JP4428721B2 - Construction method of ramen railway viaduct - Google Patents

Description

The present invention relates to a method for constructing a ramen railway viaduct, and more particularly to a method for constructing a ramen railway viaduct directly above a traffic roadbed such as an existing railway or road.

  Conventionally, for example, as a method of constructing a ramen viaduct directly above an existing railway, as shown in FIG. 8 (A), assembling column bars and column molds on both sides of the track R and placing cast-in-place concrete. After constructing the reinforced concrete column P by the above, assemble a large beam / slab support S on the building limit G via the upper part of the concrete column P, then assemble the bottom frame of the beam / slab, Then, the beam / slab rebar and side frame were assembled, and finally the beam / slab cast-in-place concrete was placed to construct the reinforced concrete beam / slab T.

  However, the above conventional construction method has a problem that the entire construction period is long and the economy is lacking because all construction steps of columns, beams and slabs are performed on site. In addition, since the above conventional method requires a large-scale formwork support work, it not only lacks labor saving, but also requires a work space for installing a large span support work such as a beam / slab support work S. As a result, it was necessary to increase the height of the ramen structure.

The present invention has been made in order to solve the above-described conventional problems. The object of the present invention is not only to shorten the construction period and save labor, but also to reduce the work space and increase the height of the ramen structure. The object is to provide a method for constructing a ramen railway viaduct that can be kept low.

Method for constructing a rigid frame railway viaduct present invention, existing on both sides of the foundation of the track, Nde circumferential direction into a number of hoop multiple denominated write keeping appropriate intervals precast Column buried, many on these precast pillar The half-precast beam is installed along both sides of the existing track, the half-precast beams are joined together, and a number of half-precast slabs are installed along the existing track along the existing track. In the construction method of the viaduct, the half precast beam is composed of a U-shaped beam member, and the exposed end portion joined to the exposed end portion of the main reinforcing bar on the beam lower edge side of the adjacent half precast beam by the joint. The U-shaped beam portion is pre-arranged with the lower edge side main rebar having a beam and a number of stirrups partially exposed upward. Many cotter formed on the inner surface of the above Precast beams, PC (prestress) previously Prestressing to resist its own weight and the working load of its own weight and medium filling concrete weight slab during construction using steel And
In the half precast slab, joint bars to be joined to joint bars of adjacent half precast slabs are arranged, and a large number of cotters are formed on the inner surface. Further, the half precast slab includes a PC (prestress) steel material. Pre-stress that resists the weight of the slab concrete and the weight of the slab concrete is installed in advance, and after the half precast slab is installed on the half precast beam, the upper bar is arranged on the half precast beam and the half precast slab. Then, spot-cast concrete is simultaneously cast on these half precast beams and half precast slabs .

1) Precast members are pre-manufactured on the ground in the vicinity of the factory or the site in all columns, beams, and slabs, and are constructed by on-site joining, thereby shortening the construction period and saving labor. Moreover, since the shape of the precast member can be selected, it becomes possible to cope with all construction conditions.
2) By introducing prestress into the precast members of the beams and slabs, the conventional large span support S as shown in FIG. 8A becomes unnecessary, and the work space W as shown in FIG. 8B is obtained. As a result, it is possible to reduce the height of the ramen structure and easily perform the construction directly on the existing route.

  Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a track as an existing traffic roadbed, and half precast columns 3 are built on the foundations 2 on both sides thereof. The half precast column 3 is pre-manufactured in the factory or on the ground near the site.

   2, the half precast column 3 is mainly composed of a hollow column shell 3a, and a large number of sheath tubes are inserted into the column shell 3a. An axial rebar insertion hole 3b is formed, and a number of column strip rebars 3c are embedded in the circumferential direction. A large number of cotters 3d are formed on the inner surface of the half precast column 3 so as to achieve structural integration with the below-described in-filled (on-site) concrete.

   When the half precast column 3 is built, a column main rebar 3e is inserted into the reinforcing bar insertion hole 3b, and a lower end portion of the column main rebar 3e is connected to a fixing rebar 2a fixed to the foundation 2 with a joint 4 ( In this embodiment, they are joined via a mechanical joint).

   In the joined half precast column 3, in order to secure the cover of the exposed rebars 2 a, 3 e and the joint 4, root-wrapped (in-place) concrete is placed, and the half precast column 3 is placed inside the hollow of the half precast column 3. Placing stuffed (on-site) concrete. Furthermore, grout injection is performed to ensure adhesion between the reinforcing bar insertion hole and the column reinforcing bar.

   Then, as shown in FIG. 3, the half precast beam 5 is constructed on the half precast pillar 3 constructed | assembled as mentioned above. The half precast column 3 functions as a support or support material support for the half precast beam 5. The half precast beam 5 is installed in the line direction and the direction perpendicular to the line. The half precast beam 5 is also manufactured in advance on the ground near the factory or the site.

The Precast beam 5, as shown in an enlarged part in FIG. 4, consisting mainly U-shaped beam member 5a. Beam reinforcing bars 5b and stirrups 5c are arranged in advance in the U-shaped beam member 5a. The U-shaped beam member 5a is provided with a PC (pre-stress) steel material 5d to introduce prestress that resists the weight of the U- shaped beam member 5a when it is installed, the weight of the stuffed concrete, the weight of the slab, and the work load. is doing. 5e is a cotter. Further, the exposed end portion of the beam reinforcing bar 5b (in this embodiment, the beam lower edge side main reinforcing bar (outside) 5b ') is bent upward to improve the bonding strength.

As is apparent from FIG. 4, each half precast beam 5 is joined by connecting the exposed end of the beam reinforcing bar 5 b (in this embodiment, the main reinforcing bar (inside) 5 b ″ on the beam lower edge side) to the joint 6 (in this embodiment). Connect with mechanical joints.

   When the half precast beam 5 is installed, as shown in FIG. 5, a half precast slab 7 is installed thereon. The half precast beam 5 functions as a support or support material support for the half precast slab 7. The half precast slab 7 is also manufactured in advance in the factory or on the ground near the site. In this embodiment, the half-filled (in-place cast) concrete to be placed on the half precast beam and the slab (in-place cast) concrete to be placed on the half precast slab are placed simultaneously. A large number of the half precast slabs 7 are installed side by side between the half precast beams 5 on both sides installed in the line direction.

   The half precast slab 7 is formed with several strips 7a on the top surface (three in this embodiment) as shown in FIG. A muscle 7b (in this embodiment, a loop muscle) is arranged. The half precast slabs 7 adjacent to each other by the joint bars 7b are reliably and firmly joined to each other after the slab cast-in-place concrete is placed. Moreover, the PC steel material 7c is provided in the said half precast slab 7, and the prestress which resists the dead weight at the time of erection, the slab (site cast) concrete weight, etc. is introduced. 7d is a cotter.

   On the half precast beam 5 and the half precast slab 7 laid as described above, upper bars (not shown) are arranged, and the cast-in-place concrete is simultaneously placed.

Finally, as shown in FIG. 7, the soundproof wall 8 is installed, and the track 9 is laid on the slab to complete the railway viaduct .

It is construction explanatory drawing which shows the 1st process of one Example of the construction method of this invention. It is a block diagram of the half precast pillar in the construction of FIG. It is construction explanatory drawing which shows the 2nd process of the construction method of this invention. It is a block diagram of the half precast beam in the construction of FIG. It is construction explanatory drawing which shows the 3rd process of the construction method of this invention. It is a block diagram of the half precast slab in the construction of FIG. It is a completion figure of one Example of the construction method of this invention. It is a comparison figure of the work space of the conventional construction method and the construction method of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Track 2 Foundation 2a Anchor reinforcement 3 Half precast column 3a Column shell 3b Reinforcing bar insertion hole 3c Column strip reinforcement 3d Cotter 3e Column main reinforcement 4 Joint 5 Half precast beam 5a U-shaped beam member 5b Beam reinforcement 5b 'Beam lower edge side main reinforcement (Outside)
5b "beam lower edge side reinforcement (inside)
5c Stirrup 5d PC steel 5e Cotter 6 Joint 7 Half precast slab 7a Ridge 7b Joint bar 7c PC steel 7d Cotter 8 Sound barrier 9 Track G Building limit P Reinforced concrete column R Track S Beam / slab support T Reinforced concrete beam / slab

Claims (1)

On basis of both sides of the existing track, Nde circumferential direction into a number of hoop multiple denominated write keeping appropriate intervals precast Column buried, along a number of Precast beam on these precast columns on both sides of the existing track In the construction method of the ramen railway viaduct, these half precast beams are joined to each other, and a large number of half precast slabs are installed on these half precast beams along existing tracks.
The half precast beam is composed of a U-shaped beam member, and the U-shaped beam member has a beam lower edge side main portion having an exposed end portion joined to the exposed end portion of the beam lower edge side main reinforcing bar of the adjacent half precast beam by a joint. Reinforcing bars and a number of stirrups, some of which are exposed upwards, are pre-arranged, and a number of cotters are formed on the inner surface of the U-shaped beam member. Introducing pre-stress that resists the own weight at the time of erection, the weight of packed concrete, the weight of the slab and the work load,
In the half precast slab, joint bars to be joined to joint bars of adjacent half precast slabs are arranged, and a large number of cotters are formed on the inner surface. Further, the half precast slab includes a PC (prestress) steel material. Pre-stress that resists the weight of the slab concrete and the weight of the slab concrete is installed in advance, and after the half precast slab is installed on the half precast beam, the upper bar is arranged on the half precast beam and the half precast slab. Then, a construction method for a ramen railway viaduct, characterized by simultaneously placing cast-in-place concrete on these half precast beams and half precast slabs .