JP2010024742A - Bridge floor slab removing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To take the reaction of a jack without influencing a floor slab and to facilitate removal of the floor slab by lowering the degree of composition of a girder and the floor slab. <P>SOLUTION: Circular cut lines 20 are formed until reaching the girders 2 in opposed positions of the floor slab 1 on main girders 2 using a hole saw. Cut lines C1-C4 are formed on the concrete floor slab 1 along the main girders 2 to partition a removal area of suitable size. Holes 22 are formed in the floor slab 1 at intermediate parts between the oppositely provided circular cut lines 20, and threaded steel rods 42 are inserted therein and fixed to the bottom face of the floor slab 1. Jacks 3 are set into the positions of the circular cut lines 20, and a separation frame 4 is placed between the jacks 3 and fixed. The threaded steel rods 42 are fixed to the separation frame. The jacks are operated to lift the floor slab and to separate it from the girders for removal. Since the jacks 3 are installed on the main girders 2, sufficiently large reaction can be obtained, and the floor slab can be surely and rapidly removed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for removing concrete floor slabs and joints such as elevated roads and bridges that need to be repaired due to aging or the like.

It is necessary to dismantle and remove the repaired parts to repair or replace the concrete floor slabs and joints of bridges that have been damaged or deteriorated by traffic loads. In addition, the design load has been raised by changing the bridge design standards, and it has become necessary to remove the old standard floor slabs and replace them with new standards.
Breaking and removing a floor slab with a breaker, etc. caused a lot of noise and vibration, and it was not efficient because protection work was necessary to prevent the shredded pieces from falling, resulting in prolonged construction costs.
In the case of the method of cutting the floor slab with a cutter and pulling it up with a crane, etc., the connection between the floor slab and the girder is strong, so remove the floor slab leaving the floor slab on the girder and remove the floor slab on the remaining girder. Because it was crushed and removed, protective work such as a safety fence was required, which was inefficient.

Therefore, the floor slab of the part to be removed is cut to an appropriate size, and a removal device consisting of a jack and a lifting beam is used to lift the removal area defined by forming a cutting line on the floor slab with a cutter. Patent Document 1 (Japanese Patent Publication No. 7-26369) and Patent Document 2 (Japanese Patent Publication No. 7-26371) propose methods for breaking and releasing the connection between the floor slab and the girders.
As shown in FIG. 4, these construction methods form a cutting line with a cutter on a concrete floor slab and divide it into blocks, install a peeling frame that straddles the block, and block the block with a center hole jack provided on this peeling frame. Pull up and peel off the floor slab from the girder, or as shown in Fig. 5, bridge the peeling stand across the block, connect the peeling stand and the block with steel bars, and peel with the jacks placed at both ends of the peeling stand The platform is lifted and the block is peeled off from the beam.
Further, Patent Document 3 (Japanese Patent Laid-Open No. 2001-226914) has been proposed as a method in which a removal beam or the like used for removal is reduced in size.

Japanese Patent Publication No. 7-26369 Japanese Patent Publication No. 7-26371 JP 2001-226914 A

A concrete floor slab is integrated into a girder by a gibber or the like, and requires a large force to peel off the floor slab even if it is cut and divided to an appropriate size. If a large force acts as a reaction force on the jack that lifts the floor slab, an accident may occur in which the floor slab deteriorated due to aging changes or the floor slab comes off.
The present invention prevents the floor slab from coming out even if it is a deteriorated floor slab, ensures that the reaction force of the jack can be taken, and removes the floor slab by reducing the degree of synthesis of the girder and the floor slab. Is easy to do.

  The area where the jack is installed at the upper part of the main girder is cut off from the floor slab, a cutting line reaching the girder is formed on the floor slab on the parallel main girder, and a cutting line is formed at a right angle to the main girder. Define the cutting and removal area, install the jack of the removal device consisting of the jack and the base in the area cut off from the floor slab, operate the jack and lift the floor slab of the area defined by the cutting line to connect the floor slab and the girder The floor slab can be easily removed by releasing the connection.

  The jack is installed directly above the main girder, and the reaction force of the jack when the floor slab is peeled off is borne by the main girder. Since a cutting line is formed in the floor slab and the edge of the floor slab and the main girder are cut off from the other floor slab parts, the floor slab can be securely peeled from the girder. It can be removed reliably and easily.

Example 1
As shown in FIG. 1 and FIG. 2, a circular cutting line 20 reaching the main beam 2 is formed on the floor slab 1 on the main beam 2 of the cutting region with a hole saw of φ110 mm to φ200 mm, and an inner region of the circular cutting line 20 The edge is cut from the floor slab 1. The diameter of the circular cutting line 20 is selected according to the size of the jack 3 used for removing the floor slab 1. When the jack 3 is placed in the area within the circular cutting line 20 and the floor slab 1 is lifted, The jack 3 prevents the floor slab 1 from interfering.

  As shown in the sectional view of FIG. 1 and the plan view of FIG. 2, cutting lines C <b> 1 and C <b> 2 indicated by alternate long and short dash lines are formed along the main beam 2 in order to define the region of the floor slab 1 to be removed. These cutting lines are deep enough to reach the main girder 2, and weaken the degree of coupling between the floor slab 1 and the main girder 2. Next, cutting lines C3 and C4 are formed on the cross beams (not shown) at right angles to the cutting lines C1 and C2. The cutting lines C3 and C4 are also deep enough to reach the cross beam, and the removal region is defined in the floor slab 1 by the cutting lines of C1, C2, C3, and C4.

  Note that the cutting lines C3 and C4 may be formed at arbitrary positions without being formed on the upper part of the cross beam. Next, a flat foam polystyrene having a thickness of 5 cm is bonded to the bottom surface of the floor slab 1 along the cutting line with modified silicone, and a concrete structure is cut by rotating a circular cutter at a high speed. Although the concrete cutter blade protrudes from the bottom surface of the floor slab 1, only a cut is formed in the polystyrene foam, and the cooling water does not flow out to the outside.

A hole 22 having a diameter of 50 mm is formed in the floor slab 1 in the middle of the circular cutting line 20 or the circular cutting lines 20 and 20 provided at the position opposite to the main girder 2, and the depth of the hole 22 is measured to measure the floor slab. Measure the thickness of 1 and adjust the cutting depth of the concrete cutter so that the concrete cutter does not collide with the girder 2 and damage it. Cut the floor slab 1 along the main girder 2 with a cutter. A cutting line is formed.
Next, a threaded steel rod 42 is inserted into the formed hole 22 and fixed to the bottom surface of the floor slab 1 with a nut.

  Next, the jack 3 is set inside the circular cutting line 20, and the peeling frame 4 in which the slit 41 is formed in the axial direction is bridged between the jacks 3 and fixed, and the floor 41 is already fixed to the slit 41. The nut is fixed to the upper surface of the peeling frame 4 through a threaded steel bar 42.

  The jack 3 is actuated to raise the peeling frame 4, and this lifting force is transmitted to the lower surface of the floor slab 1 through the threaded steel bar 42, so that the area defined by the cutting lines C1 to C4 of the floor slab 1 is the main girder. 2 and the horizontal girder are peeled off, it is confirmed that the connection between the floor slab 1 and the main girder 2 and the horizontal girder is released, the operation of the jack 3 is canceled, and the peeled area of the floor slab 1 is returned to the original state. The peeling cradle 4 and the jack are moved, and the peeled floor slab area is removed with a forklift or a crane.

Example 2
As in Example 1, a circular cutting line 20 reaching the main beam 2 is formed on the floor slab 1 above the main beam 2 in the cutting area with a hole saw of φ110 mm to φ200 mm, and the cylindrical core inside the circular cutting line is removed. A hole for installing the jack 3 is formed in the floor slab above the main girder 2, and the jack 3 installed in the hole is in a state where the edge of the floor slab 1 is cut.
The subsequent steps are the same as those in the first embodiment. A cutting line is formed on the main beam 2 along the main beam 2, and a cutting line is formed on the floor slab perpendicularly to the cutting line. And the jack 3 is actuated to release the connection between the floor slab and the girder in the peeling area.

  The area where the jack is installed is cut from the floor slab by forming a circular cutting line on the concrete slab above the main girder, and the jack is installed directly on the rigid girder, so a sufficiently large reaction force can be obtained. It is possible to use a jack with a large capacity, and a cutting line is formed on the main girder to weaken the coupling between the floor slab and the girder, so that the floor slab can be removed from the girder reliably and in a short time. It can be peeled off, and the work period of repair work can be shortened. The method of the present invention is also effective for a pedestrian bridge where the strength of the floor slab is not large.

Sectional drawing at the time of removal work of this invention. The top view at the time of the removal work of this invention. Sectional drawing of the other Example of this invention. Sectional drawing of a prior art example. Sectional drawing of another prior art example.

Explanation of symbols

1 Concrete floor slab 11 Removal block 2 Main girder 20 Circular cutting line 3 Jack 4 Peeling frame 41 Slit 42 Threaded steel bar C Cutting line

Claims (3)

The area where the jack is installed at the upper part of the main girder is cut off from the floor slab, a cutting line reaching the girder is formed on the floor slab on the parallel main girder, and a cutting line is formed at a right angle to the main girder. Define the cutting and removal area, install the jack of the removal device consisting of the jack and the gantry in the area cut from the floor slab, operate the jack and lift the floor slab in the area defined by the cutting line to connect the floor slab and the girder How to remove the bridge deck to release the bond. 2. The method for removing a bridge floor slab according to claim 1, wherein a circular cutting line that reaches the upper surface of the main girder is formed on the floor slab by a hole saw at the upper part of the main girder, thereby rimming an area where the jack is installed from the floor slab. 3. The method for removing a bridge deck according to claim 2, wherein a circular core is formed by removing a cylindrical core inside a circular cutting line formed by a hole saw, and a jack is installed in the hole.

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