JP2008106549A - Reinforcing body for ground improvement work and ground improvement construction method using this reinforcing body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ground improvement construction method capable of very easily and efficiently improving any type of the weak ground in the strong ground; and to provide a reinforcing body for ground improvement work suitably usable for such a ground improvement construction method. <P>SOLUTION: This reinforcing body 1 for the ground improvement work is connected by welding the outer periphery of respective ring bodies 2a, 2b, 2c and 2d to the outer periphery of separate support arms 3, 3 and 3. The respective support arms 3, 3 and 3 are put in a vertically juxtaposed state in parallel, and the respective ring bodies 2a, 2b, 2c and 2d are put in a horizontally arranged state at a vertically substantially equal interval by vertically separating a predetermined distance to the respective support arms 3, 3 and 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a ground improvement method for improving soft ground to strong ground.

  As a ground improvement construction method, the applicant excavates the ground with an auger to form vertical holes, mixes the cemented solidified material with the excavated current soil to generate improved soil, and combines the improved soil and water or cement-containing water. A method of creating a columnar improved body in the ground by kneading in a vertical hole with a screw auger to produce a slurry-like wet improved soil, embedding a steel pipe pile in the wet improved soil, and then solidifying the wet improved soil Was proposed (Japanese Patent Laid-Open No. 2003-3462). According to this ground improvement method, a columnar improved body having high strength can be created, and the soft ground can be strengthened very easily.

JP 2003-3462 A

  However, in the ground improvement method described above, depending on the ground to be improved, the bond strength between the steel pipe pile and the columnar improvement body may not necessarily be sufficient, and depending on the construction work on the improved ground, There may be situations where the strength is insufficient. Moreover, since the weight of the steel pipe pile embedded in the columnar improvement body is large, the ground improvement work may become large.

  An object of the present invention is to provide a ground improvement method capable of improving a strong ground very easily and efficiently regardless of the type of soft ground. It is providing the reinforcement body for ground improvement construction which can be used suitably for a construction method.

  Among the present inventions, the invention described in claim 1 is that the columnar improvement body is formed by excavating the ground to form a vertical hole, and solidifying by adding cement-containing water to the excavated current soil in the vertical hole. In the ground improvement work to be created, a reinforcement body for ground improvement work embedded in the columnar improvement body before the columnar improvement body solidifies, wherein a plurality of ring bodies are connected by a plurality of support arms. To do.

  When the ring body has an outer diameter of 100 mm or more and 1,000 mm or less and a thickness of 5 mm or more and 35 mm or less, the strength of the columnar improved body can be effectively increased, and the reinforcement body can be easily transported. This is preferable. Further, when the ring body is formed in a so-called donut shape, the difference between the outer diameter and the inner diameter is preferably 50 mm or more and 900 mm or less, while the support arm is not limited to a simple columnar reinforcing bar, Deformed reinforcing bars (reinforcing bars with large diameter nodes at predetermined intervals) and the like can be suitably used. Moreover, when using a reinforcing bar as the support arm, adjusting the diameter of the support arm to be 6 mm or more and 60 mm or less can effectively increase the strength of the columnar improvement body and facilitate the transportation of the reinforcement body. This is preferable.

  The invention described in claim 2 is characterized in that, in the invention described in claim 1, the ring body is flat.

  The invention described in claim 3 is the invention described in claim 1 or claim 2, wherein the inner diameter of the ring body arranged at a position other than the uppermost position is smaller than that of the uppermost ring body. It is a feature.

  The invention described in claim 4 is characterized in that, in the invention described in any one of claims 1 to 3, the outer diameter of at least one ring body is larger than that of other ring bodies. is there.

  The invention described in claim 5 is the invention described in any one of claims 1 to 4, characterized in that an outer peripheral edge and an inner peripheral edge of at least one ring body are connected to a support arm. To do.

  The invention described in claim 6 is the invention described in any one of claims 1 to 5, wherein the support arm penetrates at least one ring body, and the ring body is fixed to the support arm. It is characterized by being. As a method of fixing the ring body to the support arm, a method such as welding or bolting can be employed.

  The invention described in claim 7 is the invention described in any one of claims 1 to 6, wherein at least one ring body is formed in a spiral shape.

  In the invention described in claim 8, the ground is excavated with an auger to form a vertical hole, and the excavated current soil and cement-containing water are kneaded in the vertical hole to produce improved soil, and the improved soil Then, the ground improvement work reinforcement according to any one of claims 1 to 7 is inserted, and then the improved soil is solidified together with the inserted ground improvement work reinforcement, and the columnar improvement body is submerged in the ground. It is a ground improvement method characterized by creating

  In the ground improvement method of the present invention, it is preferable to adjust the ratio of the diameter of the columnar improvement body and the diameter of the ring body of the reinforcing body within a range of 1: 1 to 5: 1. By adjusting the ratio between the diameter of the columnar improvement body and the diameter of the ring body of the reinforcing body within the above range, the strength of the columnar improvement body can be efficiently increased.

  The invention described in claim 9 is the invention described in claim 8, wherein the tip of a rod-shaped pushing member (a so-called yatco or the like) with a sharp tip is disposed in a ring body arranged at a position other than the uppermost position. The reinforcing member for ground improvement work is pushed vertically into the columnar improvement body before solidification by the pushing member while being engaged with the periphery.

  The invention described in claim 10 is the invention described in claim 8 or claim 9, wherein the pushing member has a spiral blade, and the pushing member pushed into the columnar improvement body before solidification is swiveled. It is characterized in that it is pulled out while letting it go.

  Since the reinforcement body for ground improvement construction of claim 1 is a structure in which a plurality of ring bodies are connected by a support arm, when the columnar improvement body is solidified by being embedded in the columnar improvement body before solidification, the columnar improvement is performed. In addition to high adhesion strength to the body, the ring body increases the vertical support force of the columnar improvement body, and the support arm increases the horizontal support force of the columnar improvement body, so that the strength of the columnar improvement body can be effectively increased. . Therefore, according to the ground improvement work reinforcing body of claim 1, it is possible to efficiently strengthen the soft ground without increasing the diameter of the columnar improvement body. Moreover, since it is lightweight and easy to handle, the ground improvement work can be facilitated by using the ground improvement work reinforcement according to claim 1.

  In the reinforcing body for ground improvement work according to claim 2, since the ring body is formed flat, when the columnar improvement body is solidified by being embedded in the columnar improvement body before solidification, it is joined to the columnar improvement body. Furthermore, since the strength is very high and the ring body greatly increases the vertical support force of the columnar improvement body, the strength of the columnar improvement body can be increased extremely effectively.

  Since the inner diameter of the ring body disposed at a position other than the uppermost position is smaller than the uppermost ring body, the tip of the rod-shaped pushing member with a sharp tip is set to the inner diameter of the reinforcing member for ground improvement work according to claim 3. Since it can be pushed into the columnar improvement body before solidification by the pushing member while being engaged with the inner peripheral edge of the small ring body, the ground improvement work can be performed very efficiently. Moreover, it becomes possible to push the reinforcement body for ground improvement work vertically into the columnar improvement body before solidification.

  Since the outer diameter of at least one ring body is larger than the other ring bodies, the reinforcing body for ground improvement work according to claim 4 has a larger outer diameter when embedded in the columnar improvement body. The vertical bearing capacity of the buried part is extremely high. Therefore, according to the ground improvement work reinforcement of claim 3, it is possible to partially increase the strength of the columnar improvement body in accordance with the high-strength formation.

  The ground improvement work reinforcing body according to claim 5 is a structure in which the outer peripheral edge and the inner peripheral edge of at least one ring body are connected to each other by a support arm. The strength of the columnar improvement body can be dramatically increased by embedding it inside the body and solidifying the columnar improvement body.

  In the ground improvement work reinforcing body according to claim 6, since the support arm is fixed in a state of penetrating at least one ring body, similarly to the ground improvement work reinforcement body according to claim 4, Since the assembly strength is high, the strength of the columnar improvement body can be dramatically increased by embedding it in the columnar improvement body before solidification and solidifying the columnar improvement body.

  The ground improvement work reinforcing body according to claim 7 is very easy to rotate by embedding it in the columnar improvement body before solidification because at least one ring body is formed in a spiral shape. Can be embedded in a columnar improvement body.

  According to the ground improvement method of claim 8, it is possible to effectively strengthen the ground without increasing the diameter of the columnar improvement body to be created. Therefore, compared with the conventional ground improvement construction method, the ground can be reinforced more easily and cheaper than before.

  According to the ground improvement construction method of claim 9, since it becomes possible to push the reinforcing body for ground improvement construction vertically into the columnar improvement body before solidification using the pushing member, the horizontal bearing force and the vertical support in the improved ground Power can be increased effectively.

  According to the ground improvement construction method of claim 10, by rotating the pushing member when pulling out from the columnar improvement body (for example, when the spiral blade is provided clockwise from the upper side to the lower side, it is counterclockwise. (By rotating), the improved soil improved in the form of a slurry around the pushing member is compacted, and the hole after drawing out quickly disappears, so the strength of the columnar improved body can be effectively increased, The strength of the soft ground can be increased efficiently.

  Hereinafter, a ground improvement work reinforcing body (hereinafter simply referred to as a reinforcing body) of the present invention and a ground improvement method using the reinforcing body will be described in detail with reference to the drawings. 1 to 4 each show a reinforcing body according to the present invention. The reinforcing body 1 includes four ring bodies 2a, 2b, 2c, 2d and three support arms 3, 3, respectively. 3.

  The uppermost ring body 2a, the second ring body 2b from the top, and the third ring body 2c from the top are all formed into a ring shape having an outer diameter of 350 mm and an inner diameter of 250 mm by cutting an iron plate having a thickness of about 19 mm. Is formed. Similarly to the ring bodies 2a, 2b, 2c, the lowermost ring body 2d is formed by cutting an iron plate having a thickness of about 19 mm, and has an outer diameter of 350 mm and an inner diameter of the ring body 2a. , 2b, 2c slightly smaller than 250mm. In addition, a rectangular notch 4 is provided on the inner peripheral edge of the uppermost ring body 2a for engaging with the tip of a pushing member (yatco) during lifting. Each of the ring bodies 2a, 2b, 2c, 2d is provided with three connecting cutouts 5, 5, 5 having an arc shape of about 22 mmφ at equal intervals on the outer peripheral edge. Each of the connection cutouts 5, 5, 5 has a size (area) of about ½ of the horizontal cross section of the support arm 3. On the other hand, each support arm 3 is formed of a deformed reinforcing bar having a diameter of about 22 mm, and has a length of 3,000 mm.

  The reinforcing body 1 is connected by welding the connection notches 5, 5, 5 on the outer periphery of the ring bodies 2a, 2b, 2c, 2d to the outer periphery of the separate support arms 3, 3, 3, respectively. Yes. The support arms 3, 3 and 3 are in a state of being arranged vertically and in parallel, and the ring bodies 2a, 2b, 2c and 2d are perpendicular to the support arms 3, 3 and 3 and are predetermined Are arranged horizontally at substantially equal intervals and horizontally. In addition, the tips of the support arms 3, 3, and 3 protrude about 50 mm above the uppermost ring body 2a, and the lower ends of the support arms 3, 3, and 3 are in the lowest position. The ring body 2d protrudes by about 50 mm below.

  An example of soft ground improvement work using the reinforcing body 1 configured as described above will be described with reference to FIG. When performing the improvement work of the soft ground, the excavating machine 14 and the plant vehicle (not shown) are carried into the construction site, the auger 11 is attached to the carried excavating machine 14 and set at the construction position. Then, the ground is excavated by rotating the auger 11 while the cement slurry (mixture of cement and water) supplied by the plant car is ejected from the cutting edge of the rotating auger 11, and a predetermined size (for example, A vertical hole 12 having a diameter of about 600 mmφ and a depth of about 3,500 mm is formed (see FIG. 5A). Note that when excavating the ground as described above, the vertical hole 12 is formed using the leader 13 mounted on the excavating machine 14 so as to be exactly vertical (exactly perpendicular to the ground surface). By excavating the vertical hole 12 in this manner, a columnar improvement body (before solidification) 16 in which cement slurry and soil are uniformly mixed is formed inside the vertical hole 12.

  Thereafter, the auger 11 attached to the excavating machine 14 is replaced with a YATCO 15, and the YAGCO 15 is used to push the reinforcing body 1 into the columnar improvement body 16 that has not yet been cured. FIG. 6 shows the tip portion of the yatco 15. The yatco 15 is formed in a rod shape, and the tip portion is pointed. Further, a strip-like spiral blade 17 is provided in a spiral shape (counterclockwise spiral shape from the top to the bottom) at the end portion. In addition, an engaging protrusion 18 for engaging with the reinforcing body 1 is provided on the outer peripheral surface at the end of the Yatco.

  When the reinforcing body 1 is pushed into the columnar improvement body 16 using the Yattco 15, the Yatco 15 and the reinforcing body 1 are engaged. The engagement between the YATCO 15 and the reinforcing body 1 is performed after the engagement protrusion 18 at the end of the YATCO 15 is passed from the notch 4 portion of the uppermost ring body 2a to the lower side of the ring body 2a. This is done by slightly rotating 15. After the Yatco 15 and the reinforcing body 1 are thus engaged, the Yatco 15 is arranged so that its tip is located above the center (the center in the diameter direction) of the columnar improvement body 16.

  Thereafter, the Yatco 15 is lowered vertically into the columnar improvement body 16 (perpendicular to the ground surface). As such, when the yatco 15 is lowered, the tip of the yatco 15 sequentially passes through the inside of the ring bodies 2b and 2c of the reinforcing body 1 and engages with the inner peripheral edge of the ring body 2d at the lowest position of the reinforcing body 1. Match. When the yatco 15 is further lowered, the reinforcing body 1 is pushed into the columnar improvement body 16 together with the yatco 15 (see FIG. 5B). The Yatco 15 engaged with the reinforcing body 1 is accurately pushed in the vertical direction by the leader 13.

  And after pushing in the reinforcement body 1 to sufficient depth, it pulls out from the inside of the columnar improvement body 16, rotating the Yatco 15 clockwise. By pulling out the Yatco 15 while rotating in this manner, the improved soil made into a slurry by the cement slurry is compacted, and the hole after the Yatco 15 is pulled out quickly disappears (see FIG. 5C). . When the tip of the yatco 15 reaches the near surface, the engagement protrusion 18 at the tip of the yatco 15 is passed from the notch 4 portion of the ring body 2a of the reinforcing body 1 to the upper side of the ring body 2a. As a result, the engagement state between the Yatco 15 and the reinforcing body 1 is released. Then, spend a sufficient amount of time to cure and solidify the improved soil. By such a series of operations, a columnar improvement body (soil column) 16 having a predetermined depth is formed in the ground, and the surrounding soft ground is strengthened.

  As described above, the reinforcement body 1 is formed by connecting a plurality of flat ring bodies 2a, 2b, 2c, and 2d by a plurality of support arms 3, 3, and 3. Therefore, the interior of the columnar improvement body 16 before solidification is provided. When the columnar improvement body 16 is solidified by being embedded in the ring-shaped improvement body 16, the bonding strength with the columnar improvement body 16 is high, and the ring bodies 2 a to 2 d increase the vertical support force of the columnar improvement body 16, thereby supporting arms 3, 3. Increases the horizontal support force and the vertical support force of the columnar improvement body, so that the strength of the columnar improvement body 16 can be effectively increased. Therefore, according to the reinforcement body 1, even if it does not design the diameter of the columnar improvement body 16 large, it becomes possible to strengthen a soft ground efficiently. Moreover, since the reinforcement body 1 is lightweight and easy to handle, the ground improvement work can be facilitated.

  In addition, since the ring bodies 2a to 2d are formed flat in the reinforcing body 1, when the columnar improvement body 16 is solidified by being embedded in the columnar improvement body 16 before solidification, Since the adhesion strength is very high and the ring bodies 2a to 2d greatly increase the vertical supporting force of the columnar improvement body 16, the strength of the columnar improvement body 16 can be increased extremely effectively.

  Further, since the inner diameter of the ring body 2d arranged at the lowest position is smaller than that of the other ring bodies 2b, 2c, 2d, the reinforcing body 1 has the tip of the Yachto 15 at the inner peripheral edge of the ring body 2d. In the engaged state, it can be pushed into the columnar improvement body 16 before solidification by the yatco 15, so that the ground improvement work can be performed very efficiently. Moreover, it becomes possible to push the reinforcement body 1 vertically in the columnar improvement body 16 before solidification.

  On the other hand, the reinforcement improvement method in the above embodiment is to excavate the ground with the auger 11 to form the vertical hole 12, and in the vertical hole 12, the excavated current soil and the cement-containing water are kneaded to generate the improved soil, The reinforcing body 1 is inserted into the improved soil, and then the improved soil is solidified together with the inserted reinforcing body 1 to form the columnar improved body 16 in the ground. Therefore, according to the ground improvement method, it is possible to effectively strengthen the ground without increasing the diameter of the columnar improvement body 16. Therefore, compared with the conventional ground improvement construction method, the ground can be reinforced more easily and cheaper than before.

  Moreover, the reinforcement improvement construction method in the said embodiment is the state before making the reinforcement body 1 solidify by the Yatco 15 in the state which made the front-end | tip of the Yatco 15 engage with the inner periphery of the ring body 2d arrange | positioned in the lowest position. It is pushed vertically into the columnar improvement body 16. Therefore, according to this ground improvement method, it becomes possible to push the reinforcement body 1 vertically into the columnar improvement body 16 before solidification using the Yatco 15, so that the vertical supporting force in the improved ground is effectively increased. be able to.

  Further, the reinforcement improvement method in the above embodiment is such that the Yatco 15 has the spiral blades 17 and is pulled out while turning the Yatco 15 pushed into the columnar improvement body 16 before solidification. According to the construction method, when the pulling out from the columnar improvement body 16 is performed, the improved soil improved in a slurry state around the Yatco 15 is compacted, and the holes after the pulling out disappear quickly, so the columnar improvement body 16. Can be effectively increased, and the strength of the soft ground can be increased efficiently.

  The configuration of the reinforcing body of the present invention is not limited to the aspect of each embodiment described above, and the configuration of the shape and structure of the ring body, the support arm, etc., does not depart from the spirit of the present invention. Thus, it can be appropriately changed as necessary. Moreover, the structure of the ground improvement construction method of this invention is not limited to the aspect of the said embodiment at all, The structure, such as the shape of a pushing member, can be suitably changed as needed.

  For example, the reinforcement body is not limited to the ring body and the support arm formed of iron, but the ring body and the support arm are changed to those formed of another material such as stainless steel, casting or forging. It is also possible to do. In addition, at least a part of the surface can be coated with rust preventive coating or the like.

  Further, the reinforcing body is not limited to a structure in which a plurality of ring bodies are connected by three arms as in the above-described embodiment, and a structure in which two reinforcing arms are connected by two arms, or four or more arms as shown in FIG. It is also possible to change to a concatenated one. Further, the braces 21, 21,... Can be attached to the support arm for connecting the reinforcing members as shown in FIG. As described above, by connecting a plurality of ring bodies with a larger number of support arms or attaching braces to the support arms, the strength of the reinforcing body can be further increased, and the strength of the columnar improved body is further increased. It becomes possible to improve efficiently.

  Further, the reinforcing body is not limited to the one in which the outer peripheral edge of the ring body is connected to the support arm as in the above embodiment, but the one in which the inner peripheral edge of the ring body is connected to the support arm as shown in FIG. For example, the arm is penetrated through the ring body (the support arm is fixed in a state of passing through the ring body), or the outer periphery and inner periphery of the ring body are connected to the support arm as shown in FIG. It is also possible to change. In this way, it is possible to increase the strength of the reinforcement body by connecting the inner and outer peripheral edges of a plurality of ring bodies to the support arm, or by penetrating the support arm into the ring body, improving the columnar shape. It becomes possible to improve the strength of the body more efficiently.

  Further, the reinforcing body is not limited to the one in which all the ring bodies have the same size as in the above-described embodiment, and some of the ring bodies have different sizes as shown in FIG. As described above, it is possible to change all ring bodies to different sizes. By enlarging a part of the ring body in such a manner, it becomes possible to increase the vertical supporting force of the part, and it becomes possible to partially reinforce the columnar improvement body according to the state of the ground. .

  Further, the reinforcing body is not limited to a structure in which all the ring bodies are connected by a cylindrical support arm as in the above embodiment, and as shown in FIG. It is also possible to change to H-shaped steel or the like.

  In addition, the reinforcing body is not limited to a structure in which all the ring bodies are connected by the same number of support arms as in the above embodiment, and the number of support arms that connect some of the ring bodies may be increased or decreased. Is possible. FIG. 14 shows a reinforcing body in which the number of support arms that connect the ring bodies positioned in the upper portion is increased from the number of support arms that connect the ring bodies positioned in the lower portion by adopting such a configuration. It is. By increasing the number of support arms that connect the upper ring bodies in this way, it is possible to increase the strength of the upper part of the reinforcing body, increase the strength of only the upper part of the columnar improvement body, and support horizontally. It is possible to prevent the situation where the strength of the lower part of the columnar improvement body that is not applied with much force is unnecessarily increased, and to perform inexpensive and efficient ground improvement work.

  Further, the reinforcing body is not limited to a simple flat plate shape as in the above embodiment, and at least a part of the ring body is formed in a spiral shape as shown in FIG. The ring-shaped ring body is partly cut in the diametrical direction, and the entire ring body forms a spiral so that the edges of the cut portion are positioned vertically. is there. In the case of adopting such a configuration, when pushing into the columnar improvement body before solidification, it can be pushed very easily by rotating, and the ground improvement work can be efficiently advanced.

  Further, the reinforcing body is not limited to the one in which all the ring bodies form a continuous circumferential surface as in the above-described embodiment. It is also possible to change the ring body to one formed in a divided shape. In this way, by providing a cut in a part of the ring body or by forming the ring body in a divided shape, the resistance when pushing into the columnar improvement body is reduced, and the ground improvement work is smoothly carried out. It is possible to proceed.

  In addition, the reinforcing body is not limited to a so-called donut in which all the ring bodies have a single hole in the center as in the above embodiment, and the tip of the pushing member used when pushing into the columnar improvement body. In accordance with the shape of the ring member, the ring body to be engaged with the pushing member is formed with a plurality of holes (circular or other shape holes) at equal intervals from the center as shown in FIG. It is also possible to change to a shape in which a hole having a shape other than a circle is formed.

  Further, the reinforcing body can be changed to a structure that uses a screw rebar as a support arm and fixes the ring body by a nut member screwed to the screw rebar. FIG. 18 shows such a modified example. The reinforcing body 31 includes flat ring bodies 32, 32,... Each having a plurality of support arm insertion holes and screw grooves that function as support arms. The threaded reinforcing bars 33, 33,. Then, the screw rebar 33 is inserted through each support arm insertion hole of the ring body 32, and at the upper and lower positions of the ring body 32, the two nut members 34 screwed into the thread grooves of the screw rebar 33 are used. The ring body 32 is in a fixed state. When the reinforcing body 31 is configured as described above, the assembling of the reinforcing body 31 is extremely easy. When the reinforcing body is configured as described above, a “tough screw bar” manufactured by Kyoei Steel Co., Ltd. or the like can be suitably used. In addition, if the support arm of the reinforcement body is a screw rebar as described above, a new screw rebar can be very easily added using a nut member when adding the support arm during the ground improvement work. It is possible to add (connect).

  On the other hand, the ground improvement method using the reinforcing body of the present invention is not limited to only a single reinforcing body embedded in the columnar improvement body as in the above embodiment, according to the state of the ground to be reinforced, In the middle of the construction, it is possible to add a support arm of the reinforcing body or attach a ring body. In addition, the method of adding the support arm of the reinforcement body during the construction is to add a new support arm to the upper end of the support arm that protrudes upward from the surface of the uppermost ring body as shown in FIG. The method is not limited to this method, and a new support arm is added (welded) to the surface of the uppermost ring body, or a new support arm is penetrated (welded) to the uppermost ring body. A method or the like can also be adopted.

  Since the reinforcing body of the present invention exhibits excellent effects as described above, it can be suitably used for ground improvement work for forming a columnar improvement body. Moreover, since the ground improvement method using the reinforcing body of the present invention has excellent effects as described above, it can be widely used as a method for effectively reinforcing soft ground at low cost.

It is a front view of a reinforcement body. It is a top view of a reinforcing body. It is a bottom view of a reinforcing body. It is a perspective view of a reinforcement body. It is explanatory drawing which shows the procedure of the ground improvement construction using a reinforcement body. It is explanatory drawing which shows a mode that a reinforcement body is embed | buried in an improved body with a Yatco. It is a perspective view which shows the example of a change of a reinforcement body. It is a perspective view which shows the example of a change of a reinforcement body. It is a perspective view which shows the example of a change of a reinforcement body. It is a perspective view which shows the example of a change of a reinforcement body. It is a perspective view which shows the example of a change of a reinforcement body. It is a perspective view which shows the example of a change of a reinforcement body. It is a perspective view which shows the example of a change of a reinforcement body. It is a perspective view which shows the example of a change of a reinforcement body. It is a perspective view which shows the example of a change of a reinforcement body. It is a perspective view which shows the example of a change of a reinforcement body. It is a perspective view which shows the example of a change of a ring body. It is a perspective view which shows the example of a change of a reinforcement body (a shows the state before fastening a ring body with a nut member, b shows the state after fastening a ring body with a nut member. Is shown). It is a perspective view which shows the example of a change of the ground improvement construction of a reinforcement body.

Explanation of symbols

  1 ·· Reinforcement body, 2a, 2b, 2c, 2d ·· Ring body, 3 ·· Support arm, 11 ·· Auger, 15 ·· Yatco (pushing member), 16 ·· Columnar improvement body, 17 ·· Helix wing .

Claims (10)

Excavating the ground to form vertical holes, and in the ground improvement work to create a columnar improvement body by adding cement-containing water to the existing soil that has been excavated and solidifying in the vertical hole, before the columnar improvement body solidifies It is a reinforcement body for ground improvement work to be embedded inside the columnar improvement body,
A reinforcement body for ground improvement work, wherein a plurality of ring bodies are connected by a plurality of support arms.   The reinforcement body for ground improvement work according to claim 1, wherein the ring body is flat.   The reinforcing body for ground improvement work according to claim 1 or 2, wherein an inner diameter of the ring body arranged at a position other than the uppermost position is smaller than that of the ring body at the uppermost position.   The reinforcement body for ground improvement work according to any one of claims 1 to 3, wherein an outer diameter of at least one ring body is larger than that of other ring bodies.   The reinforcement body for ground improvement work according to any one of claims 1 to 4, wherein an outer peripheral edge and an inner peripheral edge of at least one ring body are connected to a support arm.   The reinforcement body for ground improvement work according to any one of claims 1 to 5, wherein the support arm passes through at least one ring body, and the ring body is fixed to the support arm.   The reinforcement body for ground improvement work according to any one of claims 1 to 6, wherein at least one ring body is formed in a spiral shape.   The ground is excavated with an auger to form a vertical hole, and in the vertical hole, the excavated current soil and cement-containing water are mixed to produce improved soil, and the improved soil is any one of claims 1 to 7 The ground improvement is characterized in that a ground improvement work is formed in the ground by inserting the ground improvement work reinforcement described in 1. and then solidifying the improved soil together with the inserted ground improvement work reinforcement. Construction method.   With the tip of a rod-shaped pushing member with a sharp tip engaged with the inner periphery of the ring body arranged at a position other than the uppermost position, the pushing member is used to form a columnar structure before solidification of the ground improvement work. The ground improvement method according to claim 8, wherein the ground improvement method is pushed vertically into the improved body. The pushing member has a spiral wing,
The ground improvement method according to claim 8 or 9, wherein the pushing member pushed into the columnar improvement body before solidification is pulled out while turning.

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