JP7266799B2 - Concrete floor slab cutting method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method and a wire saw device for cutting a concrete floor slab of a bridge. The present invention relates to a method of cutting using and a wire saw device.

In bridges such as road bridges, the concrete floor slabs are damaged by the passage of vehicles. It is being replaced and updated. There are various types of floor slabs to be newly replaced, such as RC concrete floor slabs cast on site, precast PCa floor slabs cast in advance at a factory, etc., and steel floor slabs. There may be cases where new floor slabs are used.

As a method for removing such an existing concrete floor slab, Patent Document 1 discloses that the concrete of the floor slab 3 is drilled with a drill 10 from the lower surface side of the floor slab 3 toward the dowel 2d together with the dowel 2d. 2d is cut, and the deck slab 3 with the cut dowel 2d is peeled off from the main girder 2 and removed (Claim 1 of the scope of claim of Patent Document 1, (see paragraphs [0023] to [0035] of the specification, FIGS. 8 to 18 of the drawings, etc.).

However, in the floor slab removal method of the composite girder described in Patent Document 1, it is necessary to cut the dowel 2d of the floor slab 3 to be removed by drilling work, and a large number of holes must be drilled. Drilling work required time and labor, and as a result, removal work could not be easily done in a short time. In addition, when drilling a part with different haunch heights on the left and right sides of the floor slab, which is inclined to the left and right in the cross section by providing a drainage slope, the drilling distance is the same if the haunch heights are the same on the left and right sides. There is a problem that the drilling work becomes longer, and the drilling work takes more time and labor.

Further, in Patent Document 2, a hole 40 is drilled in the haunch portion 22 by a drilling process, a crack 60 is generated in the haunch portion 22 starting from the hole 40 and reaching the stud dowel 13 by a crack generation process, and the dowel is cut. A concrete floor slab removal method is described in which the stud dowel 13 inside the haunch portion 22 is cut from the crack 60 in the process, and the concrete floor slab 20 is separated from the girder 10 with the crack 60 as the boundary in the floor slab separation process ( See claim 1 in the scope of claims of Patent Document 2, paragraphs [0018] to [0029] of the specification, and FIGS. 2 to 8 of the drawings, etc.).

In the concrete floor slab removal method described in Patent Document 2, a jack, a wedge, or the like is inserted into the drilled hole and pushed open by them to cause a crack. It is said that it can be removed. However, in the part where the height of the haunch of the concrete floor slab inclined to the left and right with a drainage slope is different on the left and right, the hole to be drilled must be drilled not horizontally but at an angle. The distance between the left and right sides of the girder is longer than that of the point where the height of the haunch is the same, and the problem that drilling work takes time and labor has not been solved.

Further, in Patent Document 3, a hole 40 reaching the upper surface 12 of the flange 11 is drilled from the lower surface 13 of the flange 11 so as to hollow out the periphery of the stud dowel 14 by a drilling process, and is covered by the concrete 21 by a floor slab separation process. A concrete floor slab removal method for separating the concrete floor slab 20 from the flange 11 of the girder 10 together with the stud dowel 14 attached thereto is described (Patent Document 3, claim 1, paragraph of the specification). [0015] to [0020], see FIGS. 3 and 5 of the drawings).

However, the concrete floor slab removal method described in Patent Document 3 involves drilling the periphery of the stud dowel 14 together with the flange 11 of the steel girder. In addition, the exact position of the welded stud dowel 14 must be drilled from the bottom surface of the flange 11, and the circumference of the stud dowel 14 must be accurately hollowed out. There was a problem that it was extremely difficult to drill a hole in the hole.

JP 2017-89302 A JP 2018-91062 A JP 2018-71275 A

Therefore, the present invention has been devised in view of the above-mentioned problems, and its object is to shorten the concrete floor slab and the girder even if the height of the haunch is different on the left and right sides of the concrete floor slab. To provide a concrete floor slab cutting method and a wire saw device capable of easily cutting and separating in time.

A concrete floor slab cutting method according to a first aspect of the present invention is a method for cutting a concrete floor slab tilted left and right due to a drainage slope in a cross section along a direction perpendicular to a bridge axis in order to remove the concrete slab from a girder. A method for cutting a floor slab, in which horizontal holes are drilled in the following process by cutting vertically from the lower surface side of the concrete floor slab in the haunch on the side of the lower drainage slope with respect to the girder of the bridge in the direction of the bridge axis. A vertical groove forming step of forming a vertical groove of a predetermined depth along the bridge axis direction according to the tip , and a bridge from the haunch on the side with a high drainage slope toward the haunch on the low side with respect to the girder A horizontal hole drilling step of drilling substantially horizontally in a direction perpendicular to the axis to form a horizontal hole communicating with the vertical groove , and a vertical through hole drilling step of drilling a vertical through hole penetrating vertically through the concrete floor slab. and a wire saw cutting step of inserting a wire saw into the horizontal hole formed in the horizontal hole drilling step to cut the concrete floor slab, wherein the wire saw cutting step includes a forwarding route of the wire saw. passes through all of the vertical grooves, the horizontal holes, and the upper and lower through-holes, and a driving device for the wire saw is placed on the upper surface of the concrete floor slab to remove the concrete floor slab and the girder. The concrete floor slab is separated from the girder by cutting the connecting portion with the girders substantially horizontally.

A method for cutting a concrete floor slab according to a second aspect of the invention is the method for cutting a concrete floor slab according to the first aspect, wherein in the wire saw cutting step, the concrete floor slab is provided so as to protrude or retract relative to a support beam attached from the upper surface to the lower surface of the concrete floor slab. Using a wire saw device having a universal pulley rotatable in the same plane , forwarding of the wire saw when the length of the forwarding route of the wire saw is shortened as cutting progresses with the universal pulley. It is characterized by cutting following changes in the bending angle of the route .

A method for cutting a concrete floor slab according to a third invention is, in the first invention or the second invention, a step of cutting the concrete floor slab vertically along the direction perpendicular to the bridge axis; A lifting step of lifting the concrete floor slabs cut in the step of cutting in the direction perpendicular to the slab bridge axis with a lifting device and separating them from the girders.

According to the first to third inventions, there is a vertical groove forming step of forming vertical grooves by cutting in the vertical direction from the lower surface side of the concrete floor slab in the lower haunch with a low haunch height slope, It is possible to shorten the drilling distance of the horizontal holes formed in the horizontal hole drilling process even in concrete floor slabs with different haunch heights on the left and right sides. Therefore, according to the first to third inventions, the concrete floor slab and the girder can be easily cut and separated in a short time.

In addition, according to the first to third inventions, it is possible to proceed as a preparatory work in advance before the start of traffic regulation, and it is possible to reduce the work under traffic regulation, so that the regulation time can be shortened. can be planned.

Moreover, according to the first to third inventions, the concrete floor slab can be cut by placing the driving device of the wire saw on the upper surface of the concrete floor slab. Therefore, it is not necessary to provide a large space below the floor slab for installing the driving device of the wire saw, and the number of temporary facilities can be reduced, thereby reducing the working cost of cutting the concrete floor slab. In addition, according to the first to third inventions, the heavy wire saw driving device is placed on the floor slab, which is less likely to fall, so safety is improved.

In particular, according to the second invention, even if the bending angle of the wire saw changes as the cutting progresses, the free pulley can rotate to follow it. For this reason, according to the second invention, in the wire saw cutting process, it is not necessary to place personnel under the floor slab for monitoring, and labor costs in this process can be reduced.

In particular, according to the third invention, the lifting process can be performed in parallel with the wire saw cutting process. Lateral cracks can occur in the floor slab. Therefore, the concrete floor slab and the girder can be cut and separated in a shorter time.

FIG. 1 is a vertical cross-sectional view showing a state in which a bridge to which a concrete floor slab cutting method according to an embodiment of the present invention is applied is cut vertically in the direction perpendicular to the bridge axis. FIG. 2 is an enlarged view of part A in FIG. FIG. 3 is a process explanatory view showing a longitudinal groove forming process of the concrete floor slab cutting method according to the first embodiment of the present invention, which is a cross-sectional view cut along the direction Y perpendicular to the bridge axis. FIG. 4 is a process explanatory view showing a horizontal hole drilling process of the concrete floor slab cutting method according to the first embodiment of the present invention with a cross-sectional view cut along the direction Y perpendicular to the bridge axis. FIG. 5 is a process explanatory diagram showing a wire saw cutting process of the concrete floor slab cutting method according to the first embodiment of the present invention in a perspective plan view. FIG. 6 is a process explanatory diagram showing a cross-sectional view cut along the direction Y perpendicular to the bridge axis of the upper and lower through-hole drilling process of the concrete floor slab cutting method according to the modified example of the first embodiment. FIG. 7 is a forwarding route explanatory diagram showing a modification of the forwarding route of the wire saw used in the above concrete floor slab cutting method in a perspective plan view. FIG. 8 is an installation state explanatory diagram showing the installation state of the wire saw device in the wire saw cutting step of the above concrete floor slab cutting method in a cross-sectional view cut along the direction Y perpendicular to the bridge axis. FIG. 9 shows a state before the concrete floor slab cutting process according to the second embodiment of the present invention, in which the concrete floor slab is cut along the cutting lines Y1 and Y2 by performing the step of cutting in the direction perpendicular to the bridge axis, and before the lifting step is performed. It is a top view. FIG. 10 is a process explanatory view showing a lifting process of the concrete floor slab cutting method according to the second embodiment of the present invention in a cross-sectional view cut along the direction Y perpendicular to the bridge axis. FIG. 11 is a forwarding route explanatory diagram showing a forwarding route of a wire saw used in the concrete floor slab cutting method according to the third embodiment of the present invention in a perspective plan view. FIG. 12 is a front view of a wire saw device used in the same concrete floor slab cutting method as seen along the direction perpendicular to the bridge axis, and a process explanatory diagram showing a wire saw cutting process using the wire saw device. FIG. 13 : is process explanatory drawing which shows the right side view which looked at the wire saw apparatus same as the above along the bridge axis direction, and the wire saw cutting process using the wire saw apparatus it.

An embodiment for carrying out a concrete floor slab cutting method according to the present invention will be described in detail below with reference to the drawings.

A concrete floor slab cutting method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 10. FIG. In the concrete floor slab cutting method according to the embodiment of the present invention, in the concrete floor slab, which is a composite floor slab connected to the steel girder, the steel girder located at the outermost edge, which is the most downstream side in the drainage slope, is inclined to the left and right. A case will be described by exemplifying a case where the connected portion of the concrete floor slab is cut off from the steel girder.

<Bridge>
First, a bridge in which a floor slab is cut by applying a concrete floor slab cutting method according to an embodiment of the present invention will be briefly described with reference to FIGS. FIG. 1 is a vertical cross-sectional view showing a state in which a bridge to which a concrete floor slab cutting method according to an embodiment of the present invention is applied is cut vertically in the direction perpendicular to the bridge axis, and FIG. 2 is a section A in FIG. It is an enlarged view.

A bridge B1 to which the present invention is applied is a bridge used as a road bridge, and as shown in FIGS. Concrete floor slabs F1, etc., which are composite floor slabs made of reinforced concrete, are joined via non-slip materials such as stud dowels. In addition, along the edges on both sides of the concrete floor slab F1, ground covering portions W1 and W2 are formed as car stops, and a pavement P1 such as asphalt pavement is laid above the concrete floor slab F1. However, facilities such as wall balustrades installed above the ground covering portions W1 and W2 are omitted.

The X direction in the figure indicates the axial direction along the axial direction of the steel girders G1 to G4 of the bridge B1, and the Y direction is the horizontal direction perpendicular to the axial direction X of the bridge B1. pointing in the direction. Also, the Z direction indicates the up-down direction, which is the vertical direction.

Normally, the bridge B1 of such a road bridge is provided with a drainage slope on the upper surface of the floor slab F1. Plate F1 has different haunch heights on the left and right sides. For this reason, in the cutting method of separating the joint portion of the concrete floor slab F1 and the steel girder G1 (bridge girder) having different haunch heights on the left and right sides from the steel girder G1, the haunch portion is horizontally cut like the conventional cutting method. Not only is it difficult to drill, but the distance to be drilled is longer than the joints with the steel girders (G2, G3) on the middle side, and the drilling work takes time and labor. .

As shown in FIG. 1, the bridge B1 illustrated and illustrated when applying the present invention is a straight line with a drainage slope provided only in one direction with one edge raised instead of the central part of the main girder. It is a bridge with a cross slope. Of course, a bridge with a higher center and lower edges on both sides may be used.

Further, as shown in FIG. 2, the inclination angle α (the angle formed with the horizontal plane, the same shall apply hereinafter) of the haunch h1 on the right side of the steel girder G1 positioned on the most downstream side is about 20.0° in the illustrated embodiment. The inclination angle β of the lobe h2 on the left side of the drawing is about 2.5° in the illustrated embodiment. That is, when the thickness H1 of the floor slab F1 is 160 mm, the lobe height H2 of the right haunch h1 is 100 mm, which is a general lobe height (tan α = about 100 mm/250 mm), and the left haunch The haunch height H3 of h2 is almost no haunch height and is about 20 mm (tanβ=about 20 mm/430 mm). Of course, the bridge to which the present invention can be applied is a case where the height of the haunches is different on the left and right sides, and the drilling distance between the haunches is long, and is limited to the exemplified haunch inclination angle and haunch height. can't

[First embodiment]
Next, specific procedures of the concrete floor slab cutting method according to the first embodiment of the present invention will be described with reference to FIGS. 3 to 8. FIG.

(Flat groove forming process)
FIG. 3 is a process explanatory view showing a longitudinal groove forming process of the concrete floor slab cutting method according to the first embodiment of the present invention, which is a cross-sectional view cut along the direction Y perpendicular to the bridge axis. In the concrete floor slab cutting method according to the present embodiment, first, as shown in FIG. 3, a vertical groove forming step is performed in which vertical grooves are formed by cutting the concrete floor slab from the lower surface side in the vertical direction.

Specifically, using a large rotary cutting device 1 such as a wall saw or a diamond cutter, the height of the haunch with a small inclination angle is obtained by cutting in the vertical direction (vertical direction Z) from the lower surface side of the concrete floor slab F1. A flute 2 is cut in the low haunch h2.

This vertical groove 2 is a groove along the bridge axis direction X with a predetermined depth corresponding to the tip of the drilling position of the horizontal hole 4 described later. The length is set to a predetermined length according to the width cut along the direction Y perpendicular to the bridge axis. Determination as to whether or not the predetermined depth has been reached is made using a depth measuring jig 1a provided in the rotary cutting device 1 and having a bar with a scale.

(Horizontal drilling process)
FIG. 4 is a process explanatory view showing a horizontal hole drilling process of the concrete floor slab cutting method according to the first embodiment of the present invention with a cross-sectional view cut along the direction Y perpendicular to the bridge axis. In the concrete floor slab cutting method according to the present embodiment, next, as shown in FIG. 4, a horizontal drilling step of drilling laterally to form horizontal holes is performed.

Specifically, using a special drilling device 3 that can drill even in a narrow space, in the haunches h1 and h2 with different inclination angles and heights on the left and right, the height of the haunch above the drainage slope (inclination) A horizontal hole 4 is drilled substantially horizontally from the side of the haunch h1 with the higher slope toward the side of the haunch h2 with the lower haunch on the lower side of the drainage gradient (inclination).

The special drilling device 3 used in the concrete floor slab cutting method according to the present embodiment includes a drill bit 33 in which a spindle 31, which is the central axis of the device main body 30, is positioned above the spindle 31 via a gear 32. can be driven to rotate. For this reason, the drilling device 3 uses a large-diameter device body 30 with a high driving force (for example, the ability to drill a core drill with a diameter of 40 mm at about 10,000 revolutions/minute), so that the haunch height H2 is Drilling is possible even in a narrow place where there is no height space such as haunch h1, which is a normal haunch height of about 100 mm, and drilling to a desired depth is possible in a short time. Further, by drilling the hole substantially horizontally, the hole can be drilled in the shortest distance, and in this respect also the drilling can be performed in a short time.

The drilling device 3 is installed on the lower surface of the floor slab. The drilling device 3 is placed on a support jig 34, and the support jig 34 is suspended and supported on the lower surface of the floor slab by an anchor. As another installation method, there is also a method of fixing to the lower surface of the floor slab with suction cups.

The support jig 34 has a function of positioning the drilling device 3 installed in a suspended state and a function of moving the mounted drilling device 3 back and forth. can be moved back and forth to remove pieces of concrete in the core after drilling. Further, the moving function of the support jig 34 not only facilitates the mounting of the core extension jig for extending the core bit, but also enables position adjustment by moving the drilling device 3 vertically and horizontally. there is

In addition, the support jig 34 is capable of adjusting the angle of the drilling device 3, so that the drilling device 3 can perform drilling inclined with respect to the horizontal plane or directional drilling with an angle. is possible. The angle adjustment by this support jig can be detected by an infrared laser or the like, and it is possible to confirm the inclination angle and ensure parallelism with the steel girder.

In the conventional drilling device, the core bit connected to the device main body attached to the lower surface of the floor slab may be positioned closer to the upper flange of the steel girder or in contact with the steel girder upper flange than the planned position. The reason is that since general drilling equipment is designed for drilling large-diameter cores, the center of the core is located close to the center of the drilling equipment, making it possible to drill large-diameter cores. , is affected by the mechanical height of the device. For this reason, the conventional drilling device needs to set the upper edge of the core at a position closer to the lower edge of the floor slab.

The drilling device 3 according to the embodiment of the present invention is configured so that the upper edge of the core can be placed at a position 10 mm below the lower surface of the floor slab by giving the core part of the drilling device an eccentric function. . Therefore, even if the height of the haunch is small, for example, the height of the haunch is 50 mm, the upper edge of the upper flange of the steel girder is 40 mm.

Therefore, the drilling device 3 can drill a hole if the outer peripheral portion of the core drilling diameter is φ35 mm or less because a space of 5 mm or more is secured. However, there is a possibility of hitting the steel girder with a slight angle change, so it is desirable to drill a core with a smaller diameter. Therefore, the drilling device 3 according to the present embodiment has a core outer diameter of φ25 mm, and can secure a clearance of 15 mm to the upper edge of the flange on the steel girder.

Of course, the core drilling diameter of the drilling device 3 is more preferably φ20 mm, more preferably φ15 mm. A theoretical core drilling diameter of the drilling device 3 can be installed with a wire saw if the drilling diameter is equal to or greater than the diameter of the wire saw.

Although the case where the horizontal hole drilling process is performed after the above-described vertical groove forming process has been described as an example, it is also possible to perform the vertical groove forming process after performing this horizontal hole drilling process. This is because the same result can be obtained by confirming the depth of the horizontal hole 4 to be drilled in the horizontal hole drilling process and then cutting the vertical groove 2 toward the steel girder G1 side.

(Wire saw cutting process)
FIG. 5 is a process explanatory diagram showing a wire saw cutting process of the concrete floor slab cutting method according to the first embodiment of the present invention in a perspective plan view. In the concrete floor slab cutting method according to the present embodiment, next, as shown in FIG. A wire saw cutting process for cutting F1 is performed.

Specifically, using a wire saw device 50, which is a driving device capable of rotating the wire saw 5, the wire saw 5 is used to move the concrete floor slab F1 together with a non-slip material such as a stud dowel (not shown) substantially horizontally. Cut and separate from steel girder G1.

As shown in FIG. 5, the forwarding route of the wire saw 5 is a rectangular forwarding route on the same plane from the first route R1 to the fourth route R4. The wire saw device 50 is used by installing a temporary scaffold supported by steel girders G1 or the like under the concrete floor slab F1, and fixing the wire saw device 50 thereon. Further, the direction of the forwarding route is changed using a pulley (pulley) and a conversion frame (not shown).

As shown in FIG. 5, the first route R1 is a route from the wire saw device 50 along the already cut end surface F1a of the concrete floor slab F1, that is, along the direction Y perpendicular to the bridge axis, and passes over the upper flange of the steel girder G1. This is the route that leads to the position. The second route R2 is substantially orthogonal to the first route R1 and extends from the end point of the first route R1 to the haunch h1 side of the horizontal hole 4 along the axial direction X.

A third route R3 is a route that passes through the horizontal hole 4 substantially perpendicular to the second route R2 and reaches the haunch h2 side of the horizontal hole 4 . The fourth route is a route that passes through the longitudinal groove 2 substantially orthogonal to the third route R3 and is a route that returns to the wire saw device 50 .

For the first route R1, the cut end surface F1a of the concrete floor slab F1, which is substantially vertical along the direction Y perpendicular to the bridge axis, is first cut to form a notch so that the wire saw 5 can be hooked thereon. At that time, it is preferable to receive (hold) the wire saw 5 with a shoring so that it does not drop off from the route.

In this process, as the cutting with the wire saw 5 progresses, the entire forwarding route shrinks, and finally the concrete floor slab F1 is separated from the steel girder G1. The work time for this process is 8 to 9 hours for cutting 6m×3 places with two wire saw devices 50 at an actual site. By the end of this process, the floor slab cutting operation by the concrete floor slab cutting method according to the present embodiment is completed.

<Modified example of forwarding route of wire saw>
Next, modified examples of the forwarding route of the wire saw 5 will be described with reference to FIGS. 6 to 8. FIG. FIG. 6 is a process explanatory diagram showing a cross-sectional view cut along the direction Y perpendicular to the bridge axis of the upper and lower through hole drilling process of the concrete floor slab cutting method according to the modification of the first embodiment of the present invention, FIG. 7 is a forwarding route explanatory diagram showing a modification of the forwarding route of the wire saw in a see-through plan view. Further, FIG. 8 is a cross-sectional view showing the installation state of the wire saw device in the wire saw cutting step of the concrete floor slab cutting method according to the modified example of the present embodiment, taken along the direction Y perpendicular to the bridge axis. It is a diagram.

(Upper and lower through-hole drilling process)
As shown in FIGS. 6 and 7, when the wire saw cutting process is performed in the forwarding route according to the modified example of the wire saw 5, the concrete floor slab F1 is penetrated in the vertical direction Z before the wire saw cutting process is performed. It is necessary to perform an upper and lower through-hole drilling process for drilling the upper and lower through-holes 6 to be formed.

Specifically, the vertical through-holes 6 are drilled from the upper surface to the lower surface of the concrete floor slab F1 using a drilling device 7 that is a common commercially available core drill. As shown in FIGS. 6 and 7, the drilling position of the upper and lower through-holes 6 is in the immediate vicinity of the haunch h1 side opening of the horizontal hole 4, which is the intersection of the second route R2 and the third route R3. . Needless to say, the drilling position of the vertical through hole 6 can be appropriately changed according to the installation position of the wire saw device 50, such as the intersection of the third route R3 and the fourth route R4. Alternatively, a plurality of wire saw devices 50 may be used for cutting.

In this way, the upper and lower through-holes 6 are drilled, and as shown in FIG. A second route R2' and a modified third route R3' extending vertically downward are provided. As a result, the forwarding route of the wire saw 5 can be a forwarding route that bypasses the upper surface of the concrete floor slab F1, and as shown in FIG. can be used as Therefore, there is no need to provide a temporary pedestal that requires a large space for installing and fixing the wire saw device 50 below the concrete floor slab F1 and that is difficult to move up and down. Therefore, not only can temporary construction costs be reduced, but safety is also significantly improved.

Reference numeral 51 shown in FIG. 8 denotes a conversion frame 51 for converting the second route R2 to the modified second route R2′ and the modified third route R3′ to the third route R3, and reference numeral 52 denotes a protective net 52. showing. The protective net 52 is a net that covers the wire saw device 50 as a whole, and has a function of protecting a worker from coming into contact with the sharp wire saw 5 on which diamond is adhered.

[Second embodiment]
Next, a method for cutting a concrete floor slab according to a second embodiment of the present invention will be described with reference to FIGS. 9 and 10. FIG. The difference from the concrete floor slab cutting method according to the above-described first embodiment is the step of cutting in the direction perpendicular to the floor slab bridge axis and the lifting step. Since the process, the horizontal drilling process, and the wire saw cutting process are performed in the same manner as described above, the description thereof is omitted. FIG. 9 shows a state before the concrete floor slab cutting process according to the second embodiment of the present invention, in which the concrete floor slab is cut along the cutting lines Y1 and Y2 by performing the step of cutting in the direction perpendicular to the bridge axis, and before the lifting step is performed. It is a top view.

(Cutting process perpendicular to floor slab bridge axis)
In the concrete floor slab cutting method according to the second embodiment of the present invention, as shown in FIG. A perpendicular cutting step is performed.

Specifically, as shown in FIG. 9, the above-described large-sized rotary cutting device 1 is used to vertically penetrate the concrete floor slab F1 from the upper surface to the lower surface, and cut a cutting line along the direction Y perpendicular to the bridge axis. The concrete floor slab F1, which is the floor slab to be cut, is separated from the already cut floor slab F1' by cutting across the entire width along the cutting line Y1. In addition, the concrete floor slab F1 is cut across the entire width along a cutting line Y2 along the direction Y perpendicular to the bridge axis to separate it from the uncut floor slab F1''.

Here, the cut floor slab F1′ is a part of the concrete floor slab F1 that has already been cut substantially horizontally at the joint with the steel girder G1 by the concrete floor slab cutting method according to the first embodiment. It points to the concrete floor slab F1. In addition, the uncut floor slab F1″ refers to the concrete floor slab F1 whose joint portion with the steel girder G1 has not yet been cut by the concrete floor slab cutting method according to the first embodiment.

This step may be performed after the wire saw cutting step of the concrete floor slab cutting method according to the first embodiment described above, or may be performed before or concurrently with the vertical groove forming step or the horizontal hole drilling step. You can go with In short, it is sufficient that the concrete floor slab F1, which is the floor slab to be cut, is separated from the cut floor slab F1' and the uncut floor slab F1'' along the cutting lines Y1 and Y2 before the lifting process described later.

(Lifting process)
Next, in the concrete floor slab cutting method according to the second embodiment of the present invention, as shown in FIGS. A lifting process is performed in which the floor slab F1 is lifted upward by a lifting device and separated from the steel girder G1. FIG. 10 is a process explanatory view showing a lifting process of the concrete floor slab cutting method according to the second embodiment of the present invention in a cross-sectional view cut along the direction Y perpendicular to the bridge axis.

Before performing this process, it is necessary to perform a vertical through-hole drilling process for drilling the vertical through-hole 6' penetrating the concrete floor slab F1 in the vertical direction Z, in the same manner as the above-described vertical through-hole drilling process. . Specifically, using a drilling device 7 having a diameter smaller than that of the core drill, upper and lower through-holes 6' for inserting high-strength steel rods 90, which will be described later, are drilled from the upper surface to the lower surface of the concrete floor slab F1. do.

A hoisting frame 9 made of steel material is assembled on a hydraulic jack 8 as a lifting device, and the hoisting frame 9 is lifted by the hydraulic jack 8, and a tension member that bears the tensile force screwed to the hoisting frame 9 is used. A concrete floor slab F1, which is a floor slab to be cut, is lifted by a certain high-tensile steel rod 90 and separated from the steel girder G1. This process makes it possible to remove the concrete floor slab F1 from the steel girder G1 even if the anti-slip steel material such as the stud dowel is not completely cut in the wire saw cutting process, thereby shortening the cutting work time. be able to.

As shown in FIG. 9, the hydraulic jack 8 and the base portion 91 of the lifting platform 9 are placed on the cut floor slab F1′ and the uncut floor slab F1″, respectively, so as to straddle the cutting lines Y1 and Y2. Of course, the method of assembling the lifting frame 9 and the number of hydraulic jacks 8 to be installed may be appropriately set according to the size and weight of the concrete floor slab F1 to be lifted, and are not limited to the illustrated form.

Also, high-tensile steel refers to steel materials with a tensile strength of 490 MPa or higher, which is higher than the guaranteed value of 400 MPa for tensile strength of SS400 materials, although the standards differ depending on the steel manufacturer. Of course, the diameter of the high-strength steel rod 90 may be appropriately set according to the size and weight of the concrete floor slab F1 to be lifted.

Although the hydraulic jack 8 has been exemplified as the lifting device, the lifting device according to the present invention is not limited to the jack, and may be a crane, a portal crane, or a combination thereof.

[Third Embodiment]
Next, a concrete floor slab cutting method according to a third embodiment of the present invention will be described with reference to FIGS. 11 to 13. FIG. The concrete floor slab cutting method according to the third embodiment uses a special wire saw device 50'' fixed on the concrete floor slab F1 with a post-construction anchor, without installing the conversion frame 51 under the floor slab. It is a cutting method that can perform the wire saw cutting process very well.

FIG. 11 is a forwarding route explanatory diagram showing a forwarding route of a wire saw used in the concrete floor slab cutting method according to the third embodiment of the present invention in a perspective plan view. FIG. 12 is a front view of a wire saw device used in the concrete floor slab cutting method according to the third embodiment, viewed along the direction perpendicular to the bridge axis, and a process explanation showing a wire saw cutting process using the wire saw device. FIG. 13 is a right side view of the wire saw device according to the third embodiment as seen along the bridge axis direction, and a process explanatory diagram showing a wire saw cutting process using the wire saw device. In FIG. 13, the adjustment pulley 56'' is omitted because it overlaps and is difficult to see.

(Flat groove forming process)
11 and 13, the concrete floor slab cutting method according to the third embodiment is similar to the concrete floor slab cutting method according to the first embodiment in the vertical direction from the lower surface side of the concrete floor slab F1. A vertical groove forming step for forming the vertical grooves 2 by cutting is performed.

(Horizontal drilling process)
Next, in the concrete floor slab cutting method according to the third embodiment, as shown in FIGS. A horizontal drilling step for forming the horizontal hole 4 is performed. However, in the concrete floor slab cutting method according to the third embodiment, unlike the concrete floor slab cutting method according to the first embodiment, as shown in FIG. Drill holes in places.

(Upper and lower through-hole drilling process)
Next, in the concrete floor slab cutting method according to the third embodiment, as shown in FIGS. A vertical through-hole drilling step is performed to drill a vertical through-hole 6″ penetrating the floor slab F1 in the vertical direction Z. However, in the concrete floor slab cutting method according to the third embodiment, drilling is not performed in this step. Using the device 7, two upper and lower through holes 6'' are drilled from the upper surface to the lower surface of the concrete floor slab F1. As shown in FIGS. 11 and 12, the drilling positions of the two upper and lower through-holes 6'' are located in the vicinity of the haunch h1 side opening of the horizontal hole 4. The drilled upper and lower through-holes 6'' , a hole having a diameter larger than that of the vertical through-hole 6 (for example, a diameter of 225 mm) for inserting universal pulleys 57'' and 58'', which will be described later.

(Wire saw cutting process)
Next, in the concrete floor slab cutting method according to the third embodiment, as shown in FIGS. A wire saw cutting step is performed in which a wire saw 5 is inserted into the horizontal hole 4 formed in the step to cut the concrete floor slab F1.

As shown in FIGS. 12 and 13, the wire saw device 50'' used in this process includes a support 51'' whose lower end can be fixed on the concrete floor slab F1 by post-installation anchors, and a support 51'' which is perpendicular to the support 51''. and a protective frame 53'' attached to the upper end of the column 51''. A protective net 54 ″ is suspended from the protective frame 53 ″ so that the dangerous wire saw 5 cannot be easily approached.

A drive pulley 55 ″ for rotationally driving the wire saw 5 is attached to the top of the support 51 ″, and a plurality of adjustment pulleys 56 ″ for adjusting the length of the wire saw 5 are mounted on the support beam 52 ″. is installed.

Further, as shown in FIGS. 12 and 13, the wire saw device 50 ″ is flexible (protrudes or retreats) from the upper surface of the concrete floor slab F1, which is the lower end of the installed pillar 51 ″, to a lower surface than the lower surface. It has a pair of universal pulleys 57'' and 58'' which are rotatable 360 degrees (in the same horizontal plane). For this reason, the wire saw device 50 ″ simply extends and inserts the universal pulleys 57 ″ and 58 ″ into the above-mentioned upper and lower through holes 6 ″, and does not require the above-mentioned conversion frame 51 to install the wire under the concrete floor slab F 1 . The wire saw cutting process can be performed by forwarding the saw 5. - 特許庁

As shown in FIG. 11, the forwarding route of the wire saw 5 performed in this process includes a linear first route R1″ to third route R3″ under the concrete floor slab F1 and a wire saw device above the concrete floor slab F1. It consists of a fourth route R4'' running within 50''.

The first route R1″ is a straight route under the floor slab that reaches the vertical groove 2 via the horizontal hole 4, and the second route R2″ is a straight route through the vertical groove 2 to the next horizontal hole 4. The third route R3″ is a straight route of the horizontal hole 4.

As shown in FIGS. 11 and 12, the fourth route R4'' extends from the horizontal hole 4 through the curved vertical through-hole 6'' to the bottom of the concrete floor slab F1 with a universal pulley 58''. up to a free pulley 57" via a plurality of adjusting pulleys 56" and a driving pulley 55".

In this step, the concrete floor slab F1 is cut using the forwarding route of the wire saw 5 described above. Even if the bending angle of the wire saw 5 changes from the position of , the free pulleys 57'' and 58'' can be rotated to follow it. Therefore, in this step, the wire saw cutting step can be performed without installing the above-described conversion mount 51 in the portion where the wire saw 5 changes direction. In addition, there are no pulleys or other parts where the wire saw 5 bends under the floor slab, such as the conversion base 51, and there is no possibility that the wire saw 5 may come off. Visual confirmation is possible from F 1. Therefore, in the wire saw cutting process, it is not necessary to place personnel under the floor slab for monitoring, and labor costs in this process can be reduced.

According to the concrete floor slab cutting method according to the first to third embodiments described above, the height of the haunch is reduced because the flute formation step of forming the flute 2 in the haunch h1 with a low haunch height is provided. Even if the concrete floor slabs F1 are different on the left and right sides, the drilling distance of the horizontal holes 4 formed in the horizontal hole drilling process can be shortened. Therefore, according to the concrete floor slab cutting methods according to the first and second embodiments, the concrete floor slab F1 and the steel girder G1 can be easily cut and separated in a short time.

Further, according to the concrete floor slab cutting methods according to the first to third embodiments, the forwarding route of the wire saw 5 is changed so as to pass through the upper surface of the floor slab, and the wire is cut on the upper surface of the concrete floor slab F1. The saw device 50 can be placed to cut the concrete floor slab F1. Therefore, it is not necessary to provide a large space below the floor slab for installing the wire saw device 50, and the number of temporary facilities can be reduced, thereby reducing the work cost of cutting the concrete floor slab F1. Moreover, since the wire saw device 50, which is a driving device for a heavy wire saw, is placed on the floor slab that is less likely to fall, safety is also improved.

Moreover, according to the concrete floor slab cutting method according to the second embodiment, even if the concrete floor slab F1 and the steel girder G1 are not completely separated in the wire saw cutting process, they are lifted by the hydraulic jack 8 as a lifting device. can cause lateral cracks in the concrete floor slab F1. Therefore, the concrete floor slab and the girder can be cut and separated in a shorter time.

In addition, according to the concrete floor slab cutting method according to the third embodiment, even if the bending angle of the wire saw 5 changes due to contraction of the wire saw 5 as cutting progresses, the free pulleys 57'' and 58'' can still be cut. can rotate and follow it. Therefore, the wire saw cutting process can be performed without installing the conversion frame 51, and in the wire saw cutting process, it is not necessary to place personnel under the floor slab for monitoring, thereby reducing the labor cost in this process. can do.

The concrete floor slab cutting method according to the embodiments of the present invention has been described in detail above, but the above-described or illustrated embodiments are all specific embodiments for carrying out the present invention. Not too much. Therefore, the technical scope of the present invention should not be construed to be limited by these.

In particular, the concrete floor slab to which the present invention is applied is explained by exemplifying the case where the connecting portion between the steel girder located at the outermost edge on the most downstream side in the drainage gradient and the concrete floor slab is cut off from the steel girder. However, the present invention can also be applied to the connecting portion between the steel girder and the concrete floor slab located at the outermost edge, which is the most upstream side of the drainage gradient, such as the portion B in FIG. In short, the present invention can be applied to a concrete floor slab having left and right haunch heights that are different from each other.

1: Rotary drilling device (cutting device)
1a: Depth measuring jig 2: Vertical groove 3: Drilling device 30: Device body 31: Spindle 32: Gear 33: Drill bit 34: Support jig 4: Horizontal hole 5: Wire saw 50, 50″: Wire saw Device 51: Conversion racks 52, 54'': Protective net 51'': Post 52'': Support beam 53'': Protective frame 55'': Drive pulley 56'': Adjusting pulleys 57'', 58'': Universal pulleys R1, R1'': 1st route R2, R2″: Second route R2′: Modified second route R3, R3″: Third route R3′: Modified third route R4, R4″: Fourth route 6, 6′, 6″: Vertical penetration Hole 7: Drilling device 8: Hydraulic jack (lifting device)
9: Lifting platform 90: High-tensile steel bar (tensile member)
91: Foundation B1: Bridge F1: Concrete floor slab (floor slab to be cut: floor slab)
F1a: Cut end face F1′: Cut floor slab F1″: Uncut floor slabs G1 to G4: Steel girder (bridge girder)
H1: Floor slab thickness H2, H3: Haunch height h1: Haunch (upper slope) h2: Haunch (lower slope) α, β: Angle of inclination P1: Pavement W1, W2: Covering part X : Bridge axis direction Y: Bridge axis perpendicular direction Z: Vertical direction

Claims (3)

A concrete floor slab cutting method for cutting a concrete floor slab tilted left and right due to a drainage slope in a cross section along a direction perpendicular to the bridge axis in order to remove the concrete floor slab from a girder, comprising:
With respect to the girder of the bridge, cut vertically from the lower surface side of the concrete floor slab in the haunch on the side of the low drainage slope in the bridge axis direction according to the tip of the horizontal hole to be drilled in the next process a flute forming step of forming flutes of a predetermined depth along the
Horizontal hole drilling for forming a horizontal hole communicating with the vertical groove by drilling substantially horizontally in the direction perpendicular to the bridge axis from the haunch on the side with the high drainage slope to the haunch on the side with the low drainage slope. process and
a vertical through-hole drilling step of drilling vertical through-holes vertically penetrating the concrete floor slab;
A wire saw cutting step of inserting a wire saw into the horizontal hole formed in the horizontal hole drilling step to cut the concrete floor slab,
In the wire saw cutting step, a wire saw is inserted so that a forwarding route of the wire saw passes through all of the vertical groove, the horizontal hole, and the vertical through hole, and a driving device for the wire saw is installed on the upper surface of the concrete floor slab. and cutting the connection portion between the concrete floor slab and the girder substantially horizontally to separate the concrete floor slab from the girder. In the wire saw cutting step, a wire saw device having a free pulley rotatable within the same plane provided so as to protrude or retreat relative to a support beam attached from the upper surface to the lower surface of the concrete floor slab is used. 2. A flexible pulley is used to perform cutting following a change in bending angle of the forwarding route of the wire saw when the length of the forwarding route of the wire saw is shortened as the cutting of the wire saw progresses. 2. The method for cutting a concrete floor slab according to 1. A step of cutting the concrete floor slab vertically along the direction perpendicular to the bridge axis, and lifting the concrete slab cut in the step of cutting the concrete slab perpendicular to the bridge axis with a lifting device. The method for cutting a concrete floor slab according to claim 1 or 2, further comprising a lifting step of tearing off the girders.

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