JP2973177B2 - PC girder installation method - 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 of installing a prestressed concrete (PC) girder used for constructing a quay.

[0002]

2. Description of the Related Art For example, in a quay rehabilitation work, a seaside fixed structure is constructed by supporting a pile in a sea area in front of the normal of the old quay, and the seaside fixed structure and the old quay (landside fixed structure) are constructed. Stuff)
A method of installing a PC girder between them and forming a quay may be adopted. In such a construction, the installation of the PC girder is conventionally carried out by transporting a single PC girder manufactured in a factory to the installation site, lifting it one by one, and bridging between the land-side fixed structure and the sea-side fixed structure. Side by side, and horizontal construction was performed.

[0003]

However, according to the above-mentioned conventional method of installing a PC girder, since a single PC girder is lifted one by one at a site and bridged and constructed horizontally, it takes a long time to install the same. was there. In addition, as in the case of the Great East Japan Earthquake, it is not only difficult to secure roads leading to the site, but it is also difficult to carry PC girders to the site under congested surrounding roads. There was also a problem that it was not possible to sufficiently meet the demand for repairing the garbage.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to carry a large group of PC girder at a location remote from the site, to transport the sea to the site, and to cope with road conditions. It is an object of the present invention to make it possible to install a PC girder in a short period of time without being affected by the influence.

[0005]

In order to solve the above-mentioned problems, the present invention provides a PC installed in an assembly yard remote from an installation site.
A single girder is carried in, a plurality of the PC girder are arranged in a row in the assembly yard, and the PC girder is passed through the PC girder alone.
A PC slab with a lateral prestress applied by tensioning a steel material was manufactured, and this PC slab was transported by sea and installed between the land-side fixed structure and the sea-side fixed structure. It is characterized by the following.

In the method of installing a PC girder constructed as described above, a wide PC slab is transported by sea and installed, so that the installation work on site is completed in a short period of time. Moreover, P
Since the C slab is given a lateral prestress by the post-tension method, there is no concern about strength.

According to the present invention, concrete may be cast between each PC girder before the PC steel material is tensioned. In this case, the installation work on the site is completed in a shorter period of time because it is not necessary to cast concrete at the installation site.

The present invention also provides a PC girder having a structure in which hollow portions and solid portions are alternately arranged in the longitudinal direction.
The C steel material can be extended by inserting the solid portion. In this case, the weight of the PC girder alone is reduced by the presence of the hollow portion, and a sufficiently large prestress can be applied by passing the PC steel material through the solid portion.

[0009]

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

FIG. 5 shows a PC installed by the method of the present invention.
This shows the structure of the quay including the girder 1. This PC digit 1
Is a land-side fixed structure 2 obtained by reconstructing an old quay wall, and a sea-side fixed structure 3 built in a sea area in front of the land-side fixed structure 2.
Has been bridged between. The land-side fixed structure 2 is roughly composed of a caisson 5 installed on a rubble mound 4 and a reinforced concrete curb block 6 installed on the caisson 5. The caisson 5 is fixed in position by its own weight and the weight of the filling material 6 filled therein, and has a backing material 7 deposited on its back side and a filling material deposited on its front side. 8 (both are deposited on the rubble mound 4). Also,
On the back side of the curb block 6, a reinforced ground 11 composed of a compacted layer 9 and a sand layer 10 laid on the compacted layer 9 is formed, and an asphalt layer 13 is formed on a ground 12 including the reinforced ground 11. Are formed.

On the other hand, the seaside fixed structure 3 is
And a plate-like quay block 16 fixed on a plurality of piles 15 placed in the pier. The quay block 16 is made of reinforced concrete, has a thickness of about 2 to 3 m, and is entirely positioned slightly above the highest tide HWL. The upper surface of the quay block 16 and the upper surface of the curb block 6 are positioned on the same horizontal plane, and steps 16a and 6a for mounting the PC girder 1 are provided at corners on opposite sides of both. Is formed. Also,
On the upper surfaces of the quay block 16 and the curb block 6, for example, a concave groove 16 for laying a rail for running a crane is provided.
b and 6b are formed. Reference numeral 17 denotes a rubber fender provided on the sea side wall surface of the quay block 16, and reference numeral 18 denotes a mooring post provided on the upper surface of the quay block 16 for mooring a ship.

Here, as shown in FIGS. 1 and 2, the PC girder 1 is installed in units of a wide PC slab 21 in which a predetermined number of square pillar-shaped PC girder units 20 are integrally assembled. As shown in FIGS. 3 and 4, the PC girder unit 20 has a structure in which hollow portions 22 and solid portions 23 are alternately arranged in the longitudinal direction. Multiple PC steel wires 2 for giving stress
4 are buried by a pretension method. A plurality of through holes 25 are formed in the solid portion 23 of the PC girder 20 in the lateral direction. The through hole 25 is for inserting a PC steel bar 26 (FIG. 2) described later,
The girder unit 20 is provided by a tube (not shown) embedded in concrete when the girder unit 20 is manufactured. Also, PC digit unit 2
0, the base 20b is formed slightly wider than the upper main body 20a. Therefore, as shown in FIG. 3, a plurality of PC girders 20 are arranged in rows so that the respective bases 20b contact each other. , Predetermined gaps 27 (FIG. 3) are formed between them.

The PC slab 21 is composed of a plurality of the above-mentioned PC girders 20 arranged in a row, a filling concrete layer 28 cast in a gap 27 between the PC girders 20, and each P girder.
The above-described PC steel rod 26 which is extended through the through hole 25 of the C-girder unit 20 and gives a lateral prestress to the assembly of the above-mentioned PC girder unit 20 and the concrete layer 28.
And side concrete layers 29 cast on both lateral sides of the assembly (FIG. 2). As an example, the PC girder 20 has a total height h of 500 to 1000 mm, a width (total width) w of the base 20b of 500 to 1000 mm, and a total length L (FIG. 1).
Is formed in a size of 10 to 20 m.
Is set to 40 to 100 mm, and the total width W of the PC slab 21 is set to 20 to 30 m.

In the present embodiment, the PC girder unit 2
0 is manufactured in a factory, and the PC slab 21 is manufactured in an assembly yard (not shown) remote from the quay construction site (installation site). As an assembly yard, a place convenient for land transportation or sea transportation is selected, and the PC girder unit 20 manufactured at the factory is carried in here. When assembling the PC slab 21, a plurality of the PC girders 20 are arranged in a row with their bases 20b in contact with each other, and a PC steel bar 26 with a screw is passed through the through hole 25 of each PC girder 20. Thereafter, concrete is poured into the gaps 27 between the individual PC girders 20 to produce an assembly composed of the PC girders 20 and the filling concrete layer 28. After the solidified concrete is solidified, the PC steel bar 26 is tightened with a nut to apply a lateral prestress to the assembly. Finish the three-dimensional side, and use this to make PC slab 2
1 is completed.

The PC manufactured in the assembly yard as described above
The slab 21 is lifted by, for example, a crane ship and transported by sea to the quay construction site described above, and as shown in FIG. 5, the curb block 6 of the land-side fixed structure 2 and the sea-side fixed structure 3
Between the quay block 16 By the way, since the PC slab 21 cannot leave an extra projection on the upper surface for the purpose of use, a general-purpose hanging metal fitting such as a hanging duck cannot be used. Therefore, in the present embodiment, a hanging bracket 31 as shown in FIGS. 6 and 7 is used, and a plurality of the hanging brackets 31 are connected to a PC as shown in FIG.
A hanging wire 32 provided along two opposing side edges of the slab 21 and extending from a crane ship (not shown) is hung on a hook 33 of the hanging bracket 31.

The hanging bracket 31 includes an anchor portion 34 previously embedded in the PC girder 20, a main body portion 35 mounted on the upper surface of the completed PC slab 21 and supporting the hook 33, And a connecting portion 36 for detachably connecting the portion 35 to the anchor portion 34. The anchor portion 34 includes a PC steel rod 37 having a total thread and a nut 38 screwed to a lower end of the PC steel rod 37. P
The C steel rod 37 is the PC girder unit 2 on the side where the nut 38 is screwed.
The two PC girders 20 are provided in the width direction of the PC girders 20 so as to be located near the bottom of the zero and the upper end thereof is located in the concave portion 39 provided on the upper surface of the PC girders 20.

On the other hand, the main body 35 comprises a rectangular block 42 having two through holes 40 penetrating vertically and a lateral through hole 41 for attaching the hook 33,
Box body 4 surrounding the upper and lower surfaces and left and right side surfaces of this block 42
3 and a plurality of support legs 44 projecting from the lower surface of the box 43.
And The two vertical through holes 40 are provided at positions matching the two PC steel bars 37 embedded in the PC girder unit 20. The connecting portion 36 is inserted through a coupler 45 that can be screwed to a PC steel rod 37 embedded in the PC girder 20 and a vertical through hole 40 provided in a block 42 of the main body 35. A PC threaded steel rod 46 having a total thread extending and having a lower end screwed to the coupler 45;
A tightening nut 48 screwed to the upper end of the PC steel rod 46 via a washer 47 is provided.

In order to assemble the hanging bracket 31, after the completion of the PC slab 21, first, the coupler 45 is screwed into the PC steel rod 37 of the anchor portion 34 which is to be seen in the recess 39 of the PC girder unit 20, and then the PC slab is The main body 35 is placed on 21,
The tip of the PC steel rod 46 passing through the through hole 40 is screwed into the coupler 45. Next, a nut 48 is screwed into the upper end of the PC steel bar 46 via a washer 47 and tightened, whereby the main body 35 is firmly fixed on the PC slab 21. Therefore, if the hanging wires 32 extending from the crane ship are hung on the hooks 33 attached to the main bodies 35 fixed as described above, the entire PC slab 21 can be stably lifted. Then, the PC slab 21 is transported by sea and bridged between the curb block 6 of the land-side fixed structure 2 and the quay block 16 of the sea-side fixed structure 3 as described above. With body 35
From the anchor part 34 and the coupler 45
Is removed, no obstacles (projections) remain on the upper surface of the PC slab 21.

[0019]

As described in detail above, according to the PC girder installation method of the present invention, a wide PC slab is manufactured in an assembly yard, and the PC slab is transported by sea to the installation site for installation. Installation work on site will be completed in a short time, and the quay will be able to be constructed efficiently. In addition, since the installation work can be performed regardless of road conditions, it is an extremely useful construction method when an emergency is required, such as in the case of a major earthquake.

[Brief description of the drawings]

FIG. 1 is a plan view showing a partial cross section of a structure of a PS slab used in a method of installing a PC girder according to the present invention.

FIG. 2 is a cross-sectional view showing the structure of the PC slab shown in FIG.

FIG. 3 is a perspective view showing a structure of a single PC girder constituting a PC slab.

FIG. 4 is a longitudinal sectional view showing a structure of a single PC girder constituting a PC slab.

FIG. 5 is a sectional view showing a structure of a quay to which the PC girder installation method is applied.

FIG. 6 is a perspective view showing a structure of a hanging bracket using a PC slab for lifting.

FIG. 7 is a cross-sectional view showing a structure of the hanging bracket shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 PC girder 2 Land side fixed structure 3 Sea side fixed structure 20 PC girder unit 21 PC slab 24 PC steel wire 26 PC steel rod 28 Filling concrete layer 31 Suspension fitting 32 Suspension wire

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shinji Yoshioka 4-1-1 Komyo-bashi, Chuo-ku, Osaka-shi, Osaka Toyo Construction Co., Ltd. (56) References JP-A-56-93916 (JP, A) JP-A-7-207641 (JP, A) JP-A-63-251504 (JP, A) JP-A-4-146312 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) E02B 3 / 06 E04B 1 / 06,1 / 22 F term 2D059

Claims (3)

(57) [Claims] In a method of installing a prestressed concrete (PC) girder between a land-side fixed structure and a sea-side fixed structure, a single PC girder is carried into an assembly yard remote from an installation site, and the assembly is performed. Within the yard, a plurality of the PC girders are arranged in a row, and a PC slab is given a lateral prestress by tensioning the PC steel material passing through the PC girders, and this PC slab is transported by sea. And installing between the land-side fixed structure and the sea-side fixed structure. 2. The method according to claim 1, wherein concrete is cast between the individual PC girders before the PC steel is tensioned. 3. A single PC girder, wherein hollow portions and solid portions are alternately arranged in a longitudinal direction thereof, and a PC steel material is extended through the solid portion. Item 1
Or the method of installing a PC girder according to 2.