JP3288024B2 - Jack lever device for removing floor slabs - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for removing a concrete slab of a bridge.

[0002]

2. Description of the Related Art In the work to repair concrete decks of deteriorated bridges, conventionally, hanging scaffolds are installed on the sides and below the decks, and cross beams of the bridges are added to reinforce the existing concrete decks. Has been removed and a new PC precast slab has been installed. An apparatus used for removing such a concrete slab is proposed in JP-A-9-67809.
This device includes a girder 66 arranged on a block 63a to be removed via a stock 67, a reaction jack 68 fixed to the center of the girder 66, and a gimbal 66 disposed at both ends of the girder 66. Lever means 69 provided. The lever 69 is composed of a fulcrum member 69a and a rod 69b. The fulcrum member 69a is fixed on the beam 66 by bolts or the like, and one end of the rod 69b is hinged to the piston 68a of the reaction force jack 68. Movably connected to a rod 69
The other end of b is mounted on the roller 71 of the fulcrum member 69a. A hanging bar 70 is rotatably connected to the bar 69b by a hinge 75b.
And is connected downward by a hinge 75c to an insertion bolt 70a penetrating the removal target block 63a.

[0003]

In the above-mentioned conventional apparatus,
Since the lever means 69 and the reaction force jack 68 are erected on the girder member 66 and the whole apparatus is high and unstable, when the removal target block 63a is released from the bridge girder, the impact causes the apparatus to be removed. It is easy to fall and is dangerous for work. Further, in the above-mentioned conventional apparatus, when lifting the block 63a to be removed from the floor slab, in order to prevent excessive bending stress or shearing force from acting on the hanging bar 70, the insertion bolt 70a and the hanging bar 70 are hinged together with the hinge 15c. , The parts are complicated and the parts cost of the apparatus is increased.

Accordingly, the present invention has been made to solve the above-mentioned problems of the conventional apparatus, and an object of the present invention is to prevent the apparatus from overturning even if an impact occurs when the floor slab is separated from the bridge girder. It is an object of the present invention to provide a device for removing a floor slab which can perform the operation safely.

Another object of the present invention is to provide a device which has a simple structure for connecting to a floor slab to be removed and which can prevent an excessive bending stress or shear force from being generated in a hanging bar. is there.

[0006]

According to the present invention, there is provided an apparatus for cutting a concrete floor slab of a bridge and releasing the cut block from anchoring the bridge girder, the apparatus being mounted on both sides of the cut block. Reaction girder erected between the rootstocks
Reaction jacks provided at both ends of the reaction girder, a pair of lever members each having a fulcrum separately provided on the reaction girder and one end pivotally connected to each reaction girder, and for lifting the block. And a suspension rod connected to the other end of the pair of lever members, respectively. A slit having a predetermined width is extended in the axial direction in the reaction force beam, and a pair of bearings are provided on both sides of the slit on the upper surface thereof. A pair of lever members each having a convex portion on the upper side and being inserted into the slit, the fulcrum is provided with a pivot axis penetrating the convex portion of the lever member and the bearing member, and the block is connected to a bridge. When the lower end of the suspension bar is connected to the block to release from the anchoring of the spar, when the connection between the upper end of the suspension bar and the lever member is located below the pivot, and the block is released from the anchoring of the bridge spar, The connection between the upper end of the hanging rod and the lever member In jack lever device, characterized in that than serial pivot is formed so as to be located above.

In the present invention, the pair of lever members are inserted into the slits of the reaction force girder, so that they are not bulky at the time of transportation and are easy to handle at the time of installation. The lever member has a convex portion on the upper side and is inserted into a slit of the reaction girder,
Since the fulcrum is formed by piercing the projecting part and the bearing material on the upper surface of the reaction force girder with a pivot, the height of the entire device is suppressed, the center of gravity is lowered, and an impact is generated when the floor slab block peels off. However, the device can safely work without falling down.

According to the present invention, each lever member is formed such that a slope is formed on a lower side of an end pivotally connected to the reaction force jack so as to become thinner toward the pivotal connection portion, and is connected to a suspension rod. It is also preferable to form an inclination on the lower side of the end so that the inclination becomes smaller toward the tip. By providing the inclination at both ends of each lever member in this way, the lever member is prevented from protruding upward from the reaction force girder, and a large angle capable of turning from the horizontal position of the lever member tip in both up and down directions is secured. can do.

Further, according to the present invention, in order to release the block from fixing of the bridge girder, when the apparatus is installed, the connecting portion between the lever member and the suspension bar is located below the pivot, and immediately after the block is released, the suspension is suspended. Since the connecting portion between the upper end of the rod and the lever member is formed above the pivot, the bending stress and shear stress acting on the hanging rod from this connecting portion are dispersed and transmitted in both directions, and these stresses are transmitted. Can be prevented from occurring excessively.

[0010]

The present invention will be described in more detail with reference to the following examples.
The present invention is not limited to these. FIG. 1 is a side view showing an embodiment of the jack lever device of the present invention, and FIG. 2 is a plan view of the jack lever device of FIG.
FIG. 3 is a side view of the jack lever device of FIG. 1 as viewed from an end. 1 to 3, a lever jack device 1 is shown.
A reaction force girder 10, reaction force jacks 23, 23 arranged at both ends of the reaction force girder, a pair of lever members 15, 15 having one end pivotally connected to each reaction force jack 23, and a pair of levers. Hanging rods 25, 2 provided at the other ends of the members 15, 15, respectively.
5

The reaction force girder 10 comprises a pair of girder members 1.
The slits 10b are formed between the beams 10a, 10a by disposing the beams 0a, 10a in parallel at predetermined intervals, and the connecting members 11, 12 are fixed to the upper, lower, center and both ends of the beams 10a, 10a. It is formed. In each of the beam members 10a, two shaft members are connected at the center by a connection plate 27 and bolts and nuts.

At both ends of the reaction girder 10, jack support members 14 are provided for installing the reaction jacks 23. This jack support 14 is, as shown in FIG.
Vertical members 14b, 14b are respectively placed on the beam members 10a, 10a.
And the upper ends of the vertical members 14b, 14b are connected to the horizontal members 14a.
To form a connection. Then, the upper end of the reaction force jack 23 is fixed to the cross member 14a by a hinge 21 via a bracket, and the lower end of the reaction force jack 23 is connected to the rear end of the lever member 15 by the hinge 22. Further, the girder material 10
a, 10a, bearing material 1 is provided at two opposing positions.
7 and 17 are fixed.

Each of the lever members 15 has a convex portion 15a formed on the upper side substantially from the center to the rear end, and has an inclined portion on the lower side of the rear end so as to taper toward a pivotal connection portion with the reaction force jack 23. 15c is formed, and an inclination 15b is formed below the tip connected to the hanging bar 25 so as to become thinner toward the tip. Each lever member 15 having such a shape is inserted into a slit of the reaction force girder 10, and a rear end thereof is pivotally connected to a reaction force jack 23 by a hinge 22.
A pivot 16 is inserted through the shaft member a and the bearing members 17, 17 to form a fulcrum of the lever member 15. Further, a bush mounting plate 20 is fixed to the upper surface of the tip of each lever member 15, and a hole is formed in the center of the bush mounting plate 20, and the lever member is penetrated downward from the hole. 15 is provided with a slit or a hole.

The bearing members 17, 17 and the lever member 1
The position and dimensions of the lever 5 relative to the protrusion 15a are set so that the parts other than the protrusion 15a of the lever member 15 are accommodated in the slit of the reaction girder 10 when the two members are pivotally connected by the pivot 16. Form. In such a positional relationship, the jack lever device 1
Is formed, the height of the entire apparatus is suppressed, the center of gravity is lowered, and even if an impact occurs when the floor slab block 32 peels off, the apparatus can be prevented from tipping over.

The hanging rod 25 is a steel rod having a thread formed at the upper and lower ends, is inserted into a hole of a bush mounting plate 20 provided on the lever member 15, and is passed through the spherical bush 19 at the upper end. The nut 18 is screwed until it comes into contact with the spherical bush 19. On the other hand, the lower end of the hanging bar 25 is inserted into a through hole formed in the floor slab block 32, and the lower end is brought into contact with the back surface of the floor slab block 32 through the bush mounting plate 20. A nut 18 is screwed into and fixed to the lower end through a spherical bush 19.

As described above, when the lower end of the suspension bar 25 is fixed to the floor slab block 32, before the floor slab block 32 is removed, as shown in the right half of FIG. The bush 19 is located below the pivot 16 and has a horizontal line H extending from the center of the pivot 16 and a spherical bush 19.
And an inclination of the angle β is generated between them. In addition, floor slab block 3
When the bridge 2 is released from the anchoring of the bridge girder, the spherical bush 19 on the upper surface of the lever member 15 is located above the pivot 16 as shown in the left half of FIG. And the spherical bush 19 have an inclination of an angle α. Therefore, before and after the floor slab block 32 is lifted, the hanging bar 2
Since the bending stress and the shear stress acting on 5 are dispersed in both the left and right directions, it is possible to prevent these stresses from being excessively generated on the suspension rod 25.

Next, the operation of the jack lever device 1 according to the present invention will be described with reference to FIGS. When removing an existing concrete slab, first, the concrete slabs 31 and 32 are cut with a concrete cutter, and a through hole for inserting the hanging bar 25 is formed in a predetermined position of the slab blocks 31 and 32. Then, the stocks 30, 30 are arranged on both sides of the floor block 32 to be removed, and the floor slab removal device 1 is placed on the stocks 30, 30, and the jack lever device 1 is mounted as shown in FIG. Install.

Next, the reaction force jack 23 is extended to apply a downward pushing force to the rear end of the lever member 15, and this force is transmitted about the fulcrum 16 as a force for pushing up the distal end of the lever member 15. . Thereby, the floor slab block 32
Is transmitted as a force for lifting the floor slab block 32 upward through the suspension rod 25. When the force for lifting the floor slab block 32 exceeds a predetermined level, the anchorage between the bridge girder and the floor slab block 32 is broken, and the floor slab block 32 is broken. Is ready to be removed. The floor block 32 whose fixing has been destroyed is appropriately lifted by a crane, loaded on a transport vehicle, and removed.

FIG. 5 is a side view of a jack lever device different from the embodiment of FIGS. 1 and 2, and this jack lever device comprises a pair of beam members 10 forming a reaction force beam 10.
adjustment pieces 28a, 28a at the centers of
Are arranged and connected by a connection plate 27 and bolts and nuts.
Can be appropriately adjusted. Therefore, the adjustment piece 28 having the optimum length is set for each construction site or construction site.
a, 28a can be connected to form floor slab blocks 3 of various lengths.
2 can be removed.

[0020]

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a jack lever device of the present invention.

FIG. 2 is a plan view of the jack lever device of FIG.

3 is a side view of the jack lever device of FIG. 1 before and after lifting of the floor slab block, in which the left and right sides are divided into front and rear portions and the reaction girder is partially cut away.

FIG. 4 is a side view of the jack lever device of FIG. 1 as viewed from an end.

FIG. 5 is a side view showing a jack lever device different from the embodiment of FIGS. 1 and 2;

FIG. 6 is a side view schematically showing a conventional removing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Jack lever device 10 Reaction girder 10b Slit 15 Lever member 15a Convex part 16 Axis 17 Bearing material 19 Spherical bush 23 Reaction jack 25 Hanging rod

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoki Konno 1-42-5 Chuo, Nakano-ku, Tokyo Inside Protec Co., Ltd. (56) References JP-A-6-136722 (JP, A) JP-A-9-92 41325 (JP, A) JP-A-9-67809 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E01D 21/00 E01D 19/12 E01C 23/12

Claims (1)

(57) [Claims] 1. A device for cutting a concrete floor slab of a bridge and releasing the cut block from anchoring of a bridge girder, comprising: a bridge installed between stocks placed on both sides of the cut block. Power girder, and reaction force jacks provided at both ends of the reaction girder,
A fulcrum is separately provided on the reaction force girder, and a pair of lever members each having one end pivotally connected to each reaction force jack are connected to the other end of the pair of lever members to lift the block. A hanging bar is provided, and a slit of a predetermined width is extended in the axial direction in the reaction girder, and a pair of bearing members are provided on both sides of the slit on the upper surface thereof, and the pair of lever members are respectively disposed on the upper side. A projection is provided and inserted into the slit. The fulcrum is formed by pivoting the projection of the lever member and the bearing member, and the lower end of the hanging rod is connected to the block to release the block from fixing of the bridge girder. When the connecting portion between the upper end of the hanging rod and the lever member is located below the pivot, when the block is released from the anchoring of the bridge girder, the connecting portion between the upper end of the hanging bar and the lever member is higher than the pivot. Also shaped to be located above Jack lever device being characterized in that the.