JPH0359203B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a method for laying floor slabs.

[Prior art]

In bridge deck repair work, etc., deck slabs may be replaced with precast concrete slabs. In other words, the existing floor slab is demolished and a plurality of new rectangular floor slabs are successively laid.

In order to minimize traffic restrictions, construction work is generally limited to nighttime hours. Therefore, the parts to be replaced were divided into multiple parts, each part being worked on overnight, and the prestressed steel members inserted through each of the multiple floor slabs laid were temporarily connected with tension. Add a new slab to the slab that was laid the night before the next day, insert the prestressing steel into the slab, connect it to the prestressing steel of the slab that was laid the night before with a coupling device such as a coupler, and tighten it. Repeat this process to complete the entire replacement.

[Problems to be solved by this invention]

The problems with the above construction methods are as follows.

First, due to unevenness of the deck support (main girder, etc.) or an error in the dimensional accuracy of the deck, the axis of the prestressed prestressing steel material and the newly placed prestressing steel material do not match, resulting in tension. If left as is, it will be difficult to connect steel materials.

Furthermore, the tin of the PC steel shafts due to misalignment of the floor slab connections is often accompanied by not only eccentricity, but also angular deviation between the shaft centers, and it is extremely difficult to connect the steel materials together under tension.

Furthermore, if a new steel member is connected to an existing tension steel member and tension is introduced, the anchor plate at the connection end of the existing tension steel member is no longer required, but if it is connected with tension, it may be used for other purposes. The problem is that it can't be done. In particular, when there is an angular misalignment between the axes of the steel materials, it is necessary to remove the existing tension steel fixtures before connecting the steel materials.

[Means for solving problems]

In this invention, a plurality of rectangular panel-shaped floor slabs each having a prestressed steel insertion hole penetrating in the direction of road travel and open at both ends on two parallel sides are placed in a position where the existing floor slab has been removed. PC in the PC steel material insertion hole of the floor slab
Insert the steel material and temporarily connect it by tensioning it, and when installing the deck slab continuously on the slab, the tension in the prestressing steel material is temporarily released, and the new prestressing steel material is connected to the existing prestressing steel material using a connecting tool. The above problem is solved by inserting it into a new floor slab and tensioning it again to integrate the whole.

〔Example〕

The present invention will be explained below for each construction order based on an embodiment shown in the drawings.

The example is a bridge deck replacement work.

[B] Floor slab In the figure, 1 is a rectangular panel-shaped floor slab made of precast concrete. Floor slab 1 has openings on two parallel sides and penetrates in the direction of road travel.
A plurality of PC steel material insertion holes 2 are formed.

[B] Removal of existing floor slab (Figure 3) Remove existing floor slab 3. In order to secure traffic during construction, only the right half of the diagram was removed.
Leave the left half intact so it can be driven.
A temporary railing 4 will be installed in the center in the direction of road travel.

[C] Auxiliary girder installation (Fig. 4) Auxiliary girders 5, 5 are installed parallel to the position where the floor slab 3 was removed.
Set up.

[D] Floor slab installation (Figure 5) New floor slab 1 will be installed at the location where the existing floor slab 3 was removed.
Set up. A plurality of floor slabs 1 are installed successively in the direction of road travel at night. Multiple floor slabs 1
A prestressed steel material 6 is inserted into the prestressed steel material insertion hole 2, tensioned, fixed, and temporarily connected.

[E] Connection of floor slabs (Figures 6a to 6c) A new floor slab 1 is connected continuously to the floor slab 1 installed the previous day. When connecting, insert the prestressed steel material 6 into the prestressed steel material insertion hole 2 of the newly installed floor slab 1 and connect the new prestressed steel material 6 to the prestressed steel material 6 that was fixed on the previous day using a coupling tool 7 such as a coupler. Then, the entire floor slab 1 is connected together. This work is repeated to install the floor slab 1 along the entire length.

The figure shows the case where a jack 8 is installed at the end of the first installed floor slab 1 to tension the PC steel material 6.

When connecting PC steel materials 6 and 6, the existing
Temporarily release the tension on the PC steel material 6. If the tension is released, even if the axes of the PC steel materials 6, 6 are misaligned or the angles are misaligned, the connection can be easily made using the coupling tool 7. Further, once the tension is released, the fixing device 9 such as a bearing plate can be removed.

[F] Other connection methods (Figures 7a to 7f) If the jack 8 cannot be placed on the other end, a recess 10 is provided on the top surface of one of the floor slabs 1 as shown in the figure, It is possible to open the PC steel material insertion hole 2 on both opposing inner surfaces of the recess 10 so that the ends of the PC steel material 6 protrude, and to grip and tighten the ends. The tension order will be explained below.

One end of the PC steel material 6 inserted into the PC steel material insertion hole 2 of the plurality of floor slabs 1, ... installed on the previous day is connected to the end of the rear floor slab 1 by a connector 7, and the other end is connected to the end of the rear floor slab 1. is fixed by a fixing device 9 to the inner surface of the recess of the front floor slab 1 provided with the recess 10, and the plurality of floor slabs 1, . . . are temporarily connected.

Remove the fixing tool 9 and release the tension on the steel material, and
One side of a coupling tool 7 such as a coupler is newly attached to the end of the removed PC steel material 6 protruding into the recess 10.

The front end of the prestressed steel material 6 inserted into the prestressing steel material insertion hole 2 of the newly installed plurality of floor slabs 1,... is fixed to the end of the front floor slab 1 by the fixing device 9, and the rear end is inserted into the recessed part. Protrude into the recess 10 of the provided floor slab 1, install the jack 8 in the recess 10,
The rear end of the steel material 6 is passed through the insertion hole of the chuck provided in front of the jack 8 and grasped. (Chapter 7a
Figure) Using the jack 8, tension the PC steel material 6 inserted the previous day and the newly inserted PC steel material 6, and attach the end of the PC steel material 6 gripped by the chuck to the connector 7, which was installed the previous day (Figure 7b). Floor slab 1,
... and the newly installed floor slabs 1, ... are integrated with prestressed steel and the plate material 26 is placed in the recess 10, allowing vehicles to pass through. (Fig. 7c) Once the tension is released, the fixing tool 9 is removed. (Fig. 7d) The PC steel material 6 is further connected to the end of the PC steel material 6 and inserted into the continuously laid floor slab 1. (7th
Fig. e) The PC steel material 6 is tensioned by the jacks 8 to connect the entire deck 1 together. (Fig. 7f) As the jack 8, for example, a twin-barrel jack 8 as shown in Fig. 8 can be used. The jack 8 has two cylinders 11, 11 whose ends are connected by bearing pressure parts 13, 13 in which a U-shaped notch 12 is formed in the middle.
A wedge pressing cylinder 14 is installed between 1 and 11. A pressing portion 15 is fixed to the rod tip of the wedge pressing cylinder 14.

A method of using the jack 8 having the above structure will be explained.

One bearing pressure part 13 of the jack 8 shown in FIG.
The prestressing steel material 6a is inserted into the notch 12, and its tip is gripped by one wedge 17 of the connector 7, and the rear end of the connector 7 is brought into contact with the inside of the bearing pressure part 13. The holding cylinder 16a of the chuck 16 (see FIG. 9) is inserted into the notch 12 of the other bearing pressure part 13 and attached, and the PC steel material 6b is inserted into the chuck 16 and gripped.

Hydraulic pressure is sent into the cylinder 11 to bring both bearing pressure parts 13 close together to tension the PC steel members 6a and 6b, and the tip of the PC steel member 6b is inserted into the wedge 18 and the wedge 18 is pressed by the pressing part 15 of the wedge pressing cylinder 14. grasp the prestressed steel material 6b, and connect the prestressed steel materials 6a and 6b with the connector 7. (FIGS. 9 to 11) Release the hydraulic pressure in the cylinder 11, remove the chuck 16, and then remove the jack 8.

[G] Other jacks As shown in FIGS. 12 and 13, a ram 19 is slidably provided on the rectangular sliding portion 28, and forks 20 are protruded from the ram 19 and the lower surface of the sliding portion 28, respectively. do. The ram 19 is slid by the cylinder 21 and the PC is gripped by forks 20, 20.
Tension the steel members 6a and 6b. After applying tension, connect the PC steel materials 6a and 6b using the separately prepared connecting tool 7.
Concatenate.

14 and 15 show that hook-shaped locking parts 23, 23 are provided on the casing and rod tip of a single-body cylinder 22, and the PC steel materials 6a, 6b are wedged by the locking parts 23, 23. Pull the connectors 7, 7 fixed by the . After being tensioned with a predetermined force, the bolt 24 is passed over the coupling tools 7, 7 and fixed with a nut 25. After that, just remove the jack 8.

In addition, as shown in FIG. 16, the ends of the PC steel materials 6, 6 are positioned between the twin cylinders 21, 21, and the sleeve body 7a has a cylindrical shape, and the lid body 7b can be screwed onto the body. The grip 27 is fixed to the bottom of the main body 7a of the connector 7, and the lid 7
The grip fitting 27 is rotatably inserted into the bottom of the main body 7a, and the cylinders 21 and 21 are actuated to draw the ends of the PC steel materials together, tensioning the steel materials, and tightening the steel materials.
Screw the lid 7b onto the connecting tool 7 to connect the PC steel materials to each other.
They may be connected by

〔Effect of the invention〕

This invention has the above-mentioned configuration, and when connecting prestressing steel materials, the tension of the prestressing steel materials is first released and then the tension is released, so even if there is a deviation or angular misalignment due to eccentricity of the axis of the prestressing steel materials. PC steel materials can be blended together and easily connected. Further, when the tension is released, the fixing device such as the bearing plate can be removed and used for other purposes.

[Brief explanation of drawings]

Figure 1 is a side view of the bridge, Figure 2 is its plan view,
Figures 3 to 5 are longitudinal cross-sectional views of the construction sequence, Figures 6a to 6c are explanatory diagrams of the order of connecting floor slabs, and Figure 7
Figures a to 7f are explanatory diagrams of the order of connecting work for other floor slabs, Figure 8 is a perspective view of the jack, and Figures 9 to 11 are partially cutaway plan views showing the order of tension work by the jack. Fig. 12 is a plan view of another jack, Fig. 13 is a side view thereof, Fig. 14 is a partially cutaway plan view of another jack, Fig. 15 is a side view thereof, and Fig. 16 is a side view of another jack. FIG. 1... Floor slab, 2... PC steel material insertion hole, 3... Existing floor slab, 4... Temporary railing, 5... Auxiliary girder, 6...
PC steel material, 7... Connector, 8... Jacket, 9...
... Fixing tool, 10 ... recess.

Claims (1)

[Claims] 1 A plurality of rectangular panel-shaped floor slabs with prestressed steel insertion holes penetrating in the direction of road travel with openings at both ends on two parallel sides are placed in the position where the existing floor slabs have been removed, and the PC of each slab is installed. Insert the PC steel material into the steel material insertion hole,
Temporarily connect the prestressed steel materials under tension, and when installing the slabs consecutively to the slab, the tension in the prestressed steel materials is temporarily released, and a new prestressed steel material is connected to the existing prestressed steel materials using a connecting tool to create a new floor. A method of laying floor slabs, which is characterized by inserting the slab and tensioning it again to unify the whole.