JPH0718261B2 - Horizontal cutting demolition method for underwater reinforced concrete structures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a horizontal cutting and demolition method for a bridge pier or other reinforced concrete structure (hereinafter abbreviated as a unit underwater reinforced concrete structure) partially or wholly immersed in water. Regarding

[Prior art] Usually, as a method of dismantling a reinforced concrete structure on land, a method of destroying it on the ground by utilizing the expansion pressure or gas pressure of explosives or chemicals, or crushing with steel balls, vibration hammers, hydraulic pressure, etc. Known methods include a method of cutting and disassembling with a circular blade or a water jet.

When dismantling an underwater reinforced concrete structure,
Conventionally, a method in which a worker soaks his body in water and further operates a compressed air type breaker in a state of diving, or a method of crushing from the ground with an impact crusher is used.

[Problems to be Solved by the Invention] However, in dismantling the above-mentioned underwater reinforced concrete structure, a dismantling method that uses expansion pressure or gas pressure of explosives or the like that is performed on the ground completely destroys and dismantles the target structure. However, it is extremely difficult to control the expansion pressure and gas pressure in water, and therefore it is not possible to use it for the partial disassembled structure of the structure, particularly for the partially disassembled structure at the accurate size or the accurate position. It was In addition, these dismantling methods have a problem that the place of use and the use conditions are severely limited because the influence of the blast, vibration, impact noise, noise, etc. on the surrounding environment is great. In addition, the method of crushing with steel balls, vibration hammers, hydraulic pressure, etc., and the method of cutting and dismantling with a circular blade or water jet are suitable for cutting and dismantling reinforced concrete structures on the ground, but application in water is The resistance of water is so great that it is almost impossible and it is not profitable.

On the other hand, when a diver wears diving equipment, walks on the bottom of the water or uses a pneumatic breaker by hand while swimming in the water, it is inefficient to work by hand and further diving for a long time. Etc. are extremely dangerous. In addition, the transparency is poor due to pollution of seawater in ports and rivers around the city, and it is the actual situation that the work is done with the intuition of a diver. Furthermore, the work efficiency decreases in proportion to the working water depth, and it is extremely dangerous to work for a long time especially in water exceeding a water depth of 10 m, which is a heavy burden on the operator both physically and mentally, and the construction period is prolonged. It was Further, the breaker has a problem that it is inferior in crushing ability because it is small in size and light in weight for convenience in handling and handling.

Thus, the object of the present invention is to include an underwater reinforced concrete structure, including internal rebars, without being limited to the cutting cross-sectional area or the depth of the cutting position, at an extremely high cutting speed,
An object of the present invention is to provide a construction method capable of performing workability and safety, and horizontally cutting and dismantling in a state in which adverse effects such as vibration and noise hardly affect the external environment.

[Means for Solving Problems] A method for horizontally cutting and dismantling a submerged reinforced concrete structure according to the present invention is a guide pulley mounted on a pulley stand installed in water with a cutting cable formed by imparting cutting ability to a wire rope. Through the underwater portion of the underwater reinforced concrete structure and the cutting cable is run on a rail installed above the ground to make a cut into the underwater reinforced concrete structure, and wedge-shaped spacers in the cutting gap generated as the cutting progresses. Are sequentially driven, and while the tension of the cutting cable is adjusted by the cable driving device, the underwater reinforced concrete structure is horizontally cut by running.

In the above, for the cutting cable, for example, a known structure in which beads having a diamond abrasive grain layer are arranged on a wire rope at an appropriate pitch, with or without a coil spring or other spacer interposed therebetween, can be adopted. . Further, the cutting cable is provided by a cable drive device installed on the ground via a vertical and horizontal guide pulley base provided with a pair of horizontal guide pulleys and a pair of vertical guide pulleys adjacent to them. It may be cut into underwater reinforced concrete structures.

The cable drive device may employ a structure including, for example, a cable drive pulley that travels a wound cutting cable, a hydraulic motor or an electric motor that rotates the cable drive pulley, and another accessory mechanism. It is possible to appropriately use, for example, a unit in which the drive pulleys and the like are integrally moved on the rail by the drive wheels, or a unit integrally moved on the rack by the drive pinion.

[Operation] In the above, by operating the cable drive device on the ground and cutting the cutting cable into the underwater reinforced concrete structure, accurate horizontal cutting is possible. Also, due to this, the underwater work of the diver only has to wind the cutting cable around the cutting position of the reinforced concrete structure, and after that, the cutting cable is circulated by the cable drive device installed on the ground and at the same time tension is applied. The cable drive is retracted while adding. As a result, a cutting cable is cut into the underwater reinforced concrete structure, and accurate horizontal cutting proceeds.

At that time, the cutting cable is cut into the underwater reinforced concrete structure through vertical and horizontal guide pulley bases each having a pair of horizontal guide pulleys and a pair of vertical guide pulleys adjacent to the horizontal guide pulleys, so that an accurate horizontal level is obtained. Can be cut. Also, by doing so, underwater work of a diver is only required to install a guide pulley stand and wrap the cutting cable around the cutting position of the reinforced concrete structure, and sequentially drive wedge-shaped spacers into the cutting gap generated as the cutting progresses, The cutting cable runs under the required tension to horizontally cut the underwater portion of the underwater reinforced concrete structure. The maintenance or adjustment of the tension of the cutting cable with the progress of cutting and disassembling can be performed, for example, by gradually moving the above cable drive pulley along with its accessories and the like rearward along rails, racks, and the like. The cable drive pulley may be fixed and another tension pulley may be gradually moved. Furthermore, it is also possible to mount the rack on a dolly and move the cable drive pulley and the like along the rack and at the same time move the dolly along the rail.

The running speed and tension of the cutting cable are appropriately selected depending on the type of cutting object and other cutting conditions, but normally, the running speed is about 20 to 30 m / sec and the tension on the tension side is 50 to 1
Under water, the running speed of the cutting cable is about 15 to 20 m / sec, and the tension is about 150 to 200 kgf. , It will be completely cut including the internal rebar.

According to the cutting comparative test example according to the present invention, the underwater portion of the underwater reinforced concrete structure having a diameter of 180 cm in which the reinforcing bars having a diameter of 16 to 25 mm are reinforced in a normal manner, when performing a crushing operation by hand in conventional water, Since an average of 0.10 m ^{3 is} crushed by 2 divers per day, the cutting amount is 0.9 ² × 3.
14 × 0.5 = 1.27m ³ , which means 1.27 ÷ 0.10 ＝ 13 to cut and dismantle the reinforced concrete structure by crushing it in water.
It will take about 13 days. On the other hand, according to the horizontal cutting dismantling method according to the present invention, the area of 1 m ² is about 3
Since it can be cut in 0 minutes, a 180 cm diameter underwater reinforced concrete structure can be cut in about 45 minutes. Moreover,
In that case, there is no restriction on the depth of the cutting position or the cutting cross-sectional area, and therefore, a marked difference in working efficiency between the two is recognized.

When cutting the above-water part, water is poured into the cutting place for cooling, lubrication, washing, etc., but when cutting the underwater part, such cutting is unnecessary because the cutting place is just in the water.

In such a method of cutting and dismantling with a cutting cable in water, after the cutting cable is once placed between the cutting point and the cable drive pulley, the cutting work is complete cutting including the internal reinforcing bar. Since it is controlled remotely by the cable drive device up to, it is possible for a worker to operate a disc blade type cutting machine or breaker in the state of being constantly in contact with or in proximity to the cutting site in water or above water as in the past. The situation is completely different and it is easy to introduce automatic driving.

The cable drive device is installed on land or on a vehicle on the land, and the change in the load received by the cutting cable during traveling during cutting is, for example, the tension on the tension side at the rotating shaft of the cable drive pulley. It can be quantitatively grasped to some extent by detecting the strain in the right angle direction, and thus, for example, the cutting of the concrete layer and the cutting of the reinforcing bar can be easily discriminated during cutting progress, or the cutting cable It is possible to prevent breakage in advance.

On the other hand, in the cable drive device, a hydraulic control unit including at least a hydraulic pump that supplies hydraulic pressure may be installed outside the water.

Further, the arrangement of the cutting cable between the cable drive pulley and the underwater reinforced concrete structure is carried out by installing a vertical and horizontal guide pulley stand including a pair of horizontal guide pulleys and a pair of vertical guide pulleys adjacent to them. Can be easily bent at each bend and at any length, so the cutting cable can be passed through a narrow space in water, or it can be squeezed into a narrow space to reduce the resistance in water and reduce obstacles in the middle. Objects can be easily bypassed and the underwater portion of underwater reinforced concrete structures of all shapes and conditions can be easily horizontal cut at the required position and angle.

In addition, the wedge-shaped spacers are sequentially driven into the cutting gap that occurs as the cutting of the underwater reinforced concrete structure progresses, so that the columnar reinforced concrete structure above the cutting is prevented from sinking, which hinders the cutting cable from breaking and its running. Not done.

EXAMPLES Next, the present invention will be described based on examples. FIG. 1 is a front view of an essential part for explaining an example of a cutting and dismantling method of an underwater reinforced concrete structure according to the present invention, FIG. 2A is a plan view of an essential part at the time of bottom cutting in the cutting and dismantling method, and FIG. 2B is its cutting. It is a principal part top view at the time of upper part cutting in a dismantling method.

First, as shown in FIG. 1, a vertical columnar ferroconcrete structure (1) to be used for cutting and dismantling is built in water, and vertical and horizontal guide pulley stands ( 2) and (2a) are detachably installed by anchors. The vertical and horizontal guide pulley bases (2) and (2a) are composed of a pair of horizontal guide pulleys (3), (3) and (3a), (3a) and a pair of vertical guide pulleys (4) adjacent to them. , (4) and (4a), (4a), respectively. The vertical / horizontal guide pulley base (2) of the water bottom may be installed on the water bottom by the weight attached to the concrete base in advance, suspended from the water by a crane.

Further, a vertical guide pulley stand (7) and a rail (8) are detachably installed on the quay wall (6) in front of the above-mentioned pole-reinforced concrete structure (1). The vertical guide pulley base (7) is provided with a pair of vertical guide pulleys (9), (9), and drive wheels (11) supporting a cable drive device (10) are fitted on rails (8). There is. The cable driving device (10) includes a cable driving pulley (12), a tension side tension pulley (13) and a slack side tension pulley (14) adjacent to the cable driving pulley (12), and a rotation driving mechanism (not shown) of the cable driving pulley (12). A rotary drive mechanism (not shown) for the drive wheel (11) is installed.

As an example of a procedure for horizontally cutting and dismantling the columnar reinforced concrete structure (1) in water, the bottom part is cut first, a wedge-shaped spacer is driven into the cutting gap, and then the upper part is cut, and then the columnar part is cut off. A method of dismantling and removing the reinforced concrete structure (1) can be adopted.

In that case, first, the cutting cable (17) is wound around the bottom of the columnar reinforced concrete structure (1) and guided by the vertical and horizontal guide pulley stands (2) on the water bottom, and further the vertical guide pulley stand on the quay (6). Guided by (7), tension pulley (13) on tension side of cable drive (10)
And the tension pulley (14) on the slack side, and is endlessly hung on the cable drive pulley (12). The vertical / horizontal guide pulley base (2) adjoins the cutting cable (17) wound around the bottom of the columnar reinforced concrete structure (1) by a pair of lateral guide pulleys (3), (3) at narrow intervals. A pair of vertical guide pulleys (4), (4) guides from underwater to a pair of vertical guide pulleys (9), (9) of the vertical guide pulley stand (7) on the quay (6). . The vertical guide pulley stand (7) is a cutting cable (17) guided by the vertical and horizontal guide pulley stand (2) in water.
To the cable drive (10) on the rail (8).

In the above structure, when the cable drive pulley (12) of the cable drive device (10) and each rotation drive mechanism of the drive wheel (11) are operated, the cable drive pulley (12) rotates and moves along the rail (8). The change in the load received by the cutting cable while it is moving backwards and while the cutting is in progress is detected by detecting the tension on the tension side by the strain in the direction perpendicular to the rotation axis of the cable drive pulley. 17) circulates endlessly with the required tension and cuts the bottom of the columnar reinforced concrete structure (1). Further, by sequentially driving the wedge-shaped spacers into the cutting gap generated as the cutting progresses, the columnar reinforced concrete structure (1) at the upper part of the cutting is prevented from sinking, so that the cutting cable (17) is ruptured and runs. Not hindered.

After completely cutting the bottom of the columnar reinforced concrete structure (1) as described above, the cutting cable (17) is wound around the top of the columnar reinforced concrete structure (1) in the same manner as above, and the cutting cable (17) ) Is run by the cable drive device (10) through the vertical and horizontal guide pulley stand (2a) installed on the upper part of the columnar reinforced concrete structure (1) and the vertical guide pulley stand (7) on the quay (6), and the columnar reinforced concrete structure is (1) Cut the upper part.

In the above cutting, if necessary, more guide pulleys may be used in various places in order to arrange the cutting cable (17) more smoothly.

In addition, at the time of the above cutting, a protective device, such as a protective net, is provided around the cutting cable (17) or the cable drive device (10) traveling underwater or above the water for work safety, if necessary. Is desirable.

Further, the present invention will be described based on another embodiment. FIG. 3 is a plan view of essential parts at the time of bottom cutting in the horizontal cutting and demolition method of the underwater reinforced concrete structure according to the present invention.

First, in FIG. 3, a vertical columnar reinforced concrete structure (101) to be used for cutting and dismantling is erected in water, and a cable drive pulley (112) similar to the above is placed at an upper cutting point on the water. It is detachably installed by an anchor.

In addition, two U-shaped supports (18) and (18) whose height can be adjusted are detachably and immovably erected on the water bottom in front of the columnar reinforced concrete structure (101) by anchors. Between support (18), (18),
A cylindrical rack (19) with gears is mounted so that the rotation angle around the axis can be adjusted, and the rack (1
The self-propelled table (20) is fitted in 9) so as to be movable in the axial direction. The self-propelled table (20) has a cable drive (11
0) is installed.

When cutting the bottom of the columnar reinforced concrete structure (101), the mounting angle of the rack (19) is adjusted so that the rotating surface of the cable drive pulley (112) is horizontal, and the cutting cable (17) is connected to the columnar reinforced concrete structure (101). ) Endlessly hook between bottom and cable drive pulley (112). When the cable drive pulley (112) of the cable drive device (110) is then actuated, the cable drive pulley (112) moves rearward along the rack (19) while rotating, and the cutting cable (17) moves to the required position. Cylindrically running endlessly under tension and columnar reinforced concrete structure (10
The bottom of 1) is cut.

Similar to the first embodiment, many guide pulleys may be used in various places in the above cutting.

It should be noted that the first and second embodiments described above do not limit the present invention. According to the present invention, not only simple cutting and dismantling of columnar reinforced concrete structures (1) and (101) in water but also, for example, vertical and horizontal cutting of a wall in water and opening of the wall are involved. Cutting and dismantling is also possible. As the opening method, for example, two holes on the periphery of the planned opening are drilled, and the cutting cable (1
The work of running through 7) and cutting between the two points may be repeated over the entire circumference of the planned opening.

[Effects of the Invention] As described above, the horizontal cutting and demolition method for an underwater reinforced concrete structure according to the present invention has the following effects.

1. The cutting work is shortened, and especially the working time of a person underwater is short. That is, in the present invention, the guide pulley base is installed in an appropriate place in water, the work of winding the cutting cable around the underwater reinforced concrete structure, and the work of sequentially driving the wedge-shaped spacers into the cutting gap generated by the cutting work. Is performed only in water, and thereafter, only by driving the cutting cable with a driving device installed on the ground, the reinforced concrete structure in water can be automatically cut and disassembled at high speed.

2. In the cutting and dismantling method of the ground reinforced concrete structure using the cutting cable, heat is generated due to the large friction between the cutting cable and the reinforced concrete structure, so cooling water is required, and for lubrication, cleaning, etc. Although water is injected into the cutting place, like the present invention, since the place for cutting the reinforced concrete structure in water is just underwater,
Such water injection is unnecessary and it is not necessary to use cooling water.

3. In the cutting and dismantling method using the cutting cable of the ground reinforced concrete structure, when the cutting cable cuts,
Whereas long cutting cables splash far and beads attached to the cables may scatter, when cutting the underwater reinforced concrete structure of the present invention, due to the large resistance of water, the above-mentioned troubles occur. There is no problem and you can work safely.

4. The cutting shape of the reinforced concrete structure is accurately made into a predetermined shape, and due to the large resistance of the water, there is no scattering of debris after cutting, and the work of removing debris is also unnecessary.

5. The cutting speed is high, the construction period can be greatly shortened, and no special skill is required for the work.

6.Large reinforced concrete structures can be easily cut without changing much from small ones and can be cut with large blocks.When dismantling and removing after cutting, even large blocks are light in water due to buoyancy, so use a floating bag etc. Since it can be removed and transported while swimming, it is the most suitable method for cutting and dismantling large underwater objects.

7. If the cut surface of the reinforced concrete structure is smooth and the opening is to be used after cutting, for example when forming a predetermined opening on the wall surface, use it as is without any finishing work after cutting. it can.

8.Because cutting and dismantling of reinforced concrete structures in water,
Generation of vibration and noise is small, and the construction method of the present invention can be adopted even in urban areas.

9. Since the cutting cable drive mechanism is installed on the ground,
Regardless of underwater cutting work, all of its main mechanisms can be installed on the ground, and there is no need to give special consideration to the waterproofing of these electrical and hydraulic equipment, and cutting is as easy as on the ground. Can be dismantled.

10. Between the cable drive pulley and the underwater reinforced concrete structure, a vertical and horizontal guide pulley base, which includes a pair of horizontal guide pulleys and a pair of vertical guide pulleys adjacent to the horizontal guide pulleys, is installed to distribute the cutting cable. Since it is installed, the cutting cable can be easily bent at each bending point and at a free length.
The cutting cable can be passed through a narrow space in water, or can be squeezed into a narrow space to reduce the resistance in water to easily bypass obstacles on the way, and the underwater portion of an underwater reinforced concrete structure of any shape and condition is required. It is possible to easily cut horizontally at the position.

In particular, since a pair of lateral guide pulleys and vertical guide pulleys adjacent to the lateral guide pulleys are provided, it is possible to minimize the opening or twisting between the tension side and the slack side in the cutting cable, and to cut underwater. The running resistance of the cable can be minimized.

11.Since the wedge-shaped spacers are sequentially driven into the cutting gap that occurs as the cutting of the underwater reinforced concrete structure progresses, the columnar reinforced concrete structure at the top of the cutting is prevented from sinking, preventing the cutting cable from breaking,
The running can be promoted.

12. The fluctuation of the load received by the cutting cable during running while cutting is running endlessly circulating with the required tension, and it is not necessary for the operator to constantly monitor the cutting status of the underwater columnar reinforced concrete structure underwater. .

In addition, at the time of the above cutting, if necessary, by providing a protective device, for example, a protective net, around the cutting cable or the cable drive device that runs underwater for work safety, The body can be protected from the danger of breaking the cutting cable.

[Brief description of drawings]

FIG. 1 is a front view of a main part for explaining an example of a cutting and dismantling method of an underwater reinforced concrete structure according to the present invention, FIG. 2A is a plan view of a main part when a bottom part is cut in the cutting and dismantling method, and
FIG. 2B is a plan view of a main part at the time of upper cutting in the cutting and demolition method, and FIG. 3 is a front view of a main part at the bottom cutting in the cutting and demolition method of an underwater reinforced concrete structure according to the present invention. (Explanation of main symbols) 1,101… Columnar reinforced concrete structure 2,2a,… Vertical / horizontal guide pulley stand 7… Vertical guide pulley stand 8… Rail 10,110… Cable drive device 11… Drive wheel 12,112… Cable drive pulley 17… Cutting cable 18… Support 20 ... Self-propelled table

 ─────────────────────────────────────────────────── ─── Continued Front Page (56) References US Patent No. 2577545 (US, A) De Beers Industrial Dimension Limited Pty Limited 1981 "IDR 2181 VOLUME 41 Numeral 483 De Beers LVD 183 rd Librium edu s ed. Number 498 "

Claims (3)

[Claims] 1. A cutting cable formed by imparting cutting ability to a wire rope is passed through a guide pulley attached to a pulley stand installed underwater, and is wound around the underwater portion of an underwater reinforced concrete structure and the cutting cable is installed on the ground. A submerged reinforced concrete structure is cut by a cable drive that travels on a rail, and wedge-shaped spacers are sequentially driven into the cutting gap that occurs as the cutting progresses.
A horizontal cutting and demolition method for an underwater reinforced concrete structure, characterized in that the underwater reinforced concrete structure is horizontally cut by running while adjusting the tension of a cutting cable by the cable driving device. 2. An underwater reinforced concrete structure by a cable drive device in which a cutting cable is installed on the ground via vertical and horizontal guide pulley bases each having a pair of horizontal guide pulleys and a pair of vertical guide pulleys adjacent to them. The method for horizontally cutting and dismantling a submerged reinforced concrete structure according to claim 1, wherein the method is for cutting. 3. The method for horizontally cutting and dismantling a submerged reinforced concrete structure according to claim 1, wherein a protective device is arranged around the cable driving device and the like.