JP6203101B2 - Ground improvement method by high-pressure jet stirring method and special head used in this ground improvement method - Google Patents

Description

  The present invention jets a hardened material into the ground at a high speed and a high pressure, stirs and mixes the hardened material and the ground while cutting the ground with this jetting energy, and creates a consolidated improvement body in the ground to form the ground. The present invention relates to a ground improvement method using a high-pressure jet agitating method and a special head used in this ground improvement method.

  Conventionally, as a ground improvement method by a high-pressure jet agitating method, a high-pressure jet agitator is used, and a tube rod 42 is inserted into the ground with a construction machine 41 of the high-pressure jet agitator to a predetermined depth, and then, shown in FIG. As described above, a hardener such as cement milk is jetted at a high speed and a high pressure from the jet nozzle 44 of the special head 43 attached to the pipe rod 42 while rotating the pipe rod 42. Then, the hardened material and the ground sprayed while cutting the ground with the spray energy of the hardened material are agitated and mixed, and the tube rod 42 is rotated once. Then, by repeating this operation upward while pulling up the tube rod 42, a structure in which a vertical columnar consolidated improvement body Tc is formed in the ground to improve the ground is generally used. Was known to.

  And in the ground improvement method by such a high-pressure jet agitation method, when trying to create a wall-shaped consolidation improvement body in the ground, as shown in FIG. A large number of Tc were formed on a straight line, whereby a wall-shaped consolidated improvement body was formed in the ground. In addition, when improving the ground directly under an existing structure, a large number of vertically-oriented columnar consolidated improvement bodies Tc are formed in the ground after inserting the tube rod 42 in the vicinity of the existing structure, and immediately below the existing structure. I was trying to improve the ground.

  In the ground improvement method using the conventional high-pressure jet agitation method, when a wall-shaped consolidation improvement body is created in the ground, a large number of vertical cylindrical consolidation improvement bodies Tc are formed on a straight line. As a result, the construction work time is significantly increased, which may lead to an increase in the construction period. Since the improved body Tc was formed on a straight line, unnecessary portions were formed as shown by the hatched portions in FIG. 19, and by using a large amount of the curing material, There was also a risk that the construction cost would increase. Further, when improving the ground directly under the existing structure, the solidified improvement body Tc is formed up to the ground immediately under the existing structure in order to create a vertical columnar consolidation improvement body Tc in the ground. In some cases, the ground could not be improved satisfactorily.

  Therefore, in view of the problems in the ground improvement method by the conventional high-pressure jet agitation method, the present invention creates the wall-shaped consolidation improvement body when creating the wall-shaped consolidation improvement body in the ground. It is an object of the present invention to provide a ground improvement method by a high-pressure jet agitation method that makes it easy and shortens the construction work time by shortening the construction period and also reduces the construction cost.

  In the first invention, the tube rod is inserted into the ground up to a predetermined depth, and after the insertion, the hardened material is sprayed from the injection nozzle of the special head attached to the tube rod at a high speed and high pressure, and the ground is injected with the spray energy of the hardened material. In the ground improvement method by the high pressure jet stirring method, which stirs and mixes the hardened material sprayed while cutting and the ground, and creates a consolidated improvement body in the ground to improve the ground, two or more sprays to the special head The nozzles are provided so as to be separated from each other in a substantially lateral direction, and the curing material is cross-injected so that the curing material intersects at the positions where the ejection directions are slightly shifted in the plurality of ejection nozzles. The cross-injection of the hardener is rotated by a predetermined angle without moving up or down to a predetermined range or while moving upward, and then the tube rod is pulled upward by a predetermined length. Or from above, the cross-injection of the curing material from the plurality of injection nozzles is performed by rotating by a predetermined angle without moving up or down to a predetermined range or while moving upward. This is a ground improvement method using a high-pressure jet agitation method in which a wall-shaped consolidation improvement body is created in the ground by repeatedly performing the process toward the ground.

  According to a second invention, in the first invention, the cross-injection of the curing material from the plurality of injection nozzles is performed by rotating by a predetermined angle without moving up and down within a predetermined range or while moving upward. When rotating in the upward direction, the rotation direction in the cross injection of the hardened material from the injection nozzle is rotated in one direction. This is a ground improvement method using a high-pressure jet stirring method in which the rotation direction is changed alternately.

  The third invention is a special head used in the ground improvement method by the high-pressure jet agitation method of the first or second invention, comprising a head body extending vertically, and projecting laterally on both the left and right sides of the head body. This special head is used in a ground improvement method in which a plurality of jet nozzles are provided on the head body and the stirring blade.

  According to a fourth invention, in the third invention, in the plurality of spray nozzles provided in the head main body and the stirring blade, the angle of each of the nozzles can be changed, and the intersecting position of the sprayed cement milk can be arbitrarily set. It is a special head used in the ground improvement method that can be changed to the position.

  According to a fifth invention, in the third or fourth invention, in the plurality of spray nozzles provided in the head body and the stirring blade, the nozzle body is provided at a tip of the nozzle body, and the nozzle body is provided in the head body and the stirring blade. It is a special head used in the ground improvement method that protrudes from the ground.

  6th invention is the special head used for the ground improvement method which attached the injection nozzle and the nozzle body, or the balancer member to the other side of the location which provided the injection nozzle and the nozzle body in the stirring blade in 5th invention. .

  A seventh invention is the invention according to any one of the third, fourth and fifth inventions, wherein two stirring blades are vertically attached to the head body, and a plurality of jet nozzles are provided on both front and rear sides of the head body and the two stirring blades. The upper side with the upper stirring blade and the lower side with the lower stirring blade are rotatably connected to each other, and a plurality of injection nozzles provided on both the front and rear sides of the upper side and the front and rear sides of the lower side This is a special head used in the ground improvement method in which a plurality of spray nozzles provided in is directed in different directions.

  According to the present invention, the curing material is cross-injected so that the curing material intersects at the point of injection from the plurality of injection nozzles provided in the special head, and this is rotated by a predetermined angle so as to move up and down within a predetermined range. It is performed without moving or while moving upward, and then the tube rod is pulled upward by a predetermined length or moved upward, and then cross injection of the curing material from a plurality of injection nozzles by a predetermined angle. Rotating without moving up and down to a predetermined range or while moving upwards, by repeatedly doing this upward, when creating a wall-shaped consolidated improvement body in the ground, Eliminates the need to create a large number of vertical columnar consolidated improvement bodies on a straight line as in the past, making it easy to create a wall-shaped consolidation improvement body. It is possible to shorten shorten the construction period, it is possible to also reduce the construction cost. Moreover, even when the ground directly under the existing structure is improved, a wall-shaped consolidation improvement body can be created up to the ground immediately under the existing structure, and the ground directly under the existing structure can be improved satisfactorily. it can.

  In addition, when the rotation direction in the cross injection of the hardened material from the injection nozzle is rotated in one direction, the tube rod is pulled up and then rotated in the opposite direction so that the rotation direction is changed alternately. As a result, the efficiency of the work is greatly improved, and the construction period can be further shortened.

  According to the present invention, the special head includes a head body that extends vertically, and a stirring blade that protrudes laterally on both the left and right sides is attached to the head body, and a plurality of jet nozzles are provided on the head body and the stirring blade. By doing in this way, the wall-shaped solidification improvement body of desired width and a magnitude | size can be easily created in the ground.

  In addition, it is possible to change the angle of each of the spray nozzles and to change the crossing position of the injected cement milk to an arbitrary position. The size can be changed to a desired size. In addition, a plurality of injection nozzles are provided at the tip of the nozzle body, and the nozzle body protrudes from the head body and the stirring blade, so that the length of the conduit in the nozzle body can be increased. Further, the straightness of the hardened material sprayed from the spray nozzle can be improved, the hardened material sprayed in the ground can be prevented from diffusing to the surroundings, and the hardener can be sprayed well. Moreover, when the special head is rotated in the ground by attaching the injection nozzle and the nozzle body or the balancer member to the side opposite to the location where the injection nozzle and the nozzle body are provided in the stirring blade, Balance is maintained, whereby the special head and the tube rod can be rotated well in the ground. In addition, two stirring blades are attached to the head body at the top and bottom, and the upper side to which the upper stirring blade is attached and the lower side to which the lower stirring blade is attached are rotatably connected. By directing the spray nozzles and the multiple spray nozzles provided on the front and rear sides of the lower side in different directions, a specially shaped wall-shaped consolidation improvement body can be easily formed in the ground by a single operation. And can be easily constructed.

It is explanatory drawing of the high pressure injection stirrer used in the ground improvement method by the high pressure injection stirring method of this invention. It is a front view of the special head used for the ground improvement method of the present invention. It is a side view of the special head used for the ground improvement method of this invention. It is a top view of the special head used for the ground improvement method of this invention. It is explanatory drawing about the injection nozzle of the special head used for the ground improvement method of this invention. (A) It is explanatory drawing of the operation | work process of the ground improvement method by the high pressure injection stirring method of this invention. (B) It is explanatory drawing of the operation | work process of the ground improvement method by the high pressure jet stirring construction method of this invention. (C) It is explanatory drawing of the operation | work process of the ground improvement method by the high voltage | pressure injection stirring construction method of this invention. (D) It is explanatory drawing of the operation | work process of the ground improvement method by the high voltage | pressure injection stirring construction method of this invention. (E) It is explanatory drawing of the work process of the ground improvement method by the high-pressure jet stirring method of this invention. (F) It is explanatory drawing of the operation | work process of the ground improvement method by the high voltage | pressure injection stirring construction method of this invention. It is a state explanatory view when cement milk is made to cross-inject in the ground improvement method by the high-pressure injection stirring method of the present invention. It is a perspective view of the wall-shaped consolidation improvement body built in the ground in the ground improvement method by the high-pressure jet stirring method of the present invention. It is a front view of another example of the special head used for the ground improvement method of the present invention. It is a front view of another example of the special head used for the ground improvement method of the present invention. It is a top view of another example of the special head used for the ground improvement method of the present invention. It is explanatory drawing of the wall-shaped solidification improvement body built in the ground in the ground improvement method by the high-pressure jet stirring method of this invention. It is a front view of another example of the special head used for the ground improvement method of the present invention. It is a top view of another example of the special head used for the ground improvement method of the present invention. It is explanatory drawing of the wall-shaped solidification improvement body of the special form created in the ground in the ground improvement method by the high-pressure jet stirring method of this invention. It is explanatory drawing when improving the ground just under the existing structure in the ground improvement method by the high-pressure jet stirring method of the present invention. It is explanatory drawing of the ground improvement method by the conventional high-pressure jet stirring method. It is explanatory drawing of the wall-shaped consolidation improvement body created in the ground in the ground improvement method by the conventional high-pressure jet stirring method.

An embodiment of the ground improvement method by the high-pressure jet stirring method of the present invention and an embodiment of a special head used in the ground improvement method will be described.
First, the high-pressure jet agitator used in the ground improvement method by this high-pressure jet agitation method will be described. As shown in FIG. The construction machine 1 is, for example, a small pile driver capable of self-propelling. However, the construction machine 1 is not limited to a small pile driving machine, and may be a boring machine or other machines depending on the scale of improvement such as the depth of construction for ground improvement. In this construction machine 1, the mast 3 is erected and the tube rod 2 is attached vertically along the mast 3, and the tube rod 2 is inserted into the ground above the mast 3. An elevating device 4 for pulling out and a rotating device 5 for rotating the tube rod 2 are provided. The tube rod 2 is a hollow steel tube through which a hardener, compressed air, etc. pass, and a special head 6 is attached to the tip which is the lower end thereof.

  Further, the peripheral equipment of the construction machine 1 in the high-pressure jet agitator is equipment for supplying a hardener, compressed air, or the like to the tube rod 2 and the special head 6 attached to the construction machine 1. The hardener is cement milk, but various additives may be mixed with the cement milk. The equipment for supplying compressed air is the compressor 11, and the compressed air is supplied from the compressor 11 to the tube rod 2 via the flow meter 12. In addition, as equipment for supplying the hardener, a mixing device 14 is provided, in which the cement raw material flows from the cement silo 15 and water flows from the water tank 17 provided with the submersible pump 16. These are mixed to produce cement milk as a hardener. Then, the cement milk is supplied to the hardener supply device 20 including the high-pressure pump 19 through the flow meter 18, and the cement milk is supplied from the hardener supply device 20 to the tube rod 2. Each device is operated by a generator (not shown).

  On the other hand, as for the special head 6 attached to the tip which is the lower end of the tube rod 2, as shown in FIGS. 2, 3, and 4, a substantially cylindrical head which is provided with a number of bits 31 on the tip side and which extends vertically. A main body 30 is provided, and a horizontal prismatic stirring blade 32 protruding in the lateral direction on both the left and right sides is attached to the head main body 30, and a bit 33 is also provided below the stirring blade 32. The horizontal length of the stirring blade 32 is, for example, about 400 to 1000 mm. The head main body 30 and the stirring blade 32 are formed therein with passages for passing cement milk, compressed air, or the like as a hardener. The compressed air passage is connected to an air nozzle 35 described later. Moreover, although the shape of the stirring blade 32 is a horizontally oriented substantially prismatic shape, the shape is not limited to this, and it may be a horizontally oriented substantially cylindrical shape.

  The head body 30 and the stirring blade 32 are provided with three jet nozzles 34 directed forward on the front side thereof. The jet nozzles 34 are provided at the tip of the nozzle body 38 and communicate with the inside of the tube rod 2. Cement milk, which is a hardening material, is sprayed from here. The three injection nozzles 34 and the nozzle body 38 are provided in the head body 30 and are provided on the left and right sides of the stirring blade 32, respectively, and are arranged so that the injection nozzles 34 are separated substantially in the lateral direction. The distance in which the three injection nozzles 34 are separated in the substantially lateral direction is, for example, about 200 to 500 mm. The number of the injection nozzles 34 is not limited to three, but two or more injection nozzles 34 such as two, four, five, or six are separated in a substantially lateral direction. It may be provided. In addition, the two or more injection nozzles 34 may have a slight vertical difference in the vertical direction as long as they are provided so as to be separated in the substantially horizontal direction.

  In the three injection nozzles 34 provided on the head main body 30 and the stirring blade 32, as shown in FIG. 5, the central injection nozzle 34 provided on the head main body 30 goes straight forward. The injection nozzles 34 on both sides of the wing 32 are arranged so as to face each other with a slight shift toward the center, and thus the three injection nozzles 34 perform the injection by slightly shifting the injection direction. The cement milk sprayed at the one point is crossed, that is, the cement milk is cross-sprayed.

  Further, the angles (orientations) of the three spray nozzles 34 can be changed. However, in the three spray nozzles 34, the cement milk sprayed at the sprayed tip is always crossed even if the angle is changed. As a result, as represented by the dotted line in FIG. 5, the crossing position of the injected cement milk can be changed to an arbitrary position, and the size of the consolidation improvement body formed in the ground is changed to a desired size. can do.

  In addition, a plurality of air nozzles 35 are provided around the injection nozzle 34, and the cement milk injected from the injection nozzle 34 by the compressed air injected from the air nozzle 35 is wrapped so as to be injected into the ground. Can reach farther.

  Further, in the nozzle body 38 provided with the injection nozzle 34 at the tip, the nozzle body 38 protrudes forward from the head body 30 and the stirring blade 32. The protruding dimension of the nozzle body 38 is about 100 to 300 mm. It is. A guard cover 36 is attached to the outside of the protruding nozzle body 38, and the guard cover 36 has a configuration in which panels are provided on the upper, lower, left, and right sides. The guard cover 36 protects the protruding nozzle body 38. As a result, the nozzle body 38 is prevented from being worn or damaged. As described above, the nozzle body 38 protrudes forward, so that the straightness of the cement milk sprayed from the spray nozzle 34 provided at the tip of the nozzle body 38 is improved, and the hardened material sprayed in the ground diffuses around. This makes it possible to suppress the injection of the curing material.

  Further, in the agitating blade 32, a balancer member 37 having substantially the same shape as the guard cover 36 is attached to the rear side opposite to the left and right portions where the injection nozzle 34 and the nozzle body 38 are provided on the front side. When the special head 6 is rotated in the ground by the balancer member 37 attached to the right and left rear sides of the stirring blade 32, the balance between the balancer member 37 and the nozzle body 38 and guard cover 36 provided on the front side is a mechanical balance. Thus, the special head 6 and the tube rod 2 can be rotated well in the ground.

  Next, the ground improvement method by the high-pressure jet stirring method of the present invention performed using the special head and the high-pressure jet stirrer having such a configuration will be described.

  As shown in FIG. 6A, the tube rod 2 is attached to the construction machine 1. And as shown in FIG.6 (b), it inserts in the ground, rotating the pipe rod 2 with the construction machine 1. FIG. Then, the ground is excavated by the special head 6 attached to the lower end of the tube rod 2. At this time, if the insertion into the ground is difficult, the injection of the special head 6 is performed to assist the insertion of the tube rod 2. This is performed while jetting water or compressed air from the nozzle 34 or the air nozzle 35. Then, as shown in FIG. 6C, the tube rod 2 is inserted to a predetermined depth.

  Then, the cement milk is cross-injected so that the cement milk, which is a hardening material, intersects at the point of injection from the three injection nozzles 34 provided in the special head 6. At the same time, compressed air is also ejected from a plurality of air nozzles 35 provided around the periphery. Thereby, the cement milk sprayed and the ground are agitated and mixed while cutting the ground with the sprayed cement milk and the spray energy of the compressed air, and the work of creating the wall-shaped consolidation improvement body T in the ground is performed.

  This is because, as shown in FIG. 7 (d), the three injection nozzles 34 are rotated while the tube rod 2 and the special head 6 are rotated after the three injection nozzles 34 provided on the special head 6 are directed to the ground. The cement milk is cross-injected from 34, and the cross-injection of cement milk from the three injection nozzles 34 is performed by rotating a predetermined angle without moving up and down within a predetermined range. This rotation direction is only one direction, for example, it is rotated in the left direction, and this left direction is the clockwise direction when viewed from above.

  As shown in FIG. 8, the rotation in the cement milk cross-injection is performed after the three injection nozzles 34 are directed toward the right end of the wall-shaped consolidated improvement body T to be formed in the ground. Cement milk is cross-injected from the injection nozzle 34. Then, it is rotated in the clockwise direction when viewed from above, which is the left direction. Then, the three spray nozzles 34 cross-inject the cement milk so far toward the left end of the wall-shaped consolidated improvement body T to be formed in the ground.

  In addition, although the predetermined angle of rotation at this time varies depending on the distance between the three injection nozzles 34, in the wall-shaped consolidated improvement body T formed in the ground, an attempt is made to have a lateral width of 500 mm or more. Then, for example, about 3 to 30 degrees.

  Then, the cement milk was cross-injected from the three injection nozzles 34 while rotating the tube rod 2 and the special head 6, and the cross-injection was performed by rotating a predetermined angle without moving up and down to a predetermined range. Thereafter, the tube rod 2 and the special head 6 are pulled upward by a predetermined length. The length of the upward pulling is about 30 to 200 mm. Further, when the tube rod 2 and the special head 6 are pulled upward, they are pulled up without rotating.

  Then, as shown in FIG. 7 (e), the pipe rod 2 and the special head 6 are pulled upward, and then the cement milk is cross-injected from the three injection nozzles 34 while the pipe rod 2 and the special head 6 are rotated. The cross injection is performed without rotating up and down to a predetermined range by rotating by a predetermined angle. The direction of rotation at this time is the opposite direction to the previous direction, and is the counterclockwise direction when viewed from above, which is the right direction.

  Thereafter, the tube rod 2 and the special head 6 are pulled upward by a predetermined length. Then, after pulling up the tube rod 2 and the special head 6, the cement milk is cross-injected from the three injection nozzles 34 while rotating the tube rod 2 and the special head 6, and this cross-injection is rotated by a predetermined angle. And without moving up and down within a predetermined range. The rotation direction at this time is the clockwise direction when viewed from above, which is the left direction which is the opposite direction.

  As described above, when the cement milk is cross-injected from the three injection nozzles 34 while rotating the tube rod 2 and the special head 6, the tube rod 2 is rotated in the left direction which is one direction. Next, the rotation direction is changed to the right direction, which is the opposite direction, and the rotation direction is changed alternately.

  Then, while rotating the tube rod 2 and the special head 6, cement milk is cross-injected from the three injection nozzles 34, and this is performed without rotating up and down within a predetermined range by rotating it by a predetermined angle. The operation is repeated upward. As a result, by performing the above-described series of operations while pulling up the tube rod 2 and the special head 6 upward, as shown in FIG. Will be created. In addition, although the consolidation improvement body T is formed in steps, the consolidation improvement body T positioned above and below is formed by forming the consolidation improvement body T on the upper side before the lower consolidation improvement body T is solidified. Can be integrated without being divided.

  Then, by repeating the above-described series of operations upward and forming the wall-shaped consolidation improvement body T to a predetermined depth, the three injection nozzles 34 while rotating the tube rod 2 and the special head 6. Then, the operation of cross-injecting the cement milk is stopped, and the tube rod 2 and the special head 6 inserted into the ground are pulled out to the ground. As a result, the ground is improved by creating a wall-shaped consolidation improvement body T as shown in FIG. 9 in the ground.

  On the other hand, the ground improvement method by the high-pressure jet agitation method of the present invention and the special head used in this ground improvement method are not limited to those described in the above-described embodiment, and may be other types.

  For example, in the ground improvement method using the high-pressure jet agitation method of the present invention, in the above-described method, cement milk is cross-injected from three injection nozzles 34 while rotating the tube rod 2 and the special head 6, and the three injections are performed. The cross injection of cement milk from the nozzles 34 is performed by rotating a predetermined angle without moving up and down to a predetermined range. Instead, the cross injection of cement milk from the three injection nozzles 34 is performed. The injection is rotated by a predetermined angle and gradually moved upward within a predetermined range, and then the crossing injection of the hardened material from the three injection nozzles 34 is rotated by a predetermined angle from the point where it has moved upward. Then, it may be performed while gradually moving upward within a predetermined range, and this may be repeated upward. Thus, when the cross injection of cement milk from the three injection nozzles 34 is performed while rotating by a predetermined angle and moving upward to a predetermined range, the above-described cross injection of cement milk is predetermined. It is necessary to pull up the tube rod 2 and the special head 6 upward by a predetermined length after rotating by an angle of [deg.] To a predetermined range, but this work can be eliminated and the work time can be shortened. Can do.

  In the ground improvement method using the high-pressure jet agitation method of the present invention, the cement milk is cross-injected from the three injection nozzles 34 while rotating the tube rod 2 and the special head 6 to cross-inject cement milk. However, when the cement milk is cross-injected from the three injection nozzles 34, the rotation of the tube rod 2 and the special head 6 is stopped instead. Then, the cement milk may be cross-injected from the three injection nozzles 34 in a rotation stopped state, and this may be performed in a predetermined range by rotating it by a predetermined angle a plurality of times. When the cement milk is jetted in such a state where the rotation is stopped, the distance to which the jetted cement milk reaches can be extended. The wall-shaped consolidation improvement body T having a long length in the longitudinal direction can be formed in the ground.

  Further, in the above-mentioned, when the cross injection from the three injection nozzles 34 is rotated by a predetermined angle to be performed in a predetermined range, and this is repeated upward, the rotation in the cross injection from the injection nozzle 34 is performed. When the direction is rotated to the left, which is one direction, the tube rod 2 and the special head 6 are pulled upward, and then rotated to the right, which is the opposite direction, so that the rotation direction is changed alternately. However, instead of this, when the cross injection from the three injection nozzles 34 is rotated by a predetermined angle to a predetermined range and then the pipe rod 2 is pulled upward, the pipe rod 2 and the special head 6 In the upper direction, the rotation direction when cross injection is performed from the three injection nozzles 34 is rotated in the same direction as before, and the rotation direction is alternately changed in this way. Rather, always it may be in the same direction. However, if the rotation direction is always the same in this way, when the tube rod 2 is pulled upward or before and after the tube rod 2 is pulled up, it is necessary to return the tube rod 2 to the original direction, and the efficiency of the operation may be slightly reduced.

  As for the special head 6, the above-described head is provided with the head body 30, the stirring blade 32 is attached to the head body 30, and a plurality of injection nozzles 34 are provided at the tip of the head body 30 and the stirring blade 32. However, for example, as shown in FIG. 10, only the head main body 30 is configured without attaching the stirring blade 32, and the head main body 30 has a slightly larger diameter. Here, a plurality of injection nozzles 34 may be provided so as to be spaced apart substantially in the lateral direction.

  The special head 6 is composed of a head body 30 and a stirring blade 32, and a plurality of injection nozzles 34 are provided in a substantially lateral direction here. The head main body 30 and the stirring blade 32 may be provided in two upper and lower stages. Furthermore, as shown in FIG. A plurality of injection nozzles 34 may be provided in two upper and lower stages on the upper and lower two stirring blades 32. Note that the plurality of injection nozzles 34 may be provided in two or more upper and lower stages so as to have three or more stages. In this way, by providing a plurality of injection nozzles 34 in a plurality of upper and lower stages, a large consolidated improvement body T having a thickness in the vertical direction can be formed by a single cross injection of cement milk. As a result, the speed at which the consolidated improvement body T is formed can be increased, and an efficient operation can be performed.

  Further, the plurality of injection nozzles 34 project forward from the head body 30 and the stirring blade 32. However, in the injection of cement milk, which is a hardening material, from the injection nozzle 34, a desired straightness is achieved. If it comes to have, you may make it inject directly from the side surface of the head main body 30 and the stirring blade 32, without projecting the injection nozzle 34 ahead from the head main body 30 and the stirring blade 32.

  Further, in the special head 6, the plurality of jet nozzles 34 are provided in front of the head main body 30 and the stirring blade 32, but instead, as shown in FIG. 12, the stirring blade 32. The balancer members 37 provided on the left and right rear sides of the head main body 30 and the stirring blade 32 are eliminated, and the head body 30 and the stirring blade 32 are provided with a plurality of injection nozzles 34 having the same shape at the same positions as the plurality of injection nozzles 34 provided on the front side. The rear side of the wing 32 is provided rearward, and the guard cover 36 is provided in the same manner. As a result, as shown in FIG. 13, the wall-shaped solidified improvement body T can be formed in the ground simultaneously on both the front and rear sides with the tube rod 2 and the special head 6 as the center, and the work efficiency is greatly improved. Can be planned.

  In the special head 6, two stirring blades 32 are vertically attached to the head body 30, and three injection nozzles 34 and nozzle bodies 38 are provided on both front and rear sides of the head body 30 and the two stirring blades 32. Provide each. And as shown in FIG. 14, the rotation mechanism part 39 is provided between the upper part side to which the upper stirring blade was attached, and the lower part side to which the lower stirring blade was attached. Connect side to side freely. Then, the three injection nozzles 34 provided on both the front and rear sides of the upper side and the three injection nozzles 34 provided on the front and rear sides of the lower side are rotated by the rotation mechanism unit 39 and directed in different directions. To do. For example, as shown in FIG. 15, the upper side and the lower side are directed in different directions by 90 degrees.

  As a result, as shown in FIG. 16, a wall-shaped consolidation improvement body T having a cross shape can be formed in the ground by a single operation, and a special wall shape such as a cross shape can be formed. The consolidation improvement body T can be easily and easily created. The different directions on the upper side and the lower side are not limited to 90 degrees, and may be other angles such as 30 degrees and 45 degrees.

  Moreover, in the ground improvement method by the high-pressure jet agitation method of the present invention, even when the ground directly under the existing structure K is improved, the wall-shaped solidified improvement body T is created in the ground, so that the existing structure A wall-shaped consolidation improvement body T can be created up to the ground directly under the object K, and the ground directly under the existing structure K can be improved satisfactorily. As shown in FIG. 17, the tube rod 2 is inserted in the vicinity of the existing structure K, and a wall-shaped consolidation improvement body T is formed in the ground to the depth of the existing structure K. By performing a large number of this, a large number of wall-like consolidation improvement bodies T can be created in the ground directly under the existing structure K, and thereby the ground directly under the existing structure K is improved.

  Further, the ground improvement method by the high-pressure jet agitation method of the present invention is not applied to the one that only improves the ground by creating a wall-shaped solidified improvement body T in the ground. In addition, by installing a plate-shaped water shielding plate extending vertically in the ground and creating a wall-shaped consolidation improvement body T around it, the ground is insulated by a water shielding plate and a wall-shaped consolidation improvement body T. In order to improve the ground by dividing by, specifically, in the ground where the contaminated soil has pollutants in the ground, a water shielding plate and a wall-shaped consolidated improvement body T around the contaminated soil To prevent the contaminated soil from flowing out to the surrounding ground by enclosing the contaminated soil, or in the adjustment pond and river embankment, a water shielding plate around the adjustment pond and river And by creating a wall-shaped consolidated improvement body T, water, etc. Can be applied to soil improvement methods such prevented from flowing out to the surroundings containment.

  DESCRIPTION OF SYMBOLS 1 ... Construction machine, 2 ... Pipe rod, 3 ... Mast, 4 ... Elevating device, 5 ... Rotating device, 6 ... Special head, 11 ... Compressor, 12 ... Flow meter, 14 ... Mixing device, 15 ... Cement silo, 16 ... Submersible pump, 17 ... water tank, 18 ... flow meter, 19 ... high pressure pump, 20 ... curing material supply device, 30 ... head body, 31 ... bit, 32 ... stirring blade, 33 ... bit, 34 ... injection nozzle, 35 ... air nozzle 36 ... Guard cover, 37 ... Balancer member, 38 ... Nozzle body, 39 ... Rotating mechanism, 41 ... Construction machine, 42 ... Pipe rod, 43 ... Special head, 44 ... Injection nozzle

Claims (7)

The tube rod is inserted into the ground to a predetermined depth, and after insertion, the hardened material is sprayed at high speed and high pressure from the spray nozzle of the special head attached to the tube rod, and the hardened material is sprayed while cutting the ground with the spray energy of this hardened material In the ground improvement method by high-pressure jet stirring method to improve the ground by stirring and mixing the material and the ground, creating a consolidated improvement body in the ground,
Two or more spray nozzles are provided in the special head so as to be separated from each other in the horizontal direction, and the curing materials are crossed so that the curing materials intersect at the spray heads with slightly different ejection directions. In addition, the cross-injection of the curing material from the plurality of injection nozzles is performed by rotating by a predetermined angle without moving up or down to a predetermined range or moving upward, and then the tube rod is moved to a predetermined length. After being pulled up or moved upward, the cross-injection of the curing material from the plurality of injection nozzles is performed by rotating by a predetermined angle without moving up and down to a predetermined range or while moving upward. The ground improvement method by the high-pressure jet agitation method, characterized in that a wall-shaped consolidation improvement body was created in the ground by repeating this upward. .   When the cross-injection of the hardened material from a plurality of injection nozzles is rotated by a predetermined angle without moving up or down to a predetermined range or while moving upward, this is repeated upwardly from the injection nozzle. In the direction of rotation in the cross-injection of the hardener, after rotating in one direction, the tube rod is pulled up and then rotated in the opposite direction to change the direction of rotation alternately. The ground improvement method by the high-pressure jet stirring method according to claim 1. A special head used in the ground improvement method by the high-pressure jet agitation method of claim 1 and claim 2,
A ground improvement characterized by having a head body that goes vertically and agitating blades that protrude laterally on both the left and right sides are attached to the head body, and a plurality of jet nozzles are provided on the head body and the agitating blade. Special head used in the method.   In the plurality of spray nozzles provided in the head body and the stirring blade, the respective angles can be changed, and the intersecting position of the injected cement milk can be changed to an arbitrary position. A special head for use in the ground improvement method according to claim 3.   4. The plurality of spray nozzles provided on the head main body and the stirring blade are provided at the tip of the nozzle body, and the nozzle body protrudes from the head main body and the stirring blade. And 4. A special head used in the ground improvement method described in 4.   6. The special head used in the ground improvement method according to claim 5, wherein a jet nozzle and a nozzle body or a balancer member are attached to the agitating blade on the opposite side of the place where the jet nozzle and the nozzle body are provided.   Two agitating blades are attached to the head body at the top and bottom, a plurality of injection nozzles are provided on both the front and back sides of the head body and the two agitating blades, and an upper side and a lower agitating blade to which the upper agitating blade is attached. The attached lower side is rotatably connected, and a plurality of injection nozzles provided on both the front and rear sides of the upper side and a plurality of injection nozzles provided on the front and rear sides of the lower side are directed in different directions. The special head used for the ground improvement method of any one of Claim 3 thru | or 5.

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