JP2013036213A - Ground division improvement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for improving divided ground including unimproved ground.SOLUTION: On a peripheral surface of a rod distal end, in order to jet a hardener liquid by a high pressure at a prescribed angle in a circumferential direction, a first nozzle 2 is arranged downwards on a rod axial direction ground hand side and a second nozzle 3 is arranged upwards on a rod axial direction underground distal end side, keeping such a distance that the hardener liquids jetted from the first nozzle 2 and the second nozzle 3 are not brought into contact with each other at the same time and at the same spot. By mixing the hardener liquid into the ground by the high pressure from the first nozzle 2 and the second nozzle 3 while axially rotating a rod 1 at the prescribed angle in one circumferential direction at a prescribed depth, a dish-like first nozzle planar improvement body 51 and a second nozzle planar improvement body 52 inclined at the prescribed angle respectively are formed simultaneously. Also, the first nozzle planar improvement body 51 and the second nozzle planar improvement body 52 are crossed and connected with each other with a short time difference on a prescribed radius circumference in the circumferential direction centering on the rod 1, an improvement area 61 in an abacus bead shape containing unimproved ground 71 is formed, and thus the ground of a prescribed area is divided.

Description

The present invention inserts a rod into the ground and injects a hardened material liquid from an injection nozzle provided on the rod to create a plate-like improved body, thereby encapsulating the unimproved ground and dividing and improving the predetermined ground On how to do.

Ground improvement methods have been known for the purpose of soft ground stabilization, ground support, tunnel support, structure foundation, structure foundation reinforcement, liquefaction prevention, underground walls for water shielding, groundwater spring prevention, etc. Yes. In this ground improvement method, there is an improved body forming method in which a rod is inserted into the ground and a hardened material liquid is injected from an injection nozzle provided on the rod to form an improved body. It is disclosed.

In this improved method disclosed in Patent Document 1, the injection pipe is connected to the lower end of the injection pipe (rod) in a swingable manner, the injection nozzle is provided at the tip of the injection pipe, the injection pipe is inserted into the ground, Injecting the curing material from the injection nozzle at high pressure while moving or stopping the position of the injection nozzle by swinging the injection pipe from side to side with the injection pipe positioned downward from the connection point between the injection pipe and the injection pipe. Then, the hardened material is mixed into the ground, the injection tube is pulled out and / or rotated, and a wall-like improved body having a wall-like portion and a plate-like portion orthogonal to the wall-like portion is formed. In addition, by connecting and forming a plurality of the wall-like improvement bodies, a grid shape is formed in both the planar direction and the vertical direction, and the fluidity of ground water, sand, etc. in the non-hardened portion surrounded by the wall-like improvement bodies is blocked or inhibited.

That is, a wall-like improvement body formed in the insertion or extraction direction in which the injection tube moves and a wall-like improvement body formed in the left-right direction in which the injection nozzle injects into a lattice-like or polygonal cylindrical body group. An improved body is constructed.

Japanese Patent No. 3219372

However, in the conventional improvement method, it was possible to form a square or lattice improvement region by arranging several to a dozen or more improvement members adjacent to or connected to each other. The ground on the rod peripheral surface cannot be subdivided into a predetermined size in the direction, and it has been difficult to divide and improve the predetermined ground finely by the improved body by the ground improvement method.

This invention is made | formed in view of an above-described problem, Comprising: An unimproved ground is included by creating a plate-shaped improvement body, and it aims at providing the method of dividing and improving a ground finely.

In order to achieve the above object, the ground division improving method of the present invention has a plurality of injection nozzles individually set so as to inject a hardener liquid at a predetermined angle in the circumferential direction onto the peripheral surface of the rod tip. And a plurality of injection nozzles are injected from the first nozzle and the second nozzle with the first nozzle facing downward on the ground axial side of the rod axis and the second nozzle facing upward on the underground tip side of the rod axis direction. The hardener liquids are arranged at the same point so as not to contact each other at the same time, and the rod is inserted into the ground, and the rod is rotated at a predetermined depth in one circumferential direction while rotating the rod by a predetermined angle. A forming step 1 for simultaneously forming a dish-like first nozzle plate-like improved body and a second nozzle plate-like improved body inclined at a predetermined angle by mixing a hardener liquid into the ground at a high pressure from one nozzle and a second nozzle. In the creation process 1, The one-nozzle plate-like improved body and the second nozzle-plate-like improved body are cross-linked with each other at a connecting point on the circumference of a predetermined radius in the circumferential direction centering on the rod, and the unmodified ground is internally enclosed. The ground of a predetermined area is divided | segmented by forming the abacus ball-shaped improvement area.

According to this, because it is possible to create an abacus ball-shaped improved area in which unmodified ground is internally incorporated into an abacus ball shape with a plate-like improved body, which could not be created simultaneously in one process, in a single process. It becomes easy to divide and improve the predetermined ground in a short time.

In addition, after forming the abacus bead-shaped improved region in the creation step 1, the rod is pulled out to a different depth in the axial direction by a predetermined distance, and a creation step 2 similar to the creation step 1 is performed, so that the first step in the creation step 1 The unimproved ground that is internally enclosed in the abacus bead-shaped improved area formed in (2) can be subdivided by the second nozzle plate-shaped improved body formed in the forming step 2. According to this, since it is possible to finely divide the unimproved ground internally contained in the abacus beaded improved area, the separation interval of the ground becomes smaller, thereby improving the waterstop and the strength of the abacus beaded improved area. Will improve.

After forming the abacus ball-shaped improved region in the creation step 1, the rod is pulled out a predetermined distance in the axial direction to another depth, and the creation step 2 similar to the creation step 1 is carried out, whereby the creation step 1 and the creation step The unimproved unencapsulated ground adjacent to both of the two abacus ball-shaped improved areas formed in 2 is divided into a predetermined shape by the first nozzle plate-shaped improved body and the second nozzle plate-shaped improved body. can do. According to this, since the ground adjacent to the abacus bead improvement area can be included, not only the efficiency of the division is good, but also the waterstop and strength of the whole improvement body centering on the abacus bead improvement area. improves.

In addition, according to the present invention, since the abacus bead improved area in which the unmodified ground is included in the abacus bead shape that could not be simultaneously formed in one step in the past, the abacus bead shape can be created in one step. By continuously creating the improved area at a predetermined interval in the rod drawing direction, the cylindrical area ground centered on the rod is finely divided, so that fine response to the required design strength and fine volume setting per unit are set. Is possible.

Moreover, it is also easy to obtain the water-stopping effect in the vertical and horizontal directions without improving the total soil volume by joining the improved bodies in a predetermined direction at a horizontal position.

In addition, dividing the unimproved ground with a plate-shaped plate-shaped improved body not only reduces the load on the target ground, but also reduces the amount of materials used and the amount of sludge. The effect of reducing and shortening the work period can be expected.

It is a schematic block diagram of the apparatus which performs the ground division improvement method. 1 is a schematic perspective view of a rod of Example 1. FIG. 1 is a schematic sectional view of a rod of Example 1. FIG. It is a schematic sectional drawing of the rod which performs a ground division improvement method. It is a schematic sectional drawing of the rod which performs a ground division improvement method. It is a schematic side view of the rod of Example 1. 1 is a view showing an improved body created in Example 1. FIG. 1 is a view showing an improved body created in Example 1. FIG. It is a figure which shows the improvement body created in Example 2. FIG. It is a figure which shows the improvement body created in Example 2. FIG.

Next, a first embodiment of the improved body construction method according to the present invention will be described. As shown in FIG. 1, the ground division improving method according to the present invention is provided with a first nozzle 2 and a second nozzle 3 for injecting a hardening material liquid on the peripheral surface of the rod 1, and is inserted at a predetermined depth in the ground. Forming a abacus-shaped improved body by injecting the hardened material liquid at a high pressure from the first nozzle 2 and the second nozzle 3 rotating the rod 1 in the circumferential direction by the nozzle 2 construction machine 21 by the nozzle 2 construction machine 21 And the improvement body which divides | segments a ground into a predetermined shape is created, performing the extraction process which draws out this rod 1 for a predetermined distance to an axial direction with the construction machine 21 alternately. In the following, the specific contents will be described.

The rod 1 has a swivel at the end on the ground side, and a hardener liquid sent from a ground plant by a dedicated hose is supplied to the rod 1 through the swivel. Accordingly, the rod 1 ejects the supplied hardening material liquid or the like from the first nozzle 2 and the second nozzle 3, thereby mixing the hardening material liquid into the ground around the rod 1 and having a predetermined angle. Create a shape improvement.

In addition, although the rod 1 of this embodiment is circular in cross-sectional shape, it is not restricted to this in particular. Further, the rod 1 is provided with a necessary number of passages to which a hardening material liquid, compressed air and water are supplied, respectively, and may be a double tube, triple tube or quadruple tube or a porous tube structure. In addition, in addition to the rod 1, a mud passage and a communication passage may be provided as appropriate.

In FIG. 2, an example of arrangement | positioning of the several injection nozzle in the front-end | tip part of the rod 1 was shown. The first nozzle 2 is arranged at 15 degrees downward with respect to the circumferential direction of the rod on the axial ground side, and the second nozzle 3 is arranged at 15 degrees upward with respect to the circumferential direction of the rod on the underground side of the rod axis direction. In FIG. 2, the distance between the first nozzle 2 and the second nozzle 3 is 60 cm, but the distance and arrangement including the angles of the respective nozzles are appropriately changed according to the ground range to be divided, the division interval, the number of divisions, and the like. it can.

FIG. 3 shows a state in which the hardening material liquid is sprayed from the first nozzle 2 and the second nozzle 3 at the tip of the rod 1 in FIG. 2 as viewed from above. The first nozzle 2 and the second nozzle 3 have different heights along the circumferential direction of the rod 1 as shown in FIG. Are arranged so as to be 30 °, and at the same time, the curing material liquid is jetted. At this time, since the first nozzle 2 and the second nozzle 3 are arranged at a wide angle (30 °), the curable material liquid jet 11 of the first nozzle and the curable material liquid jet 12 of the second nozzle ejected from each of them are simultaneously. Even if it is jetted, it will not collide, nor will it interfere with each other's flight distance. Therefore, in FIG. 2 and FIG. 3, the arrangement of the first nozzle 2 and the second nozzle 3 in the axial direction of the rod circumferential surface is shifted, but it can also be arranged in the coaxial direction. Also, the angle of the wide angle arrangement can be freely set in a range where the curable material liquid jet 11 of the first nozzle and the curable material liquid jet 12 of the second nozzle do not contact each other at the same point at the same time.

FIG. 3 shows an example in which the first nozzle 2 and the second nozzle 3 are arranged so that the included angle formed by connecting the centers of the rods 1 is 30 °. They can be arranged in parallel with each other, or can be arranged on the back as shown in FIG. 4 and 5, the curable material liquid jet 11 of the first nozzle and the curable material liquid jet 12 of the second nozzle do not collide with each other and do not interfere with each other's flight distance. 1, 2, and 3, each of the first nozzle 2 and the second nozzle 3 is represented by a single nozzle hole. However, a plurality of nozzles are used to increase the flight distance and to mix the curing material. The 1st nozzle 2 and the 2nd nozzle 3 may be comprised by a group, respectively. In addition, a third nozzle or a fourth nozzle may be provided, and the larger the nozzle diameter, the larger the flying distance of the curable material liquid to be sprayed. It may be changed.

FIG. 6 shows a side view of the state in which the curing material liquid is injected from the first nozzle 2 and the second nozzle 3 at the tip of the rod 1 shown in FIGS. 2 and 3. Since the 1st nozzle 2 and the 2nd nozzle 3 are wide angle (30 degrees) arrangement | positioning, the hardening material liquid jet 11 of the 1st nozzle injected from each and the hardening material liquid jet 12 of the 2nd nozzle are injected simultaneously. Will not collide nor interfere with each other's distance.

FIG. 7 shows a first nozzle plate-like improvement body 51 formed by the first nozzle 2 and a second nozzle plate-like improvement body formed by the second nozzle 3 when the rod 1 of FIG. 52. The first nozzle plate-like improvement body 51 having a 15-degree downward dish shape and the second nozzle plate-like improvement body 52 having a 15-degree upward dish shape have a predetermined radius circle in the circumferential direction around the rod 1. They are cross-linked with each other at a connecting point 53 on the circumference with a short time difference to form an abacus ball-shaped improved area 61. The abacus bead improvement area 61 internally includes an unimproved inclusion ground (divided inclusion ground) 71.

Here, the first nozzle plate-like improvement body 51, the second nozzle plate-like improvement body 52, the improvement body described below, and the like are generally hardened and cured with a predetermined time. However, for the sake of convenience of explanation, the state before hardening immediately after the hardening material liquid is mixed into the ground is also described as an improved body.

FIG. 8 shows a plan view of the abacus bead improvement area 61 formed in FIG. A first nozzle plate-like improvement body 51 and a second nozzle plate-like improvement body 52 are formed around the rod 1 and are cross-connected at a connection point 53.

Next, a second embodiment in which an improved body is created by the ground division improving method will be described with reference to FIG. In the present embodiment, by using the formation of the abacus bead improvement area 61 described in the first embodiment, an unimproved inclusion ground (divided inclusion ground) 71 in which the abacus bead improvement area 61 is internally incorporated is used. A method of re-dividing, and an unimproved unencapsulated ground adjacent to the plurality of abacus bead-shaped improved areas 61 are combined into a predetermined shape by the first nozzle plate-shaped improved body 51 and the second nozzle plate-shaped improved body 52. Will be described. The contents described above will be omitted as appropriate.

After the abacus ball improvement area 61 of FIG. 7 is created, after the rod 1 is pulled 30 cm above the ground as shown in FIG. 9, the second abacus ball improvement area 61 is similarly created at this position, as shown in FIG. An improved area in which two such abacus bead-shaped improved areas 61 are combined is formed. At this time, an unimproved inclusion ground (divided inclusion ground) 71 internally included in the first abacus bead improvement area is used as a second nozzle for forming a second abacus bead improvement area 61. Subdivided by the plate-like improved body, an unimproved inclusion ground (divided and mixed ground) 72 is formed inside the unimproved inclusion ground (divided and mixed ground) 71. Further, unimproved unencapsulated undivided ground adjacent to both the first abacus bead improvement area 61 and the second abacus bead improvement area 61 is designated as the first abacus bead improvement areas 61 and 2. The first nozzle plate-like improvement body 51 and the second nozzle plate-like improvement body 52 constituting the first abacus ball-like improvement area 61 are combined into a donut shape having a diamond shape in cross section, and the adjacent unmodified improved ground (divided) Forming a composite ground) 73;

In Example 2, the two abacus bead improved areas 61 were formed with a rod drawing distance of 30 cm, but several or several tens of abacus bead improved areas 61 may be formed in the same manner. The rod pull-out distance is not limited to 30 cm and can be set freely.

As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

DESCRIPTION OF SYMBOLS 1 ... Rod 2 ... 1st nozzle 3 ... 2nd nozzle 11 ... Hardening material liquid jet 12 of 1st nozzle ... Hardening material liquid jet 21 of 2nd nozzle ... Construction machine 51 ... 1st nozzle plate-shaped improvement body 52 ... 2nd Nozzle plate-like improved body 53 ... Connection point 61 ... Abacus ball-like improved area 71 ... Unimproved inclusion ground (division-enclosed ground)
72: Undivision-enclosed mixed ground (divided mixed ground)
73 ... Adjacent unimproved ground (divided ground)

Claims (3)

On the peripheral surface of the rod tip, it has a plurality of injection nozzles individually set to inject the curing agent liquid at a high pressure at a predetermined angle in the circumferential direction,
The plurality of injection nozzles are hardened materials that are injected from the first nozzle and the second nozzle with the first nozzle facing downward on the ground axial side of the rod axis and the second nozzle facing upward on the underground distal end side of the rod axis direction. The liquids are placed at the same point at the same time so as not to contact each other.
Insert the rod into the ground and rotate the rod at a predetermined depth in one circumferential direction at a predetermined angle while mixing the hardener liquid into the ground at high pressure from the first nozzle and the second nozzle. Having a creation step 1 for simultaneously producing the first nozzle plate-like improved body and the second nozzle plate-like improved body,
In the creation step 1, the first nozzle plate-like improvement body and the second nozzle plate-like improvement body are cross-linked with each other with a short time difference at a connection location on a predetermined radial circumference in the circumferential direction around the rod, A ground division improving method, wherein a ground of a predetermined area is divided by forming an abacus ball-like improved area in which the unimproved ground is internally included. After forming the abacus ball-shaped improved region in the creation step 1, the rod is pulled out a predetermined distance in the axial direction to another depth, and the creation step 2 similar to the creation step 1 is performed, so that in the creation step 1 first. 2. The ground division improvement according to claim 1, wherein the unimproved ground internally enclosed in the formed abacus bead improvement area is subdivided by the second nozzle plate-like improvement body created in the creation step 2. Method. After forming the abacus ball-shaped improved region in the creation step 1, the rod is pulled out a predetermined distance in the axial direction to a different depth, and the creation step 2 similar to the creation step 1 is performed, whereby the creation step 1 and the creation step The unimproved unencapsulated ground adjacent to both of the two abacus ball-shaped improved areas formed in 2 is divided into a predetermined shape by the first nozzle plate-shaped improved body and the second nozzle plate-shaped improved body. The ground division improving method according to claim 1 or 2, characterized in that: