Method for removing expansion joints

Abstract

To provide a method for removing expansion joints that can shorten the construction period of repair work by stabilizing the height position of the wire immediately after cutting begins, thereby preventing unevenness from occurring on the cut surface. [Solution] When cutting the concrete slab 2 and expansion joint 1 horizontally by installing a wire 41 in the cutting groove 3, lift-up prevention members 61 and 62 that prevent the wire 41 installed in the cutting groove 3 from lifting are inserted and fixed into the cutting groove 3, and the wire 41 is driven in a circulating manner by the drive mechanism of the wire saw 4, thereby cutting the concrete slab 2 and expansion joint 1 horizontally.

Description

Technical Field

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[0001] The present invention relates to a method for removing an expansion joint of an elevated road, a bridge, etc. that needs to be replaced due to aging or the like with low noise and low vibration.

Background Art

[0002] As a method for removing an expansion joint of an elevated road, a bridge, etc. that has aged or been damaged without using a breaker that is a source of vibration and noise with low noise and low vibration, a method of removing the expansion joint using a wire saw has been proposed and put into practical use (for example, see Patent Documents 1 and 2). <00000***10***>

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when removing an expansion joint by the method of removing an expansion joint using a wire saw disclosed in Patent Documents 1 and 2, especially when using a wire with a large wire diameter having high durability, the position of the wire in the height direction immediately after the start of cutting becomes unstable, and unevenness is likely to occur on the cutting surface, and it was necessary to correct the unevenness.

[0005] In view of these problems, the first objective of the present invention is to provide a method for removing expansion joints that improves upon the wire saw technology disclosed in Patent Documents 1 and 2, thereby enabling quiet removal of expansion joints without the use of breakers, which are a source of vibration and noise during the removal of expansion joints, and without the use of peeling aids or jacks, and allowing for partial or complete removal, while enjoying the advantages of the technology disclosed in Patent Documents 1 and 2. Furthermore, by stabilizing the height position of the wire immediately after the start of cutting, the invention prevents unevenness from occurring on the cut surface and shortens the construction period of the repair work.

[0006] Furthermore, a second objective of the present invention is to provide a method for removing expansion joints that allows for the simple formation of a pit for installing a guide pulley that guides the wire of a wire saw, and that does not cause unevenness on the bottom surface of the pit. [Means for solving the problem]

[0007] To achieve the first objective described above, the present invention provides a method for removing an expansion joint, comprising forming a cutting groove surrounding the expansion joint in a concrete slab, installing a wire saw wire in the cutting groove, and cutting the concrete slab and the expansion joint horizontally, characterized in that a lift-up prevention member is inserted and fixed into the cutting groove to prevent the wire saw wire installed in the cutting groove from lifting, and the wire saw wire is driven in a circulating manner to cut the concrete slab and the expansion joint horizontally.

[0008] In this case, the lift-prevention member may consist of a flat plate member installed on the straight portion of the cutting groove and a curved plate member installed on the corner of the cutting groove.

[0009] Furthermore, auxiliary guide pulleys can be provided on the wire saw cutting side of the guide pulleys provided on the wire feed side and return side of the wire saw, respectively, supported via a buffer mechanism and in contact with the upper surface of the wire.

[0010] Furthermore, in order to achieve the second objective described above, the method for removing the expansion joint of the present invention is characterized in that a pit for installing a guide pulley that guides the wire of the wire saw is drilled using a core drill equipped with a plurality of circular bits arranged concentrically. [Effects of the Invention]

[0011] According to the inventions of claims 1 to 3, while enjoying the advantages of the technology disclosed in Patent Documents 1 to 2, the vertical position of the wire is stabilized (prevents lifting) immediately after cutting begins with a wire saw, which tends to have an unstable vertical position of the wire. This prevents unevenness from occurring on the cut surface and shortens the construction period of the repair work.

[0012] According to the invention of claim 4, a pit for installing a guide pulley that guides the wire of a wire saw can be easily formed and without causing unevenness on the bottom surface of the pit. [Brief explanation of the drawing]

[0013] [Figure 1] The present invention provides an example of an expansion joint in an elevated road or bridge, which is the target of the expansion joint removal method. (a) is a plan view, (b1) is a cross-sectional view of the main part, (b2) is a cross-sectional view of (b1), and (c) and (d) are explanatory diagrams showing examples of curved plate members. [Figure 2] The guide pulley, auxiliary guide pulley, and dust collection cover are shown, with (a) being a front view, (b) a right side view, (c) a rear view, (d) a bottom view, (e) a perspective view from diagonally above, and (f) a perspective view from diagonally below. [Figure 3] The image shows a core drill, with (a) being a front cross-sectional view and (b) being a bottom view. [Modes for carrying out the invention]

[0014] Hereinafter, embodiments of the method for removing expansion joints according to the present invention will be described with reference to the drawings.

[0015] Figures 1 to 3 show one embodiment of the method for removing expansion joints according to the present invention. This method for removing the expansion joint is similar to the technology disclosed in Patent Documents 1 and 2, and involves removing the expansion joint 1 by horizontally cutting it with the wire 41 of a wire saw 4, as shown in Figure 1. The concrete floor slab 2 surrounding the expansion joint 1 is cut to a predetermined cutting depth with a rotating blade or the like to form a rectangular cutting groove 3 surrounding the expansion joint 1. Here, the corners 32 of the cutting groove 3 are cut using core drills of different diameters to form an arc shape (a quarter-circular shape of a circular cutting groove cut using a large-diameter core drill) so that the wire 41 can run smoothly. Furthermore, the concrete slab 2 is provided with pits 21 for installing guide pulleys 51 and 52, which are provided on the feed and return sides of the wire 41 of the wire saw 4.

[0016] Then, when installing the wire 41 in the cutting groove 3 to cut the concrete slab 2 and the expansion joint 1 horizontally, lift-prevention members 61 and 62, which prevent the wire 41 installed in the cutting groove 3 from lifting up, are inserted and fixed into the cutting groove 3, and the wire 41 is driven in a circulating manner by the drive mechanism of the wire saw 4, thereby cutting the concrete slab 2 and the expansion joint 1 horizontally. In this embodiment, the locations where the anti-lifting members 61 and 62 are provided are, in particular, locations where the height position of the wire 41 tends to become unstable when cutting by the wire saw 4 begins. Specifically, these are four locations: the straight section 31 of the cutting groove 3 on the wire 41 feeding side, both corners 32 of the cutting groove 3, and the straight section 31 of the cutting groove 3 connecting both corners 32. However, the anti-lifting member 61 can also be provided on the straight section 31 of the cutting groove 3 on the wire 41 returning side, or one of these can be omitted.

[0017] The anti-lifting members 61 and 62 consist of a flat plate member 61 installed on the straight section 31 of the cutting groove 3 and a curved plate member 62 installed on the corner section 32 of the cutting groove 3. Here, the anti-lifting members 61 and 62 can be made of a rigid synthetic resin material. Further, as shown in Fig. 1(c), the curved plate member 62 can use a member with an arc-shaped planar shape, or as shown in Fig. 1(d), a member with a circular (cylindrical) planar shape can be used.

[0018] The anti-lifting members 61 and 62 are fixed at a predetermined position by operating with a link mechanism 63 installed on the non-cutting side of the concrete floor slab 2, thereby preventing the wire 41 installed in the cutting groove 3 from lifting.

[0019] Thereby, particularly by stabilizing (preventing lifting) the position of the wire 41 in the height direction immediately after the start of cutting by the wire saw 4 where the position of the wire 41 in the height direction is likely to become unstable, unevenness on the cutting surface is prevented, and the construction period of the repair work can be shortened.

[0020] Auxiliary guide pulleys 53 and 54 that are supported via a buffer mechanism 55 and contact the upper surface side of the wire 41 are provided on the cutting side by the wire saw of the guide pulleys 51 and 52 provided on the feeding side and the returning side of the wire 41 of the wire saw 4, respectively. Here, the buffer mechanism 55 includes a coil spring, and suppresses the vertical movement of the wire 41 via the auxiliary guide pulleys 53 and 54 that contact the upper surface side of the wire 41. Thereby, by stabilizing the position of the wire 41 in the height direction, unevenness on the cutting surface is prevented, and the construction period of the repair work can be shortened.

[0021] The guide pulley 52 on the returning side of the wire 41 of the wire saw 4 is covered entirely with a dust collection cover 56, and dust generated from the wire 41 is prevented by sucking the air inside the dust collection cover 56 with a dust collector connected via a dust collection pipe 57. Here, the lower surface of the dust collection cover 56 is open, and a rubber seal plate 58 is arranged at the same level as the lower edges of the guide pulleys 51 and 52. Furthermore, the dust collection pipe 57 can be selectively attached to either of the mounting portions 57' formed on the faceplates 56a and 56b of the dust collection cover 56, depending on the installation conditions in the pit 21. Furthermore, the guide pulley 51 on the wire saw 4's wire feeding side does not generate dust from the wire 41, so the dust collection cover 56 can be omitted.

[0022] By the way, when forming the pit 21 for installing the guide pulleys 51, 52, etc. that guide the wire 41 of the wire saw 4, a core drill 7 equipped with multiple circular bits 71 arranged concentrically, as shown in Figure 3, is used to drill multiple holes in close proximity. In this embodiment, the bit 71 of the core drill 7 is composed of circular bits with diameters of φ130, φ80, and φ50 arranged concentrically. This makes it possible to easily create a pit 21 for installing guide pulleys 51, 52, etc., that guide the wire 41 of the wire saw 4, and to form the bottom surface of the pit 21 without causing unevenness.

[0023] The method for removing expansion joints of the present invention has been described above based on its embodiments. However, the present invention is not limited to the configuration described in the above embodiments, and its configuration can be modified as appropriate without departing from the spirit of the invention. [Industrial applicability]

[0024] The method for removing expansion joints according to the present invention can be used in construction work using wire saws, including the repair of drainage ditches with water channels embedded in roads, because it prevents unevenness from occurring on the cut surface and shortens the construction period of repair work. [Explanation of symbols]

[0025] 1. Expansion joint 2. Concrete slab 21 Pit 3 Cutting groove 31 Straight section 32 corners 4 Wire saw 41 wires 51 Guide Pulley 52 Guide Pulley 53 Auxiliary guide pulley 54 Auxiliary guide pulley 55 Buffer mechanism 56 Dust collection cover 56a Face plate 56b Face plate 57 Dust collection pipe 57' Mounting section 58 Seal plate 61. Anti-lifting member (flat plate member) 62. Anti-lifting member (curved plate member) 63 Link Mechanism 7 Core Drill 71 bit

Claims

1. A method for removing an expansion joint, comprising forming a cutting groove surrounding the expansion joint in a concrete slab, installing a wire saw wire in the cutting groove to cut the concrete slab and the expansion joint horizontally, characterized in that a lift-up prevention member, made of a curved plate member to prevent the wire of the wire saw installed in the cutting groove from lifting immediately after cutting by the wire saw begins, is inserted into the corner of a cutting groove formed in an arc shape, and while fixed to the concrete slab on the non-cutting side, the wire of the wire saw located below the lower end surface of the curved plate member is driven in a circulating manner to cut the concrete slab and the expansion joint horizontally.

2. The method for removing an expansion joint according to claim 1, characterized in that a lift-prevention member made of a flat plate is further inserted into the straight portion of the straight cutting groove, and the wire of a wire saw located below the lower end surface of the curved plate member is circulated while the member is fixed to the concrete floor slab on the non-cutting side.

3. The method for removing an expansion joint according to claim 1 or 2, characterized in that auxiliary guide pulleys are provided on the wire saw cutting side of the guide pulleys provided on the wire feed side and return side of the wire saw, respectively, which are supported via a buffer mechanism and contact the upper surface side of the wire.

4. The method for removing an expansion joint according to claim 1 or 2, characterized in that a pit for installing a guide pulley that guides the wire of the wire saw is drilled using a core drill equipped with a plurality of circular bits arranged concentrically.

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