JP7290320B2 - Bridge deck cutting device and method - Google Patents

Description

The present invention relates to a floor slab cutting apparatus and method used for removing a floor slab from a steel girder for replacement of a concrete floor slab in a bridge renewal construction method.

When replacing the floor slabs as part of the countermeasures against aging bridges, the existing floor slabs are removed. The protrusion is cut together with the anchor bolt.

FIG. 1 shows a cutting device similar to the device disclosed in Patent Document 1 below. A drive pulley 3 that is lifted and lowered by a lifting mechanism consisting of a pinion rack mechanism that does not lift and is driven to rotate by a rotation drive mechanism including a motor, a mounting rod 4 that spans across the lower part of the support, and a conversion pulley that is mounted on the mounting rod 4. 5a, 5b, 5c and 5d, supporting rods 6 attached downward in parallel to both ends of the mounting rod 4, and conversion pulleys 7 attached to the lower ends of the supporting rods 6, respectively. , 5b, 5c, 5d and 7, an endless diamond wire (hereinafter simply referred to as wire) 11 is wound in a predetermined order.

In the construction method using the above equipment, first, a pair of vertical holes 8 are formed in the steel slab 1, which is fixed to the steel girder 9 by anchor bolts (not shown). A horizontal through hole 12 (hereinafter referred to as a wire through hole ) or a cutting groove is formed in the downwardly bulging convex portion 1a, and a support rod 6 having a conversion pulley 7 at its lower end is inserted into each vertical hole 8 and arranged.

Wires 11 hooked to the drive pulleys 3 are hooked to the conversion pulleys 5a, 5b, 5c, 5d and the conversion pulleys 7 in the vertical holes 8, and the wires 11 between the conversion pulleys 7 are opened to the convex portion 1a on the steel girder 9. The wire is passed through the wire through-hole 12 and horizontally spanned so as to surround the floor slab convex portion 1a. Next, while the wire 11 is connected endlessly, it is driven to run by rotating the driving pulley 3, and the lifting mechanism raises the driving pulley 3 in the direction of the arrow in the figure to pull the wire 11, thereby pulling the floor slab convex portion. 1a is horizontally cut together with the anchor bolts (not shown) to be separated from the steel girder 9. As shown in FIG.

In the above construction method, the illustrated conversion pulley 7 is housed in the vertical hole 8 because the wire 11 that turns downward from the conversion pulley 7 must be positioned at the horizontal cutting position.

As another construction method, Non-Patent Document 1 below proposes a device for horizontally cutting the floor slab above the steel girder by attaching an entire cutting device consisting of a wire saw to the steel girder under the floor slab.

JP 2009-114688 A

Nihon Keizai Shimbun published on August 9, 2019

In the construction method disclosed in Patent Document 1, the cutting device is installed on the floor slab. Although there is an advantage that the installation work to the plate is easy, the wire 11 hung on the conversion pulley 7 arranged in the vertical hole is cut at a desired horizontal cutting position on the steel girder 9 so as not to interfere with the steel girder 9. It is necessary to adjust the vertical position of the conversion pulley 7 in order to set the cutting position by the wire 11 because it needs to be positioned.

The vertical position of the conversion pulley 7 is adjusted by raising and lowering the conversion pulley 7 together with the support rod 6. After the vertical position adjustment, the support rod 6 is fixed. In other words, a worker who raises and lowers the conversion pulley 7 under the floor slab and a worker who fixes the support rod 6 to which the conversion pulley 7 is attached above the floor slab is required. becomes.

If the support rod is fixed and the vertical position can be adjusted by raising and lowering the conversion pulley 7 with respect to the fixed support rod 6 under the floor slab, the adjustment work can be performed by one worker. It is not easy to adjust the conversion pulley in the narrow vertical hole 8 with a limited diameter.

The wire is also divided between the feed side to the drive pulley and the feed side from the drive pulley, the former being the tight side and the latter being the slack side. The wire tends to sag, and if there is even a slight sag, the wire cut into the floor slab gradually reaches the steel girder 9 made of H-shaped steel supporting the floor slab and may damage the steel girder.

Therefore, when cutting the floor slab convex part horizontally, it is necessary to cut a place away from the steel girder 9 so that the wire does not contact the steel girder 9. , the more concrete remains on the steel girder 9 after the floor slab is cut, the more time it takes to remove the concrete after cutting.

The present invention provides a cutting device comprising a wire saw mounted on a concrete floor slab of a bridge. To provide a floor slab convex part cutting device and method capable of easily performing a cutting operation with a steel girder, performing horizontal cutting at a location near the steel girder, and reducing chipping work of concrete remaining on the steel girder after cutting. aim.

The invention according to claim 1 comprises a support vertically installed on a concrete floor slab of a bridge, a drive pulley attached to the support so that it can move up and down, a drive device for rotating the drive pulley, and the drive pulley. A lifting mechanism that raises and lowers along the pillar, a conversion pulley placed on the floor slab, and a pair of raised parts on both sides of the steel girder for the floor slab supported by the steel girder at the raised part that swells from the bottom surface. Support rods arranged in the vertical holes, pulley devices attached to the support rods protruding downward from the floor slab so that the vertical position can be adjusted, the drive pulley and conversion pulley on the floor slab, and pulleys under the floor slab. Each pulley device comprises a plurality of conversion pulleys, and the wire that is hooked to the highest conversion pulley among them is positioned at the horizontal cutting position.

The invention according to claim 2 is the invention according to claim 1, wherein the pulley device comprises upper and lower conversion pulleys, and a wire passed through the vertical hole is hooked on the conversion pulley above the conversion pulley on the lower side of the pulley device. characterized by being

The invention according to claim 3 is the invention according to claim 1 or 2, wherein the vertical hole is located on one side of the protrusion and the groove bottom is located on the other side at the vertical groove or horizontal cutting position. Positioned wire through holes are formed, and among the inclined side surfaces on both sides of the protrusion sandwiching the steel girder, at least at the groove end or wire through hole end that opens on the side surface on the wire introduction side to the vertical groove or wire through hole, A receiving guide for the wire is provided.

The invention according to claim 4 is a method for cutting floor slab projections using the cutting device according to claim 1, which includes the steps of forming vertical holes in the floor slab through which wires are passed, and installing posts on the floor slab. Mounting work, work of horizontally suspending a mounting rod equipped with a conversion pulley on the support, work of passing a support rod through a vertical hole drilled in the floor slab, after adjusting the vertical position of the pulley device on the support rod projecting from the vertical hole , mounting work, drive pulley and conversion pulley on the floor slab, and work of hooking wires to the pulley device attached to the support rod protruding under the floor slab, then the drive pulley is rotated by the drive device. In addition to driving, the wire is moved upward by an elevating mechanism and pulled while driving to horizontally cut the floor slab projections.

According to the invention of claim 1, the operation of attaching the cutting device to the floor slab is performed on the floor slab, except for the operation of attaching the pulley device to the support rod projecting downward from the floor slab. Compared to the described device, it does not bring about a great difference in workability, and like the device described in Patent Document 1, the entire cutting device can be easily attached to the floor slab, and the pulley device can be attached to the support rod. , One worker can visually check the vertical position of the support rod that protrudes downward from the floor slab, making it easy to adjust the mounting position of the pulley device to the support rod. It can be done at low cost. In addition, the wire hanging on the uppermost conversion pulley in the pulley device on the slack side of the wire feeding side of the pulley device is about to be blown upward by the centrifugal force due to the rotation of the pulley, so the conventional device shown in FIG. In comparison, it is difficult to contact the steel girder that supports the floor slab, so the cutting position with the wire can be easily brought closer to the steel girder, the amount of concrete remaining on the steel girder after cutting is reduced, and the work of chipping the concrete is reduced. become able to.

According to the second aspect of the invention, the minimum number of conversion pulleys of the pulley device attached to the support rod is two, and the wire hooked on the upper conversion pulley can be positioned at the horizontal cutting position.

According to the third aspect of the invention, the horizontal cutting position is performed in a state in which the wire that is hung so as to surround the floor slab projection is constrained to the groove bottom of the vertical groove formed in the floor slab or the wire through hole, It is possible to easily and reliably perform horizontal cutting at a predetermined position. Damage to the girders can be further prevented.

According to the fourth aspect of the invention, the cutting apparatus of the first aspect of the invention can be used to horizontally cut the raised portion of the floor slab.

Sectional drawing of the floor slab cutting apparatus by a conventional method. Sectional drawing of the cutting device which concerns on this embodiment. The front view of the pulley apparatus under the floor slab attached to the support bar. The top view of the same pulley apparatus. The bottom view of the floor slab with a steel girder when horizontally cutting the floor slab protrusion. FIG. 3 is an enlarged cross-sectional view of c part shown in FIG. 2 provided with a receiving guide;

Hereinafter, a floor slab cutting apparatus according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 2 shows an outline of a cutting device comprising a wire saw. Similar to the known cutting device of this kind, a support 21 is detachably installed vertically on the floor slab 1 and attached to the support 21 so that it can be raised and lowered. The drive pulley is driven to rotate by a drive device having a drive source such as an electric motor or a hydraulic motor (not shown), and is moved up and down along the column 21 by an elevating mechanism consisting of a pinion rack mechanism (not shown) using the motor as a drive source. 22, a mounting rod 23 that extends across the lower end of the support, conversion pulleys 24a and 24b that are located on both sides of the lower side of the drive pulley 22 and are attached to the mounting rod 23 so that the left and right positions can be adjusted; Supporting rods 25 having an arbitrary cross-sectional shape, for example, square rods, and floor slabs, which are located at both left and right end portions of the mounting rod 23 and are detachably attached or fixed to the mounting rod 23 and vertically provided. A pulley device 27 attached to a lower support rod 25 so that its vertical position can be adjusted, the drive pulley 22 on the floor slab, conversion pulleys 24a, 24b and 26a, 26b, and the pulley device 27 under the floor slab. It consists of an endless wire 28 that is

As shown in FIG. 3, the pulley device 27 is vertically slidably attached to the support rod 25 protruding below the floor slab. a bracket 32 supported by a pivot 31 supported on the mounting portion 30 in parallel with the support rod 25; It consists of two conversion pulleys 33a and 33b, and as shown in FIG. 4, these upper and lower conversion pulleys 33a and 33b can turn left and right in FIG. The wire 28 passed through a vertical hole 37 (to be described later) and is hooked to the lower conversion pulley 33a from the lower side. The vertical position of the entire pulley device 27 with respect to the support rod 25 is adjusted so that the vertical position of the wire 28, which is hung on the conversion pulley 33b and extends laterally from the conversion pulley 33b, coincides with the cutting position. The arrows in FIGS. 1, 2 and 6 indicate the traveling direction of the wire 28, and in the examples shown in FIGS.

In FIG. 2, a steel girder 9 whose cross section is made of H-shaped steel is laid horizontally on a bridge pier (not shown), and a mountain-shaped convex portion 1a protruding downward from the floor slab 1 is fixed thereon by an anchor bolt (not shown). there is

When removing the floor slab 1 from the steel girder 9, first, as shown in FIG. A pair of are penetrated using a tool such as a core drill, and a horizontal wire through hole 38 for passing the wire 28 is formed on the other side of the convex portion in parallel with the steel girder 9 and at a location corresponding to the horizontal cutting position. be done. FIG. 5 shows a state in which both ends of the wire through-hole 38 are open on the slope of the projection 1a. As shown in FIG. 6, each of the inclined openings formed on the convex slope of the wire through-hole 38 is provided with a guide 40 for receiving the wire 28 having a plate-like or curved cross-section, so that when the wire 28 hangs down, the guide 40 is provided. It is desirable to receive the wire 28 and prevent the wire 28 from contacting the steel girder 9 .

In the illustrated example, the support rod 25 and the wire 28 are passed through one vertical hole 37 together. 25 and wire 28 may be individually passed. Also, the wire through hole 38 for restraining the vertical position of the wire 28 may be replaced by a longitudinal groove formed in the floor slab 1 from the bottom surface upward. In this case, the longitudinal groove is formed so that the groove bottom at the upper end is positioned at the horizontal cutting position. In the case of forming a vertical groove, a receiving guide 40 is provided at the end of the groove as well as the wire through hole 38 .

After forming the vertical hole 37 and the wire passage hole 38, the post 21 is fixed to the floor slab 1 with bolts (not shown) as shown in FIG. The mounting rod 23 equipped with the conversion pulleys 24a and 24b may be horizontally mounted on the support 21 in advance, or may be mounted on the support 21 after the support 21 is attached to the floor slab 1 as described above. may

Next, the support rod 25 is passed through the vertical hole 37 and fixed to the mounting rod 23, but the support rod 25 may also be mounted to the mounting rod 23 in advance. If the support rod 25 is attached to the mounting rod 23 in advance, the support rod 25 is inserted into the vertical hole 37 when mounting the mounting rod 23 to the column 21 . The pulley device 27 is attached to the portion of the support rod 25 inserted into the vertical hole 37 which protrudes from the floor slab 1 by adjusting its vertical position.

After that, a wire 28 is hung from the drive pulley 22 on the floor slab to the conversion pulleys 24a, 24b, 26a, and 26b, and passed through the vertical hole 37. After hooking on the pulley 33a and then the upper conversion pulley 33b, the wire 28 between the conversion pulleys 33b is passed along the foot of the convex portion 1a (inclined surface) and passed through the wire-horizontal hole 38 so as to surround the convex portion 1a. After that, the free ends of the wire 28 are connected to form an endless wire. The order in which the wire 28 is passed through the drive pulley 22, the conversion pulleys 24a, 24b, 26a, 26b and the conversion pulleys 33a, 33b is not limited to the above-mentioned order. Just do it. Also, the wire 28 may be connected in an endless manner anywhere after passing the wire through hole 38, for example, it may be connected anywhere on the floor slab.

Work of forming a vertical hole in the floor slab 1, work of forming a wire passage hole, work of mounting a support on the floor slab, work of mounting a mounting rod 23, work of mounting a support rod 25, vertical position to the support rod 25 The work for mounting the pulley device 27 including adjustment, the work for mounting the wire 28, and the like are not limited to the order described above, and even if the work order is different from the above, the point is that the cutting device is mounted as shown in FIG. It is good if there is

After the wire saw device is attached to the floor slab 1 and the wire 28 is hooked to each pulley as described above, the drive pulley 22 is driven to rotate by the drive device, and the lifting mechanism moves in the direction of the arrow in FIG. As a result, the wire 28 circulates and is pulled to horizontally cut the floor slab convex portion 1a on the steel girder 9. During this horizontal cutting, an anchor (not shown) connecting the floor slab 1 and the steel girder 9 is performed. Bolt cutting is also performed.

During horizontal cutting, the wire 28 engages with the floor slab projections 1a in a mountain shape as shown in FIG. The conversion pulleys 33a and 33b also gradually turn around the pivot 31 according to the gradient of the wire 28 and change their direction. At the end of cutting, the conversion pulleys 33a and 33b are turned 90 degrees inward and the wire 28 is also straightened. By rotating the conversion pulleys 33a and 33b in accordance with the inclination of the wire 28, the wire 28 circulates without being detached from the conversion pulleys 33a and 33b.

The convex portion 1a of the floor slab 1 is cut horizontally on the steel girder as described above. After each projecting portion 1a of the floor slab 1 is separated from the steel girder 9, the floor slab 1 is lifted by a crane operation and removed from the steel girder 9. After the floor slab is removed, the remainder of the floor slab 1 remaining on the steel girder 9 is removed using a rock drill or the like.

Reference Signs List 1 Floor slab 9 Steel girder 21 Strut 22 Drive pulley 23 Mounting rods 24a, 24b, 26a, 26b, 33a, 33b Conversion pulley 25 Support rod 27 Pulley device 28 Wire 31 Pivot 37 Vertical hole 38 Wire through hole 40 Receiving guide

Claims (4)

A column vertically installed on a concrete floor slab of a bridge, a driving pulley attached to the column so that it can be raised and lowered, a driving device that drives the driving pulley to rotate, and an elevating mechanism that raises and lowers the driving pulley along the column. and a conversion pulley arranged on the floor slab, and the floor slab supported by the steel girder at the convex portion protruding from the bottom surface, the support arranged in a pair of vertical holes drilled in the convex portion on both sides of the steel girder. A pulley device attached to a rod, a support rod protruding downward from the floor slab so that the vertical position can be adjusted, the drive pulley and conversion pulley on the floor slab, and an endless pulley device under the floor slab. A cutting apparatus for bridge deck slabs, comprising a wire, each of said pulley devices comprising a plurality of conversion pulleys, wherein a wire hung between the highest conversion pulleys is positioned at a horizontal cutting position. 2. The bridge floor slab cutting according to claim 1, wherein said pulley device comprises upper and lower conversion pulleys, and a wire passed through a vertical hole is hooked on the conversion pulley above the conversion pulley on the lower side of the pulley device. Device. The vertical hole is formed on one side of the projection, and the vertical groove whose groove bottom is located at the horizontal cutting position or the wire passage hole located at the horizontal cutting position is formed on the other side, and both sides of the projection sandwiching the steel girder are inclined. 3. A wire receiving guide is provided at a groove end or a wire through-hole end, which is open at least on a side surface on a wire introduction side to the longitudinal groove or the wire through-hole, among the side surfaces formed by the wire through-hole. bridge deck cutting equipment. Work to make vertical holes in the floor slab for passing wires through, work to attach posts to the floor slab, work to horizontally suspend mounting rods equipped with conversion pulleys on the posts, and insert support rods into the vertical holes drilled in the floor slab. After adjusting the vertical position of the pulley device on the support rod protruding from the vertical hole, the work of attaching the drive pulley and conversion pulley on the floor slab, and the wire to the pulley device attached to the support rod protruding under the floor slab After performing each work of the work of hanging the floor slab, the drive pulley is rotated by the drive device and moved upward by the lifting mechanism to pull the wire while driving to cut the floor slab convex part horizontally. A method of cutting a floor slab projection using the cutting device of the invention according to claim 1.

Images