JP2010071013A - Method for chipping circumference of existing pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for chipping the circumference of an existing pipe, passing through a reinforced concrete wall, allowing chipping to the inside of the wall with excellent work efficiency without a repairing work of reinforcing bar. <P>SOLUTION: This method for chipping the circumference of the steel pipe 5 passing through the reinforced concrete wall 3 includes a water jet chipping process for jetting water to the surface of the reinforced concrete wall to chip the reinforced concrete wall in the predetermined scope around the steel pipe, and a striking chipping process for chipping the wall by giving a striking force to the concrete. In the water jet chipping process, the pressure of the water jet is set to be 155-255 MPa, its flow rate is set to be 15-35L/min, and concrete is left in the predetermined scope around the steel pipe 5. In the striking chipping process, the striking force is given to the concrete around the steel pipe left in the water jet chipping process to remove the concrete. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for hanging around an existing pipe such as a gas pipe that penetrates a reinforced concrete wall.

As a pipe that is piped so as to penetrate the reinforced concrete wall, for example, in the gas pipe, the gas pipe may be piped so as to penetrate the wall of the pier of the gas pipe bridge.
When the gas pipe penetrates the reinforced concrete wall, the gas pipe expands and contracts due to a change in temperature or the like, so that a gap is likely to occur at the joint between the reinforced concrete wall and the pipe (steel pipe). And the water which passes along a wall surface accumulates in this clearance gap, and corrosion tends to advance.
In addition, gas pipes are generally anti-corrosion-proof, but the anti-corrosion is less effective when the reinforcing bars inside the wall come into contact with the surface of the gas pipe, and there is a concern about corrosion of the gas pipes inside the wall. .

As described above, in the gas pipe that is piped so as to penetrate the reinforced concrete wall, the gas pipe inside the wall may be corroded, so that repair is required.
As a precondition for such repair work, it is necessary to crush the concrete wall around the gas pipe and expose the gas pipe embedded in the wall. As a general method for crushing a concrete wall, there are a core cutter method and a breaker or hammer drill method.
However, these methods have various problems as described below.

<Problems with core cutter>
Since the core cutter uses a motor for rotation, the size and weight of the apparatus are large, and there is a problem that work efficiency is poor for work in a wall penetrating part present in a narrow place such as a manhole or under a bridge.
Also, since it is necessary to hold the core cutter to the wall during work to support the reaction force of the core cutter on the wall side, it is necessary to remove it from the wall every time it is moved in the circumferential direction around the pipe. There is also a problem that it takes time.
Furthermore, in the case of work with a core cutter, the reinforcing bars in the concrete wall are also cut out. Therefore, when the removal part is restored with concrete, it is necessary to add and restore the reinforcing bars as a reinforcement. Is difficult.
Furthermore, the core cutter can also cut iron, and there is also a problem that there is a risk of damaging the pipe steel surface if the mounting accuracy or mounting angle of the core cutter on the wall is wrong. In particular, when flammable gas is contained inside the gas pipe, there is a strong demand for not damaging the gas pipe, and there is a serious problem that the gas pipe may be damaged.

<Problems with breakers and hammer drills>
Breakers and hammer drills are heavy, and using them sideways in the direction of the wall is heavy labor and the work efficiency is poor.
In a narrow work space, it is difficult to use a breaker with sufficient striking ability.
Further, these devices are heavy and recoil, and there is a risk of damaging the piping if they contact the piping during work.
Furthermore, depending on the thickness of the wall, the reinforcing bar in the concrete wall may become an obstacle, and the breaker tip does not reach the back, and may not be applicable.
Furthermore, since these devices are accompanied by vibrations, micro cracks are generated not only in the removal portion but also in the nearby concrete wall, so it is necessary to consider the influence such as a decrease in strength of the structure.

  Thus, since there are various problems in the method of crushing the periphery of the concrete wall through which the steel pipe penetrates, a method for crushing a part in the depth direction of the concrete wall through which the steel pipe penetrates to repair the steel pipe is, for example, patented It is proposed in Document 1. Patent Document 1 discloses a method for replacing a steel pipe for piping inside a concrete by hanging a wall around a steel pipe protruding from a concrete wall by an appropriate depth, and cutting a part of the steel pipe exposed by the fishing. Then, a new steel pipe is connected to the cut portion, and reinforcement is performed to ensure the plate thickness.

In addition to the repair of steel pipes, a water jet method in which ultra-high pressure water is injected from a nozzle is known as a method of crushing various objects in a civil engineering work site (see Patent Document 2).
Japanese Patent Application Laid-Open No. 64-30987 JP-A-6-170271

In the method of Patent Document 1, since the suspension is carried out only at a predetermined depth instead of penetrating the wall, it is possible to work with relatively simple equipment, and the wall is penetrated using a core cutter, a breaker, and a hammer drill. Thus, it seems that the above-described problems that occur when crushing are unlikely to occur.
However, in the case of Patent Document 1, the purpose is to repair the corrosion near the wall surface in the steel pipe with water transmitted through the wall in the first place, not for the purpose of repairing the corrosion deep inside the wall surface, Therefore, no disclosure has been made about the method of handling the case.

  In addition, since the water jet method described in Patent Document 2 is originally intended for crushing an object, even if the water jet method described in Patent Document 2 is used for crushing a wall through which a steel pipe passes, Although it is necessary to consider the special circumstances regarding whether or not to use in an aspect, Patent Document 2 does not disclose anything about it.

  In the above explanation, gas pipes (steel pipes) have been explained. However, as pipes that penetrate reinforced concrete walls, there are PVC pipes that are used in water pipes, etc., and even in the case of PVC pipes, deterioration inside the walls is confirmed. In addition, it is necessary to hang the reinforced concrete wall for repair.

  The present invention has been made to solve such a problem, and has a method of suspending around an existing pipe that penetrates a reinforced concrete wall that is excellent in workability and can hang concrete into the wall without damaging the rebar. It is intended to provide.

(1) The suspension method around an existing pipe according to the present invention is a suspension method around an existing pipe that penetrates a reinforced concrete wall, and a water jet is sprayed onto a reinforced concrete wall surface to reinforced concrete wall in a predetermined range around the pipe. The water jet has a hanging step and a hanging step by applying a striking force to the concrete. In the water jet, the water jet has a water jet pressure of 155 MPa to 255 MPa, and a flow rate of 15 L / min to 35 L / min, and the concrete is allowed to remain for a predetermined range around the pipe, and in the hitting process, the water jet applies hitting force to the concrete around the pipe remaining in the hanging process. To remove And it is characterized in and.

(2) Further, in the above described (1), the water jet is characterized in that the water jet is jetted by installing a plate material in a predetermined range around the pipe on the surface of the reinforced concrete wall in the hanging process. It is.

(3) In the above (1) or (2), the water jet suspending step is a step of performing a remote operation of the traveling carriage by fixing a water jet gun to the traveling carriage running around the pipe. It is characterized by having.

(4) In any one of the above (1) to (3), when the reinforced concrete wall penetrates by the water jet on the back side of the surface to which the water jet hits, water is prevented from leaking to the back side. It is characterized by having been cured for.
In addition, by performing such curing, the water jet also has an effect of preventing sound generated in the suspension process from leaking to the back side.

In the present invention, the predetermined range around the pipe is removed by water jet, and then the concrete remaining around the pipe is removed by applying a striking force. It is possible to remove only the concrete without giving it, and the concrete remaining around the pipe can be removed with a light striking force. For example, if the pipe is covered with a coating, the coating is damaged. There is nothing.
In addition, since the rebar is not cut, it is easy to recover the surroundings of the pipe, and since microcracks are not generated in the concrete wall in the vicinity of the hanger, there is no need to consider the effects such as strength reduction of the structure. There are various effects that construction is possible even in places where use is prohibited.

FIG. 1 is an explanatory view of a method of hanging around an existing pipe according to an embodiment of the present invention. In the example shown here, a steel pipe 5 (gas pipe) is connected to a reinforced concrete wall 3 of a pier where a reinforcing bar 1 is arranged. The steel pipe 5 in the case of penetrating is a case where it is suspended.
First, the equipment used for the fishing method around the steel pipe 5 according to the present embodiment will be described with reference to FIG.

As shown in FIG. 1, the equipment used is a high-pressure pump (not shown) for sending ultra-high pressure water to the water jet hand gun 7, and a water jet hand gun for injecting high-pressure water sent from the high-pressure pump. 7. Water supply truck (not shown) for supplying water to the high-pressure pump, submersible pump 9 for pumping the water sprayed to the concrete wall to the recovery tank of the water treatment facility, water treatment facility for processing the water collected in the recovery tank ( (Not shown).
In the present embodiment, a high-pressure pump having a pressure of 155 MPa to 255 MPa and a flow rate of 15 L / min to 35 L / min is used.

Next, the work procedure of the fishing method around the steel pipe 5 using the above-described equipment will be described.
<Preparation process>
Bring the equipment to be used to the work site. And the rubber sheet 11 is wound around the steel pipe 5 which protrudes from a wall surface, and the steel pipe 5 surrounding surface is cured. In addition, marking is performed to clarify the range in which the water jet is suspended.
This marking is a predetermined range around the steel pipe 5 as shown by oblique lines in FIG. At the same time, a square region of 70 × 70 cm is clarified in the periphery of the suspension, for example, in the radial direction of the steel pipe 5. Note that the range in which the water jet is hung varies depending on the diameter of the steel pipe, and may be set as appropriate depending on the diameter of the target steel pipe.

After the marking is completed, a framework for preventing water splashing is formed by a support pipe 13 in the work side space, and this framework is covered with a water splash curing sheet 15 to create an area serving as a work space. Further, a curing sheet 17 is installed on the ground so that the treated water is not sucked into the ground. And the submersible pump 9 for pumping the water collected on the sheet | seat 17 for curing is installed.
On the back side of the working side, a shielding plate 19 is installed to prevent water from splashing when the concrete wall penetrates by the water jet. The shielding plate 19 may be a simple one that covers, for example, the veneer plate 19a with the tin plate 19b. The curing sheet 17 is also installed on the ground on the back side. And the submersible pump 9 for pumping the water collected on the sheet | seat 17 for curing is installed similarly to the operation | work side.
The water scattering curing sheet 15 and the shielding plate 19 have an effect of preventing the leakage of the hanging sound in addition to the effect of preventing the water from scattering to the surroundings.
When the above preparation is completed, the operation of the devices is checked.

<Hanging process with water jet>
When the preparation process is completed, as shown in FIG. 3, the high-pressure water is jetted from the water jet hand gun 7, and the range marked in the preparation process is suspended. The water pressure at this time is 155 MPa to 255 MPa, and the flow rate is 15 L / min to 35 L / min. The reason for this range is as follows.
In the lifting operation, it is desirable that the concrete is crushed so as not to damage the rebar 1. Therefore, by setting the water jet pressure and flow rate within the above ranges, the concrete can be crushed and the suspension work that does not damage the rebar 1 can be performed.

  During the suspending operation, the jetted water is collected on the curing sheet, and this is collected by the submersible pump 9 in the collection tank of the water treatment device. And a flocculant is added in a water treatment apparatus, sedimentation processing is performed, it confirms that the sewer discharge standard value is cleared, and it discharges.

<Hand picking process>
With the water jet, the concrete having a thickness of about 5 cm is left around the steel pipe 5, and when the suspension work in a predetermined range around the steel pipe 5 is completed, the concrete having a thickness of about 5 cm remaining around the steel pipe 5 is lightly struck with, for example, a hammer. , Crack and remove the concrete. At the time of the concrete removing operation, care is taken not to damage the asphalt or polyethylene coating covering the steel pipe 5.

<Appearance inspection process>
The exposed steel pipe 5 is visually inspected, and the presence or absence of damage and corrosion due to the contact of the reinforcing bar 1 is confirmed.
If damage or corrosion is observed, a detailed survey will be performed and data such as a schematic drawing of the pipe body and photography will be taken.

<Repair process>
As a result of the appearance inspection, when it is confirmed that the rebar 1 is in contact with the steel pipe 5, a part of the contact portion is removed with a grinder or the like to eliminate the metal touch.
In addition, the part where damage such as peeling is seen in the coating is restored.
Furthermore, when corrosion is confirmed in the steel pipe 5 and it is determined that repair is necessary, repair work such as covering a half pipe is performed.

  As described above, in the present embodiment, the water jet handgun 7 is used to suspend a predetermined range around the steel pipe 5 by the water jet, and then the concrete remaining around the steel pipe 5 is removed by hand suspending. Therefore, only the concrete can be hung without damaging the rebar 1, and the concrete is removed by hand around the steel pipe 5, so that the asphalt or polyethylene covering the steel pipe 5 is coated. There is no hurt.

Further, if the work site has only the water jet hand gun 7, the work can be performed, which is suitable for work in a narrow space.
Further, if no vibration is generated, there is no risk of micro cracks in the concrete wall around the portion to be suspended.
Further, as long as the nozzle of the water jet hand gun 7 is appropriately selected, even if the wall thickness is thick, it can be removed to the back, and there is no restriction due to the wall thickness.
In addition, since the water jet blasts concrete with high-pressure water, sparks are not generated, and it can be safely constructed even when hanging around gas pipes that are prohibited from using fire.

  In the above-described embodiment, an example of a suspending operation using only water has been described. However, a suspending operation including the removal of the reinforcing bar 1 by mixing abrasive (garnet waste) with water to improve the cutting ability. It is also possible to perform.

  Further, in the above embodiment, an example of marking a range to be suspended depending on the water jet has been shown. However, for a predetermined range around the steel pipe 5 (for example, a range of 5 cm), for example, a veneer plate is used as the reinforced concrete wall 3. It may be installed on the surface so that the water jet does not directly hit the concrete. If it does in this way, it can prevent reliably that a water jet hits the radial direction predetermined range around the steel pipe 5, and it can prevent reliably that the coating of the steel pipe 5 is damaged.

[Embodiment 2]
In the first embodiment, the method of hanging around the steel pipe 5 that penetrates the pier portion made of reinforced concrete has been described. This embodiment relates to a method of hanging around a steel pipe 5 passing through a pit wall made of reinforced concrete.
4 and 5 are explanatory views for explaining the state of the steel pipe 5 penetrating the pit, FIG. 4 is a front view of the wall surface 21 in the pit, and FIG. 5 is a side sectional view.
As shown in FIG. 5, in the case of a steel pipe 5 (gas pipe) penetrating the pit, an extraction preventing plate 23 may be welded to the steel pipe 5. Therefore, in this case, as shown in FIG. 4, the range in which the concrete is hung by the water jet is extended to the outside of the steel pipe 5 in the radial direction 5 cm and to the outside of the extraction preventing plate 23.
The depth direction is up to the extraction preventing plate 23 (shaded portion in FIG. 5) or to a position where the reinforcing bar 1 can be confirmed beyond the extraction preventing plate 23.

The working process of the present embodiment is the same as that of the first embodiment. However, as described above, the present embodiment is different from the first embodiment in that it hangs without penetrating the wall surface 21 of the reinforced concrete.
As described above, according to the present invention, even when the extraction preventing plate 23 is installed, only the concrete is applied to the desired range without damaging the extraction preventing plate 23 and the reinforcing bar 1. The workability is extremely excellent.

[Embodiment 3]
FIG. 6 is an explanatory diagram of the third embodiment of the present invention, and the same reference numerals are given to the same parts as those in FIG. 1 showing the first embodiment. FIG. 6 shows a high-pressure pump 24 and a water treatment facility 25 that are not shown in FIG.
In the method of hanging around the steel pipe 5 according to the present embodiment, the work side and the back side are covered with a box 27 for preventing water scattering, and the water jet gun 29 is fixed to a traveling carriage 31 that moves around the pipe on the work side. By remotely operating the traveling carriage 31, the desired range of the reinforced concrete wall 3 can be accurately lifted.
First, the traveling carriage 31 will be described.

<Travel cart>
The traveling carriage 31 is hung around the carriage main body 33, the wheel 35 provided on the lower portion of the carriage main body 33 and rolling on the pipe circumferential surface, the carriage main body 33 and the steel pipe 5. And a chain 37 for restricting the traveling track, and a drive mechanism 39 for driving the wheels 35 by remote control. The drive mechanism 39 is connected to a gear transmission mechanism 41 for transmitting rotational force to the wheel 35, a remote operation cable 43 for transmitting drive rotational force to the gear transmission mechanism 41, and one end of the remote operation cable 43. A remote operation unit 45 that applies a rotational force to the operation cable 43 is provided.

In the traveling cart 31 configured as described above, when an operator turns a handle 47 provided in the remote operation unit 45, the rotational force is transmitted to the gear transmission mechanism 41 via the remote operation cable 43, and the wheel 35. Rotates, the traveling carriage 31 circulates around the steel pipe 5. Therefore, it is possible to make a cut at an accurate position around the steel pipe 5 by injecting the water jet from the water jet gun 29 while the traveling carriage 31 circulates around the peripheral surface of the steel pipe 5.
The mounting position of the water jet gun 29 with respect to the carriage main body 33 can be changed freely.

  Next, the work procedure of the suspension method around the steel pipe 5 according to the present embodiment will be described. In addition, since the cutting can be made at an accurate position around the steel pipe 5 by using the traveling carriage 31, as a suspending method that takes advantage of this feature, in this embodiment, the steel pipe 5 is used as a reinforced concrete wall to be hanged. A case where a predetermined range around the box is unboxed and no reinforcing bars are arranged in the range will be described as an example. In this case, the work procedure has different parts in the contents of the “preparation process” and the “working work process by water jet” described in the first embodiment, so these different parts will be described below.

<Preparation process>
The equipment to be used is carried into the work site, and after the rubber sheet 11 is wound around the steel pipe 5 protruding from the reinforced concrete wall 3 and cured, the traveling carriage 31 is installed on the steel pipe 5. At this time, the water jet gun 29 is oriented at a right angle to the wall surface, and is set at a position approximately 5 cm away from the outer peripheral surface of the steel pipe 5 in the radial direction.
After the traveling carriage 31 is set, boxes 27 for preventing water scattering are installed on the work side and the back side.

<Hanging process with water jet>
When the preparation process is completed, as shown in FIG. 6, ultra high pressure water is ejected from the water jet gun 29 and the handle 47 of the remote control unit 45 is operated to cause the traveling carriage 31 to travel on the circumferential surface of the steel pipe 5. Thus, a score line is made in the concrete wall at a position about 5 cm away from the circumferential surface of the steel pipe 5 in the radial direction of the steel pipe 5. The photograph shown in FIG. 7 is a photograph showing a state in which a cut line has been entered.

  Next, the installation position of the water jet gun 29 on the carriage main body 33 is changed to a position away from the circumferential surface of the steel pipe 5 by about 70 cm in the radial direction of the steel pipe 5. In the same manner as described above, ultra high pressure water is ejected from the water jet gun 29 and the handle 47 of the remote control unit 45 is operated to cause the traveling carriage 31 to travel on the circumferential surface of the steel pipe 5. A score line is made in the concrete wall at a position about 70 cm away from the 5 circumference. Then, when a cut line enters the position about 70 cm in the radial direction from the peripheral surface of the steel pipe 5, the traveling carriage 31 is removed from the steel pipe 5.

Next, a straight cut line is formed with the water jet hand gun 7 so as to connect a cut line at a position of about 5 cm in the radial direction from the peripheral surface of the steel pipe 5 and a cut line at a position of about 70 cm (within the boxed construction). Are inserted at predetermined intervals in the circumferential direction. By doing in this way, a concrete wall can be easily removed as a fan-shaped block.
The suspension method shown in the present embodiment is also effective for suspension when the concrete wall is boxed and resin-based rubber or resin-based mortar is filled between the pipe and the concrete wall. .

As described above, according to the work procedure of the present embodiment, the area for crushing concrete is extremely small, and work efficiency can be improved.
In addition, since the water jet gun 29 is attached to the traveling carriage 31 and the steel pipe 5 is caused to travel around, the steel pipe 5 can be cut into a predetermined position from the peripheral surface of the steel pipe 5 accurately and efficiently. Efficient work is possible without worrying about damaging the covering.

In the above description, an example in which a score line is made by traveling of the traveling carriage 31 at positions of about 5 cm and about 70 cm in the radial direction from the peripheral surface of the steel pipe 5 is shown. Only a 5 cm incision line may be entered by traveling of the traveling carriage 31, and then the predetermined range may be suspended by the water jet hand gun 7 in the same manner as described in the first embodiment.
In the above description, the gas pipe (steel pipe) has been described. However, as a pipe penetrating the reinforced concrete wall, there is a PVC pipe used in a water pipe or the like, and the deterioration in the wall also occurs in the case of the PVC pipe. In order to confirm and repair the work, it is necessary to work on a reinforced concrete wall. In this case, the same work as in the above embodiment can be performed.

It is explanatory drawing of the suspension method around the existing pipe of one embodiment of this invention. It is explanatory drawing of the hanging method around the existing pipe | tube of one embodiment of this invention, and is a figure which shows the range suspended depending on a water jet. It is explanatory drawing of the hanging method around the existing pipe of one embodiment of this invention, and is a figure which shows a working state. It is explanatory drawing of the hanging method around the existing pipe | tube of Embodiment 2 of this invention, and is a figure which shows the range suspended according to a water jet. It is explanatory drawing of the hanging method around the existing pipe | tube of Embodiment 2 of this invention, and is a figure which shows the range suspended according to a water jet. It is explanatory drawing of the hanging method around the existing pipe | tube of Embodiment 3 of this invention. It is explanatory drawing of the suspension method of the existing pipe circumference of Embodiment 3 of this invention, and is a photograph which shows the state in the middle of work.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reinforcement 3 Reinforced concrete wall 5 Steel pipe 7 Water jet hand gun 9 Submersible pump 11 Rubber sheet 13 Support pipe 15 Water scattering curing sheet 17 Curing sheet 19 Shielding plate 19a Plywood 19b Tin plate 21 Wall 23 Extraction prevention plate 24 High pressure pump 25 Water treatment Equipment 27 Box 29 Water jet gun 31 Traveling cart 33 Cart body 35 Wheel 37 Chain 39 Drive mechanism 41 Gear transmission mechanism 43 Remote operation cable 45 Remote operation unit 47 Handle

Claims (4)

It is a suspension method around an existing pipe that penetrates a reinforced concrete wall, and a water jet that injects a water jet onto a reinforced concrete wall surface and hangs a reinforced concrete wall in a predetermined range around the pipe gives a striking force to the concrete. In this case, the water jet has a suspension process, and the water jet has a water jet pressure of 155 MPa to 255 MPa, a flow rate of 15 L / min to 35 L / min, and a predetermined range around the pipe. The concrete is made to remain, and in the suspension process, the water jet removes the concrete by applying a striking force to the concrete around the pipe remaining in the suspension process. How to hang. 2. The method of suspending an existing pipe according to claim 1, wherein the water jet is sprayed by installing a plate material in a predetermined range around the pipe on the surface of the reinforced concrete wall in the suspending step. The water jet suspending step includes a step of performing a remote operation of the traveling carriage by fixing a water jet gun to a traveling carriage traveling around the pipe. How to hang. The curing method for preventing water from leaking to the back side when the reinforced concrete wall is penetrated by the water jet is provided on the back side of the surface on which the water jet strikes. The method of hanging around the existing pipe as described in the section.