JP2013087515A - Upper part removal method of left pile for earth retaining - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems that reduction of noise and vibrations is limited and a work environment becomes inferior causing decline of work efficiency in a method using a concrete breaker or the like, and it becomes impossible to execute construction depending on a position of a buried object because of a work device in a method of cutting and removal using a wire saw, in the case of removal construction of a left columnar object comprising reinforced concrete.SOLUTION: In a method of cutting and removing a left pile for earth retaining, a left columnar object upper part removal method by high pressure water includes: a boring step of boring a work hole from the upper end face; a high pressure water jetting step of inserting a high pressure water supply pipe to the work hole, jetting the high pressure water from a high pressure water jetting nozzle provided on the distal end thereof in an outer peripheral direction of a columnar object, and crushing a non-ferrous part of the left pile; a fusion cutting step of fusion-cutting the ferrous part of the left pile; and a removing step of taking out the cut-off upper part of the pile onto the ground.

Description

  The present invention relates to a method for removing an upper part of a residual pile for soil retaining, which is a columnar product made of concrete (including mortar) using a reinforcing bar or a shape steel as a core material.

  When constructing underground structures such as subway tunnels using the excavation method, prior to the construction of the underground structure, a retaining wall will be constructed on both sides of the construction site of the underground structure to prevent the sediment from flowing out. . As a method for constructing the retaining wall, there is a column-row pile retaining method in which the retaining piles are embedded in one row. The retaining piles that make up this retaining wall remain in the ground even after finishing the role of retaining soil after the construction of the underground structure. Need to be removed. Thus, it may often occur when it is necessary to remove the upper part of the remaining pile in the ground.

  Since such removal work is generally performed at night in consideration of traffic conditions and the like, it is required to suppress noise and vibration as much as possible so as not to affect surrounding residents. In addition, there are many underground buried objects such as communication lines represented by optical fiber cables in addition to water and sewage pipes and gas pipes in urban areas. Removal work must be performed while avoiding them, as well as cost reduction. Therefore, it is required to reduce the excavation area of the work space around the retained pile for soil retaining as much as possible.

  Conventionally, this type of construction has been done mainly by excavating around the residual pile for excavation with a power shovel, etc., with the upper part exposed, crushing the concrete of the residual pile for detention with a concrete breaker, and gassing the remaining steel bars. The procedure was to cut. However, in the case of this conventional method, there is a limit to reducing noise and vibration even if a soundproof panel is installed, and there is a problem that the working environment is poor due to the generation of dust, etc. There was a problem that the excavation area of the surrounding work space was large and the risk of damaging underground objects was high.

  In addition, as another method, there is a method of cutting and removing the upper removal portion of the retaining pile using a wire saw (Patent Document 1), but in this method, it is necessary to completely expose the retaining pile removal portion. For this reason, a large work space is required, and if there are buried objects around the pillars, it is difficult to secure the work space, and the construction itself may become impossible.

JP 2003-155746 A

  The problem to be solved by the present invention is to eliminate such problems of the conventional method. In other words, noise and vibration associated with construction methods using concrete breakers, etc., reduced work efficiency due to poor work environment, and risk of damage to underground objects resulting from the need for a large excavation area in the working space around the retaining pile It is. Also, in the case of the construction method using a wire saw, depending on the problem that it is necessary to completely expose the remaining pile removal part for retaining the earth to secure the work space, and depending on the position of the buried object due to work equipment construction The problem that this is impossible is the solution of the present invention.

In the present invention, the following technical means are taken in order to solve the above problems.
That is, the invention described in claim 1 includes a drilling step of drilling a work hole along the length direction of the remaining pile on the upper end surface of the remaining pile for earth retaining, and a high-pressure water supply pipe inside the work hole. A high-pressure water ejection process in which high-pressure water is ejected from the high-pressure water ejection nozzle provided at the tip of the remaining pile in the outer circumferential direction to crush the non-ferrous portion of the remaining pile, and the remaining pile remaining in the high-pressure water ejection process It is an upper removal method of the retained pile for soil retaining, which includes a fusing process of cutting the iron part with a burner and cutting the upper part of the remaining pile, and an upper removing process for taking out the upper part of the cut remaining pile on the ground.

  The invention according to claim 2 is characterized in that the high-pressure water supply pipe is rotatably installed around its axis, and jets high-pressure water while rotating the supply pipe. It is an upper part removal construction method of the left pile for earth retaining described in 1.

  Further, the invention described in claim 3 is the method of removing an upper part of the retained pile for earth retaining according to claim 1 or 2, wherein the high-pressure water supply pipe is rotated by a motor.

  According to a fourth aspect of the present invention, the tip of the high-pressure water supply pipe is installed rotatably about the axis of the high-pressure water supply pipe, and the high-pressure water is ejected while rotating the tip. It is the upper part removal construction method of the residual pile for earth retaining of Claim 1 characterized by the above-mentioned.

  Further, in the invention of claim 5, in the high-pressure water ejection step, a center position holding plate having the same diameter as the work hole and having a through hole in the center thereof is inserted into the work hole, 5. The upper part of the left pile for retaining soil according to claim 1, wherein a high-pressure water supply pipe is passed through the through hole, and the high-pressure water supply pipe is held on a central axis of the working hole. It is a removal method.

  According to the first aspect of the present invention, it is possible to reduce noise and vibration compared to a concrete breaker by drilling a work hole in the retained pile for retaining soil and ejecting high-pressure water from the work hole toward the outer peripheral direction. In addition, there is an effect that generation of dust and the like can be suppressed. Furthermore, since the remaining piles are destroyed from the inside, the work space for the construction is narrower than that of the wire saw, so there is less risk of obstructing the construction even if there are buried objects, resulting in shortening the construction period and construction costs. There is an excellent effect that it can be suppressed.

  In addition, there are two processes, a high-pressure water ejection process for crushing the non-ferrous part of the remaining pile and a fusing process for fusing the iron part of the remaining pile, thereby cutting the rebar in the high-pressure water. Compared with the case where the abrasive component is contained and cut in one step, the amount of high-pressure water can be greatly restricted, and the influence on the soil with the remaining pile can be reduced. In addition, the wastewater used can be easily treated, and it is not necessary to tighten the curing iron plate for preventing damage to the buried objects around the retained pile, and the effect of reducing the curing process can be reduced. is there

  According to the second aspect of the present invention, the high-pressure water supply pipe is rotatably installed around its axis, and the high-pressure water can be ejected while rotating the high-pressure water supply pipe. It is no longer necessary to process the high-pressure water processing apparatus having a pipe while moving around the remaining pile for soil retaining, and the crushing process of concrete or the like can be performed efficiently. Further, the same amount of concrete or the like can be crushed radially in any direction.

  According to the third aspect of the present invention, the high-pressure water supply pipe can be rotated at a high speed with a constant rotation by rotating the high-pressure water supply pipe with a motor, and the entire circumference of the remaining pile for earth retaining can be obtained. And concrete can be crushed evenly. In addition, because the crushing efficiency of concrete, etc. is constant, the amount of work can be accurately grasped by a simple method of managing work time, process management becomes easy, and the amount of high-pressure water supplied is controlled. It becomes easy to limit the amount of high-pressure water.

  According to the fourth aspect of the present invention, the tip of the high-pressure water supply pipe is rotatably installed around the axis of the high-pressure water supply pipe, and the high-pressure water is ejected while rotating the tip. A large output driving device for driving the entire supply pipe is not required. Especially when the high-pressure water supply pipe becomes long, the system can be simplified.

  According to the fifth aspect of the present invention, the center position holding plate having the same diameter as the work hole is inserted into the work hole, and the high-pressure water supply pipe is passed through the through hole at the center of the center position holding plate. Because the high-pressure water supply pipe is positioned on the central axis of the work hole, even if there is only one high-pressure water jetting point, it can be bent to the opposite side by the reaction force of the high-pressure water. The lifetime can be secured. Further, since the center position holding plate is provided near the tip of the high-pressure water supply pipe, the natural frequency of the high-pressure water supply pipe can be increased to prevent resonance.

It is the front view which showed the drilling process which drills the work hole of the residual pile for earth retaining which concerns on one Embodiment of this invention. It is the front view which showed the high pressure water ejection process which crushes the nonferrous part of the remaining pile among the cutting processes which concern on one Embodiment of this invention. It is the front view which showed the fusing process which cut | disconnects the reinforcement etc. which remain | survived in the residual pile for earth retaining which concerns on one Embodiment of this invention. It is the top view which showed the burial condition of the residual pile for earth retaining.

Embodiments specifically configured based on the above technical idea will be described below with reference to the drawings.

  FIG. 4 is a view of the state in which the retaining piles 1a and 1b constituting the retaining wall are embedded from above. Here, the remaining pile refers to a columnar pile made of concrete (including mortar) whose core material is a reinforcing bar or shaped steel. The left piles 1a and 1b for earth retaining are embedded in a row with a diameter of 400 mm and a length of 10 m or more. The inside of the retaining pile 1a is arranged with ten long reinforcing bars 2 along the axial direction on the same circumference of the circumference of the retaining pile as the main reinforcement, and at equal intervals in the axial direction. The structure is assisted by using a circular band reinforcing bar 2a. In addition, the retained pile 1b is made of concrete around the H-shaped steel 5, and some of the piles that make up the retaining wall are the retained pile 1b using a more rigid H-shaped steel. To do. By setting it as such a structure, the rigidity of the whole earth retaining wall can be improved. In addition, although the cross-sectional shape of the retained piles 1a and 1b is circular, it is not limited thereto, and includes those having a polygonal shape such as a quadrangle and a hexagon.

  FIG. 1 is a front view showing a drilling process for drilling the work hole 3 of the retained pile 1a for earth retaining according to the embodiment of the present invention. For example, it may be necessary to make the upper end surface 4 of the retained pile 1a around 1 m underground 1.5 m below the ground due to a change in city planning or the like. In the case of such construction, as shown in FIG. 1, first of all, the top of the retained pile for soil retaining is exposed, and in order to secure the working space for cutting and removing work, A groove having the same depth as that of the upper pile end face 4 is excavated along the row. Thus, in the case of construction in urban areas, it is necessary to make the groove width as small as possible due to the buried objects and make the groove depth as shallow as possible.

  The drilling device 100 including the drill main body 15 is installed so as to be adjacent to the exposed retaining pile 1a. In the drilling device 100, a column 11 with a rack is erected on a column base 12, and a drill carriage 13 to which a drill body 15 is fixed is provided on the column 11 with a rack so that the position of the drill carriage 13 can be operated up and down by a handle. It has become. A drill core 14 having the same diameter as the work hole 3 is attached to the drill body 15. Since the diameter of the soil retaining pile 1a is 400 mm, the size of the work hole 3 to be drilled is preferably about 200 mm.

  The drilling device 100 is fixed to an adjacent unsettled residual pile 1a by an anchor bolt. After the drill core 14 is rotated by the drill body 15, the operator lowers the drill carriage 13 using the handle of the drill carriage 13, so that the drill core 14 drills the predetermined work hole 3. It is necessary to make the depth of the working hole 3 longer than the length of the retaining pile for cutting and removing. In the subsequent process of jetting high-pressure water inside the pit, the concrete debris with high specific gravity generated by the process cannot be discharged depending on the flow of water, and it is necessary to temporarily accumulate the debris It is. In addition to the length of the length to be cut and removed, it is desirable to add a depth that can secure 1.3 to 1.5 times the volume of concrete crushing waste.

  When the drilling process of the work hole 3 is performed using the cylindrical drill core 14, noise vibration is significantly reduced as compared with a method using a concrete breaker. Although it is difficult to take countermeasures against vibrations in night city work, it is possible to reduce vibrations by using this drilling process. In addition to extending the life of the drill core 14 by supplying a small amount of cooling water to the work portion of the drill, it is also possible to suppress the generation of dust. In addition, since the perforation work can be performed only by exposing the top surface of the soil retaining pile 1a, the work can be performed regardless of whether there is an embedded object around the soil retaining pile 1a.

  In the case of the retained pile 1a, the work hole 3 is perforated in the center of the retained pile 1a. However, in the case of the retained pile 1b using H-shaped steel, the work hole 3 is 2 Perforate the book.

  FIG. 2 is a front view showing a high-pressure water ejection process according to an embodiment of the present invention. The high-pressure water ejection process is a process of crushing non-ferrous parts such as concrete by high-pressure water ejection. After finishing the drilling process, the drilling device 100 is removed and the high-pressure water processing device 200 is installed instead. In the high-pressure water processing apparatus 200, a column 11 with a rack is erected on a column base 12. The column 11 with a rack is provided with a supply pipe carriage 26 that rotatably fixes a high-pressure water supply pipe 24, and is supplied by a handle. The position of the tube carriage 26 can be moved up and down. High-pressure water from a high-pressure water generator (not shown) is supplied to the rotatable joint 27 above the supply pipe carriage 26 through a high-pressure hose 28, and the high-pressure water supply pipe 24 has an axis centered on the supply pipe carriage 26. It can rotate freely around the center. In addition, a supply pipe rotation motor 29 is installed in the supply pipe carriage 26, and the high-pressure water supply pipe 24 can be electrically rotated via a speed reducer in the supply pipe carriage 26. At the lower end of the high pressure water supply pipe 24 is a nozzle body 22 provided with a rectifier, in which the propulsion direction of the high pressure water is changed by 90 degrees. The nozzle body 22 is provided with one high-pressure water ejection nozzle 21 in the radial direction of the soil retaining pile 1a. The length of the high-pressure water jet nozzle 21 is desirably 50 mm or more in order to arrange the jet of high-pressure water.

  In this way, the high-pressure water supply pipe 24 is installed so as to be rotatable about its axis, and the high-pressure water can be ejected while the high-pressure water supply pipe 24 is rotated. It is not necessary to process the water processing apparatus 200 while moving around the soil retaining pile 1a, and the crushing process of concrete or the like can be performed efficiently. In addition, the same amount of concrete can be crushed radially in any direction.

  Further, by rotating the high-pressure water supply pipe 24 by the supply pipe rotation motor 29, the high-pressure water supply pipe 24 can be rotated at a high speed with a constant rotation, and evenly over the entire circumference of the soil retaining pile 1a. Concrete can be crushed. In addition, because the crushing efficiency of concrete, etc. is constant, the amount of work can be accurately grasped by a simple method of managing work time, process management becomes easy, and the amount of high-pressure water supplied is controlled. It becomes easy to limit the amount of high-pressure water.

  In the present embodiment, only one high-pressure water jet nozzle 21 is provided in the nozzle body 22 to reduce the amount of high-pressure water used. This is because the surrounding ground is not loosened by supplying an excessive amount of water. Therefore, there is a possibility that the high-pressure water supply pipe 24 is greatly deformed by the reaction force of the high-pressure water jet, so that the center position holding plate 23 having the same diameter as the work hole 3 is inserted into the work hole 3 and the center position is held. A high-pressure water supply pipe 24 is fitted into a through hole provided at the center of the plate 23. In addition, a supply pipe supporter 24 that maintains the positional relationship between the column with rack 11 and the high-pressure water supply pipe 24 is provided outside the work hole 3. The center position holding plate 23 is made of a material having a small specific gravity such as urethane, and is not between the high pressure water supply pipe 24 and the work hole 3 so as not to hinder the rotation when the high pressure water supply pipe 24 is rotated. A structure is provided with an appropriate gap. That is, the “same diameter” as that of the work hole 3 is smaller than the work hole 3 but has a clearance that does not allow the high-pressure water supply pipe 24 to be greatly touched. The number of high-pressure water jet nozzles 21 can be changed depending on the capacity of the high-pressure water generator and the amount of concrete crushed. When two nozzles are provided, it is desirable to provide them in the opposite direction of 180 degrees.

  In this way, the center position holding plate 23 having the same diameter as the work hole 3 is inserted into the work hole 3, and the high pressure water supply pipe 24 passes through the through hole in the center of the work hole 3. By being located on the central axis of the working hole 3, even when there is only one high-pressure water ejection point, it is not bent to the opposite side by the reaction force of the high-pressure water, and its life is reduced. Can be secured. Further, since the center position holding plate 23 is provided near the tip of the high-pressure water supply pipe 24 inside the work hole 3, it is possible to increase the natural frequency of the high-pressure water supply pipe 24 to prevent resonance. it can. In addition, in order to maintain the positional relationship between the rack-equipped column 11 and the high-pressure water supply pipe 24, by providing the supply pipe supporter 24 outside the work hole 3, the natural frequency of the high-pressure water supply pipe 24 can be increased and the high pressure can be increased. The water ejection process can be carried out stably.

  Further, the high-pressure water supply pipe 24 can be configured by adding supply pipes per unit length. Thereby, when the length of the removal part of the retained pile is long, a plurality of supply pipes are added and used as the high-pressure water supply pipe 24. In this case, instead of rotating the high-pressure water supply pipe 24 as a whole, the rotary universal joint 27 is provided at the lower end of the high-pressure water supply pipe 24 and the direction of the jet water from the high-pressure water jet nozzle 21 is shifted to thereby increase the pressure. It is also possible to cause the nozzle body 22 to rotate with the ejection of water. Further, when the high-pressure water supply pipe 24 is lengthened, it is preferable to provide a plurality of center position holding plates 23.

  In this way, the tip of the high-pressure water supply pipe 24 is installed so as to be rotatable about the axis of the high-pressure water supply pipe 24, and the entire high-pressure water supply pipe 24 is driven by ejecting high-pressure water while rotating the tip. This eliminates the need for a large output drive device. In particular, when the high-pressure water supply pipe 24 becomes long, the system can be simplified.

  Before performing the processing by the high-pressure water processing apparatus 200, an iron plate for curing is embedded in the side surface of the retained pile 1a so that the high-pressure water does not affect the surroundings. Thereafter, the high-pressure water processing apparatus 200 is first fixed to the adjacent unsettled retained pile 1a by an anchor bolt. The height of the high pressure water jet nozzle 21 is finely adjusted by a handle on the supply pipe carriage 26, and the high pressure water jet nozzle 21 is moved to a predetermined cutting position. By driving the supply pipe rotation motor 29, the high-pressure water supply pipe 24 including the high-pressure water jet nozzle 21 is rotated at a speed of about 20 times per minute. Thereafter, the high-pressure water from the high-pressure water generator is passed in the order of the high-pressure hose 28, the rotary universal joint 27, the high-pressure water supply pipe 24, and the nozzle body 22 with the rectifier in the radial direction of the residual pile 1a. The disc-shaped removal space 6 is formed by crushing the non-ferrous portion such as concrete of the retained pile 1a for earth retaining with the water pressure. As high-pressure water, about 18 [MPa] used for normal water jet work is supplied about 40 [l / min], and the supplied water is discharged from the upper part of the work hole 3 and the concrete crushing waste. Accumulates at the bottom of the working hole 3.

  Similarly, in the case of the retained pile 1b using H-shaped steel, the high-pressure water supply pipe 24 or the like is inserted into the two drilled holes, and the non-ferrous portion such as concrete is crushed with high-pressure water.

  In the high-pressure water jetting process that crushes concrete with high-pressure water, vibrations are significantly reduced as in the drilling process, and noise can be dealt with by taking local noise countermeasures. By using it, the generation of dust can be suppressed and the working environment can be prevented from deteriorating. In addition, since the concrete crushing apparatus 200 can be installed and crushing work such as concrete can be performed only by exposing the top surface of the soil retaining pile 1a, whether there are any buried objects around the soil retaining pile 1a. Work can be done regardless.

  FIG. 3 is a front view showing a fusing process for fusing the reinforcing bars 2 remaining in the retained pile 1a for earth retaining according to an embodiment of the present invention with gas. Reinforcing bars 2 remain in the retaining pile 1a for retaining the earth in which the disk-shaped removal space 6 is formed by the high-pressure water ejection process. Normally, the reinforcing bar 2 performs gas cutting from the work hole 3 using a gas cutting burner 31 with its tip bent.

  Such a fusing process from the work hole 3 can significantly reduce noise and vibration as in the drilling process and the high-pressure water jetting process. Moreover, no dust is generated and the working environment is not deteriorated. In addition, since the rebar 2 can be cut from the work hole 3 using the gas cutting burner 31 only by exposing the top surface of the retained pile 1a, the buried object around the retained pile 1a. Work can be done with or without.

  In addition, it is possible to incorporate abrasive components such as garnet in high-pressure water and to crush the non-ferrous portion of the retained pile 1a for soil retaining, but at the same time to break the iron portion, but unlike the non-ferrous portion, iron In order to break the portion, it is necessary to use high-pressure water several times as large as when the non-ferrous portion is broken. If high pressure water is used excessively in this way, the surrounding ground may loosen, causing ground subsidence, and in addition, it is necessary to collect wastewater containing abrasive components as industrial waste. In addition, there is a problem that the buried objects around the retained pile for soiling are damaged by high-pressure water. By providing two steps of a high-pressure water jetting step and a fusing step as in this embodiment, it becomes possible to suppress the amount of high-pressure water to be used, and a step of breaking the residual pile for soil retaining by containing an abrasive component Compared to the above, it is possible to prevent ground subsidence.

  In the case where all the removed portions of the soil retaining pile 1a can be exposed, it is possible to cut from the outer periphery with gas or with a cutting tool using a grindstone.

  Similarly, in the case of the retained pile 1b using the H-steel steel concrete 5, the gas cutting burner 31 is inserted through the two drilled work holes to cut the steel frame.

  When the cutting of the reinforcing bars is completed, the upper removed portion of the retained pile 1a or 1b is separated, and the portion is removed with an excavator or the like, and then backfilling is performed.

  As the embodiment of the invention, the soil retaining piles 1a and 1b are described in detail as being buried, but not only in the buried state but also in the soil retaining piles 1a and 1b exposed at the time of installation. On the other hand, by using the method according to the present invention, similar effects such as noise and vibration reduction and process shortening can be obtained.

1a Retained piles (using rebar)
1b Dwelling pile (using H-section steel)
2 Main Reinforcing Bar 2a Band Reinforcing Bar 3 Work Hole 4 Columnar Top End Surface 5 H-Shaped Steel 6 Disc Removal Space 11 Rack-equipped Column 12 Column Base 13 Drill Carriage 14 Drill Core 15 Drill Body 21 High Pressure Water Jet Nozzle 22 Nozzle Body 23 Center position holding plate 24 High pressure water supply pipe 25 Supply pipe supporter 26 Supply pipe carriage 27 Rotating joint 28 High pressure hose 29 Supply pipe rotating motor 31 Gas cutting burner 100 Punching device 200 High pressure water processing device

Claims (5)

A drilling step of drilling a work hole along the length direction of the remaining pile on the upper end surface of the remaining pile for earth retaining,
A high-pressure water ejection step for inserting a high-pressure water supply pipe into the working hole, and ejecting high-pressure water from the high-pressure water ejection nozzle provided at the tip of the working hole toward the outer periphery of the remaining pile to crush the non-ferrous portion of the remaining pile;
Fusing process of fusing the iron part of the remaining pile left in the high pressure water jetting process with a burner and cutting the upper part of the remaining pile,
An upper removal step of taking out the upper part of the cut remaining pile to the ground;
A method for removing the upper part of the remaining pile for soil retaining. The high-pressure water supply pipe is
2. The method for removing an upper part of a retaining pile for earth retaining according to claim 1, wherein the upper pile is installed so as to be rotatable about its axis, and high-pressure water is ejected while rotating the supply pipe. The rotation of the high-pressure water supply pipe is
The method for removing the upper part of the retained pile according to claim 1 or 2, wherein the method is performed by a motor. The tip of the high-pressure water supply pipe is
2. The method for removing an upper part of a retaining pile for earth retaining according to claim 1, wherein the upper pile is installed so as to be rotatable about the axis of the high-pressure water supply pipe, and high-pressure water is ejected while rotating the tip. In the high pressure water ejection step,
A center position holding plate having the same diameter as the working hole and having a through hole in the center thereof is inserted into the working hole,
Penetrating the high-pressure water supply pipe through the through hole,
5. The method for removing an upper part of a retaining pile for earth retaining according to claim 1, wherein the high-pressure water supply pipe is held on a central axis of the working hole.

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