JPH03194009A - Method of forming joint part of composite structure vertical member - Google Patents

Abstract

PURPOSE:To enhance the close contact ability and to prevent cracks by building a steel cell in which stud dowels are arranged on the lower inner side surface of a horizontal opening, on the lower structure of a reinforced concrete section, by placing core concrete from the opening, and by applying a tension to a PC steel member. CONSTITUTION:A steel cell 5 is built on the lower structure 13 of reinforced concrete section, reinforcement 14 is arranged along stud dowels 11 using a horizontal opening 9 as an access opening, and then PC steel members 15 is arranged. Further, reinforcement 14' in the reinforced concrete section in the lower structure 13 is connected to reinforcement 14, and the PC steel members 15 are connected to PC steel members 15' in the lower structure 13 through the intermediary of couplers 16. Thereafter, core concrete 17 is placed through the opening 9 after a fixing plate 21 is set below a horizontal plate 10, and after the hardening of the concrete, the PC steel members 15 are applied with a tension so as to give a prestress to the core concrete 17. Further, a plate 18 is laid on the horizontal plate 10 so as to block the opening 9, and then the horizontal plate 10 and the plate 18 are fixed by using bolts 20. Further, a gap at the top of the core concrete section 17 is filled therein with a grout material 19.

Description

[Detailed description of the invention] [Industrial application field].

The present invention relates to a construction method for joints when vertical members such as piers, columns, and main towers are constructed into a composite structure.

[Conventional technology]

Vertical members with large cross sections, such as bridge piers and main towers of cable-stayed bridges, are conventionally
In most cases, it is constructed from a single member made only of steel or concrete.

[Problem to be solved by the invention]

As shown in Fig. 5, for example, when a composite structure is constructed in which the lower part of the pier 1 is made of reinforced concrete 2 and the upper part made of steel 3, the joint part 4 between the reinforced concrete 2 and the steel 3 is constructed.
This is because the technology to create a structure that can transmit both compressive force and tensile force has not been established.

In addition, when combining structures with different structures, such as when the piers are made of concrete and a steel tower is installed on top, the base plate of the upper structure is embedded in the lower structure and the anchor frame and anchor are installed. Connection methods such as fixing with bolts etc. are used, but this type of connection cannot be applied to the above-mentioned composite structures made of large cross-section vertical members made of steel, concrete, etc. with smooth cross-sectional changes. .

The present invention eliminates the disadvantages of the conventional example, and allows a joint part that can sufficiently transmit both compressive force and tensile force to be obtained by on-site construction, and as a result, it is possible to obtain a vertical member with an unprecedented composite structure. It is about providing law.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention connects a lower concrete structure to a steel upper structure, has a horizontal opening for working, has a stud dowel on its lower inner surface, and has a stud dowel at its lower end. The steel cell forming the base plate is built on a reinforced concrete substructure, and the filling concrete is cast from the opening, and the filling concrete is tensioned with prestressing steel. After the opening is closed with a plate, the filling concrete is placed directly under the The idea is to fill the gaps with grout.

[Effect]

According to the joint constructed according to the present invention, the compressive force transmitted from the steel superstructure to the steel cell is transmitted to the filling concrete by the plate and stud dowel, and the base plate at the lower end of the steel cell is connected. Relieve the bearing stress of the reinforced concrete substructure on the lower surface.

In addition, the tensile force transmitted from the steel cells is transmitted to the prestressed concrete by reinforcing bars placed along the stud dowels, with each dowel being loaded evenly.

Furthermore, the tension introduced by the PC steel increases the adhesion between the steel structure and the concrete structure, and prevents cracks in the concrete.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional side view showing one embodiment of the construction method of the joint part of a composite structure vertical member of the present invention, and 5 in the figure is a steel cell.

As shown in FIG. 3, this steel cell 5 has internal partitions 6
It is divided into rectangular small sections 7, and each section 7 is provided with stiffening ribs 8 that project vertically inward and outward, as shown in FIG.

In addition, the section 7 has a horizontal plate 10 with an opening 9 formed in the middle of the depth.
A stud dowel 11 is provided to protrude from the horizontal plate 10 on the inner surface of the lower part. Furthermore, the lower end of the steel cell 5 was formed into a flange shape to serve as a base plate 12.

The present invention uses such a steel cell 5, and the first
As shown in the figure, a steel cell 5 is built on a reinforced concrete substructure 13.

Then, reinforcing bars 14 are arranged along the stud dowel 11 using the horizontal opening 9 as a work opening, and the PC steel material 1
5 will be placed. This reinforcing bar 14 is connected to the reinforcing bar 14' of the reinforced concrete of the substructure 13, and the PC steel material 15 is also connected to the PC steel material 151 of the reinforced concrete of the substructure 13.
is connected to via a coupler 16.

After that, the fixing plate 21 is set under the horizontal plate 10 from the opening 9, and then the filling concrete 17 is poured, and after the filling concrete 17 hardens, the PC steel material 15 is tensed, and the filling concrete 17 is prestressed. Grant.

Although there is a gap between the upper end of this filling concrete 17 and the horizontal plate 10 with the opening 9, the plate 18 is placed on the horizontal plate 10 to close the opening 9, and the horizontal plate 10 and the plate 18 are fixed with bolts 20, and the upper four gaps of the filling concrete 17 are filled with grout material 19 using a method such as backfilling.

The above is the construction for the first section fA7, but the same construction is performed for all the sections 7 of the steel cell 5 to complete the joint portion 4. Although not shown, the upper end of the steel cell 5 is joined to a steel upper structure.

Note that the steel cell 5 may be integrally provided as a part of this steel upper structure.

In this way, by using the steel cells 5 as the joints 4, vertical members such as the bridge piers 1 can be formed with a composite structure in which the lower part is made of reinforced concrete 2 and the upper part is made of 83, as shown in FIG.

In the vertical member of this composite structure, the compressive force due to the cross-sectional force (M, H, V) transmitted from the steel 3 of the superstructure to the steel cell 5 is
1 to the filling concrete 17, and the base plate 12 at the lower end of the steel cell 5 relieves the bearing stress of the reinforced concrete 2 on the lower surface of the joint surface.

Further, the tensile force transmitted from the steel cells 5 is evenly transmitted to the filling concrete 17 into which prestress has been introduced by the stud dowels 11 and the reinforcing bars 14 arranged along the stud dowels 11.

Furthermore, the PC steel material 15 enhances the adhesion between the upper structure of the steel 3 and the lower structure of the reinforced concrete 2, thereby preventing the occurrence of cracks in the concrete.

〔Effect of the invention〕

As described above, the construction method of the joint part of the composite structure vertical member of the present invention can satisfy the transmission of both compressive force and tensile force at the joint part of the upper structure and the lower structure,
This makes it possible to construct vertical members with large cross sections, such as large piers, main towers of cable-stayed bridges, and other large columns, into composite structures of steel and concrete with smooth cross-sectional changes through on-site construction.

[Brief explanation of drawings]

Fig. 1 is a longitudinal side view showing one embodiment of the construction method of the joint part of a composite structure vertical member of the present invention, Fig. 2 is a sectional view taken along the line A-A in Fig. 1, and Fig. 3 is a steel cell. B-B in Figure 4
A line sectional view, FIG. 4 is an explanatory diagram of a composite structure vertical member according to the present invention, and FIG. 5 is a conceptual diagram of the composite structure vertical member. 1... Pier 2... Reinforced concrete 3
...Steel 4...Joint part...Steel cell 6...Inner partition 7...Small section 8
... Supplementary rib 9 ... Opening 10 ... Horizontal plate 11 ... Stud dowel 12 ... Base plate 13 ... Reinforced concrete substructure 14.14
"...Reinforcing bar 15.15'...PC9il material 16...Coupler 17...Filled concrete 18...Plate 19...Grout material 20
... Bolt 21 ... Fixing plate

Claims (1)

[Claims] A lower concrete structure is connected to a steel upper structure, and has a horizontal opening for working, a stud dowel is arranged on the lower inner surface of the opening, and a steel cell with a base plate formed at the lower end is connected to a reinforced concrete cell. After building on the substructure and pouring filling concrete from the opening, tensioning this filling concrete with PC steel and closing the opening with a plate, fill the gap directly below with grout material. Features: Construction method for joints of vertical members in composite structures.