JP3319709B2 - Construction method of prestressed concrete steel beam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a prestressed concrete steel pipe applied to a large span structure such as a roof frame of a building structure or a bridge of a civil engineering structure.

[0002]

2. Description of the Related Art Precast concrete or SRC beam members with prestress are used for beams of large span structures, but when precast in solid sections, Since the weight per beam member is large, depending on the size of the span, it cannot be installed as a beam member having a length over its entire length between the lower structures.

[0003] For this reason, at the site, the beam members are erected between the lower structures by joining the beam members each time they are suspended or by sending out the beam members while joining them from one lower structure. However, any of the methods requires the work of hanging and sending out the beam members, so that the efficiency of the erection work is low. In addition, a support and a scaffold are required at a joint portion of each beam member, and time is required for temporary construction, so that the construction period tends to be longer.

The present invention proposes a construction method that eliminates the need for joining beam members after suspension from the above background.

[0005]

According to the present invention, a beam member is formed of a steel pipe concrete structure in which a prestress is introduced, and a plurality of steel pipes are provided between lower structures as steel pipe beam members having a length corresponding to the span. Pre-stressed concrete steel pipe beams with pre-stress introduced into steel pipe concrete beams by filling concrete after construction and pre-installed in a unified form, eliminating the need to join beam members after suspension To increase the efficiency of installation work and shorten the construction period.

[0006] The steel pipe is manufactured to have a length in which the span is divided into a plurality of sections, and an assembled reinforcing bar and a sheath are previously disposed inside.
The plurality of steel pipes are joined together to be unified, and the unified steel pipe beam members are collectively installed between the lower structures.

[0007] After the steel pipe beam member is erected, concrete is filled into the steel pipe beam member, and a PC steel material is inserted into the sheath. After the strength of the concrete is developed, the PC steel material is tensioned and prestress is applied to the concrete, thereby completing the prestressed concrete steel pipe.

Since the inside of the steel pipe beam member is filled with concrete after the erection between the substructures, the steel pipe beam member is substantially hollow. It can be suspended and erected.

The erection work can be simplified because the erection between the lower structures can be performed at once, and the erection efficiency is remarkably improved as compared with the case where the erection is performed in units of steel pipes. Eliminating the necessity of joining steel pipe beam members at the site eliminates the need for installation work, and as a result, eliminates the need to install supports to support steel pipe beam members, greatly simplifying temporary construction work. The construction period is shortened.

In the case where the prestressed concrete steel pipe beam constitutes a beam of a roof frame of a building structure, the construction is terminated by the above-mentioned tension of the PC steel material, but in the case of constituting a bridge, the steel pipe is constituted as described in claim 2. The stud bolt is fixed to the upper surface of the steel pipe together with the arrangement of the reinforcing steel bar and the sheath inside the steel pipe, and a plurality of unified steel pipe beam members are collectively laid in parallel between the lower structures.

Also in this case, concrete is filled into each steel pipe beam member, a PC steel material is inserted into the sheath, and after the strength of the concrete is developed, the PC steel material is tensioned to complete a prestressed concrete steel beam.

In the case where the prestressed concrete steel beam constitutes a bridge, a plate straddling between one of the steel beam members adjacent to each other and the other is fixed to one of the steel beam members adjacent to each other. By doing so, positioning and spacing can be maintained when each steel pipe beam member is erected.

The plate also serves as a scaffold when arranging reinforcing bars for floor slabs, and also serves as a floor formwork when placing concrete slabs. And no support work is required.

According to a fourth aspect of the present invention, the joined end faces of the steel pipes are inclined from the bottom to the top to the steel pipe side to be joined from the steel pipe side, and the steel pipe beam members are united in a state protruding upward. This prevents the prestressed concrete steel pipe beam from bending downward due to the live load.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a steel pipe beam member 4 in which a plurality of steel pipes 1 in each of which an assembled reinforcing bar 2 and a sheath 3 are arranged are joined to form a single steel pipe beam member 4 between lower structures 8, 8. Erection,
This is a method of completing a prestressed concrete steel beam 7 by filling concrete 5 into the inside of the steel tube beam member 4 and inserting and tensioning the PC steel material 6 into the sheath 3.

The construction procedure will be described with reference to FIGS. FIGS. 5 to 13 show an example in which the steel pipe 1 is a square steel pipe as shown in FIGS.

As shown in FIG. 5, the steel pipe 1 has a lower structure 8,8.
It is manufactured by dividing the span, which is the distance, into a plurality of sections.Specifically, after manufacturing a steel pipe with the length of the span, it is manufactured by cutting the steel pipe into the length divided into a plurality of sections. Is done.

As shown in FIG. 6, an assembled reinforcing bar 2 and a sheath 3 integrated therewith are inserted into each steel tube 1. 3 and 4 show the assembled reinforcing bar 2. The work up to the placement of the assembling rebar 2 and the sheath 3 inside the steel pipe 1 is performed in a factory.
Is transported to the site with the built-in rebar 2 and sheath 3 built-in.

The joined end faces of the steel pipes 1 are connected to each other in the manner shown in FIG. 5 so that the unified steel pipe beam member 4 is erected between the lower structures 8 and 8 in a state of projecting upward as shown in FIG. As shown, from the bottom to the top, the steel pipe 1 to be joined from the steel pipe 1 side
Tilt to the side.

As shown in FIG. 7, the steel pipes 1 containing the assembled reinforcing bars 2 and the sheaths 3 are joined together to be unified, and the unified steel pipe beam members 4 are collectively lower as shown in FIG. It is suspended between the structures 8, 8 and is erected. The joining of the steel pipes 1 and 1 is performed by welding, by fixing a flange to the end face, or by passing a splice plate 14 between the steel pipes 1 and 1 as shown in FIG.

As shown in FIG. 9, after the steel pipe beam member 4 is erected, concrete 5 is filled into the steel pipe beam member 4 and a PC steel material 6 is inserted into the sheath 3 so that the strength of the concrete 5 is developed. As shown in FIG. 10, the prestressed concrete steel pipe beam 7 in which the prestress is applied to the concrete steel pipe beam by tensioning the PC steel material 6 is completed.

When the prestressed concrete steel pipe beam 7 constitutes the beam of the roof frame, the construction is completed at the stage shown in FIG.

FIGS. 11 to 13 show the subsequent construction procedure when the beam is a bridge. When the beam is a bridge, as shown in FIGS. 1 and 11, the assembled reinforcing bar 2 and the sheath 3 are inserted as shown in FIGS. At the stage or in the stage of FIG. 7 in which the plurality of steel tubes 1 are unified, stud bolts 9 for securing the integrity with the floor slab concrete are fixed to the upper surface of the steel tubes 1.

As shown in FIGS. 1 and 11, the interval between adjacent prestressed concrete steel beams 7, 7 is held by a plate 10 laid in the width direction thereof. plate
After the prestressed concrete steel pipe beam 7 is completed, the prestressed concrete steel pipe beams 7 are installed between the adjacent prestressed concrete steel pipe beams 7, 7 and joined. In addition, the stud bolts 9 are fixed to the steel pipe 1 in advance.

Since the plate 10 is straddled between the adjacent prestressed concrete steel pipes 7, 7, it is sufficient if the plate 10 is fixed to one of the adjacent prestressed concrete steel pipes 7, 7. In some cases, the plates 10 and 10 are fixed on both sides of the steel pipe beam 7, and the plate 10 is not fixed to the prestressed concrete steel pipe beam 7 disposed therebetween.

After the plate 10 joined to one of the prestressed concrete steel pipes 7 is joined to the adjacent prestressed concrete steel pipe 7, the floor slab is placed on the prestressed concrete steel pipe 7 and the plate 10 as shown in FIG. Reinforcing bar 11 is arranged. Since the bar arrangement work can be performed using the plate 10 laid between the adjacent prestressed concrete steel pipe beams 7, 7, it is not necessary to install a special scaffolding or support.

After the rebar arrangement, as shown in FIG. 13, concrete is cast on the prestressed concrete steel pipe 7 and the plate 10 to construct the floor slab 12, and the construction of the bridge is completed.
Since the plate 10 becomes a discarded formwork of the floor slab 12, there is no need to separately provide a formwork when placing concrete.

FIGS. 14 and 15 show cross sections of a prestressed concrete steel pipe beam 7 in a case where the steel pipe 1 is formed by welding two H-shaped steel pieces in the width direction. The construction procedure in this case will be described with reference to FIGS.

Also in this case, as shown in FIG. 16, an assembled reinforcing bar 2 and a sheath 3 are arranged inside each steel pipe 1, but before welding two H-shaped steels, as shown in FIG. 17- (a). The assembled rebar 2 and the sheath 3 are arranged inside one H-shaped steel, and then the other H-shaped steel is welded to the one H-shaped steel, and as shown in FIG. The built-in steel pipe 1 is manufactured. In this example, since the steel pipe 1 is formed by welding the H-shaped steel, the stud bolt 13 for securing adhesion to the concrete 5 to be filled is provided on one side of the H-shaped steel which is the inner peripheral surface of the steel pipe 1. Can be protruded. Up to Fig. 17, the work is performed at the factory.

As shown in FIG. 18, the steel pipes 1 containing the assembled reinforcing bars 2 and the sheaths 3 are joined together to be unified, and the unified steel pipe beam members 4 are collectively lower as shown in FIG. It is erected between the structures 8,8. The joining of the steel pipes 1 and 1 is performed by welding, or by fixing a flange to an end face, or by bolts across a splice plate 14.

After the steel pipe beam member 4 is erected, concrete 5 is filled into the steel pipe beam member 4 and P
After inserting the C steel material 6 and developing the strength of the concrete 5, PC
Prestressed concrete steel pipe beam 7 by tensioning steel 6
Is the same as in FIGS. 9 and 10.

Further, as shown in FIG. 19, the gap between the adjacent prestressed concrete steel pipes 7, 7 is maintained by the plate 10, and the plate 10 is joined to the adjacent prestressed concrete steel pipe 7, and as shown in FIG. Reinforcing bars 11 for floor slabs are arranged on the prestressed concrete steel tube 7 and the plate 10, and concrete is poured on the prestressed concrete steel tube 7 and the plate 10 as shown in FIG. Construction of the bridge is completed.

[0033]

According to the present invention, a plurality of steel pipes are erected between lower structures in the form of a single steel pipe beam member having a length corresponding to the span, and after the erection, concrete is filled in the steel pipe beam member and prestressing is performed. In order to complete the prestressed concrete steel pipe beam by introducing the steel pipe beam member, it is possible to install the steel pipe beam member as a beam member having the length of the entire length of the span regardless of the size of the span. Is simplified,
Construction efficiency is improved.

Further, since there is no need to join the steel pipe beam members at the site, the workability is improved, and accordingly, it is not necessary to install a support for supporting the steel pipe beam members. The construction period is shortened.

According to a third aspect of the present invention, a plate straddling between one of the steel pipe beam members adjacent to each other and the other steel pipe beam member is fixed. Positioning and spacing at the time of erection of members can be performed.

Further, since the plate serves as a scaffold when arranging reinforcing bars for floor slabs and also serves as a floor formwork for placing concrete slabs, it is not necessary to install scaffolds and formwork, and the shoring works. It becomes completely unnecessary.

According to the fourth aspect, since the steel pipe beam members are unified in the state of being raised upward, the prestressed concrete steel pipe beam can be prevented from being bent downward by a live load.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a prestressed concrete steel pipe beam when the steel pipe is a square steel pipe.

FIG. 2 is a sectional view showing a bridge made of the prestressed concrete steel pipe of FIG. 1;

FIG. 3 is a sectional view showing an assembled reinforcing bar.

FIG. 4 is a side view showing an assembled reinforcing bar.

FIG. 5 is a side view showing a state when the steel pipe is manufactured when the steel pipe is a square steel pipe.

FIG. 6 is a side view showing a state in which an assembled reinforcing bar and a sheath are inserted into a steel pipe.

FIG. 7 is a side view showing a state when a steel pipe beam member is manufactured.

FIG. 8 is a side view showing a state when the steel pipe beam member is erected.

FIG. 9 is a side view showing a state at the end of the installation of the steel pipe beam member.

FIG. 10 is a side view showing a state in which a PC steel material is tensioned.

11 is a cross-sectional view of FIG. 10 when a prestressed concrete steel pipe forms a bridge.

FIG. 12 is a cross-sectional view showing a state where reinforcing bars are arranged on a prestressed concrete steel pipe beam.

FIG. 13 is a sectional view showing a state where concrete is cast on a prestressed concrete steel pipe beam.

FIG. 14 is a cross-sectional view showing a prestressed concrete steel pipe beam when the steel pipe is made of H-section steel.

FIG. 15 is a cross-sectional view showing a bridge made of the prestressed concrete steel pipe of FIG.

FIG. 16 is a side view showing a state at the time of inserting the assembled rebar and the sheath into the steel pipe.

17 (a) is a cross-sectional view showing a state of a steel pipe having a built-in rebar and a sheath built therein, and FIG. 17 (b) is a cross-sectional view showing a state of completion.

FIG. 18 is a side view showing a state when the steel pipe beam member is manufactured.

FIG. 19 is a cross-sectional view of FIG. 10 when a prestressed concrete steel pipe forms a bridge.

FIG. 20 is a cross-sectional view showing a state where reinforcing bars are arranged on a prestressed concrete steel pipe beam.

FIG. 21 is a sectional view showing a state where concrete is cast on a prestressed concrete steel pipe beam.

[Explanation of symbols]

1 ... steel pipe, 2 ... assembled rebar, 3 ... sheath, 4 ... steel pipe beam member, 5 ... concrete, 6 ... PC steel, 7 ...
... prestressed concrete steel tube beam, 8 ... substructure, 9 ... stud bolt, 10 ... plate, 11 ... rebar, 12 ... floor slab, 13 ... stud bolt, 14 ... splice plate.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) E04C 3/26 E01D 21/00

Claims (4)

(57) [Claims] 1. A steel pipe beam member which is manufactured by joining a plurality of steel pipes each having a span divided into a plurality of sections, and in which a plurality of steel pipes in which an assembling reinforcing bar and a sheath are arranged in advance are joined to form a single piece. After the construction is completed, the concrete is filled into the steel pipe beam member, the PC steel is inserted into the sheath, and after the strength of the concrete is developed, the PC steel is tensioned to pre-stress the concrete. Construction method of prestressed concrete steel tube beam to give and complete prestressed concrete steel tube beam. 2. A plurality of steel pipes each having a span divided into a plurality of sections and having a reinforcing bar and a sheath disposed therein in advance and joining a plurality of steel pipes having stud bolts fixed to the upper surface thereof. After a plurality of unified steel pipe beam members are collectively installed in parallel in the width direction of the steel pipe beam members between the lower structures, concrete is filled into each steel pipe beam member, and the sheath is filled. A method of constructing a prestressed concrete steel pipe beam in which a PC steel material is inserted into the steel pipe, and after the strength of the concrete is developed, the PC steel material is tensioned to give prestress to the concrete and complete the prestressed concrete steel pipe beam. 3. The method for constructing a prestressed concrete steel pipe beam according to claim 2, wherein a plate straddling between the steel pipe beam members adjacent to each other is fixed to one of the steel pipe beam members adjacent to each other. 4. An end face to be joined of each steel pipe is inclined from the bottom to the top from the steel pipe side to a mating steel pipe side to be joined,
The method for constructing a prestressed concrete steel beam according to any one of claims 1 to 3, wherein the steel tube beam member is integrated in an upwardly convex state.