied.

FIG. 2 is a front view showing a suspension bridge pier of the first embodiment to which the present invention is applied.

FIG. 3 is a side view showing a suspension bridge pier of the first embodiment to which the present invention is applied.

FIG. 4 is a side view of the steel girder according to the first embodiment of the present invention.

FIG. 5 is a longitudinal sectional front view showing a forming state of a horizontal joint beam in the first embodiment of the present invention.

FIG. 6 is a perspective view showing an overhang pier according to a second embodiment to which the present invention is applied.

FIG. 7 is a longitudinal sectional front view showing a formed state of an overhanging pier according to a second embodiment of the present invention.

FIG. 8 is a vertical sectional front view showing a molding state of a floor slab girder in a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Suspension bridge pier 2 Tower 3 Lower horizontal beam (horizontal member) 4 Upper horizontal beam 5 Cavity 6 Cradle 7 Steel girder (Erection support girder) 8 PC line 9 Sheath 10 Fixing hardware 11 Reinforcement material 12 Reinforcement material 13 Hanging material 14 Hanging scaffold Girder 15 Scaffolding plate 16 Frame scaffolding 17 Formwork 18 Formwork support 19 Tightening material 20 Concrete 21 Tension jack 31 Overhanging pier 32 Column 33 Overhanging part (horizontal member) 34 Receiving stand 35 Receiving beam 36 Receiving truss (supporting support girder) 37 floor girder 38 scaffolding girder 39 scaffolding board 40 formwork 41 formwork support 42 fixing hardware 43 PC wire 44 tension jack 51 floor slab girder (horizontal member) 52 pier 53 girder support 54 erection floor slab girder (construction support girder) 55 Formwork 56 Formwork support 57 Fixing hardware 58 PC wire 59 Pull jack

Claims (1)

(57) [Claims] 1. A form of a cast-in-place horizontal member to be erected is supported on an erection support girder, a PC line is arranged so that an upward force can be applied to the erection support girder, and concrete is placed in the form. while pouring, introducing stress to generate simultaneously a bending amount of the bending the same amount under tension the PC line to said rack設支Hoketa depending on the amount of deflection of the mold caused by the pouring A method of erection of cast-in-place concrete horizontal members, characterized in that: