Water jet nozzle device and foundation pile removal device

Abstract

To follow the cutting of an object to be cut and increase the cutting efficiency by supporting an injection nozzle movably.SOLUTION: A water jet nozzle device comprises a high-pressure hose 2 having an injection nozzle 3 at its tip for injecting a water jet at high pressure, and an adjustable pedestal connection group 5 which is fixed to the high-pressure hose 2 and to which a plurality of adjustable pedestals 4 are connected along the axial direction of the high-pressure hose 2. At side positions adjacent to the high-pressure hose 2, adjacent adjustable pedestals 4 are rotatably connected to each other by a rotation shaft 6 extending along a direction perpendicular to the axial direction of the high-pressure hose 2. A partial section of each adjustable pedestal 4 is fixed in a state of being fitted externally to the high-pressure hose 2 with respect to the axial direction of the high-pressure hose 2, so that the adjustable pedestal connection group 5 has a plurality of alternating fixed portions 7 and non-fixed portions 8 relative to the high-pressure hose 2.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a water jet nozzle device that sprays a water jet from a spray nozzle attached to the end of a high-pressure hose, and to a water jet nozzle device that enables the spray nozzle to be moved in a specific direction by spraying the water jet, and a foundation pile removal device. [Background technology]

[0002] Conventionally, methods for removing existing foundation piles buried in the ground include the edge cutting and extraction method and the crushing and removal method. Among these, the crushing and removal method is a method in which a casing having a cutting bit at the tip is rotated and inserted by a full-rotation rotating machine, the cutter bit attached to the tip of the rod is brought into contact with the outer circumferential surface of the foundation pile, the casing is rotated to cut the foundation pile to a predetermined length, and the cut upper end is grabbed and pulled up by suspending a hammer grab into the casing with a crawler crane. An example of a technology using this method is disclosed in Patent Document 1 below.

[0003] However, this crushing and removal method had the following issues. Because the crushing and cutting is done inside the underground casing, mechanical crushing and cutting is done with cutter bits that are in direct contact with the foundation piles, vibrations and noise are transmitted through the ground, affecting nearby residents, etc. Also, due to insufficient rotational reaction force during cutting, cutting takes time, the cutter bits bite into the foundation piles, bending the piles, and the casing is damaged by the rotational reaction force, etc.

[0004] One technique that can increase the efficiency of pile cutting while minimizing the impact of vibrations, noise, and other factors on the surrounding environment is the water jet method, in which water is sprayed at high pressure and speed, and the dynamic pressure, impact pressure, and water wedge effect of the jet are used to process the object to be cut. For example, the following Patent Document 2 discloses a method of using an existing pile cutting and extraction device which includes a casing having a larger diameter than the outer diameter of the existing pile, an excavation cutter attached to the lower end of the casing, a nozzle arranged directly above the cutter for spraying ultra-high pressure water in the direction of the center of the existing pile, a casing excavation device which excavates the casing into the ground so as to surround the existing pile while rotating the casing to a predetermined depth of the existing pile, an ultra-high pressure water supply pipe installed along the outer wall of the casing, and an ultra-high pressure water generator for supplying ultra-high pressure water to the pipe, in which the casing is excavated while rotating around the existing pile, and when the excavation has reached the predetermined depth, the excavation is stopped, and while rotating the casing, ultra-high pressure water is sprayed from the nozzle to cut the existing pile to a depth where it can be separated, and then the upper part of the cut existing pile is separated and pulled out. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-11551 A [Patent Document 2] JP 2002-138475 A Summary of the Invention [Problem to be solved by the invention]

[0006] As shown in Figure 1, the water jet in a water jet spreads from the upstream to downstream of the flow, and when cutting the workpiece, the initial region (in the case of repeated cutting, the continuous flow region of the main region) is used, so the nozzle standoff (the distance between the nozzle and the workpiece) is extremely important in the water jet method.

[0007] However, when cutting piles, if the jet nozzle is fixed to the casing, the distance between the jet nozzle and the cut surface of the pile increases as the pile cutting progresses, and the water jet hitting the cut surface of the pile transitions from the initial zone to the main zone, resulting in a problem of reduced cutting efficiency of the water jet. When removing foundation piles using a water jet, cutting is performed at an ultra-high pressure of 200 MPa, but if the nozzle is about 300 mm away from the object to be cut, cutting may not be possible due to the attenuation of the water jet.

[0008] Conventionally, movable nozzle structures have involved the use of telescopic cylinders, but this requires high manufacturing precision and is costly. The movable range is a straight line or arc via a cam, and requires a large width (casing thickness).

[0009] Therefore, the main object of the present invention is to provide a water jet nozzle device and a foundation pile removal device that can movably support the jet nozzle so that it can follow the cutting of the object to be cut and improve cutting efficiency. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention according to claim 1 provides a water jet device that includes a high-pressure hose having a nozzle at its tip for spraying a water jet at high pressure, and a variable seat connection group that is fixed to the high-pressure hose and has a plurality of variable seats connected along the axial direction of the high-pressure hose, At a side position adjacent to the high pressure hose, adjacent adjustable seats are rotatably connected to each other by a rotation shaft extending along a direction perpendicular to the axial direction of the high pressure hose, A water jet nozzle device is provided, characterized in that a portion of each adjustable base is fixed in an externally fitted state to the high-pressure hose in the axial direction of the high-pressure hose, and the adjustable base connection group has a plurality of alternating fixed and non-fixed portions relative to the high-pressure hose.

[0011] In the invention described in claim 1, a water jet nozzle device is configured by fixing a variable pedestal connection group, in which multiple variable pedestals are connected along the axial direction of a high-pressure hose, to a high-pressure hose equipped with an injection nozzle at its tip. Adjacent variable pedestals are rotatably connected to each other at side positions adjacent to the high-pressure hose by a rotation shaft extending along a direction perpendicular to the axial direction of the high-pressure hose. The variable pedestal connection group is fixed in a state in which a partial section of each variable pedestal is fitted onto the high-pressure hose in the axial direction of the high-pressure hose, so that multiple fixed and non-fixed parts relative to the high-pressure hose are provided alternately.

[0012] When the water jet is sprayed from the spray nozzle at high pressure, the outer diameter of the high-pressure hose expands due to the internal pressure, but since the variable pedestal is fitted to the fixed portion, the expansion of the high-pressure hose is restricted, and the adjacent non-fixed portion is stretched. Meanwhile, in the non-fixed portion, the outer diameter of the high-pressure hose expands due to the internal pressure, and as described above, the high-pressure hose is stretched due to the influence of the adjacent fixed portion. Here, since the variable pedestal connection group is fixed to the high-pressure hose at the fixed portion, and the adjacent variable pedestals are connected to the high-pressure hose by a rotating shaft at a side position adjacent to the high-pressure hose, each variable pedestal of the variable pedestal connection group rotates around the rotating shaft as the high-pressure hose expands and stretches at the non-fixed portion, thereby bending the high-pressure hose in a specific direction. As a result, the spray nozzle provided at the tip of the high-pressure hose becomes movable, and the spray nozzle follows the cutting of the cutting object, thereby improving the cutting efficiency by the water jet.

[0013] The present invention relates to claim 2, and there is provided a water jet nozzle device as described in claim 1, wherein the adjustable base connection group has, in the axial direction of the high-pressure hose, a section including the connection part connected by the rotating shaft which is the non-fixed part, and the other section is the fixed part.

[0014] In the invention described in claim 2 above, the high-pressure hose of the non-fixed part expands and stretches to move the adjustable base connecting group, so by providing a connecting part on the non-fixed part, rotation around the rotation axis of the connecting part becomes more likely to occur.

[0015] According to a third aspect of the present invention, there is provided the water jet nozzle device according to the first aspect, wherein the jet direction from the jet nozzle is a direction toward a side where the rotation shaft is located with respect to the high-pressure hose.

[0016] In the invention described in claim 3, the direction of the water jet when it is high-pressure sprayed from the spray nozzle provided at the tip of the high-pressure hose is the direction on the side where the pivot shaft is located with respect to the high-pressure hose. Normally, the high-pressure hose is bent and deformed in the opposite direction to the spray direction due to the spray pressure from the spray nozzle, but by providing the adjustable pedestal connection group, it becomes possible to bend and deform the high-pressure hose in the spray direction from the spray nozzle.

[0017] The present invention as claimed in claim 4 provides a water jet nozzle device as described in claim 1, in which an abrasive hose for spraying an abrasive together with the water jet from the spray nozzle is provided parallel to the high-pressure hose and adjacent to the direction in which the pivot shaft extends, and the adjustable base is fixed integrally to the high-pressure hose and the abrasive hose.

[0018] In the invention described in claim 4, when an abrasive hose for spraying an abrasive from a spray nozzle together with a water jet is provided, the abrasive hose is arranged parallel to the high-pressure hose and adjacent to it in the direction in which the rotation shaft extends, and the high-pressure hose and the abrasive hose are fixed together by the adjustable base. This allows the abrasive hose to deform in the same way as the adjustable base connection group deforms in response to the expansion of the high-pressure hose.

[0019] The present invention relates to claim 5, and there is provided a water jet nozzle device as described in claim 1, wherein the adjustable base is provided with a high-pressure hose insertion hole having an inner diameter equal to or smaller than the outer diameter of the high-pressure hose when not pressurized, and the high-pressure hose is fixed to the high-pressure hose by inserting the high-pressure hose through this high-pressure hose insertion hole.

[0020] In the invention described in claim 5 above, as a means for fixing the adjustable base to the high-pressure hose, a high-pressure hose insertion hole having an inner diameter equal to or less than the outer diameter of the high-pressure hose when not pressurized is formed in the adjustable base, and the high-pressure hose is fixed to the high-pressure hose by inserting the high-pressure hose into this high-pressure hose insertion hole.This allows the adjustable base to be securely fixed to the high-pressure hose and also reliably restrains expansion of the high-pressure hose at the fixed portion.

[0021] According to a sixth aspect of the present invention, there is provided a foundation pile removal device for removing an existing foundation pile buried in the ground, the device comprising a casing equipped with the water jet nozzle device according to any one of the first to fifth aspects, The casing is provided with a cutting bit for excavating ground at its tip, and the water jet nozzle device for spraying a water jet at high pressure toward the inward side at the tip portion is provided along the circumferential direction of the casing, A foundation pile removal device is provided, which is characterized in that the casing is inserted into the ground while being fitted around the foundation pile, and while the casing is stopped at a predetermined depth, the casing is rotated while spraying a water jet from the spray nozzle, thereby allowing the spray nozzle to move inward in response to the cutting of the foundation pile, thereby cutting the foundation pile horizontally.

[0022] The invention described in claim 6 above is an embodiment in which the water jet nozzle device is applied to a foundation pile removal device, and is applied as a cutting means for foundation piles in a crushing and removal method.

[0023] The present invention as claimed in claim 7 provides a foundation pile removal device as described in claim 6, in which a U-shaped portion opening inwardly along the circumferential direction of the casing is formed at the tip portion of the casing, and the water jet nozzle device is housed within this U-shaped portion.

[0024] In the invention described in claim 7 above, in order to prevent the water jet nozzle device from getting in the way when the casing is used to excavate ground, a U-shaped portion that opens inwardly along the circumferential direction of the casing is formed at the tip of the casing, and the water jet nozzle device is housed within this U-shaped portion.

[0025] According to an eighth aspect of the present invention, there is provided a foundation pile removal device for removing an existing foundation pile buried in the ground, the device comprising a casing equipped with the water jet nozzle device according to any one of claims 1 to 5, The casing is provided with a cutting bit for excavating ground at its tip, and the water jet nozzle device for spraying a water jet at high pressure toward the inward side at the tip portion is provided along the axial direction of the casing, A foundation pile removal device is provided, which is characterized in that the casing is inserted into the ground while being fitted around the foundation pile, and when the casing has penetrated to the lower end position of the foundation pile, a water jet is sprayed from the spray nozzle, causing the water jet nozzle device to bend inward, and the lower end of the foundation pile can be grasped and pulled out by the inwardly bent water jet nozzle device.

[0026] The invention described in claim 8 above is an embodiment in which the water jet nozzle device is applied to a foundation pile removal device, and is applied as a gripping means for the lower end of a foundation pile in a cutting and pulling out method.

[0027] The present invention as claimed in claim 9 provides a foundation pile removal device as described in claim 8, in which a U-shaped portion opening inward along the axial direction of the casing is formed at the tip portion of the casing, and the water jet nozzle device is housed within this U-shaped portion.

[0028] In the invention described in claim 9 above, in order to prevent the water jet nozzle device from getting in the way when the casing is used to excavate ground, a U-shaped portion that opens inward along the axial direction of the casing is formed at the tip of the casing, and the water jet nozzle device is housed within this U-shaped portion. Effect of the Invention

[0029] As described above in detail, according to the present invention, by supporting the jet nozzle movably, it is possible to follow the cutting of the object to be cut, thereby making it possible to improve the cutting efficiency. [Brief description of the drawings]

[0030] [Figure 1] FIG. 1 is an explanatory diagram of a flow velocity distribution concept. [Diagram 2] 1A shows a water jet nozzle device 1, in which (A) is a plan view, (B) is a side view, and (C) is a side view during high-pressure jetting. [Diagram 3] FIG. [Figure 4] 1 shows an adjustable base 4, in which (A) is a plan view, (B) is an end view, and (C) is a side view. [Diagram 5] FIG. [Figure 6] 1A and 1B show a foundation pile removal device according to a first embodiment, in which FIG. 1A is a vertical cross-sectional view and FIG. [Figure 7] 1 is a cross-sectional view showing the state in which the foundation pile 20 has been exposed. [Figure 8] FIG. [Figure 9] 10 is a cross-sectional view showing the process of removing the foundation pile 20. FIG. [Figure 10]2 is a vertical cross-sectional view of the tip portion of the casing 21. FIG. [Figure 11] 2 is a vertical cross-sectional view of the tip portion of the casing 21. FIG. [Figure 12] 10 is a cross-sectional view showing the process of removing the foundation pile 20. FIG. [Figure 13] 4 is a cross-sectional view showing a recovery process of the casing 21. FIG. [Figure 14] FIG. 4 is a vertical cross-sectional view showing a foundation pile removal device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0032] [Water jet nozzle device] As shown in Figure 2, the water jet nozzle device 1 of the present invention is composed of a high-pressure hose 2 having an injection nozzle 3 at its tip for injecting a water jet at high pressure, and an adjustable base connection group 5 fixed to the high-pressure hose 2 and having a plurality of adjustable bases 4, 4... connected along the axial direction of the high-pressure hose 2.

[0033] Adjacent adjustable seats 4 , 4 are rotatably connected to each other at side positions adjacent to the high-pressure hose 2 by a rotation shaft 6 extending along a direction perpendicular to the axial direction of the high-pressure hose 2 .

[0034] The adjustable base connection group 5 has multiple fixed portions 7 and non-fixed portions 8 alternately arranged relative to the high-pressure hose 2, with a portion of each adjustable base 4 being fixed in an externally fitted state to the high-pressure hose 2 in the axial direction of the high-pressure hose 2.

[0035] In the water jet nozzle device 1 according to the present invention, the jet nozzle 3 is moved in a specific direction by jetting water at high pressure from the jet nozzle 3, as shown in FIG. 2(C). Specifically, when high-pressure cutting water is supplied to the high-pressure hose 2, the high-pressure hose 2 expands due to the internal pressure, but since the variable pedestal 4 is fixed in a fitted state at the fixed portion 7, the expansion of the outer diameter is restricted, and the high-pressure hose 2 at the adjacent non-fixed portion 8 is stretched. Meanwhile, at the non-fixed portion 8, the high-pressure hose 2 expands due to the internal pressure, and the high-pressure hose 2 is stretched due to the influence of the fixed portion 7. In this way, the variable pedestal connection group 5 is intermittently fixed to the high-pressure hose 2 at the fixed portion 7, and the high-pressure hose 2 at the non-fixed portion 8 expands and stretches, so that each variable pedestal 4 of the variable pedestal connection group 5 rotates around the rotating shaft 6, bending the high-pressure hose 2 in a specific direction. The direction in which the high-pressure hose 2 is bent is the direction toward the side where the rotating shaft 6 arranged adjacent to the high-pressure hose 2 is provided. The above mechanism makes it possible for the jet nozzle 3 attached to the tip of the high-pressure hose 2 to be movable, enabling the jet nozzle 3 to follow the cutting of the object to be cut, thereby improving the cutting efficiency of the water jet.

[0036] Each component will be described in detail below. As shown in Figures 3 to 5, the adjustable base 4 has a block-shaped main body made of metal such as steel or aluminum or resin, and is formed in a substantially rectangular parallelepiped shape. A high-pressure hose insertion hole 10 through which the high-pressure hose 2 is inserted and an abrasive hose insertion hole 11 through which an abrasive hose 9 described below is inserted are disposed adjacent to each other in parallel, penetrating between two opposing faces of the main body. In addition, connecting portions 12 for connecting with adjacent adjustable bases 4 are formed at the lower portions of both end faces of the insertion holes 10 and 11, protruding outward from the main body.

[0037] 5, the adjustable base 4 is divided in the vertical direction by a plane passing through the center of the high pressure hose insertion hole 10 and the abrasive hose insertion hole 11, with the upper side forming an upper hose cover member 13 and the lower side forming a lower support member 14. That is, the upper hose cover member 13 is formed with the high pressure hose insertion hole 10 and the upper half of the abrasive hose insertion hole 11, and the lower support member 14 is formed with the high pressure hose insertion hole 10 and the lower half of the abrasive hose insertion hole 11.

[0038] To fix the adjustable base 4 to the high-pressure hose 2 and the abrasive hose 9, the high-pressure hose 2 and the abrasive hose 9 are placed in the lower half of the high-pressure hose insertion hole 10 and the abrasive hose insertion hole 11 of the lower support member 14, respectively, and the upper hose cover member 13 is then placed to clamp the high-pressure hose 2 and the abrasive hose 9 in the high-pressure hose insertion hole 10 and the abrasive hose insertion hole 11, respectively, and fixing bolts 15 such as hexagonal socket bolts are screwed into the bolt insertion holes 13a and threaded holes 14a provided on both sides of these.

[0039] The inner diameters of the high pressure hose insertion hole 10 and the abrasive hose insertion hole 11 are formed to be equal to or smaller than the outer diameters of the high pressure hose 2 and the abrasive hose 9 when no internal pressure is applied to each hose, and the adjustable base 4 is fixed to the high pressure hose 2 and the abrasive hose 9 in a state in which the high pressure hose 2 and the abrasive hose 9 are sandwiched between the lower support member 14 and the upper hose cover member 13 and fixed with fixing bolts 15. The portions of the high pressure hose 2 and the abrasive hose 9 sandwiched between the upper hose cover member 13 and the lower support member 14 form the fixed portion 7.

[0040] 4(B) and the like, the high pressure hose insertion hole 10 and the abrasive hose insertion hole 11 are disposed toward one side (upper side) with respect to the plane of the main body portion of the adjustable base 4 on which the opening ends of the insertion holes 10, 11 are formed, and the connecting portion 12 is formed on the other side (lower side) of these insertion holes 10, 11. In other words, with the high pressure hose 2 and the abrasive hose 9 inserted into the high pressure hose insertion hole 10 and the abrasive hose insertion hole 11, respectively, the connecting portion 12 is disposed at a side position adjacent to the high pressure hose 2 and the abrasive hose 9, and adjacent adjustable bases 4, 4 are connected to each other at this connecting portion 12. The connecting portion 12 is positioned so that there is almost no separation between the high-pressure hose 2 when it is not pressurized and so that it is in almost contact with the high-pressure hose 2 when it is not pressurized.This restricts the high-pressure hose 2 from expanding and deforming towards the connecting portion 12 when the high-pressure hose 2 is pressurized, and promotes the expanding and deforming in the opposite direction, making it easier for the high-pressure hose 2 to bend and deform.

[0041] 4(A), the connecting parts 12 are provided so as to protrude outward from two opposing faces on which the opening ends of the high pressure hose insertion hole 10 and the abrasive hose insertion hole 11 of the main body are formed, and the connecting part 12a provided on one face is disposed at the center, and the connecting parts 12b provided on the other face are disposed on both sides of the connecting part 12a on the one face, spaced apart by the length of the connecting part 12a on the one face. Also, each connecting part 12a, 12b is formed with a shaft insertion hole 12c through which the rotating shaft 6 can be inserted along a direction perpendicular to the axial direction of the high pressure hose insertion hole 10 and the abrasive hose insertion hole 11.

[0042] To connect adjacent adjustable pedestals 4, 4, the connecting portion 12a of one adjustable pedestal 4 is placed between the connecting portions 12b, 12b of the other adjustable pedestal 4, and the rotating shaft 6 is integrally inserted through the shaft insertion hole 12c formed in these connecting portions 12b, 12a, 12b, as shown in Figures 2(A) and 5. This allows the adjacent adjustable pedestals 4, 4 to be connected to each other so as to be rotatable about the rotating shaft 6.

[0043] In this way, the adjustable base 4 protrudes from a main body portion having a high-pressure hose insertion hole 10 and an abrasive hose insertion hole 11 to which the high-pressure hose 2 and the abrasive hose 9 are fixed, in the direction in which the high-pressure hose 2 and the abrasive hose 9 extend, forming the connecting portion 12.Since the adjustable base 4 is not fixed to the high-pressure hose 2 and the abrasive hose 9 at this connecting portion 12, as shown in Figure 2(B), when an adjustable base connection group 5 connecting multiple adjustable bases 4... is fixed to the high-pressure hose 2 and the abrasive hose 9, multiple fixed portions 7 and non-fixed portions 8 relative to the high-pressure hose 2 and the abrasive hose 9 are provided alternately.

[0044] The ratio of the lengths of the fixed portion 7 and the non-fixed portion 8 along the axial direction of the high-pressure hose 2 is preferably fixed portion 7:non-fixed portion 8=1 to 5: 1. By forming the fixed portion 7 to a length equal to or greater than that of the non-fixed portion 8, the adjustable pedestal 4 can be reliably fixed to the high-pressure hose 2 by the fixed portion 7, and deformation of the adjustable pedestal connection group 5 due to pressurization of the high-pressure hose 2 can be reliably performed.

[0045] In the adjustable base connection group 5, the section including the connecting portion 12 connected by the pivot shaft 6 in the axial direction of the high-pressure hose 2 is designated as a non-fixed portion 8, and the other section, i.e., the section in the main body portion of the adjustable base 4 where the high-pressure hose 2 and the abrasive hose 9 are sandwiched and fixed between the lower support member 14 and the upper hose cover member 13, is designated as a fixed portion 7, and these fixed portions 7 and non-fixed portions 8 are formed alternately in multiple places.

[0046] The adjustable pedestal connection group 5 is configured by connecting two or more adjustable pedestals 4, and is preferably configured of 30 or less, and more preferably 20 or less.

[0047] The injection nozzle 3 is provided at the tip of a mixing holder 16 to which the high-pressure hose 2 and the abrasive hose 9 are connected, and the cutting water pressurized through the high-pressure hose 2 and the abrasive fed through the abrasive hose 9 are mixed inside the mixing holder 16, and the cutting water mixed with the abrasive is sprayed as a water jet.

[0048] As shown in Fig. 2(B), the spray direction from the spray nozzle 3 is the direction towards the side where the rotating shaft 6 is located with respect to the high-pressure hose 2. In other words, the spray nozzle 3 is arranged at an angle so that the spray can be inclined towards the side where the rotating shaft 6 is located from the axial direction of the high-pressure hose 2. As shown in Fig. 2(C), the specific angle of inclination is 0<θ≦90°, preferably 20≦θ≦60°, where θ is the angle between the direction in which the axis of the high-pressure hose 2 extends and the direction in which the spray is from the spray nozzle 3.

[0049] The high-pressure hose 2 is a pressure-resistant hose through which cutting water at a high pressure of 10 to 40 MPa can be pumped by a high-pressure pump. The cutting water may be water alone or an aqueous polymer solution containing a highly water-absorbent polymer.

[0050] The superabsorbent polymer is a hydrophilic polymer particle having a crosslinked structure, has a water absorption capacity of about 10 to 500 times its own weight, and is characterized by being difficult to release water even when pressure is applied. The water absorption action of such a water-absorbent polymer is exerted by the osmotic pressure caused by the difference in ion concentration inside and outside the polymer. Therefore, the electric conductivity of the solvent mixed and stirred with the superabsorbent polymer can be adjusted by adding an electrolyte such as sodium chloride, and the mass ratio of absorbed water to the mass of the polymer particles (hereinafter referred to as water absorption ratio) can be changed. Note that water is used as the solvent, and tap water can be preferably used, particularly at cutting sites.

[0051] The type of superabsorbent polymer is not particularly limited, and it is preferably considered that the superabsorbent polymer is at least one type selected from the group consisting of starch-based, cellulose-based, and synthetic polymer-based polymers.

[0052] Among the above superabsorbent polymers, the synthetic polymer-based sodium polyacrylate superabsorbent polymer is particularly suitable for use because it is excellent in both performance and cost.

[0053] Sodium polyacrylate superabsorbent polymer is a gel of partially crosslinked acrylic acid polymer sodium salt with a three-dimensional network structure, which is lightly crosslinked by adding a crosslinking agent to sodium acrylate (CH2=CH-COONa). Conventionally known crosslinking agents can be used as the crosslinking agent.

[0054] It is known that when the superabsorbent polymer sodium polyacrylate absorbs water, the carboxyl groups dissociate sodium ions into a gel-like form, and in pure water, the polymer swells to a degree that is 100 to 1,000 times its own weight.

[0055] In addition, when the amount of crosslinking agent added to the sodium polyacrylate superabsorbent polymer is increased relative to the amount of sodium acrylate, the resulting gel becomes harder and absorbs less water, whereas when the amount of crosslinking agent added is decreased, the resulting gel becomes softer and absorbs more water.

[0056] Further, as a special sodium polyacrylate superabsorbent polymer, there can be mentioned the use of a sodium polyacrylate superabsorbent polymer having a double structure of a shell and a core, in which the surface of a superabsorbent polymer polymerized with a crosslinking agent is further crosslinked.

[0057] In the case of sodium polyacrylate superabsorbent polymer with a dual shell-core structure, the thicker the outer shell, the harder the gel becomes and the less water it absorbs, whereas a thinner shell makes the gel softer and increases the amount of water it absorbs.

[0058] In addition, the shell and the core are usually crosslinked by an ester bond, but there are also sodium polyacrylate superabsorbent polymers in which the shell and the core are crosslinked by an ether bond, which has excellent alkali resistance and electrochemical resistance. In the present invention, it is more preferable to use a sodium polyacrylate superabsorbent polymer in which the shell and the core are crosslinked by an ether bond.

[0059] In addition to the above characteristics, the dissociation of sodium ions in the superabsorbent polymer sodium polyacrylate also depends on the conditions under which the gel is placed, such as pH and electrolyte concentration, so other superabsorbent polymers can be appropriately selected and used depending on the conditions of use.

[0060] The concentration of the aqueous polymer solution can be appropriately adjusted depending on the water absorption performance of the highly water-absorbent polymer, the ion concentration of the absorbed water, and the properties of the object to be cut.

[0061] In general, the viscosity tends to be high when a high water-absorbing polymer with high water-absorbing performance is used, and the viscosity tends to be low when a high water-absorbing polymer with low water-absorbing performance is used. Therefore, it is desirable to set the concentration so as to obtain a polymer aqueous solution of the desired clay, taking into consideration the water-absorbing performance of the high water-absorbing polymer to be used. By using the polymer aqueous solution of this embodiment, the jet core region in the flow velocity distribution conceptual diagram shown in Figure 1 can be made longer, and cutting efficiency can be improved.

[0062] In addition, in order to adjust the water absorption rate of the water-absorbing polymer, an electrolyte such as sodium chloride may be added to the aqueous polymer solution.

[0063] The abrasive fed through the abrasive hose 9 can be, for example, a mineral-based abrasive such as sand, silica sand, or garnet. When cutting by adding an abrasive, different abrasives can be used depending on the part to be cut. That is, when cutting a concrete part, sand or silica sand can be used as the abrasive. On the other hand, when sand or silica sand is used as the abrasive, it is difficult to cut reinforcing bars. Therefore, it is preferable to use a mineral-based abrasive at least when cutting reinforcing bars embedded in concrete, that is, when cutting at least the outer periphery of a structure, since reinforcing bars are usually embedded in the outer periphery of a structure. Garnet, which is hard and highly durable, can be suitably used as this mineral-based abrasive. Incidentally, when cutting a concrete part, a mineral-based abrasive can also be used as the abrasive.

[0064] The particle size of the abrasive is not particularly limited, but considering the fluidity of the polymer aqueous solution to which the abrasive is added and the cutting ability of the abrasive, the average particle size D 50 In this case, the range of 320 to 570 μm is preferable.

[0065] Furthermore, in this embodiment, the abrasive-added polymer aqueous solution to which the abrasive is added may be directly sprayed, or the polymer aqueous solution consisting of a highly water-absorbent polymer and water may be mixed with the fluid abrasive prepared by adding the abrasive to the highly water-absorbent polymer that has absorbed water, and then mixed and sprayed at the tip of the spray nozzle. Such a mixed spray at the tip of the spray nozzle can be performed, for example, by using a nozzle with a double tube structure, by pumping the polymer aqueous solution into the inner tube and supplying the fluid abrasive to the outer tube, and then spraying the mixed solution. As the spray nozzle with the double tube structure, an abrasive nozzle generally used for cutting can be suitably used.

[0066] In addition, the highly absorbent polymer used in the above-mentioned fluid abrasive preferably has a small polymer particle size after absorbing water so that it does not easily separate after adding the abrasive.Specifically, a highly absorbent polymer having a polymer particle size of about 100 μm after absorbing water can be suitably used.By using a highly absorbent polymer having a small polymer particle size after absorbing water for the fluid abrasive, the fluid abrasive in which the abrasive is uniformly dispersed can be prepared.

[0067] The water jet nozzle device 1 configured as above is capable of bending the high-pressure hose 2 in a specific direction as shown in Fig. 2(C) by pumping cutting water into the high-pressure hose 2. The mechanism will now be described in detail.

[0068] When high-pressure water is pumped into the high-pressure hose 2, the outer diameter of the high-pressure hose 2 expands due to the internal pressure, and the hose length is shortened accordingly. For example, at a pressure of 20 MPa, the total length is shortened by about 4%.

[0069] However, at the fixed portion 7 of the adjustable base 4, the high-pressure hose 2 is inserted into a high-pressure hose insertion hole 10 having approximately the same diameter as the high-pressure hose 2, so the expansion of the high-pressure hose 2 is restricted. The energy that expands the high-pressure hose 2 is converted into energy that stretches the high-pressure hose 2 in the extension direction. Meanwhile, at the non-fixed portion 8, the outer diameter of the high-pressure hose 2 expands due to the internal pressure, and the high-pressure hose 2 stretches in the extension direction due to the effect of the fixed portion 7 described above.

[0070] The adjustable base connecting group 5 is fixed to the high-pressure hose 2 at the fixed portion 7, and adjacent adjustable bases 4, 4 are connected to each other so as to be freely rotatable by a pivot axis 6 at a side position adjacent to the high-pressure hose 2. As the high-pressure hose 2 expands and elongates at the non-fixed portion 8, each adjustable base 4 of the adjustable base connecting group 5 rotates around the pivot axis 6, thereby bending the high-pressure hose 2 in a specific direction.

[0071] Fifteen adjustable bases 4 were connected to form an adjustable base connected group 5, and each adjustable base 4 had a fixed portion 7 of 35 mm and a non-fixed portion 8 of 14 mm.When cutting water of 10 to 40 MPa was pumped into the high-pressure hose 2 with the fixed portion 7:non-fixed portion 8 ratio set to approximately 2.5:1, the displacement amount A (per 15 pieces), displacement amount a (per 1 piece), and expansion / contraction rate were measured. The displacement amount (per 15 pieces) A ​​is the displacement amount of the center position of the high pressure hose insertion hole 10 at the tip of the adjustable pedestal linkage group 5 relative to the center position of the high pressure hose insertion hole 10 at the base end of the adjustable pedestal linkage group 5, as shown in Figure 2 (C), and the displacement amount (per piece) a is a value obtained from a = A / (15 pieces - 1), and the expansion rate is a value obtained by measuring the length under no load and the length under pressure when the high pressure hose 2 is stretched without being attached to the adjustable pedestal linkage group 5 and is unconstrained, and then calculating (length under pressure - length under no load) / length under no load x 100%. The results are shown in Table 1.

[0072] [Table 1]

[0073] In addition, since the direction in which the water jet is ejected from the injection nozzle 3 is the direction in which the pivot shaft 6 is located with respect to the high-pressure hose 2, the high-pressure hose 2 bends in the direction of injection from the injection nozzle 3. Normally, the injection pressure from the injection nozzle causes the high-pressure hose to bend in the direction opposite to the injection direction, but by providing the adjustable pedestal connection group 5, it becomes possible to bend and deform the high-pressure hose 2 in the direction of injection from the injection nozzle 3. For this reason, the injection nozzle 3 can be moved in response to cutting of the workpiece by the water jet from the injection nozzle 3, so that the jet from the injection nozzle 3 can always hit the workpiece in a section suitable for cutting, improving the cutting efficiency of the water jet.

[0074] [Foundation pile removal device] An embodiment example in which the above-mentioned water jet nozzle device 1 is applied to a foundation pile removal device will be described. This foundation pile removal device includes a casing 21 equipped with the above-mentioned water jet nozzle device 1 in order to remove an existing foundation pile 20 buried in the ground. In addition to the casing 21, the following equipment includes heavy machinery such as a crawler crane or crawler crane, in which the casing 21 is attached to an auger that ascends and descends along a leader suspended from the tip, and penetrates into the ground while rotating the casing 21, a backhoe that excavates the ground surface to expose the upper end of the foundation pile 20, a high-pressure pump facility such as a high-pressure pump vehicle for pumping cutting water to the high-pressure hose 2 at high pressure, an agitator for agitating an abrasive, and a pump for feeding the agitated abrasive to the abrasive hose 9.

[0075] (First embodiment) In the first embodiment, the water jet nozzle device 1 is applied as a cutting means for foundation piles in a crushing and removal method. The casing 21 is provided with a plurality of cutting bits 22 for excavating the ground at intervals in the circumferential direction at the tip thereof as shown in Fig. 6, and the water jet nozzle device 1 for spraying water jets at high pressure inwardly is provided along the circumferential direction of the casing 21 at the tip portion of the casing 21 above the cutting bits 22.

[0076] The casing 21 has a U-shaped portion 23 formed at its tip portion along the circumferential direction and opening inward, and the water jet nozzle device 1 is housed in this U-shaped portion 23. The U-shaped portion 23 may be provided around the entire circumference of the casing 21, or may be provided only in the circumferential range in which the water jet nozzle device 1 is disposed.

[0077] The water jet nozzle device 1 is disposed with respect to the casing 21 such that the injection nozzle 3 faces inward and the rotation shaft 6 of the adjustable pedestal connection group 5 is located inward of the high-pressure hose 2. This allows the injection nozzle 3 to move inward when a water jet is injected from the injection nozzle 3, as shown in Fig. 6(B).

[0078] The water jet nozzle device 1 may be disposed in the casing 21 alone, or a plurality of water jet nozzle devices 1 may be disposed at intervals in the circumferential direction.

[0079] The high-pressure hose 2 and the abrasive hose 9 provided on the water jet nozzle device 1 extend to the ground along the outer wall of the casing 21 and are connected to a high-pressure pump equipment that pumps cutting water at high pressure and a pump that supplies abrasives, respectively.

[0080] The procedure for removing the foundation pile 20 using the foundation pile removal device will be described. First, as a preparation step, when removing the foundation pile 20, as shown in Fig. 7, the ground surface is excavated in advance with a backhoe or the like to expose the upper end of the existing foundation pile 20.

[0081] Furthermore, as shown in FIG. 8, the casing 21 is brought in and high-pressure pump equipment such as a high-pressure pump vehicle 30 for water jetting is installed.

[0082] As shown in FIG. 8, the casing 21 is attached to an auger that moves up and down along a leader suspended from the tip of heavy equipment 31 such as a crawler crane or crawler crane, and is rotated by the auger.

[0083] In addition, a jet nozzle (not shown) that sprays a water jet downward for cutting the ground may be provided at the tip of the casing 21, and used in combination with the cutting bit 22 to excavate the ground. This jet nozzle is provided separately from the jet nozzle 3 for cutting the foundation piles 20, and may spray only water or may spray an aqueous polymer solution containing a highly water-absorbent polymer.

[0084] When the above-mentioned preparation process is completed, a removal process is performed to remove the foundation piles 20. In this removal process, the following first to third steps are repeated to remove the entire length of the foundation piles 20.

[0085] In the first step, as shown in FIG. 9, the casing 21 is fitted around the foundation pile 20, and while rotating the casing 21 with the auger attached to the heavy equipment 31, the casing 21 is inserted into the ground.

[0086] In the second step, the casing 21 is stopped at a predetermined depth position, and as shown in Figure 10, the foundation pile 20 is cut horizontally by rotating the casing 21 while spraying an aqueous polymer solution containing a highly absorbent polymer together with an abrasive from the water jet nozzle device 1.

[0087] As described above, in the water jet nozzle device 1, when the high-pressure hose 2 expands due to internal pressure, the adjustable base 4 of the adjustable base connection group 5 rotates around the pivot axis 6 in response to the expansion and extension of the high-pressure hose 2 of the non-fixed part 8, thereby enabling the jet nozzle 3 to move toward the foundation pile 20, so that the jet nozzle 3 follows the cutting of the foundation pile 20, thereby improving the cutting efficiency by the water jet.

[0088] Such cutting of the foundation pile 20 by the water jet is performed over the entire cross section of the foundation pile 20. Also, as shown in Fig. 11, after cutting to a certain depth (radial position) by the water jet, a set of sear arrows 32 may be sandwiched between the foundation pile 20 and the casing 21 to cut the remaining cross section.

[0089] By adopting a cutting method using water jet technology, the impact on the surrounding environment, such as noise and vibration, can be kept extremely small compared to a method that cuts by mechanically contacting the foundation pile 20 directly. In addition, since there is no direct contact, the risk of casing damage and pile bending can be reduced.

[0090] Furthermore, because a viscous aqueous polymer solution is sprayed as the propellant for cutting piles, there is less diffusion due to air resistance compared to when water is sprayed, and the cutting ability is 1.5 to 2 times greater, improving cutting efficiency.

[0091] In addition, the inside of the drilled hole is filled with an aqueous polymer solution, also known as a drilling stabilizer, which improves the stability of the excavated ground compared to conventional bentonite-based stabilizers, forms a low-permeability layer early, and stabilizes the hole wall after the casing is removed.

[0092] In the third step, as shown in FIG. 12, the upper side of the cut foundation pile 20 is gripped with a hammer grab 33 and pulled upward for removal.

[0093] When the removal of the foundation piles 20 over their entire length is completed, the casing is recovered by pulling the casing 21 up to the ground using a crane device such as a crawler crane, as shown in Fig. 13. After the casing 21 is recovered, the hole is filled with the aqueous polymer solution used to cut the foundation piles 20, and this aqueous polymer solution protects the hole wall, preventing it from collapsing, and stabilizing the hole wall.

[0094] In the backfilling process, a separating agent is added to the aqueous polymer solution that has accumulated in the hole, causing the superabsorbent polymer that has absorbed and swollen to release water, and the hole is separated into water and mud containing the superabsorbent polymer that has released the water. This reduces the viscosity of the aqueous solution, causing the superabsorbent polymer to settle together with the adhering soil particles. Then, backfill soil is added as necessary to backfill the hole.

[0095] The separating agent has the effect of releasing water from a highly absorbent polymer that has absorbed water and swelled, and by adding divalent metal ions such as calcium chloride to increase the electrical conductivity of the solution, the water adsorbed in the polymer material is separated.

[0096] (Second embodiment) In the second embodiment, the water jet nozzle device 1 is applied as a gripping means for the lower end of a foundation pile in the edge cutting and extraction method. As shown in Fig. 14, a casing 21 in the second embodiment is provided with a plurality of cutting bits 22 for excavating the ground at intervals in the circumferential direction at its tip, and a water jet nozzle device 1 for spraying a water jet at high pressure inward is provided along the axial direction of the casing 21 at the tip portion of the casing 21 above the cutting bits 22.

[0097] The casing 21 has a U-shaped portion 23 formed at its tip end along the axial direction, the U-shaped portion 23 opening inwardly, and the water jet nozzle device 1 is housed within the U-shaped portion 23 .

[0098] The water jet nozzle device 1 is arranged so that the injection nozzle 3 faces inward and the rotation shaft 6 of the adjustable pedestal connection group 5 is located inward of the high-pressure hose 2. This makes it possible for the injection nozzle 3 to move inward when a water jet is injected from the injection nozzle 3, as shown in Fig. 14.

[0099] The water jet nozzle device 1 may be disposed in the casing 21 alone, or a plurality of water jet nozzle devices 1 may be disposed at intervals in the circumferential direction.

[0100] Regarding the procedure for removing the foundation pile 20 using the foundation pile removal device, as in the first embodiment described above, first, the casing 21 is brought into the construction site, and a preparatory process is carried out in which high-pressure pump equipment for the water jet is installed.

[0101] Next, similarly to the first embodiment, the casing 21 is inserted into the ground while being fitted around the foundation pile 20. The insertion of the casing 21 is continued up to the lower end position of the foundation pile 20, thereby separating the ground from the foundation pile 20. After that, with the casing 21 inserted up to the lower end position of the foundation pile 20, as shown in Fig. 14, a water jet is ejected from the ejection nozzle 3 to bend the water jet nozzle device 1 inward, and the lower end of the foundation pile 20 is gripped by the inwardly bent water jet nozzle device 1, and the foundation pile 20 is pulled out together with the casing 21. [Explanation of symbols]

[0102] 1...water jet nozzle device, 2...high pressure hose, 3...jet nozzle, 4...adjustable base, 5...adjustable base connection group, 6...rotating shaft, 7...fixed part, 8...non-fixed part, 9...abrasive hose, 10...high pressure hose insertion hole, 11...abrasive hose insertion hole, 12...connecting part, 13...upper hose cover member, 14...lower support member, 15...fixing bolt, 16...mixed water holder, 20...foundation pile, 21...casing, 22...cutting bit, 23...U-shaped part

Claims

1. A high-pressure hose having a nozzle at its tip for spraying a water jet at high pressure, and a variable seat connection group fixed to the high-pressure hose and having a plurality of variable seats connected along the axial direction of the high-pressure hose, At a side position adjacent to the high pressure hose, adjacent adjustable seats are rotatably connected to each other by a rotation shaft extending along a direction perpendicular to the axial direction of the high pressure hose, A water jet nozzle device characterized in that a portion of each adjustable base is fixed in an externally fitted state to the high-pressure hose in the axial direction of the high-pressure hose, such that the adjustable base connection group has a plurality of alternating fixed and non-fixed portions relative to the high-pressure hose.

2. The water jet nozzle device according to claim 1, wherein the adjustable base connection group has a section including a connection portion connected by the rotating shaft in the axial direction of the high-pressure hose as the non-fixed section, and the other section as the fixed section.

3. 2. The water jet nozzle device according to claim 1, wherein the direction of jet from the jet nozzle is a direction toward a side of the high-pressure hose where the pivot shaft is located.

4. 2. The water jet nozzle device according to claim 1, wherein an abrasive hose for spraying an abrasive together with the water jet from the spray nozzle is provided parallel to the high-pressure hose and adjacent to the direction in which the pivot shaft extends, and the adjustable base is fixed integrally to the high-pressure hose and the abrasive hose.

5. The water jet nozzle device of claim 1, wherein the adjustable base has a high-pressure hose insertion hole having an inner diameter equal to or smaller than the outer diameter of the high-pressure hose when not pressurized, and is fixed to the high-pressure hose by inserting the high-pressure hose into this high-pressure hose insertion hole.

6. A foundation pile removal device for removing an existing foundation pile buried in the ground, comprising a casing equipped with the water jet nozzle device according to any one of claims 1 to 5, The casing is provided with a cutting bit for excavating ground at its tip, and the water jet nozzle device for spraying a water jet at high pressure toward the inward side at the tip portion is provided along the circumferential direction of the casing, This foundation pile removal device is characterized in that the casing is inserted into the ground while being fitted around the foundation pile, and while the casing is stopped at a predetermined depth, the casing is rotated while spraying a water jet from the spray nozzle, thereby allowing the spray nozzle to move inward in response to the cutting of the foundation pile, thereby cutting the foundation pile horizontally.

7. A foundation pile removal device as described in claim 6, wherein a U-shaped portion opening toward the inward side is formed at the tip portion of the casing along the circumferential direction of the casing, and the water jet nozzle device is housed within this U-shaped portion.

8. A foundation pile removal device for removing an existing foundation pile buried in the ground, comprising a casing equipped with the water jet nozzle device according to any one of claims 1 to 5, The casing is provided with a cutting bit for excavating ground at its tip, and the water jet nozzle device for spraying a water jet at high pressure toward the inward side at the tip portion is provided along the axial direction of the casing, This foundation pile removal device is characterized in that the casing is inserted into the ground while being fitted around the foundation pile, and when the casing has penetrated to the lower end position of the foundation pile, a water jet is sprayed from the spray nozzle, causing the water jet nozzle device to bend inward, and the lower end of the foundation pile can be grasped and pulled out by the inwardly bent water jet nozzle device.

9. A foundation pile removal device as described in claim 8, wherein a U-shaped portion opening inward along the axial direction of the casing is formed at the tip portion of the casing, and the water jet nozzle device is housed within this U-shaped portion.

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