JP4408885B2 - Horizontal cutting removal method of expansion joint - Google Patents

Description

  The present invention relates to a method of removing expansion joints such as elevated roads and bridges that need to be replaced due to aging and the like with low noise and low vibration without using a vibration generating device such as a breaker.

In order to repair and replace the expansion joints of bridges that have been aged for a long time since construction, or damaged bridges, it is possible to avoid spilling concrete with a breaker as much as possible, and to avoid spreading vibration and noise to the surroundings. In order to do so, it has been proposed to perform a replacement operation in a silent state using a diamond wire saw.
The groove where the diamond wire saw travels is formed around the expansion joint by cutting, the diamond wire is traveled at the bottom of the groove, and the floor slab containing the joint is cut horizontally to remove the expansion joint. Both forming and horizontal cutting with a wire saw are low noise and low vibration, and the removal work can be done silently, so it is a construction method that can be applied to expansion joints in urban highways where houses and buildings are close .

  The conventional diamond wire saw driving device 1 used for horizontal cutting of the expansion joint has diamond beads attached to the base 2, the lifting guide 201, the driving pulley 3 and the wire rope at regular intervals, as schematically shown in FIG. It consists of a wire saw 4. The drive pulley 3 is attached to the elevating guide 201 so as to be movable up and down, is rotationally driven by a hydraulic motor, and the wire saw 4 wound around the drive pulley 3 is installed in a cut and formed groove, and horizontally through the conversion pulley 31. The direction is changed and wound around the object to be cut, and the wire saw 4 travels at a high speed by the rotation of the drive pulley 3 to cut the object.

In order to remove the expansion joint, the lower part of the road surface is cut horizontally. Therefore, it is necessary to install a conversion pulley for changing the direction of the wire saw led under the road surface from the diamond wire saw driving device installed on the road surface. There was a lot of work and quick removal work was not possible.
The present invention aims to speed up the construction and reduce the cost by replacing the expansion joint such as a road bridge using a diamond wire saw so that the installation of the conversion pulley can be omitted.

  An arm extending downward via a bracket is attached to a base having a moving wheel, and the end of this arm rotates around a horizontal axis and the conversion pulley extends downward from the installation surface of the wire saw driving device. The expansion joint provided on the floor slab is horizontally cut and removed by using a wire saw drive device in which the conversion pulley is pivotable with respect to the axis of the arm, and the expansion pulley is enclosed. A groove for accommodating the wire saw is formed in the floor slab, and an auxiliary groove is formed at a certain distance inside the entire circumference of the groove and in the center of the joint, and a pit for accommodating the conversion pulley of the wire saw driving device is formed between the groove and the auxiliary groove. The wire saw drive device is installed so that the conversion pulley is located in the pit, the wire saw is arranged in the groove through the conversion pulley, and the floor slab and the expansion joint are leveled to the auxiliary groove in the center. Cut off the cutting plate, remove the floor slab of the part that has been horizontally cut and divided by the auxiliary groove and the groove, move the wire saw drive device to the part where the horizontal cutting has been completed, and place it in the groove through the conversion pulley. Of the expansion joint that is to be removed by horizontally cutting the remaining part and removing the floor slab between the groove and the auxiliary groove completely after the expansion joint is completely released from the surrounding floor slab concrete. It is a horizontal cutting and removal method, which makes it possible to shorten the work time.

A conversion pulley 31 is provided on the bracket 24 provided below the base of the wire saw driving device so that the protruding length can be adjusted. Since the installation of the conversion pulley 31 is completed simultaneously with the installation of the wire saw driving device 1, the cutting is started. Can be shortened.
Horizontal cutting can be performed without installing a conversion pulley, the setup work is simplified, and the expansion joint is released from the floor slab using auxiliary grooves and grooves, reducing work time and cost. Can be achieved.

Embodiment As shown in FIG. 1, the wire saw driving device 1 used in the present invention is provided with a moving wheel 20 on a base 2, and an operator can move an operation handle 23. A fixing device 21 for fixing the device at the time of cutting work is provided below the base 2, and the device is fixed by extending the legs 22 and floating the wheels 20 from the installation surface. A drive pulley 3 and a plurality of adjustment pulleys 30 are provided on the base 2.
The wire saw 4 is reciprocated between a plurality of adjustment pulleys 30 and is adapted to absorb the excessive length of the wire saw that is generated as the cutting progresses. The drive pulley 3 is rotationally driven by a hydraulic motor, and causes the wire saw 4 wound around the drive pulley 3 to travel at a high speed.

  A bracket 24 is provided at the lower portion of the base 2, and an arm 25 extending downward is fixed to a long hole formed in the bracket 24 with a bolt. The protrusion length of the arm 25 from the base 2 can be adjusted by changing the bolt tightening position. A conversion pulley 31 that rotates about a horizontal axis is attached to the tip of the arm 25 so as to be rotatable with respect to the arm. The wire saw 4 is guided from the drive pulley 3 to the adjustment pulley 30, is disposed horizontally in the groove via the conversion pulley 31, and is wound around the object to be cut. The wire saw 4 travels at a high speed by the rotation of the drive pulley 3 to cut the object. The arm 25 itself can be telescopic and telescopic, and any means may be adopted as long as the installation depth of the conversion pulley 31 can be changed. By making the conversion pulley 31 pivotable with respect to the arm 25, the conversion pulley 31 can be parallel to the groove even when the base 2 must be installed obliquely with respect to the groove. It is possible to smoothly run the wire saw.

Next, the procedure of the horizontal cutting and removing operation of the joint will be described.
As shown in FIG. 2, a planned cutting line is drawn on the road surface around the joint 5 to be removed as a preparation stage before cutting. In addition, a protective material or a sheet (not shown) made of urethane foam is installed to prevent cooling water from flowing out to the surroundings.
FIG. 2 shows an example of a planned cutting line. A groove portion 601 that accommodates a wire saw parallel to the joint 5 and groove portions 602 on both ends of the joint 5 surround the joint 5 to define a cutting region. The auxiliary cutting lines 603 and 604 on the inner side 150 mm from the groove portions 601 and 602 and the auxiliary cutting lines 605 are provided at the center of the joint 5. Reference numeral 606 denotes an auxiliary cutting line for forming a pit for installing the conversion pulley 31 of the wire saw driving device 1.

Using a core drill, the four corners 7 are cut into a circular shape to remove the core, and the cut cylindrical core is left in place without being removed.
Further, the core is overlapped at the position 73 where the conversion pulley 31 is to be formed, and the center portion 71, 71 of the joint 5 is cut into two places, and the middle portions 72, 72 are cut into a circle with a core drill. To do.

The concrete cutter cuts the auxiliary cutting lines 603 to 606 with the concrete cutter so that auxiliary grooves having a width of about 3 mm are formed on the lines. Next, it cut | disconnects with a concrete cutter along the cutting planned lines 601 and 602 of the part used as the groove | channel which accommodates a wire saw, and forms a groove | channel about 15 mm in width. Since a groove having this width cannot be formed by a commercially available rotating blade alone, a groove having a necessary width is formed by stacking a plurality of rotating blades (three in this embodiment). Further, a special size blade capable of cutting a necessary width independently may be used.
As another groove forming means, it is possible to form the groove by thermal spraying, but it is preferable to form the groove with a concrete cutter because high heat may adversely affect the floor slab concrete and the reinforcing bar.
The diameter of the blade is selected with a diameter corresponding to the size of the expansion joint 5 to be removed.

  By inserting a wedge or a bar into the auxiliary groove of the portion 73 between the auxiliary cutting line 606 and the groove that is circularly cut by the core drill and the auxiliary groove, the concrete subdivided into small pieces is removed to apply the pits. Form.

  As shown in FIG. 3, the conversion pulley 31 of the wire saw driving device 1 is installed on the floor slab so as to be directly above the pit, and the fixing leg is extended and fixed. The hydraulic unit and the hydraulic motor of the wire saw driving device 1 are connected by a hydraulic hose. The arm 25 provided with the conversion pulley 31 changes its fixed position according to the depth of the pit and extends downward so that the conversion pulley 31 is positioned in the pit, and the wire saw 4 wound around the drive pulley 3 is placed in the groove. The inside of the groove is made to surround the portion to be cut, which is arranged in a slanted line and is indicated by hatching.

When the wire saw 4 is tensioned and the drive pulley 3 is rotated to circulate inside the groove, the wire saw 4 bites into the floor slab concrete and horizontal cutting is started.
In the present embodiment, as the primary cutting, the horizontal cutting is completed up to the auxiliary groove formed in the auxiliary cutting line 605 in the central portion, and the peripheral cutting portion (double hatched portion) shown in FIG. 4 is removed. A groove having a width of 150 mm is formed around the joint 5.

  Therefore, as shown in FIG. 5, the wire saw driving device 1 is moved to horizontally cut the remaining portion. When the horizontal cutting is completed, the double hatched portion is removed as shown in FIG. 6, the joint 5 is completely released from the surrounding floor slab concrete, and the lifting metal is welded to the joint 5 and lifted with a crane. To do.

  When horizontal cutting is performed without providing a horizontal pulley for guiding the traveling of the wire saw 4 at the intermediate portion, the pull side of the wire saw is cut first, the folded portion gradually becomes an acute angle, stress is concentrated, and the wire saw breaks. In order to cause troubles such as being cut, it is preferable to perform cutting evenly by installing a horizontal pulley in the middle part.

  As shown in FIG. 7, the horizontal pulley 35 is installed by forming a hole 8 with an electric drill on the bottom surface of a pit provided at an appropriate position in the groove, and installing and fixing a bolt 82 having an extended portion in the hole 8. A washer 83 is installed on the bolt 82, and a hard rubber disc 84 having a hole in the center is inserted into the bolt 82 and fixed to form the horizontal pulley 35 for guiding the wire saw. It is preferable to form a groove on the outer peripheral surface of the rubber disk 84 so that the wire saw 4 is guided in this groove.

  In the past, horizontal pulleys were installed using fixing brackets, but according to this method, it is only necessary to drill with a drill on the bottom surface, and the horizontal pulley can be installed quickly, and the construction period for cutting and removing work is reduced. Can be shortened.

The front view of a wire saw drive device. Explanatory drawing of the cutting line of cutting work. The top view at the time of a primary cutting operation start. The top view at the time of a primary cutting operation completion. The top view at the time of a secondary cutting operation start. The top view at the time of a secondary cutting operation completion. Sectional drawing of a horizontal pulley. The front and side view of the conventional wire saw drive device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wire saw drive device 2 Base 3 Drive pulley 31 Conversion pulley 4 Wire saw 5 Joint

Claims (1)

An arm extending downward via a bracket is attached to a base having a moving wheel, and the end of this arm rotates around a horizontal axis and the conversion pulley extends downward from the installation surface of the wire saw driving device. The expansion joint provided on the floor slab is horizontally cut and removed by using a wire saw drive device in which the conversion pulley is pivotable with respect to the axis of the arm, and the expansion pulley is enclosed. A groove for accommodating the wire saw is formed in the floor slab, and an auxiliary groove is formed at a certain distance inside the entire circumference of the groove and in the center of the joint, and a pit for accommodating the conversion pulley of the wire saw driving device is formed between the groove and the auxiliary groove The wire saw drive device is installed so that the conversion pulley is located in the pit, the wire saw is arranged in the groove through the conversion pulley, and the floor slab and the expansion joint are leveled to the auxiliary groove in the center. Cut off the cutting plate, remove the floor slab of the part that has been horizontally cut and divided by the auxiliary groove and the groove, move the wire saw drive device to the part where the horizontal cutting has been completed, and place it in the groove through the conversion pulley. Of the expansion joint that is to be removed by horizontally cutting the remaining part and removing the floor slab between the groove and the auxiliary groove completely after the expansion joint is completely released from the surrounding floor slab concrete. Horizontal cutting removal method.

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