JPH03156069A - Demolishing method for reinforced concrete wall and cutting device for reinforced concrete wall - Google Patents

Abstract

PURPOSE:To enable approximately linear cutting of a concrete wall by a method wherein a groove is formed by injecting a jet along cutting lines marked on a concrete wall, a crack starting from a hole formed in a given spot in the groove is created. CONSTITUTION:Cutting lines C... are previously marked on the reinforced concrete wall of a concrete levee A and the like. A nozzle through which extra-high pressure water or mixture fluid of high pressure water and a polishing material is injected is then moved along the cutting lines..., and through injection of an abrasive jet (having, for example, a pressure of 350kg f/cm<2>), a continuous groove is formed along the cut lines C.... By using the jet, a plurality of holes E are formed in given spots in the groove, and a crack extending starting from the holes E... and along a concrete wall is created. This method regulates the direction of the crack by means of the continuous groove, and enables cutting of the concrete wall in a desired shape.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a demolition method for dismantling a reinforced concrete wall into a plurality of blocks, and a cutting device for cutting the reinforced concrete wall or forming continuous grooves in the reinforced concrete wall. It is.

<Prior Art> Concrete embankments made of substantially upright reinforced concrete walls are constructed on rivers, coasts, etc. for the purpose of bank protection. When reconstructing or repairing this concrete embankment, the embankment is divided into a plurality of blocks and then dismantled.

To dismantle a concrete embankment, draw a cutting line on the embankment in advance with a weight corresponding to the lifting capacity of the crane, use a chisel to form multiple holes along this cutting line, and then use a chisel to form multiple holes from these holes. Dismantling is done by forming continuous cracks using split arrows, expanded concrete, dynamite, etc. in the direction of the hole and the thickness of the embankment.

During the demolition, it is necessary to cut all reinforcing bars on the planned cutting line of the concrete embankment. For this reason,
By removing the buried part of the reinforcing steel, the reinforcing steel is exposed, and
The exposed reinforcing bars are cut using gas cutting or a disc cutter.

On the other hand, there is a technology that uses ultra-high pressure water jets to cut and drill holes in rock and concrete. Also, a so-called abrasive jet has been developed in which an abrasive such as garnet or silica sand is mixed into a high-pressure water jet. When this abrasive jig T-t is used, it is possible to cut steel plates, reinforced concrete, etc.

<Problem to be solved by the invention> In the above-mentioned conventional reinforced concrete wall demolition work,
The method of breaking reinforced concrete walls used, i.e. split arrow,
A plurality of holes are independently formed at predetermined intervals and depths on the planned cutting line depending on the expanded concrete, dynamite, etc. When a crack is generated starting from a hole using the above-mentioned fracture method, the direction of the crack is non-directional. By simultaneously generating cracks from multiple holes, the cracks starting from adjacent holes are made to continue, and by growing these continuous cracks, the reinforced concrete wall is ruptured. Therefore, the fracture line is not necessarily straight, the fracture surface also has a very rough surface, and the weight of the disassembled block may differ from the planned weight.

Further, a plurality of reinforcing bars are buried in the reinforced concrete wall at predetermined burial depths and intervals. Reinforcing bars: 1 When demolishing a concrete wall, it is necessary to cut all of these reinforcing bars, so the reinforcing bars are exposed by chiseling and then cut using gas cutting or a disc cutter. Conventionally, most of the chisel work and cutting work using gas cutting disc cutters, etc., have been performed manually, requiring a lot of manpower and time, and the work also generates noise, dust, vibrations, etc. The working environment is also not good.

An object of the present invention is to provide a demolition method for efficiently demolishing a reinforced concrete wall such as a concrete embankment, and a concrete wall cutting device.

<Means for Solving the Problems> In order to solve the above problems, the reinforced concrete wall demolition method according to the present invention forms a plurality of holes along a preset cutting line, and removes cracks starting from the holes. In a demolition method for reinforced concrete walls that generates a The invention is characterized in that the direction in which the cracks occur is defined by forming continuous grooves in the grooves.

Another construction method is the above-mentioned demolition method for reinforced concrete, in which ultra-high pressure water or a mixed fluid of high pressure water and abrasive is injected from the nozzle according to the position of the reinforcing bars on the cutting line detected in advance when the nozzle moves. This method is characterized by changing the injection conditions or the moving speed of the nozzle.

Further, the reinforced concrete wall cutting device is a cutting device for cutting an upright reinforced concrete wall or forming a groove in the reinforced concrete wall, and is a cutting device for cutting an upright reinforced concrete wall or forming a groove in the reinforced concrete wall, and the cutting device is a cutting device for cutting an upright reinforced concrete wall or forming a groove in the reinforced concrete wall, and is a cutting device that applies ultra-high pressure water or a mixed fluid of high pressure water and an abrasive to the reinforced concrete wall. It has a nozzle for spraying, a moving means for moving the nozzle in the extending direction of the reinforced concrete wall, and a lifting means provided on the truck for moving the nozzle in the height direction of the reinforced concrete wall. It is composed of

Another cutting device is a cutting device for cutting the reinforced concrete wall or forming a groove in the reinforced concrete wall by sitting astride the upright reinforced concrete wall, and a cart disposed at the top of the reinforced concrete wall; a drive device for moving the cart along the top of the reinforced concrete wall; a frame provided on the cart and disposed in the height direction of the reinforced concrete wall; and ultra-high pressure water or high pressure water and an abrasive material for the reinforced concrete wall. The structure includes a nozzle for injecting a mixed fluid with the concrete wall, and a lifting device for moving the nozzle in the vertical direction of the reinforced concrete wall.

According to the above demolition method, when demolishing a reinforced concrete wall such as a concrete embankment (hereinafter simply referred to as "concrete wall J"), the nozzle is continuously moved along a preset cutting line for the concrete wall. At the same time, by injecting an ultra-high pressure water jet or a so-called abrasive jet made of a mixed fluid of high-pressure water and abrasive material from the nozzle, these jets form continuous grooves in the concrete wall. By forming a plurality of holes on the groove and causing cracks to occur from the holes, the direction in which the cracks occur can be defined by the grooves, thereby making it possible to break in a substantially straight line.

Further, the thickness of concrete that can be cut by each of the jets or the depth of the groove that can be formed depends on the transfer speed of each jet, that is, the cutting speed, and the discharge amount of the jet or the mixing rate of the abrasive material, that is, the injection conditions of the jet. Therefore, by setting the cutting conditions such as the injection conditions and cutting speed of each of the jets to appropriate values, even if the reinforcing bars are buried in the concrete wall, the reinforcing bars and the concrete layer can be cut at the same time. You can.

Furthermore, the grooves used when demolishing concrete walls do not need to be very deep; they only need to be deep enough to define the direction of cracks that occur, and deep enough to create a notch effect in the concrete wall. good. The depth of the groove varies depending on the thickness of the concrete wall, but approximately 50 mm is sufficient. This value is equal to or smaller than the depth of reinforcing bars embedded in concrete walls. That is, by forming a groove shallower than the depth at which the reinforcing bars are buried in the concrete wall, the concrete wall can be broken in a substantially straight line.

For this reason, if the cutting conditions for forming a groove in a concrete wall are the same as the cutting conditions for cutting reinforcing bars embedded in a concrete wall, a groove that is deeper than necessary will be formed in the concrete wall. For this reason, water, abrasive 1
Time etc. will be wasted.

Therefore, when injecting each jet to a concrete wall to cut the wall or form a groove in the wall, the position of the reinforcing bars on the planned cutting line of the concrete wall is determined in advance using a drawing or a reinforcing bar detection device. By detecting this and changing the cutting speed according to the position of the reinforcing steel, or changing the jet injection conditions such as the jet discharge amount or the mixing rate of abrasive material, the buried reinforcing steel can be cut at the reinforcing steel location. Moreover, a groove having an appropriate depth can be formed at the non-arranged position.

According to the first cutting device, the nozzle for injecting an abrasive jet consisting of an ultra-high pressure water jet or a mixed fluid of high pressure water and an abrasive onto an upright concrete wall is moved by the moving means to the concrete wall. It is possible to cut the concrete wall or form a groove in the concrete wall while moving it in the direction of extension of the concrete wall and in the height direction of the concrete wall by the lifting means.

According to the second cutting device, a cart configured to be able to move along the top of the standing concrete wall is disposed, and upper and lower frames are provided on the cart along the vertical direction of the concrete wall, Furthermore, since the nozzle for ejecting an ultra-high pressure water jet or an abrasive jet consisting of a mixed fluid of high pressure water and an abrasive material can be moved in the vertical direction of the concrete wall by the lifting device, each of the jets can Concrete walls can be cut or grooves can be formed in concrete walls.

<Example> An example of a concrete wall demolition method and a concrete wall cutting device to which the above-mentioned means are applied will be described below with reference to the drawings.

Figure 1 is an illustration of a groove formed in a concrete wall, Figures 2 (A) and (B) are illustrations of an embankment, Figure 3 is a front illustration of the cutting device, and Figure 4 is a side illustration of the cutting device. FIG. 5 is a block explanatory diagram.

First, a concrete wall demolition method will be explained for the case of demolishing a concrete embankment.

As shown in Figure 2, cutting lines C (C+, ct, Cs-・-) are set to divide embankment A to be demolished into multiple blocks B (Bl, th, B:l・-). Ru. The blocks B are set to have approximately the same weight in consideration of the lifting performance of the crane. For example, the dimensions are set so that each block weighs approximately 7L to 8L.

Embankment A has a plurality of reinforcing bars D placed at predetermined intervals vertically and horizontally.
(D+, Dt) is buried. The buried position and spacing of the reinforcing bars have different values depending on the height, thickness, and other dimensions of the embankment A, but for example, if the height is 4 m and the thickness is 65 m,
In the embankment A constructed from 0 to 700 I, φ19 reinforcing bars are buried at a depth of approximately 80 m from the surface at intervals of 300 m.

Further, a plurality of holes E are formed at predetermined positions on the cutting line C. The hole E is formed to have a depth approximately half the thickness of the embankment A. And when demolishing the embankment, split arrows and expanded concrete were used in Rokumi.

The embankment A is divided into a plurality of blocks B and demolished by inserting a breaking material such as dynamite and causing a crack starting at 6E with the inserted breaking material.

When creating a crack starting from the hole E as described above, by forming a groove in which all the holes E are continuous, six E
It is possible to define the direction of cracks that occur starting from the groove, and also to generate a notch effect on the embankment A by the groove. That is, when a crack is generated starting from the hole E, it is possible to make the direction of the crack coincide with the direction of the groove. Therefore, the block B can have a substantially linear fracture line and a substantially planar fracture surface along the cutting line C.

FIG. 1 is an explanatory diagram of a groove F formed in an embankment A.

The groove F shown in the figure is continuously formed with a depth of 50 to 60 m. Further, the groove F is formed to coincide with a cutting line C set in advance on the embankment A.

The grooves F can be formed by a so-called water jet in which ultra-high pressure water is injected from a nozzle, or by a so-called abrasive jet in which a mixed fluid in which high-pressure water is mixed with an abrasive such as garnet or silica sand is injected from a nozzle. It is possible.

In this embodiment, an abrasive jet is used in which silica sand is mixed as an abrasive into high-pressure water having a pressure of 350 kgf/c4. Then, a groove F with a depth of 50 mm is formed by moving the abrasive jet at a speed of 300wt5/min while injecting the abrasive jet from the nozzle at a discharge rate of 901/++in.

According to the abrasive jet, the discharge amount.

The depth of the groove F can be set to a desired value by appropriately setting cutting conditions such as the mixing ratio of abrasive to high-pressure water and the moving speed of the nozzle. It is possible to cut reinforced reinforcing bars, etc.

As mentioned above, in Embankment A, a plurality of reinforcing bars are buried at a depth of about 80 mm at intervals of about 300 squares. Furthermore, when cutting block B from embankment A, it is necessary to cut all reinforcing bars buried in embankment A and located on cutting line C.

Therefore, the concrete wall demolition method according to the present invention is
The abrasive jet forms a groove F in the embankment A and at the same time cuts the reinforcing bars buried in the embankment A.

That is, the position of the reinforcing bar on the cutting line C is detected in advance based on the construction drawings on the embankment or by scanning the embankment A with a reinforcing bar detection device, and the abrasive cutting is performed according to the position of the reinforcing bar. By appropriately changing the conditions for cutting the embankment A by the jet, it is possible to form the groove F along the cutting line C and cut the reinforcing bars buried in the embankment A.

For example, in FIG. 1, when moving the nozzle that injects an abrasive jet in the direction of arrow a, the nozzle is moved approximately 30011Il in the part where the reinforcing steel is not buried.
Form the groove F by moving the nozzle at 1/min/min, and when it reaches the vicinity of the reinforcing bar burial position, reduce the moving speed of the nozzle to about 1/min/min to form the concrete layer deeper than the groove F. and cut the rebar at the same time. After passing through the buried position of the reinforcing bars, the moving speed of the nozzle is gradually increased to return to the original moving speed. By repeating the above operation, the reinforcing bars buried in embankment A are cut and a groove F continuous with embankment A is cut.
It becomes possible to form.

Further, when cutting the reinforcing bars buried in the embankment A, the moving speed of the nozzle may be changed as described above, and the injection amount of the abrasive jet may also be changed. That is, when forming grooves F in embankment A, an abrasive jet mixed with abrasive material at a flow rate of 10 kg/win is used at a flow rate of 901 kg/win.
/min, and when cutting reinforcing bars, the flow rate is 5
By injecting an abrasive jet mixed with kg/win abrasive at a flow rate of 601/min, it is possible to form a continuous groove F in embankment A and at the same time cut the reinforcing bars buried in embankment A. It is possible.

It is also possible to form the grooves F and cut the reinforcing bars by selecting different nozzles using a plurality of nozzles with different diameters.

3 to 5 are explanatory diagrams of a cutting device for cutting the embankment A or forming a continuous groove F in the embankment A.

In the figure, a cart 1 constituting a cutting device is placed on the top A1 of an embankment A formed into a flat surface. The trolley 1 is provided with rollers 2a and 2b, and by driving the rollers 2a with a travel motor 3 provided on the trolley 1, the trolley 1 moves along the arrow mark on the top A1 along the extension direction of the embankment A. , c directions.

Parallelogram-shaped frames 4 are provided on both sides of the bogie I in the width direction so as to sandwich the embankment A in the height direction of the embankment A. Bar 4 constituting the frame 4
A and 4b are provided with a plurality of rollers 5 that come into contact with the side surfaces At and A3 of the embankment A, respectively. Further, a guide roller 4C is provided at the lower end of the frame 4. A guide rail 6 for guiding the guide roller 4C is arranged parallel to the directions of arrows A and C at a position corresponding to the guide roller 4C on the side surface A2 of the embankment A.

Therefore, the cutting device straddles the embankment A and cuts the embankment A by the rollers 2a, 2b, 5 and the guide roller 4C.
The vehicle is configured to be able to run reliably along the top A1 and side surfaces At and Ax of the vehicle.

A cheno 7 is stretched across the bar 4a of the frame 4 in the vertical direction, and a nozzle 9 for spraying an ultra-high pressure water jet or an abrasive jet is attached to a bracket 8 fixed to the cheno 7. There is. The chino 7 is driven by a lifting motor 10 provided on the trolley 1, and is configured to move the nozzle 9 up and down along the bar 4a in the directions of arrows d and e, which are the height directions of the embankment A. .

A high pressure tube 9a is attached to the nozzle 9. The nozzle 9 is connected to a high pressure pump 9b and an abrasive supply device 9c shown in FIG. 5 through the tube 9a.

In FIG. 5, 11 is a pump for supplying low-pressure water to the high-pressure pump 9b, and 12 is an abrasive supply device 9.
This is a compressor that supplies pressurized air to C and the high pressure pump 9b. Further, reference numeral 13 indicates a traveling motor 3 provided in the cutting device. Starting the lifting motor 10.

This is a control device for controlling the stop and the rotational speed of these motors 3 and 10.

The operation for cutting the embankment A or forming the groove F in the embankment A using the cutting device configured as described above will be explained.

First, the cutting device is placed on embankment A using a crane.

The nozzle 9 is raised by the lifting motor 10, and the embankment A
Move it to the position corresponding to the top A.

At the same time, the trolley 1 is moved by the traveling motor 3 in the direction of the arrow or C, so that the nozzle 9 is aligned with, for example, the cutting line C1. Then, the travel motor 3 is stopped, and while the abrasive jet is injected from the nozzle 9, the nozzle 9 is
move in the direction. The moving speed of the nozzle 9 is set to a speed at which the groove F can be formed in the embankment A, and this speed is maintained until the cutting reaches the vicinity of the reinforcing bars buried in the embankment A. When the nozzle 9 reaches the vicinity of the buried position of the reinforcing bar, the speed of the lifting motor 10 is reduced to cut the reinforcing bar.

When the cutting of the reinforcing bars is completed as described above, the speed of the lifting motor 10 is increased again to form a continuous groove F. After cutting the embankment A to a predetermined height by the above operation, the lifting motor 10 is stopped, and the traveling motor 3 is driven to move the cart 1 in the direction of the arrow or C to cut the embankment A* in a horizontal direction that coincides with C4. The groove F is formed and the buried reinforcing bars are cut.

When the above operation is continued and the cutting along the cutting line C is completed, the traveling motor 3 is stopped and the lifting motor 10 is driven to raise the nozzle 9, thereby moving the embankment A along the preset cutting line C2. At the same time, the reinforcing bars buried on the cutting line are cut.

By the above operation, a groove F corresponding to block B1 is created in embankment A.
It is possible to continuously form the reinforcing bars, . . . , and simultaneously cut the reinforcing bars, . . .

Therefore, after forming a continuous groove F on the embankment A along the cutting line CIl C4+ Cz, the cutting line CI, C4, C
By inserting a fractured material into a plurality of six E on z, generating a crack starting at the six E, and defining the direction of the generated crack by the groove F, the block B is cut along the approximate cutting line CI,
It can be broken in a straight line along C4 and Cz.

In the cutting device configured as described above, if the control device 13 is configured by a microcomputer or the like, the position information of the reinforcing bars buried in the embankment A is temporarily stored in the storage means of the control device 13. It is possible to automatically control the cutting device by reading this information appropriately.

However, if the control device 13 manually controls the opening/closing and speed of the motor 3.10, the operator may perform an operation to reduce the speed of the motor 3.10 in the vicinity of the reinforcing bar burial position. is necessary.

In addition, the abrasive jet injected from the nozzle 9 is
It is possible to collect the nozzle 9 using a cover 14 configured to cover the nozzle 9.

In the above-mentioned embodiment, a case was explained in which the groove F was formed in the embankment A and the reinforcing bars buried in the embankment A were cut, but the thickness of the concrete wall was approximately 100 mm.
When the distance is approximately 200 mm, it is possible to cut the reinforcing bars buried in the concrete wall and the concrete wall by the abrasive jet ejected from the nozzle 9.

Further, in the above embodiment, the cutting device is placed at the top A of the embankment A.
However, the cutting device is equipped with a trolley that can run on rails arranged along the base of the concrete wall, and a frame is formed on this trolley in the height direction of embankment A. Additionally, the nozzle may be configured to be movable along the frame. In this case it is possible to cut the concrete wall from one side or to form a groove on one side of the concrete wall.

<Effects of the Invention> As explained in detail above, according to the reinforced concrete wall demolition method according to the present invention, when demolishing a concrete wall such as a concrete embankment, along a preset cutting line for the concrete wall, By continuously moving the nozzle and spraying an ultra-high pressure water jet or a so-called abrasive jet consisting of a mixed fluid of high-pressure water and abrasive material, these jets can cut the concrete wall. It is possible to form continuous grooves.

For this reason, when demolishing a concrete wall, a continuous groove is formed on the surface of the concrete wall, multiple holes are formed on the groove, and cracks are generated from these holes, so that a substantially straight line is created using the groove as a reference. It can be broken.

In addition, according to the cutting device, an abrasive jet consisting of an ultra-high pressure water jet or a mixed fluid of high pressure water and abrasive material is moved along the top of the standing concrete wall and along the upper and lower frames. It has features such as being able to cut a concrete wall or form continuous grooves in a concrete wall by moving the nozzle for spraying.

[Brief explanation of the drawing]

Figure 1 is an illustration of a groove formed in a concrete wall, Figures 2 (A) and (B) are illustrations of an embankment, Figure 3 is a front illustration of the cutting device, and Figure 4 is a side illustration of the cutting device. FIG. 5 is a block explanatory diagram. A is embankment, B is block, C is cutting line, D is reinforcing bar, E is hole, F is groove, l is truck, 2a2b, 5 is roller, 3 is travel motor, 4 is frame, 4a, 4b are bars, 4c is a guide roller, 6 is a guide rail, 7 is a check 7. 8 is a bracket, 9 is a nozzle, 9a is a high pressure tube, 9b is a high pressure pump, 9c is an abrasive supply device, 10 is a lifting motor, and 13 is a control device. be.

Claims (4)

[Claims] (1) In the demolition method for reinforced concrete walls, where multiple holes are formed along a preset cutting line and cracks are generated starting from the holes and break into blocks, ultra-high pressure water or high pressure water is used. Reinforced concrete, characterized in that the direction in which the cracks occur is determined by moving a nozzle for injecting a fluid mixture of and an abrasive along the cutting line to form a continuous groove in the reinforced concrete wall. Wall demolition method. (2) In the reinforced concrete demolition method according to claim (1), ultra-high pressure water or high pressure water and an abrasive material are injected from the nozzle according to the position of the reinforcing bars on the cutting line detected in advance when the nozzle moves. A method for dismantling a reinforced concrete wall, characterized by changing the injection conditions of the mixed fluid or the moving speed of the nozzle. (3) A cutting device for cutting an upright reinforced concrete wall or forming a groove in the reinforced concrete wall,
a nozzle for injecting ultra-high pressure water or a mixed fluid of high-pressure water and an abrasive material to the reinforced concrete wall; a moving means for moving the nozzle in an extending direction of the reinforced concrete wall; and a nozzle provided on the trolley. 1. A cutting device for a reinforced concrete wall, comprising: lifting means for moving the reinforced concrete wall in the height direction of the reinforced concrete wall. (4) A cutting device for cutting the reinforced concrete wall or forming a groove in the reinforced concrete by sitting astride an upright reinforced concrete wall, the cutting device comprising: a cart disposed on the top of the reinforced concrete wall; a drive device for moving along the top of the wall; a frame provided on the cart and disposed in the height direction of the reinforced concrete wall; 1. A cutting device for a reinforced concrete wall, comprising: a nozzle for injecting water; and a lifting device for moving the nozzle in the vertical direction of the reinforced concrete wall.