JPH0410957B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wire sawing method and a guide pulley stand for buildings, bridges, foundations and other reinforced concrete structures.

[Conventional technology]

Disc blade type cutting machines have traditionally been widely used for partial demolition of reinforced concrete structures by cutting, but there are some issues with blade manufacturing, workability, etc.
Because they are small and lightweight for handling reasons, their cutting ability is poor, the cutting cross-sectional area is limited to a narrow range, and the maximum cutting depth is about 30 to 40 cm. Further, in the case of partial disassembly by rotating such a disc blade, there are problems such as overcutting is required even in areas that do not require cutting.

In order to solve these problems all at once, the present inventor has recently developed a construction method for cutting and dismantling reinforced concrete structures by wire sawing. In this construction method, a cutting cable made of a wire rope with cutting ability is hung on a reinforced concrete structure, and the cutting cable is circulated by a cable drive device while controlling the running speed and tension.

In this case, the cutting cable usually has a structure in which, for example, beads having a layer of diamond abrasive grains are arranged at appropriate pitches on a wire rope, with or without using a coil spring or other spacer. In addition, the cable drive device has a structure that includes, for example, a cable drive pulley around which a cutting cable is wound, a hydraulic motor, electric motor, or other prime mover that rotates the cable drive pulley, and other attached mechanisms. A device that moves along a rail, specifically a device that moves on a rail using drive wheels, a device that moves on a rack using a drive pinion, etc. are used as appropriate.

[Problem that the invention seeks to solve]

When wire sawing reinforced concrete structures, the cutting cable generally runs smoothly with a relatively gentle bend from the beginning to the middle of the cutting process, that is, with a large radius of curvature, cutting not only the concrete layer in contact but also the reinforcing steel without any problems. do. However, at the end of the cutting process, when the diameter and cross-sectional area of the uncut portion become smaller, the cutting cable also becomes smaller.
Since the wire rope in the cutting cable runs with small sharp bends at the part where it comes into contact with the uncut part, the metal fatigue of the wire rope in the cutting cable progresses, and the beads and spacers, etc., which cannot be bent together with the wire rope, especially get caught on the reinforcing steel. In the past, there were problems such as obstructing the running of the cutting cable, placing an abnormal load on the wire rope, and easily causing breakage of the wire rope and damage to spacers and the like.
When the wire rope of a cutting cable breaks during wire sawing of a reinforced concrete structure, it is necessary to repair the broken connection, replace it with a new cutting cable, or even reinstall the cutting cable. The interruption of wire sawing caused a significant drop in productivity, and there were also other problems such as broken cutting cables separating from the reinforced concrete structure and flying off, posing a danger to the surrounding area.

Further, even if there is no breakage accident as described above during wire sawing, the cutting cable has the problem of separating from the reinforced concrete structure and flying off as soon as cutting is completed, posing a danger to the surrounding area.

An object of the present invention is to prevent the running cutting cable from forming the above-mentioned small sharp bends that could lead to breakage at the end of cutting when wire sawing reinforced concrete structures.
Another object of the present invention is to provide a wire sawing method in which a cutting cable separated from a reinforced concrete structure does not fly around at the end of cutting, and a guide pulley stand that can be suitably used in the method.

[Technical means to solve problems]

The wire sawing method for reinforced concrete structures according to the present invention provides a pair of inner guide pulleys along the surface of the reinforced concrete structure on the same plane as the planned cutting surface, and an outer guide on the outside of each inner guide pulley on the same plane. Install the pulleys respectively, pass the cutting cable from the inside of one middle guide pulley to the outer guide pulley in an S-shape, hang it from the outside of the outer guide pulley to the reinforced concrete structure, and from the outside of the other outer guide pulley. It passes through the middle guide pulley in an S-shape, is disposed so as to be drawn out from inside the middle guide pulley, and is allowed to circulate endlessly under adjustment of tension and running speed.

In addition, in the above-mentioned basic method, in order to reduce as much as possible the running resistance of the cutting cable due to contact with the middle guide pulley and the outer guide pulley during the initial and middle stages of cutting, the cutting cable is cut along the surface of the reinforced concrete structure. A pair of middle guide pulleys are installed on the same plane, and an outer guide pulley is installed on the outside of each middle guide pulley on the same plane as that, and the cutting cable is hung from the inside of one of the middle guide pulleys to the reinforced concrete structure. At the same time, the cutting cable is arranged so as to be pulled out from the inside of the other middle guide pulley, and run in an endless state under adjustment of tension and running speed. Pass it through the outer guide pulley in an S shape,
It is hung from the outside of the outer guide pulley to the reinforced concrete structure and passed from the outside of the other outer guide pulley to the middle guide pulley in an S-shape, and pulled out from the inside of the middle guide pulley to adjust the tension and running speed. It is also possible to partially change the configuration to one in which the cutting cable runs endlessly under the cable, and the arrangement of the cutting cable may be changed midway through. In that case, since the outer guide pulley is not required initially, it may be installed at the time of the above switching.

In addition, in order to enable various arrangements of cutting cables in the above basic construction method, a pair of medium guide pulleys are placed along the surface of the reinforced concrete structure on the same plane as the planned cutting surface, and each medium guide pulley is an outer guide pulley on the same plane as the outer guide pulley, and an auxiliary guide pulley that shares a tangent line passing through the pulley groove with each inner guide pulley adjacent to each inner guide pulley, and a cutting cable. Pass it through one auxiliary guide pulley, then pass it from the inside of the middle guide pulley to the outside guide pulley in an S-shape, hang it from the outside of the outside guide pulley to the reinforced concrete structure, and pass it from the outside of the other outside guide pulley to the middle guide pulley. Partially changing the structure to one in which it is passed through in an S-shape and drawn out from the inside of the middle guide pulley to the auxiliary guide pulley, and is allowed to circulate in an endless state while adjusting the tension and running speed. You can also do it.

Furthermore, in the above-mentioned modified construction method, in order to reduce as much as possible the running resistance of the cutting cable due to contact with the middle guide pulley and the outer guide pulley during the initial and middle stages of cutting, the cutting cable is cut along the surface of the reinforced concrete structure. A pair of middle guide pulleys are placed on the same plane, an outer guide pulley is placed on the same plane as the outside of each middle guide pulley, and an auxiliary guide pulley that shares a tangent line passing through the pulley groove with each middle guide pulley is installed in each middle guide pulley. The cutting cable should be installed adjacent to the guide pulley, and the cutting cable should be passed through one of the auxiliary guide pulleys.
Furthermore, it is arranged so as to hang from the inside of the middle guide pulley to the reinforced concrete structure and to be pulled out from the inside of the other middle guide pulley to the auxiliary guide pulley, and to run endlessly in a circular manner under adjustment of tension and running speed; On the way, the cutting cable is passed through one of the auxiliary guide pulleys, passed from the inside of the middle guide pulley to the outer guide pulley in an S-shape, and is hung from the outside of the outer guide pulley to the reinforced concrete structure, and is connected to the other outer guide pulley. By changing the arrangement so that it passes in an S-shape from the outside to the middle guide pulley, and pulling it out from the inside of the middle guide pulley to the auxiliary guide pulley, it runs in an endless cycle while adjusting the tension and running speed. It is possible to partially change the configuration.

In addition, each wire sawing method mentioned above includes
A pair of middle guide pulleys are rotatably provided on the same plane, and an outer guide pulley is rotatably provided on the outside of each middle guide pulley on the same plane. A guide pulley stand may be used which includes an auxiliary guide pulley rotatably provided adjacent to each middle guide pulley.

The present invention will be explained below based on embodiments shown in the drawings.

In FIGS. 1 and 2, which are a plan view and a side view illustrating the wire sawing method and guide pulley stand for a reinforced concrete structure according to the present invention, a cylindrical reinforced concrete structure 2, which is an object to be cut, is placed on a road surface 1. The reinforced concrete structure 2 is vertically installed, and the reinforced concrete structure 2 is constructed by having reinforcing bars 4 arranged in the axial direction within a concrete layer 3. A guide pulley stand 5 is fixed to the surface of the reinforced concrete structure 2 by anchors 6, and the guide pulley stand 5 includes a pair of horizontally oriented medium guide pulleys 7a and 7b, and a medium guide pulley 7.
A pair of vertically oriented auxiliary guide pulleys 8a, 8b adjacent to the inner guide pulleys 7a, 7b and having a common tangent line passing through the pulley grooves, and a pair of outer guide pulleys located outside the middle guide pulleys 7a, 7b on the same plane as the inner guide pulleys 7a, 7b. 9a and 9b are each rotatably mounted on an axis. In addition, the above-mentioned inner guide pulleys 7a, 7b,
It is more convenient to handle and install the auxiliary guide pulleys 8a, 8b and the outer guide pulleys 9a, 9b if they are integrated by the guide pulley stand 5 as described above, but they may be installed separately. However, there is no problem, and it may be installed on a fixed object other than the reinforced concrete structure 2, for example, on the road surface 1.

On the other hand, a reinforced concrete structure 2 is placed on the road surface 1.
A rail 10 is laid at a slight distance from the rail. A cable drive device 11 is movably installed on the rail 10, and the cable drive device 11 includes a cable drive pulley 12, its drive mechanism (not shown), and a drive wheel 13 that fits into the rail 10.
and its drive mechanism (not shown).

As shown by broken lines in the drawing, the cutting cable 14 is hooked onto the cable drive pulley 12 and starts from its slack side, and is connected to one of the auxiliary guide pulleys 8a, the inner side of the middle guide pulley 7a, and the inner side of the outer guide pulley 9a. The outer guide pulley 7b is wound around the reinforced concrete structure 2, and the inner guide pulley 7b is wound around the outside of the other outer guide pulley 9b.
It is disposed in an endless state so as to pass sequentially through the inside of the cable drive pulley 8b and the auxiliary guide pulley 8b, and return to the tension side of the cable drive pulley 12.

For example, when it is necessary to cut only a predetermined section of the reinforced concrete structure 2 when partially cutting or forming an opening, instead of wrapping the cutting cable 14 around the entire circumference of the reinforced concrete structure 2, It may be hung by passing it through one or two perforations (not shown) that are passed through it.

[Action of the invention]

In the above, the cable drive pulley 12 is actuated to urge the cable drive device 11 so that it can move along the rail 10 in the right direction in the drawing.
When the cutting cable 14 is driven to rotate, the cutting cable 14 circulates under the required tension, and the reinforced concrete structure 2 that comes into frictional contact with the cutting cable 14 is gradually cut from its surface to the inside.

Note that the middle guide pulleys 7a, 7b and the outer guide pulleys 9a, 9b are oriented horizontally in the case of horizontal cutting as described above, but the same is true in the case of inclined cutting and vertical cutting, and they are aligned with the plane to be cut. Installed on a flat surface. Furthermore, the middle guide pulley 7a,
In the above case, the installation angle of the auxiliary guide pulleys 8a, 8b with respect to the cable drive pulley 12 is a right angle, but depending on the arrangement of the cutting cable 14 to the cable drive pulley 12, an angle other than the right angle may be adopted. good. Since the auxiliary guide pulleys 8a, 8b corresponding to the middle guide pulleys 7a, 7b share a tangent line passing through the pulley groove, the cutting cable 14 is connected to the middle guide pulleys 7a, 7b and the corresponding auxiliary guide pulley along the tangent line. It is possible to smoothly bridge the gap between 8a and 8b so that it can run.

In addition, the auxiliary guide pulleys 8a and 8b can run the endless cutting cable 14 hooked to the upper cut point of the reinforced concrete structure 2 to the slack side and tension side of the cable drive pulley 12 of the cable drive device 11 on the road surface 1. This will help guide the process smoothly. Therefore, depending on the arrangement relationship between the cutting location and the cable drive pulley 12,
They are not necessary, or alternative guide pulleys are installed on the road surface 1, the reinforced concrete structure 2, the cable drive 11, etc. for example,
When the cutting point is below the cable drive device 11, for example, when wire sawing the root of a reinforced concrete structure 2 in water using the cable drive device 11 installed on land, the auxiliary guide pulleys 8a, 8b are used. It is also possible to install the cutting cable 14 above the middle guide pulleys 7a and 7b to guide the cutting cable 14 upward.

As the cutting progresses, the cutting cable 14
The contact portion with the reinforced concrete structure 2 travels while being curved, and the curved portion gradually moves in the direction of the middle guide pulleys 7a and 7b.
As described above, the cutting cable 14 is connected from the outside of one outer guide pulley 9a to the other outer guide pulley 9b via the reinforced concrete structure 2.
Even at the end of cutting, the distance between the tension side and the slack side of the cutting cable 14, which is hung over the uncut portion of the reinforced concrete structure 2, is the same as that of both outer guide pulleys 9a. ,9
Since the distance does not become narrower than the distance b, the bending of the contact portion is extremely small and does not become sharp or bent, as shown by the dashed line in the drawing, and the cutting cable 14 is unlikely to break. In addition, it is preferable to install the outer guide pulleys 9a and 9b so that the distance between the tension side and the slack side of the cutting cable 14 is appropriately wide.

Moreover, even if the cutting cable 14 is separated from the reinforced concrete structure 2 after cutting is completed, the cutting cable 14 is connected to both outer guide pulleys 9a,
9b and is stopped, so no dangerous jumping occurs.

The arrangement of the cutting cable 14 as described above is particularly effective at the final stage of cutting, so it may be adopted from the middle of cutting. That is, for example, at the beginning or middle stage of cutting, the cutting cable 14 is
As shown by the thin broken line in the drawing, wire sawing is performed by hanging the reinforced concrete structure 2 from the inside of one medium guide pulley 7a and pulling it out from the inside of the other medium guide pulley 7b. At the end of the process, the cutting cable 14 is rearranged as described above,
The remaining wire sawing will be done.
In this case, if the cutting cable 14 is not relocated midway, the cutting cable 14 is
At the end of cutting, the bend becomes small and sharp, as shown by the two-dot chain line in the drawing, and the tool runs unstably in a nearly bent state.

〔Effect of the invention〕

After all, in the wire sawing method for reinforced concrete structures according to the present invention, at least at the final stage of cutting, both of the cutting cables are hung from the outside of the outer guide pulley to the reinforced concrete structure. ,
The distance between the tension side and the slack side of the cutting cable that hangs over the uncut portion of the reinforced concrete structure does not become narrower than the distance between the outer sides of both guide pulleys. Therefore, when wire sawing reinforced concrete structures, the running cutting cable does not form small sharp bends or folds that could lead to breakage at the end of cutting, and the wire rope does not break due to metal fatigue or the spacer etc. Damage is prevented.

In addition, in this wire sawing method, at least at the final stage of cutting, both cutting cables are hung from the outside of the outer guide pulley to the reinforced concrete structure, so even after the cutting cables are separated from the reinforced concrete structure at the same time as the cutting is completed. The cutting cable is held in place by its guide pulley, so it does not fly off and pose a danger to the surrounding area.

In addition, in this wire sawing method,
Wire sawing is carried out by passing the cutting cable through the reinforced concrete structure from the inside of both medium guide pulleys, preferably during the early to middle stages of the cutting, and preferably towards the end of the cutting.
If wire sawing is performed by replacing the outer guide pulleys with the reinforced concrete structure from the outside of both outer guide pulleys as described above, it will be necessary to replace the wires, but the cutting cables may come in contact with the outer guide pulleys during the initial or middle stages of cutting. This is useful for reducing running resistance.

Furthermore, in this wire sawing method, if an auxiliary guide pulley is installed adjacent to each medium guide pulley, the cutting cable can be smoothly guided in the desired direction from each medium guide pulley, allowing for a variety of layouts. becomes possible.

Furthermore, if a guide pulley stand that is integrally equipped with an inner guide pulley, an auxiliary guide pulley, and an outer guide pulley is used in each of the wire sawing methods described above, handling and installation of each pulley will be convenient.

[Brief explanation of drawings]

FIGS. 1 and 2 are a plan view and a side view illustrating a wire sawing method and a guide pulley stand for a reinforced concrete structure according to the present invention. <Description of main symbols>, 2...Reinforced concrete structure, 5...Guide pulley stand, 7a, 7b...
...Inner guide pulley, 8a, 8b...Auxiliary guide pulley, 9a, 9b...Outer guide pulley, 1
1... Cable drive device, 14... Cutting cable.

Claims (1)

[Scope of Claims] 1. A pair of middle guide pulleys are installed along the surface of the reinforced concrete structure on the same plane as the planned cutting surface, and an outer guide pulley is installed outside each middle guide pulley on the same plane as that. Specifically, the cutting cable is passed from the inside of one of the inner guide pulleys to the outer guide pulley in an S-shape, and is hung from the outside of the outer guide pulley to the reinforced concrete structure, and from the outside of the other outer guide pulley to the middle guide pulley. Pass it in an S shape,
A wire sawing method for reinforced concrete structures, which consists of disposing the wire so as to be drawn out from the inside of a middle guide pulley and running it in an endless cycle while adjusting the tension and running speed. 2 Along the surface of the reinforced concrete structure, install a pair of inner guide pulleys on the same plane as the planned cutting surface, and install an outer guide pulley on the same plane outside of each inner guide pulley, and install a cutting cable. , disposed so as to be hung on a reinforced concrete structure from the inside of one medium guide pulley and pulled out from the inside of the other medium guide pulley, and run in an endless cycle under adjustment of tension and running speed; Pass the cutting cable from the inside of one middle guide pulley to the outer guide pulley in an S-shape, hang it from the outside of the outer guide pulley to the reinforced concrete structure, and pass it in an S-shape from the outside of the other outer guide pulley to the middle guide pulley. A wire sawing method for a reinforced concrete structure, which consists of passing the wire through a shape, pulling it out from the inside of a guide pulley, and running the wire in an endless manner while adjusting the tension and running speed. 3 Along the surface of the reinforced concrete structure, place a pair of medium guide pulleys on the same plane as the planned cutting surface, and also place an outer guide pulley on the same plane outside of each medium guide pulley, and also connect each medium guide pulley and the pulley groove. Install auxiliary guide pulleys that share a common tangent line passing through the inner guide pulleys, adjacent to the opposite groove sides of each inner guide pulley, pass the cutting cable through one of the auxiliary guide pulleys, and connect the outer guide pulleys from the inside of the inner guide pulley to the outer guide pulley. Pass it through the pulley in an S shape, hang it from the outside of the outer guide pulley to the reinforced concrete structure, pass it in an S shape from the outside of the other outer guide pulley to the middle guide pulley, and from the inside of the middle guide pulley to the auxiliary guide pulley. Arrange it so that it can be pulled out,
A wire sawing method for reinforced concrete structures, which involves running the wire in an endless cycle while adjusting the tension and running speed. 4. The wire sawing method for reinforced concrete structures according to claim 3, wherein each auxiliary guide pulley is oriented at right angles to the adjacent middle guide pulley. 5. Along the surface of the reinforced concrete structure, place a pair of medium guide pulleys on the same plane as the planned cutting surface, and place an outer guide pulley on the same plane outside of each medium guide pulley, and also connect each medium guide pulley and the pulley groove. Install auxiliary guide pulleys that have a common tangent line passing through them adjacent to the opposing groove sides of each medium guide pulley, pass the cutting cable through one of the auxiliary guide pulleys, and then insert the reinforced concrete from the inside of the medium guide pulley. The cutting cable is hung on the structure and is arranged so as to be pulled out from the inside of the other inner guide pulley to the auxiliary guide pulley, and run in an endless manner while adjusting the tension and running speed. Pass it through one auxiliary guide pulley, pass it from the inside of the middle guide pulley to the outside guide pulley in an S-shape, hang it from the outside of the outside guide pulley to the reinforced concrete structure, and pass it from the outside of the other outside guide pulley to the middle guide pulley. A wire sawing method for reinforced concrete structures, which consists of threading the wire in a shape, repositioning it so as to pull it out from the inside of the middle guide pulley to the auxiliary guide pulley, and running it in an endless cycle while adjusting the tension and running speed. 6. The wire sawing method for reinforced concrete structures according to claim 5, wherein each auxiliary guide pulley is oriented at right angles to the adjacent middle guide pulley. 7 A pair of middle guide pulleys rotatably provided on the same plane, an outer guide pulley rotatably provided on the same plane outside each middle guide pulley, and a tangent line passing through each middle guide pulley and the pulley groove. A guide pulley stand equipped with an auxiliary guide pulley rotatably provided adjacent to the opposing groove side of each middle guide pulley so as to be common to each other. 8. The guide pulley stand of claim 7, wherein each auxiliary guide pulley is oriented at right angles to an adjacent intermediate guide pulley.