JP5303677B1 - Drilling and stirring shaft joint - Google Patents

Abstract

Provided is a joint shaft of an excavation stirring shaft that can surely prevent outflow of a solidified material and can prevent marine contamination by the solidified material in advance.
An excavation agitation shaft that is supported so as to be movable up and down along a leader standing on a hull, a drive unit that moves the excavation agitation shaft up and down, and a plurality of short joints that are added to the excavation agitation shaft. A shaft 30 is provided, and on the hull, a plurality of joint shafts are sequentially added to an upper end portion of the excavation stirring shaft and an upper end portion 33 of the joint shaft 30 that is added to the upper end portion of the excavation stirring shaft. The excavation agitation shaft can be freely penetrated, the solidification material is discharged and injected into the improved ground from the discharge port of the excavation agitation shaft, and the excavated soil and the solidification material in the improved ground are agitated and mixed to solidify the solidification material. A joint shaft 30 of an excavation stirring shaft used in a ground improvement device for creating an improved pile, which is provided so as to pass through a flow path 32 for supplying a solidified material from the upper end to the lower end of a shaft body 31 of the joint shaft 30. A switching valve that opens and closes the flow path 32 at the bottom of the main body 31 35 is provided.
[Selection] Figure 6

Description

  INDUSTRIAL APPLICABILITY The present invention is suitable for use in a ground improvement device for offshore construction, in which a solidified material such as cement slurry or cement milk is poured into the ground and mixed with the excavated soil and the solidified material is solidified to improve the ground. It relates to the joint shaft.

  In general, in a ground improvement device for ground agitation type ground construction, a long excavation agitation shaft of, for example, several tens of meters according to the required improvement length is arranged in the vertical direction, and the excavation agitation shaft is penetrated or pulled out. At that time, a solidified material such as cement slurry and cement milk was discharged and injected into the ground, and the excavated soil and the solidified material were agitated and mixed to solidify the solidified material to form an improved pile.

  However, in places where there are height restrictions, such as under bridges or under tower towers, it is impossible to construct with a long excavating stirring shaft, so a combination of multiple short shafts is used. (For example, see Patent Document 1).

  In the ground improvement device described in Patent Document 1, a stirring blade is attached to the tip of the lowermost stirring rod, and a plurality of additional short rods are connected to the upper end of the stirring rod by a joint. The solidification material such as cement slurry and cement milk was injected into the ground from the discharge port opened at the tip of the stirring rod at the lowest position, mixed with the excavated soil, and the ground was improved by solidifying the solidified material. .

JP 2010-1694 A

  A short rod as a joint connected to a stirring rod used in the conventional ground improvement device is provided with a flow path for supplying a solidifying material therein, and a valve for opening and closing the flow path is provided. When the short rod is added during the ground improvement or when the short rod is removed after the ground improvement is completed, the solidified material in the flow path provided in the extension rod will be exposed to the outside. There was a risk of spillage. In particular, when it is necessary to consider the environmental impact and the construction is carried out at a place where the height is restricted, the sea is contaminated by the solidified material that has flowed outside, and it is necessary to take measures against it.

  Accordingly, the present invention has been made to solve the above-described problems, and can reliably prevent the solidification material from flowing out from the flow path of the added shaft body when the solidification material is not supplied. It is an object of the present invention to provide a joint shaft of a drilling and stirring shaft that can reliably prevent marine pollution due to wood.

According to a first aspect of the present invention, there is provided an excavation stirring shaft supported so as to be vertically movable along a leader erected on the hull, a driving device for moving the excavation stirring shaft up and down, and an addition to the excavation stirring shaft. A plurality of short joint shafts, and on the hull, the short joint shaft is connected to the upper end portion of the excavation stirring shaft and the upper end portion of the short joint shaft added to the upper end portion of the excavation stirring shaft. The excavation agitation shaft is allowed to penetrate to a predetermined depth of the improved ground in the sea while successively connecting a plurality of pipes, and the solidified material is discharged and injected into the improved ground from the discharge port of the excavation agitation shaft. A joint shaft of a drilling stirring shaft used in a ground improvement device in which excavated soil and the solidified material are stirred and mixed to form an improved pile by solidification of the solidified material, the upper end of the shaft main body of the joint shaft Supply the solidified material vertically from the bottom Provided so as to penetrate through the one channel in terms circular hole shape, and the shaft to form a circular cross section hole to be perpendicular to the flow path in the lower part of the body, the flow in cylindrical in this section in a circular hole provided sWITCHING valve having one flow hole in the road the same shape rotatably, the switching valve be to a predetermined angle rotation, the the flow hole of said switching valve and a flow path of said shaft body An operation part for switching and switching the switching valve is provided at least at one end of the cylindrical switching valve, and the operation part is integrated so as to be exposed in a circular hole in the cross section of the shaft body. It is formed .

According to a second aspect of the present invention, there is provided an excavation agitation shaft that is supported so as to be vertically movable along a leader standing on the hull, a drive unit that moves the excavation agitation shaft up and down, and a digging agitation shaft. A plurality of short joint shafts, and on the hull, the short joint shaft is connected to the upper end portion of the excavation stirring shaft and the upper end portion of the short joint shaft added to the upper end portion of the excavation stirring shaft. The excavation agitation shaft is allowed to penetrate to a predetermined depth of the improved ground in the sea while successively connecting a plurality of pipes, and the solidified material is discharged and injected into the improved ground from the discharge port of the excavation agitation shaft. A joint shaft of a drilling stirring shaft used in a ground improvement device in which excavated soil and the solidified material are stirred and mixed to form an improved pile by solidification of the solidified material, the upper end of the shaft main body of the joint shaft Supply the solidified material vertically from the bottom Provided so as to penetrate through the one channel in terms circular hole shape, and the shaft to form a circular cross section hole to be perpendicular to the flow path in the lower part of the body, the flow in cylindrical in this section in a circular hole provided sWITCHING valve having one flow hole in the road the same shape slidably, the switching valve by causing a predetermined length sliding and the flow hole of said switching valve and a flow path of said shaft body An operation part for switching and switching the switching valve is provided at least at one end of the cylindrical switching valve, and the operation part is placed in a circular hole in the cross section of the shaft body. It is exposed so as not to protrude outward from the surface .

As described above, according to the first and second aspects of the invention, the cross-sectional circular hole for supplying the solidifying material in the vertical direction from the upper end to the lower end of the shaft body of the joint shaft passes through one flow path. And a switching valve that opens and closes the flow path at the bottom of the shaft body, so that the switching valve is closed when adding or removing a short joint shaft. It is possible to reliably prevent the solidified material from flowing out of the flow path, and to prevent marine contamination by the solidified material in advance. As a result, it is possible to safely and safely carry out sea construction even in places with height restrictions such as sea areas around airports where there is a need to consider environmental impact and there are air restrictions.

Further, according to the invention of claim 1, to form a circular cross section hole to be orthogonal to the flow path in the lower portion of the shaft body, the one flow path isomorphic with cylindrical this section the circular hole distribution By providing a switching valve with a hole so that it can rotate, and by rotating the switching valve by a predetermined angle, the flow hole of the switching valve and the flow path of the shaft main body are communicated with each other or closed. With a simple structure, the flow hole of the switching valve and the flow path of the shaft body can be reliably opened and closed.

Further, according to the invention of claim 2, to form a circular cross section hole to be orthogonal to the flow path in the lower portion of the shaft body, the one flow path isomorphic with cylindrical this section the circular hole distribution By slidably providing a switching valve having a hole, and by sliding the switching valve for a predetermined length, the flow hole of the switching valve and the flow path of the shaft main body are communicated or blocked. With a simple structure, the flow hole of the switching valve and the flow path of the shaft body can be reliably opened and closed.

Furthermore, according to the first aspect of the present invention, an operation portion for switching the switching valve is provided at at least one end of the cylindrical switching valve, and the operation portion is integrated so as to be exposed in the circular hole in the cross section of the shaft body. By forming, the opening and closing of the flow hole of the switching valve and the flow path of the shaft main body can be easily and reliably performed by the operation portion. According to the invention of claim 2, the operation portion is circular in cross section of the shaft main body. In addition to being able to open and close the flow hole of the switching valve and the flow path of the shaft body easily and reliably in the hole of the shaft body, it is exposed so as not to protrude outward from the outer peripheral surface of the shaft body . The operation unit does not jump out and get in the way .

It is a side view which shows the work ship provided with the ground improvement apparatus in the bow of embodiment of this invention. It is a front view of the work ship provided with the said ground improvement apparatus. It is a fragmentary perspective view of the joint axis | shaft of the drive machine used for the said ground improvement apparatus. It is a fragmentary perspective view which shows the state which connected the short joint shaft to the joint axis | shaft of the said drive machine. It is a front view of the biaxial excavation stirring shaft used for the ground improvement device. It is a perspective view of the said short joint shaft. It is a fragmentary perspective view which shows the state by which the flow path of the said short joint shaft was closed. It is a perspective view which shows the state before fixation of the fixing jig which prevents the fall of the said short joint shaft from the hull. It is a perspective view which shows the state which fixed the short joint shaft with the said fixing jig. It is a perspective view which shows the initial state of the sea construction by the said ground improvement apparatus. It is a perspective view which shows the state which fixed the joint shaft with the fixing jig after driving down the said drive machine and driving in the short joint shaft. It is a perspective view which shows the state which cut | disconnected a short joint shaft from the coupling shaft of the said drive machine, and raised the drive machine. It is a perspective view which shows the state which moved the axis | shaft storage stand just under the joint axis | shaft of the said drive machine. It is a perspective view which shows the state which connected the joint shaft accommodated in the axis | shaft accommodation stand to the joint axis | shaft of the said drive shaft. It is a perspective view which shows the state which raised the drive machine which connected the said joint shaft. It is a perspective view which shows the state which returned the said axis | shaft accommodation stand to the original position. It is a perspective view which shows the state which released the fixation of the fixing jig after connecting the joint shaft connected to the joint axis | shaft of the said drive machine, and the joint shaft fixed to the fixing jig. It is a perspective view which shows the state which drives the joint shaft which lowered | hung the said drive machine and added. It is a perspective view of the short joint shaft which has the switching valve of other forms. (A) The fragmentary perspective view which shows the state where the flow path of the short joint shaft was closed by the switching valve of another form, (b) is the state where the flow path of the short joint shaft was opened by the switching valve. It is a fragmentary perspective view shown.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view showing a work ship equipped with a ground improvement device at the bow of the embodiment of the present invention, FIG. 2 is a front view of the work ship equipped with the ground improvement device, and FIG. 3 is used in the ground improvement device. 4 is a partial perspective view of a joint shaft of a driving machine, FIG. 4 is a partial perspective view showing a state in which a short joint shaft is connected to the joint shaft of the driving machine, and FIG. 5 is a two-shaft excavation and stirring used in the ground improvement device. FIG. 6 is a perspective view of the short joint shaft, FIG. 7 is a partial perspective view showing a state in which the flow path of the short joint shaft is closed, and FIG. 8 is a view from the hull of the short joint shaft. FIG. 9 is a perspective view showing a state in which a short joint shaft is fixed by the fixing jig, and FIGS. 10 to 18 are views of the sea by the ground improvement device. It is a perspective view which shows the state of construction later on.

  As shown in FIGS. 1 and 2, the ground improvement device 10 is provided on the bow 2 a of the hull 2 of the work boat 1, and is located under the sand mat B in the sea A by two excavation stirring shafts 20 and 20. The improved ground C is excavated, the excavated soil D and the solidified material E such as cement slurry and cement milk are stirred and mixed, and the improved pile F is formed by solidifying the solidified material E. .

  On both the left and right sides of the front end side and the rear end side of the hull 2, a spud 3 having a bottom plate 3 a that descends to the sand mat B and maintains the balance of the hull 2 is provided so as to freely move up and down. A pair of ballast water tanks 4 and 4 for maintaining the balance of the hull 2 are provided on the left and right sides on the rear side of the hull 2. Furthermore, a winch 5, a grout pump 6, a slurry plant 7, a silo 8, and a water tank 9 are provided in the center of the hull 2 from the front side to the rear side. In this offshore construction line, the solidified material E such as cement slurry and cement milk generated in the slurry plant 7 is supplied to the excavation stirring shaft 20 by the grout pump 6 via the joint shaft 13 of the auger (driving machine) 12. It is like that.

  As shown in FIG. 1 and FIG. 2, the ground improvement device 10 includes two excavation and stirring shafts 20 that are supported so as to be vertically movable along a leader 11 erected vertically on the bow 2 a of the hull 2. 20, a pair of augers (driving machines) 12, 12 that raise and lower the two excavation stirring shafts 20, 20, a plurality of short joint shafts 30 that are added to each excavation stirring shaft 20, A shaft storage stand 40 for storing the short joint shafts 30, 30 standing upright and a fixing jig 50 for preventing the digging and stirring shaft 20 from falling from the hull 2 are provided.

  Then, on the hull 2, a plurality of short joint shafts 30 are sequentially added to the upper end portion of each excavation stirring shaft 20 and the upper end portion of the short joint shaft 30 added to the upper end portion of the excavation stirring shaft 20. The two excavation stirring shafts 20 and 20 can be freely penetrated to a predetermined depth of the improved ground C of A, and the solidified material E is discharged into the improved ground C from the discharge ports 26 of the two excavation stirring shafts 20 and 20. The excavated soil D and the solidified material E in the improved ground C are agitated and mixed, and the solidified material E is solidified to form the improved pile F. In addition, the height from the upper end of the leader 11 to the sea surface is set within, for example, 15 m, and construction can be performed even in places with height restrictions such as sea areas around airports where there are air restrictions.

  As shown in FIG. 1, each auger 12 moving up and down along the front surface 11 a of the leader 11 is connected to a wire 5 a wound on the base end side of the winch 5, and each auger 12 is driven by driving the winch 5. It moves up and down along the leader 11. Each auger 12 is provided with a joint shaft 13 for connecting the upper end portion of the short joint shaft 30, and each joint shaft 13 is rotated by a motor and a gear mechanism (not shown) incorporated in the auger 12. Yes.

  As shown in FIGS. 3 and 4, the joint shaft 13 provided in each auger 12 is formed in a columnar shape having a flow path 13 a having a circular cross-sectional shape for supplying the solidified material E at the center thereof. In addition, a circular hole 13b having a larger diameter than that of the flow path 13a is formed in the upper part of each joint shaft 13 so as to be orthogonal to the flow path 13a. A switching valve 15 having a flow hole 15a having the same shape as the passage 13a is rotatably provided.

  A hexagonal column-shaped operation portion 15 c for switching the switching valve 15 is integrally formed at one end 15 b of the cylindrical switching valve 15. The hexagonal column-shaped operation portion 15 c protrudes outward from the hole 13 b having a circular cross section of the joint shaft 13. Then, by operating this operation portion 15c and rotating the switching valve 15 by 90 °, the flow hole 15a of the switching valve 15 and the flow path 13a of the joint shaft 13 are communicated with each other as shown in FIG. As shown in FIG. 3, the flow path 13a can be closed by closing the flow hole 15a of the switching valve 15 with respect to the flow path 13a of the joint shaft 13 as shown in FIG. Yes.

  Furthermore, a hexagonal concave engaging recess 13c is provided at the lower end of the joint shaft 13 to be fitted to the hexagonal convex locking convex 33 at the upper end of the short joint shaft 30. Further, a pair of through holes 13e and 13e having a circular cross section are formed at the lower end of the joint shaft 13 so as to form grooves 13d having a semicircular cross section on the pair of opposing inner surfaces of the hexagonal concave engaging recess 13c. It is formed. When a pair of joint pins 18 and 18 are inserted into the pair of through holes 13e and 13e, a pair of semicircular grooves 13d and 13d in the engaging recess 13c at the lower end of the joint shaft 13 and the upper end of the joint shaft 30 are inserted. Each joint pin 18 is fitted into a pair of semicircular grooves 33a, 33a of the locking projection 33 of the part, and the upper end of the joint shaft 30 is connected to the lower end of the joint shaft 13 as shown in FIG. It is designed to be connected.

  As shown in FIG. 5, the two excavation stirring shafts 20 and 20 are each formed in a cylindrical shape, and can hold a predetermined interval by upper and lower interval holding plates 21 and 22 that also serve to prevent co-rotation. ing. Further, an excavation bit 23 for excavating the improved ground C is attached to the lower end of each excavation stirring shaft 20. Further, the upper part of the upper space holding plate 21 of each excavation stirring shaft 20, the space between the upper and lower space holding plates 21 and 22, and the space between the lower space holding plate 22 and the excavation bit 23 extend linearly in the left and right directions. A pair of agitating blades 24, 24 are attached alternately with a 90 ° phase shift. Furthermore, it is provided so as to pass through the flow path 25 for supplying the solidified material E from the upper end of each excavation stirring shaft 20 to the pair of lowermost stirring blades 24, 24. When each excavation stirring shaft 20 penetrates, the solidified material E is discharged and injected into the improved ground C from the discharge port 26 provided at the lower end of the flow path 25 of each excavation stirring shaft 20.

  Further, a hexagonal convex locking projection 27 is formed at the upper end of each excavation stirring shaft 20 and is fitted into a hexagonal concave engaging recess 34 formed at the lower end of the short joint shaft 30. It is. Grooves 28 and 28 having a semicircular cross section are formed on a pair of opposing outer surfaces of the hexagonal locking projection 27, respectively. And after engaging the engaging recessed part 34 of the lower end part of the joint shaft 30 in the latching convex part 27 of each excavation stirring shaft 20, a pair of joint is carried out to a pair of through-hole 34b, 34b of the lower end part of the joint shaft 30. When the pins 18 and 18 are inserted, each joint pin 18 is fitted into a pair of semicircular grooves 34 a and 34 a in the engaging recess 34 at the lower end of the joint shaft 30, and the upper end of each excavation stirring shaft 20 is fitted. The lower end portion of the short joint shaft 30 is connected. The excavation stirring shaft 20 is formed to have a length of 2.5 m, for example.

As shown in FIG. 6, the shaft body 31 of the short joint shaft 30 is formed in a columnar shape, and has one flow path 32 having a circular cross-sectional shape for supplying the solidified material E from the upper end to the lower end of the center. It is formed so as to penetrate in the vertical direction . Further, the upper end portion of the shaft body 31 is fitted into the engagement recess portion 13c of the hexagonal concave shape of the joint shaft 13 provided in the auger 12, or the engagement recess portion 34 of the lower end portion of the newly installed joint shaft 30 to be added. A hexagonal convex locking projection 33 is formed. A pair of outer surfaces facing each other of the hexagonal locking projection 33 is formed with a semicircular groove 33a. The joint shaft 30 is formed to have a length of 4.5 m, for example, and the maximum driving length can be changed by changing the number of joint shafts 30 to be joined.

  And after engaging the engaging recessed part 13c of the lower end part of the joint shaft 13 or the engaging recessed part 34 of the lower end part of the newly installed joint shaft 30 to the latching convex part 33 of the upper end part of the joint shaft 30 is fitted. When the pair of joint pins 18 and 18 are inserted into the pair of through holes 13e and 13e at the lower end of the joint shaft 13 or the pair of through holes 34b and 34b at the lower end of the newly installed joint shaft 30, the joint shaft 30 a pair of semicircular grooves 33a, 33a of the locking projection 33 at the upper end of the 30 and a pair of semicircular grooves 13d, 13d of the engagement recess 13c of the lower end of the joint shaft 13, or a new installation to be added Each joint pin 18 is fitted in a pair of semicircular grooves 34a, 34a of the engaging recess 34 at the lower end of the joint shaft 30, and the lower end of the joint shaft 13 is connected to the upper end of the joint shaft 30, or The lower end of the new joint shaft 30 to be added is connected. It has become to so that.

  Further, the lower end portion of the shaft body 31 is fitted to the engaging convex portion 27 at the upper end portion of each excavation stirring shaft 20 or the engaging convex portion 33 at the upper end portion of the existing joint shaft 30 that is added. A hexagonal concave engaging recess 34 is formed. Further, a pair of through-holes 34b and 34b having a circular cross section are formed at the lower end portion of the shaft body 31 so as to form grooves 34a having a semicircular cross section on the pair of opposing inner surfaces of the hexagonal concave engaging recess 34, respectively. It is formed. When the pair of joint pins 18 and 18 are inserted into the pair of through holes 34b and 34b at the lower end portion of the shaft body 31, a pair of semicircular grooves 34a and 34a in the engaging recess 34 at the lower end portion of the shaft body 31 are obtained. And a pair of cross-sections of the semicircular grooves 28, 28 of the locking projection 27 at the upper end of each excavation stirring shaft 20, or the locking projection 33 of the upper end of the existing joint shaft 30 that has been added. The joint pins 18 are fitted into the semicircular grooves 33a and 33a, and the upper end of each excavation stirring shaft 20 or the upper end of the existing joint shaft 30 that is added to the lower end of the shaft body 31 of the joint shaft 30. The parts are connected.

Further, a hole 31b having a circular cross section larger in diameter than the flow path 32 is formed in the lower portion of the shaft body 31 so as to be orthogonal to the flow path 32, and a cylindrical flow path is formed in the hole 31b having a circular cross section. A switching valve 35 having the same shape as 32 and having one flow hole 35a is rotatably provided.

The one end 3 5b of a cylindrical switching valve 35 are integrally protruded a hexagonal column of the operation unit 35c for operating switching the said switching valve 35. The hexagonal column-shaped operation portion 35 c protrudes outside the outer peripheral surface 31 a from the hole 31 b having a circular cross section of the shaft body 31. Then, by operating this operation portion 35c and rotating the switching valve 35 by 90 °, the flow hole 35a of the switching valve 35 and the flow path 32 of the shaft body 31 are communicated with each other as shown in FIG. As shown in FIG. 7, the flow path 32 can be closed by closing the flow hole 35a of the switching valve 35 with respect to the flow path 32 of the shaft main body 31. Yes.

  Further, an annular concave locking groove 36 for locking a fixing jig 50 to be described later for preventing the fall from the hull 2 is formed at the upper part of the shaft main body 31.

  As shown in FIGS. 1, 2, and 10, the shaft storage stand 40 that stores two short joint shafts 30 standing upright has a frame-like shape that protrudes horizontally from the bow 2 a of the hull 2 of the work boat 1. A carriage 41 that travels on a pair of guide rails 61, 61 attached to a work table 60 via a roller 42, and a short joint shaft 30 that is attached to the upper surface of the carriage 41 and that stands on the bottom surface of the carriage 41 so as to rotate freely. A pan 43 for storing the remaining solidified material having a pair of turntables 44 and 44, and a rectangular frame standing from both sides of the carriage 41, and holding the two short joint shafts 30 and 30 in an upright state. A pair of holding frame bodies 45, 45 and a hydraulic cylinder as a drive source (not shown) for reciprocating the carriage 41 from the standby position G to the connection position H below the joint shaft 13 of each auger 12 at the ascending position. ing.

  Further, the work table 60 of the hull 2 is fixed to prevent the excavation stirring shaft 20 and the joint shaft 30 connected to the excavation stirring shaft 20 from dropping from the work table 60 at the connection position H of the work table 60. A jig 50 is provided. As shown in FIGS. 8 and 9, the fixing jig 50 includes a pair of metal fixing plates 51, 51, and a bolt 53 and a nut 54 for fastening and fixing the pair of fixing plates 51, 51. Yes.

  The pair of fixing plates 51, 51 are symmetrical and have the same shape, and arcuate recesses 51 a that are attached to and detached from an annular concave locking groove 36 formed in the upper part of the joint shaft 30 at the opposite centers. Is formed. Further, vertical upright plates 52 are fixed by welding or the like on both sides of each fixing plate 51 across the recess 51a. Round holes 52a through which the shank portions of the bolts 53 pass are formed at positions above and below the upright plate 52, respectively. Then, the circular concave portions 51a of the pair of fixing plates 51, 51 are fitted into the annular concave locking grooves 36 on the upper portion of the joint shaft 30, and the opposed standing plates 52, 52 are connected to the bolts 53 and the nuts 54, respectively. The pair of fixing plates 51, 51 are mounted on the pair of support plates 62, 62 of the work table 60 in a state of being fastened and fixed by the digging stirring shaft 20 and the digging stirring shaft 20 from the work table 60. The fall of the joint shaft 30 can be prevented.

  Next, marine construction by the ground improvement device 10 having the above-described configuration will be described in order with reference to FIGS. 1 and 10 to 18.

  As shown in FIG. 1, the spuds 3 positioned on the left and right and front and rear sides of the hull 2 of the work boat 1 are lowered, and the bottom plate 3 a of the spud 3 is positioned on the sand mat B to keep the hull 2 in a horizontal state. As a result, the short joint shaft 30 previously connected to each joint shaft 13 of the pair of augers 12 and 12 via the joint pin 18 and the lower end portion of the short joint shaft 30 are connected via the joint pin 18. Both excavation stirring shafts 20 are set in a vertical state. That is, the short joint shaft 30 and the shaft core of the excavation stirring shaft 20 connected to the lower end portion of the joint shaft 30 are set vertically.

  From this set state, the wire 5a of the winch 5 is unwound, and as shown in FIGS. 10 to 11, the pair of augers 12 and 12 are lowered to a predetermined position along the leader 11 standing on the hull 2, The excavation stirring shaft 20 connected to the short joint shaft 30 and the lower end portion of the joint shaft 30 is lowered to a predetermined position. At this time, the switching valve 15 of the joint shaft 13 of each auger 12 and the switching valve 35 of the short joint shaft 30 are both open, but the excavation bit 23 at the lower end of the excavation agitation shaft 20 is in improved ground in the sea A. Since it has not reached C, the solidified material E such as cement slurry or cement milk is not discharged from the discharge port 26 of the excavation stirring shaft 20.

  Next, as shown in FIG. 11, in a state where the short joint shaft 30 and the excavation stirring shaft 20 connected to the lower end portion of the joint shaft 30 have been lowered, the work table is connected at the connection position H of the work table 60. The upper side of the joint shaft 30 is fixed to a pair of support plates 62, 62 via a fixing jig 50 (see FIG. 9). By fixing the fixing jig 50, the short joint shaft 30 and the excavation stirring shaft 20 connected to the lower end portion of the joint shaft 30 do not fall into the sea A from the connection position H of the work table 60 of the hull 2. . Further, the switching valve 15 of the joint shaft 13 is closed, and the joint pin 18 that connects the joint shaft 13 of the auger 12 and the upper end portion of the short joint shaft 30 is removed.

  Next, the wire 5a of the winch 5 is wound up, and the pair of augers 12 and 12 are raised to a predetermined position along the leader 11 standing on the hull 2 as shown in FIG.

  Next, as shown in FIG. 13, the shaft storage stand 40 that stores two short joint shafts 30 in a standing state is connected to the joint of each auger 12 that is in the raised position from the standby position G of the work table 60 of the hull 2. Move to a connecting position H below the shaft 13.

  Next, the wire 5a of the winch 5 is unwound, and as shown in FIG. 14, the pair of augers 12 and 12 are lowered along the leader 11 standing on the hull 2, and the lower end of the joint shaft 13 of each auger 12 The engaging convex portion 33 at the upper end portion of the newly installed joint shaft 30 that is erected on the shaft storage stand 40 is fitted into the engaging concave portion 13 c of the portion, and the new joint shaft that is added to the lower end portion of the joint shaft 13. The upper end of 30 is connected via a joint pin 18. Further, the switching valve 15 of the joint shaft 13 is opened, and the switching valve 35 of the newly installed joint shaft 30 is closed.

  Next, the wire 5a of the winch 5 is wound up, and as shown in FIG. 15, the pair of augers 12 and 12 are raised to a predetermined position along the leader 11 erected on the hull 2, and then shown in FIG. As shown, the empty shaft storage stand 40 is moved from the connection position H below the joint shaft 13 of each auger 12 in the raised position to the standby position G of the work table 60 of the hull 2 and returned. In the shaft storage stand 40 retracted to the standby position G, two short joint shafts 30 for the next addition are stored.

  Next, the wire 5a of the winch 5 is unwound and the pair of augers 12 and 12 are lowered along the leader 11 standing on the hull 2 as shown in FIG. The engaging concave portion 34 at the lower end is fitted with the engaging convex portion 33 at the upper end of each existing joint shaft 30, and the lower end of each new joint shaft 30 and the upper end of the existing joint shaft 30 are connected to the joint pin. 18 is connected. Further, the switching valve 35 of each newly installed joint shaft 30 is opened, and the fixing jig 50 that fixes the upper side of each existing joint shaft 30 is removed.

  Next, as shown in FIG. 18, the two joint shafts 30, 30 and the excavation stirring shafts 20, 20 connected via the augers 12 are lowered while rotating, respectively, so that the improved ground C in the sea A It penetrates to a predetermined depth. During this penetration, the solidified material E is discharged and injected into the improved ground C from the discharge port 26 of each excavating stirring shaft 20, and the excavated soil D and the solidified material E in the improved ground C are stirred and mixed. As shown in FIG. 1, an improved pile F is created by solidifying the solidified material E. In this way, the excavation stirring shaft 20 is penetrated to a predetermined depth of the improved ground C in the sea A while a plurality of new joint shafts 30 are sequentially added to the existing joint shaft 30. The solidified material E such as cement slurry and cement milk is discharged and injected into the improved ground C from the outlet 26, and the excavated soil D and the solidified material E in the improved ground C are stirred and mixed to solidify the solidified material E. An improved pile F having a predetermined length is created. Moreover, after construction, it removes sequentially from the joint shaft 30 located on the upper side.

  As described above, the joint shaft 13 for connecting the upper end portion of the short joint shaft 30 to the auger 12 is provided, and the shaft storage stand 40 for storing the two short joint shafts 30 in the standing state is provided on the work table on the hull 2. 60 is provided so as to be reciprocally movable from a standby position G to a connecting position H below the joint shaft 13 of the auger 12 at the ascending position. Since the fixing jig 50 for preventing the fall from the hull 2 to the sea A is detachable, the short joint shaft 30 can be sequentially added on the hull 2 in a stable state in a short time. As a result, it is possible to safely carry out sea construction even in places with height restrictions such as sea areas around airports where there are aviation restrictions, and improved piles F made of excavated soil D and solidified material E in improved ground C in the sea A It can be created efficiently and in a short time.

  Further, the joint shaft 13 of the auger 12 is provided with a flow path 13a for supplying the solidified material E, and the joint shaft 13 is provided with a switching valve 15 for opening and closing the flow path 13a. If the switching valve 15 is closed while the upper end portion of the short joint shaft 30 is connected, the outflow of the solidified material E such as cement slurry and cement milk from the flow path 13a of the joint shaft 13 is surely prevented. It is possible to prevent the marine pollution by the solidifying material E in advance.

  Furthermore, a switching valve 35 for opening and closing the flow path 32 is provided at the lower part of the shaft body 31, provided to pass through the flow path 32 for supplying the solidified material E from the upper end to the lower end of the shaft body 31 of the short joint shaft 30. Thus, if the switching valve 35 is closed while the lower end portion of the next short joint shaft 30 is connected to the upper end portion of the joint shaft 30 fixed to the work table 60 via the fixing jig 50, The solidified material E such as cement slurry and cement milk can be reliably prevented from flowing out from the flow path 32 at the upper end of the joint shaft 30 fixed to the work table 60 via the fixing jig 50. Contamination can be surely prevented.

  That is, when the short joint shaft 30 is not added and the solidified material E to be removed is not supplied, the switching valve 35 is kept closed to reliably prevent the solidified material E from flowing out from the flow path 32 of the joint shaft 30. It is possible to prevent marine contamination by the solidifying material E with certainty. As a result, it is possible to carry out sea construction safely and safely even in places with height restrictions such as sea areas around airports where there are air restrictions.

  Further, a hole 31b having a circular cross section is formed in the lower portion of the shaft body 31 of the short joint shaft 30 so as to be orthogonal to the flow path 32. The switching valve 35 having a 35a is rotatably provided, and the switching valve 35 is rotated by 90 degrees to allow the flow hole 35a of the switching valve 35 and the flow path 32 of the shaft body 31 to communicate with each other. By doing so, the flow hole 35a of the switching valve 35 and the flow path 32 of the shaft body 31 can be reliably opened and closed with a simple structure.

  Further, at least one end 35b of the cylindrical switching valve 35 is provided with an operating portion 35c for switching the switching valve 35, and the operating portion 35c is projected outward from the circular hole 31b having a circular cross section of the shaft body 31, The opening and closing of the flow hole 35a of the switching valve 35 and the flow path 32 of the shaft main body 31 can be easily and reliably performed by the operation portion 35c.

  Furthermore, a hexagonal convex locking projection 33 is provided at the upper end of the shaft body 30 of the short joint shaft 30 to be fitted into the hexagonal concave engagement recess 13c of the joint shaft 13 provided on the auger 12. In addition, the lower end portion of the shaft body 31 is fitted to the hexagonal convex locking convex portion 27 of the excavating and stirring shaft 20 and the hexagonal convex locking convex portion 33 at the upper end portion of the spliced joint shaft 30. By providing the hexagonal concave engagement recess 34, the hexagonal convex engagement convexity 33 at the upper end of the shaft body 31 is changed to the hexagonal concave engagement recess 13c of the joint shaft 13 of the auger 12. The hexagonal concave engagement recess 34 at the lower end of the shaft body 31 is engaged with the hexagonal convex engagement protrusion 27 at the upper end of the excavating and stirring shaft 20 or the hexagonal convex engagement at the upper end of the jointed shaft 30. By fitting the projections 33 respectively, the shaft body 31 can be connected to the auger without idling each other. It can be reliably connected respectively to the joint axis 13 and drilling stirring shaft 20 or spliced the coupling shaft 30 of the 12.

  FIG. 19 is a perspective view of a short joint shaft having another type of switching valve.

  In this other form, at least one end 35b of the cylindrical switching valve 35 is provided with an operating portion 35c for switching the switching valve 35, and this operating portion 35c is located in the back of the circular cross-sectional hole 31b of the shaft body 31. Thus, the shaft body 31 does not protrude outward from the outer peripheral surface 31a. As a result, the opening and closing of the flow hole 35a of the switching valve 35 and the flow path 32 of the shaft body 31 can be easily and reliably performed by the operation portion 35c, and the operation portion 35c does not jump out of the way.

  FIG. 20 (a) is a partial perspective view showing a state in which the flow path of the short shaft is closed by another type of switching valve, and FIG. 20 (b) is a diagram showing a state in which the flow path of the short shaft is opened by the switching valve. It is a fragmentary perspective view which shows the state which was put.

In this other form, a hole 31b having a circular cross section is formed in the lower portion of the shaft body 31 of the short joint shaft 30 so as to be orthogonal to the flow path 32, and the flow path 32 is formed in a cylindrical shape in the hole 31b having a circular cross section. As shown in FIG. 20A, the switching valve 35 having the same shape of the flow hole 35a is slidable in the front-rear direction, and the switching valve 35 is slid in the front-rear direction for a predetermined length. The flow hole 35a and the flow path 32 of the shaft body 31 are closed, or as shown in FIG. 20B, the flow hole 35a of the switching valve 35 and the flow path 32 of the shaft body 31 are communicated. is there. Thereby, the flow hole 35a of the switching valve 35 and the flow path 32 of the shaft main body 31 can be reliably opened and closed with a simple structure. In this case, as shown in the other form of FIG. 19, the operation portion 35 c is positioned in the back of the hole 31 b having a circular cross section of the shaft body 31 so as not to protrude outward from the outer peripheral surface 31 a of the shaft body 31. Also good. As a result, the opening and closing of the flow hole 35a of the switching valve 35 and the flow path 32 of the shaft body 31 can be easily and reliably performed by the operation portion 35c, and the operation portion 35c does not jump out of the way.

  In the above-described embodiment, the shaft storage stand that stores two short joint shafts upright on one side of the work table is provided so as to be reciprocally movable from the standby position to the connection position. A storage stand may be provided, and the supply number of joint shafts to be added may be increased by alternately reciprocating the shaft storage stands. In addition, the solidified material was discharged from the discharge port when the excavation stirring shaft penetrated, and an improved pile was created, but when the excavation stirring shaft was pulled out, the solidified material was discharged from the discharge port to create the improved pile. Also good. Furthermore, the description has been given of the two-shaft type in which the excavated soil and the solidified material are agitated and mixed with two excavation agitation shafts to form an improved pile. Of course, the above-described embodiment can be applied to a multi-shaft type using an excavation stirring shaft.

2 Hull 10 Ground Improvement Device 11 Leader 12 Auger (Driver)
13 Joint shaft 13c Engaging recess 20 Excavation stirring shaft 26 Discharge port 27 Locking projection (upper end)
30 Short joint shaft 31 Shaft body 31b Circular hole 32 Flow path 33 Locking projection (upper end)
34 engaging recess 35 switching valve 35a flow hole 35b one end 35c operation part A underwater C improved ground D excavated soil E solidified material F improved pile

Claims (2)

A drilling agitation shaft that is supported vertically up and down along a leader standing on the hull, a drive unit that moves the excavation agitation shaft up and down, and a plurality of short joints that are added to the excavation agitation shaft. A plurality of the short joint shafts in the sea while sequentially adding a plurality of the short joint shafts to the upper end portion of the excavation stirring shaft and the upper end portion of the short joint shaft added to the upper end portion of the excavation stirring shaft on the hull. The excavation agitation shaft is allowed to penetrate to a predetermined depth of the improved ground, and the solidified material is discharged and injected into the improved ground from the discharge port of the excavation agitation shaft, and the excavated soil and the solidified material in the improved ground are Is a joint shaft of an excavation stirring shaft used in a ground improvement device in which an improved pile is formed by solidification of the solidified material,
Provided so as to penetrate one flow path with a circular hole shape in cross section for supplying the solidified material in the vertical direction from the upper end to the lower end of the shaft body of the joint shaft,
A hole having a circular cross section is formed in the lower portion of the shaft body so as to be orthogonal to the flow path, and a switching valve having a circular shape in the circular cross section and having one flow hole in the same shape as the flow path is rotated. By freely providing and rotating this switching valve by a predetermined angle, the flow hole of the switching valve and the flow path of the shaft main body are communicated or closed,
An excavation characterized in that an operation part for switching the switching valve is provided at at least one end of the cylindrical switching valve, and the operation part is integrally formed so as to be exposed in a circular hole in a cross section of the shaft body. Joint shaft for stirring shaft. A drilling agitation shaft that is supported vertically up and down along a leader standing on the hull, a drive unit that moves the excavation agitation shaft up and down, and a plurality of short joints that are added to the excavation agitation shaft. A plurality of the short joint shafts in the sea while sequentially adding a plurality of the short joint shafts to the upper end portion of the excavation stirring shaft and the upper end portion of the short joint shaft added to the upper end portion of the excavation stirring shaft on the hull. The excavation agitation shaft is allowed to penetrate to a predetermined depth of the improved ground, and the solidified material is discharged and injected into the improved ground from the discharge port of the excavation agitation shaft, and the excavated soil and the solidified material in the improved ground are Is a joint shaft of an excavation stirring shaft used in a ground improvement device in which an improved pile is formed by solidification of the solidified material ,
Provided so as to penetrate one flow path with a circular hole shape in cross section for supplying the solidified material in the vertical direction from the upper end to the lower end of the shaft body of the joint shaft,
SWITCHING valve the axis to form a circular cross section hole to be perpendicular to the flow path in the lower part of the body, had the flow channel and the same shape in one flow hole in a cylindrical shape the cross-section in a circular hole the slidably installed, the switching valve by causing a predetermined length sliding, or to communicate with the flow path of the shaft body and the fluid passing holes of said switching valve, so as to occlude,
An operation portion for switching the switching valve is provided at at least one end of the cylindrical switching valve, and the operation portion is exposed so as not to protrude outward from the outer peripheral surface of the shaft body in a circular hole in the cross section of the shaft body. A joint shaft of a drilling and stirring shaft characterized by having been made .

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