JP5975709B2 - Manufacturing method for underground structures - Google Patents

Description

  The present invention relates to a method for manufacturing an underground structure, and is particularly suitable when applied to a backfilling operation performed after removing a support pile used for a building such as a building.

  Conventionally, a fluidized soil obtained by kneading and fluidizing a solidified material and water in a soil is placed in the excavation hole formed by excavating the ground, and the construction-generated soil is buried on the fluidized soil. By backfilling the backsoil, an underground structure configured in a layered manner is formed, and backfilling work is performed to return the ground to its original state (see Patent Document 1).

JP 2001-221369 A

  In such a backfilling operation, the fluidized soil and the backfilled soil are in direct contact with each other, so the backfilled soil is mixed with the fluidized treated soil, and the fluidized treated soil and the backfilled soil are mixed. Since it may not be possible to stabilize the quality of underground structures near the boundary, it is desirable to stabilize the quality.

  The present invention has been made in view of the above points, and intends to propose a method of manufacturing an underground structure that can improve quality.

In order to solve this problem, in the method for manufacturing an underground structure according to the present invention, the first soil 14 having predetermined characteristics is provided in the method for manufacturing the underground structure 1 extending in the vertical direction in a substantially cylindrical shape in the ground 3. A lower layer portion forming step for forming the lower layer portion 11 by being put inside the cylindrical portion 10 or 38 extending in a substantially cylindrical shape into the ground 3, and a rotation that is substantially cylindrical and formed by polystyrene foam , and substantially follows the horizontal direction. The partition which arrange | positions the partition material 12 which contacts the inner wall face of the cylindrical part 10 or 38, and suppresses rotation when rotating inside the cylindrical part 10 or 38 centering on the axis | shaft 50 in the upper part of the lower layer part 11 The material arranging step and the upper layer portion forming step for forming the upper layer portion 13 by introducing the second soil 15 having a characteristic different from that of the first soil 14 into the upper portion of the partition material 12 are provided.

  According to the present invention, the second soil and the first soil are physically separated by preventing the partition material from rotating due to the impact force with which the second soil collides. Since the mixing of both in the vicinity of the boundary with the first soil can be reduced, an underground structure manufacturing method capable of improving the quality can be realized.

It is a basic diagram which shows the whole structure of an underground structure. It is a perspective view which shows the structure of a partition material. It is a basic diagram which shows the mode of removal work. It is a basic diagram which shows the mode (1) of a backfilling operation | work. It is a basic diagram which shows the mode (2) of a backfilling operation | work. It is a basic diagram which shows the mode (3) of a backfilling operation | work. It is a basic diagram which shows the mode (4) of a backfilling operation | work. It is a basic diagram which shows a mode that backfill soil collides with a partition material. It is a front view which shows the structure of the partition material by other embodiment.

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

(1) Embodiment In FIG. 1, as a whole, reference numeral 1 denotes a soil by a backfilling operation in an excavation hole 10 formed by excavating the ground 3 in order to remove a support pile used for a building such as a building. The underground structure formed by backfilling etc. is shown.

  The underground structure 1 has a cylindrical excavation hole 10 extending substantially vertically downward from the ground surface 2, and a lower layer portion 11, a partition material 12, and an upper layer portion 13 are layered from below to above. They are arranged sequentially.

  The lower layer portion 11 is filled with fluidized soil 14 that is a soil obtained by kneading and fluidizing a solidifying material and water into the building-generated soil. The upper layer portion 13 is filled with backfilling soil 15 such as improved soil or earth and sand.

  The partition material 12 physically separates the lower layer portion 11 and the upper layer portion 13 by being positioned between the lower layer portion 11 and the upper layer portion 13.

  As shown in FIG. 2, the partitioning member 12 has a solid cylindrical shape, a circular lower bottom surface 20, a circular shape having a diameter equivalent to the lower bottom surface 20, an upper bottom surface 22 parallel to the lower bottom surface 20, and a lower bottom surface 20 has a peripheral side surface 24 which is erected at a right angle from the outer periphery of the lower surface 20 and is in contact with the outer periphery of the upper bottom surface 22 so as to be at a right angle to the upper bottom surface 22.

  Since the partition member 12 is formed to have an outer diameter of 740 [mm] as a width in the horizontal direction and a thickness of 500 [mm] as a height from the lower bottom surface 20 to the upper bottom surface 22, Instead, the shape has a sufficient thickness.

  Moreover, since the partition material 12 is comprised by the polystyrene foam, it is cheap, and even if it forms thickly, it is lightweight, is easy to carry by an operator, and has high workability | operativity. In addition, the polystyrene foam can be easily formed into an arbitrary shape.

  Furthermore, the partition material 12 made of expanded polystyrene can be physically separated from the lower layer portion 11 and the upper layer portion 13 without being weathered even if the years have passed, and is once manufactured by performing a backfilling operation. When the underground structure 1 is re-excavated, it is easily destroyed by the excavating tool, so that it is possible not to become an obstacle during the re-excavation.

  In addition, when the underground structure 1 is re-excavated later, the partitioning material 12 is an object that is clearly different in color and hardness from the backfilling soil 15 and the fluidized soil 14, so it is easy to serve as a mark when working. The operator can easily confirm that the re-excavated location is appropriate.

  When manufacturing the underground structure 1 having the above-described structure, the operator removes the pile to be removed 100 and the excavation hole 10 drilled when removing the pile to be removed 100 according to the procedure described below. Perform backfilling.

  As shown in FIG. 3, the rotational drive machine 34 sequentially attaches and attaches a rotation transmission cylindrical portion 38 having a bottomless cylindrical shape to the upper portion of the tip blade tip portion 36 to which a cutting claw is attached. By transmitting the rotational force of the driving machine 34 to the tip edge portion 36, the tip edge portion 36 is advanced deeply into the ground while cutting the ground 3.

  When the drilling to the predetermined depth is completed, the crawler crane 30 grasps the removal target pile 100 with the excavation tool 40 and discharges it to the outside of the excavation hole 10, whereby the removal of the removal target pile 100 is completed.

  Thereafter, as shown in FIG. 4, the tip of the placing device 42 made of a tremy tube is inserted into the rotation transmission cylinder portion 38, and the mixer wheel 31 passes through the placing device 42 to a predetermined stopping height and the fluidized soil 14. The lower layer part 11 is formed by driving.

  Subsequently, as shown in FIG. 5, the crawler crane 30 throws the partition material 12 into the rotation transmission cylinder portion 38. The partition material 12 is placed on the upper surface of the fluidized soil 14 in an uncured state so that the lower bottom surface 20 (FIG. 2) is in contact with it.

  Here, the inner diameter of the rotation transmission cylinder portion 38 is 890 [mm]. For this reason, the outer diameter (740 [mm]) of the partition member 12 is formed to be smaller by 150 [mm] than the inner diameter of the rotation transmission cylinder portion 38.

  Thus, since the partition member 12 has a slight gap between the inner wall surface of the rotation transmission cylinder portion 38, the partition member 12 flows without being caught by the inner wall surface of the rotation transmission cylinder portion 38 while being dropped. It is possible to reliably reach the upper surface of the chemical treatment soil 14.

  When the partition material 12 is placed on the upper surface of the fluidized soil 14, the operator hangs a measure with a weight at the tip vertically into the rotation transmission cylinder portion 38, and the upper and lower surfaces 22 of the partition material 12. By measuring the depth at which the weight contacts (FIG. 2), it is confirmed that the stopping height of the fluidized soil 14 is the depth designed in advance.

  Here, when confirming the stopping height of the fluidized soil 14 in the conventional backfilling operation, a measure with a weight attached to the tip is suspended in the rotation transmission cylinder portion 38, and the weight is fluidized ground 14. Even if the fluidized soil 14 is in a liquid state, the weight enters the fluidized soil 14 into the fluidized soil 14 without great resistance. For this reason, in the conventional backfilling operation, it was difficult to confirm the stopping height of the fluidized soil 14.

  On the other hand, in the backfilling operation according to the present embodiment, the weight hung in the rotation transmission cylinder portion 38 contacts the upper bottom surface 22 of the partition material 12 made of solid and does not descend further. For this reason, the operator can easily determine whether or not the weight has contacted the partition member 12, and can easily and accurately confirm the height of the fluidized soil 14 to be stopped.

  Subsequently, as shown in FIG. 6, the backfilling machine 32 made of a shovel car throws backfilling soil 15 made of improved soil or earth and sand into the rotation transmission cylinder portion 38. The backfill 15 collides with the upper bottom surface 22 (FIG. 2) of the partition member 12 and is filled inside the rotation transmission cylinder portion 38.

  At this time, as shown in FIG. 8A, when the backfill 15 collides with the center portion of the upper bottom surface 22 of the partition member 12, the partition member 12 maintains its posture without rotating.

  On the other hand, as shown in FIG. 8B, when the backfill 15 collides with the outer periphery of the upper bottom surface 22 of the partition member 12, the center of the partition member 12 is aligned along the horizontal direction by the impact force of the backfill soil 15. The partitioning member 12 tries to rotate around a rotating shaft 50 (extending in a direction perpendicular to the paper surface in FIG. 8).

  At this time, in FIG. 8B, the partition member 12 slightly rotates counterclockwise about the rotation shaft 50, and the lower end portion of the right peripheral side surface 24 and the upper end portion of the left peripheral side surface 24 transmit rotation. Since it contacts and catches on the inner wall surface of the cylinder part 38, the further rotation is suppressed.

  Thus, since the partition material 12 is hooked on the inner wall surface of the rotation transmission cylinder portion 38, the posture can be kept substantially constant even if the backfill 15 collides with a position other than the center portion.

  Thereby, the partition material 12 physically separates the fluidized treated soil 14 and the backfilled soil 15 when the backfilled soil 15 is input, and the boundary between the fluidized treated soil 14 and the backfilled soil 15. The mixing of both in the vicinity can be reduced, and thus the strength of the fluidized soil 14 can be maintained and the quality of the underground structure 1 can be improved.

  On the other hand, when a partition material with a small thickness such as a plywood plate is used, when the backfill soil 15 is introduced, the partition material is like a butterfly valve due to an impact force that the backfill soil 15 collides with the partition material. Or the backfilling soil 15 may fall on the surface of the fluidized soil 14.

  Further, when a sheet-like partition material such as a vinyl chloride sheet is used, the fluidized soil 14 and the backfill soil 15 are physically separated because they are rounded after being inserted or the end portions are broken. It was difficult to cover the entire surface of the fluidized soil 14 with a sheet-like partition material so as to be separated.

  Further, when the backfill 15 is put on the surface of the sheet-like partitioning material, the shape of the sheet-like partitioning material is easily deformed, so that the shape collapses, and the backfilling soil 15 flows out from the partitioning material and is mixed into the fluidized soil 14. There was a possibility.

  On the other hand, since the partition material 12 according to the present embodiment has a sufficient thickness, when the backfill 15 collides with the upper bottom surface 22, the partition material 12 is hooked on the inner wall surface of the rotation transmission cylinder portion 38 and is prevented from rotating. In addition, it is difficult to be damaged by the impact force of the backfilling soil 15.

  Furthermore, since the partitioning member 12 is not a sheet but is a foamed polystyrene having a sufficient thickness, it reaches the upper surface of the fluidized soil 14 without changing its shape after being inserted into the rotation transmission cylinder 38 and is embedded. Even if the impact force of the return soil 15 is applied, it is difficult to be deformed.

  By the way, in order to prevent the backfilling soil 15 from being mixed into the fluidized soil 14, after placing the fluidized soil 14 and waiting for a predetermined time, after the surface of the fluidized soil 14 has hardened. It is also conceivable to put backfill soil 15.

  However, in that case, since it is necessary to wait until the fluidized soil 14 is hardened (usually it takes about 3 days), the backfilling operation becomes extremely inefficient and the work efficiency is deteriorated.

  On the other hand, in the backfilling operation according to the present embodiment, after placing the fluidized soil 14, the partition material 12 is introduced and the backfill soil 15 is introduced before the fluidized soil 14 is cured. The quality of the underground structure 1 can be improved while maintaining work efficiency.

  Further, as described above, the outer diameter of the partition member 12 is slightly smaller than the inner diameter of the rotation transmission cylinder portion 38.

  Here, since the outer diameter of the partition member 12 is as large as possible with the inner diameter of the rotation transmission cylinder portion 38 as the upper limit, the gap between the inner wall surface of the rotation transmission cylinder portion 38 and the partition member 12 can be reduced. The backfilling soil 15 is less likely to fall onto the surface of the fluidized soil 14 through the gap, and the fluidized soil 14 and the backfilled soil 15 can be physically separated.

  However, if the outer diameter of the partition material 12 is too large, the partition material 12 is caught on the inner wall surface of the rotation transmission cylinder portion 38 when the partition material 12 is put into the rotation transmission cylinder portion 38, and the surface of the fluidized soil 14. There is a possibility not to get down.

  For this reason, the partition material 12 is designed to have an outer diameter that surely descends to the surface of the fluidized soil 14 and that physically separates the backfill soil 15 and the fluidized soil 14 as much as possible.

  After the filling of the backfill 15 shown in FIG. 6 is completed, the crawler crane 30 pulls out the rotation transmission cylinder part 38 and the tip edge part 36 as shown in FIG. Thereafter, the fluidized soil 14 is cured by elapse of a predetermined time, and the underground structure 1 is completed.

  According to the above configuration, between the lower layer portion 11 constituted by the fluidized soil 14 and the upper layer portion 13 constituted by the backfill soil 15 having different characteristics from the fluidized soil 14, approximately The partition member 12 is cylindrical and has a partitioning member 12 that is prevented from rotating by contacting the inner wall surface of the rotation transmission cylinder portion 38 when rotating inside the rotation transmission cylinder portion 38 around the rotation shaft 50 that extends substantially in the horizontal direction. It was arranged.

  As a result, the partition material 12 is prevented from rotating by the impact force with which the backfilling soil 15 collides, thereby physically separating the fluidized soil 14 and the backfilled soil 15, and the fluidized ground soil. 14 can be reduced in the vicinity of the boundary between the backfill soil 15 and the backfill soil 15, so that the manufacturing method of the underground structure 1 that can improve the quality can be realized.

(2) Other Embodiments In the above-described embodiments, the lower bottom surface 20 and the peripheral side surface 24 of the partition member 12 are in contact with each other at a right angle, whereby the side where the lower bottom surface 20 and the peripheral side surface 24 are in contact with each other has an edge shape. Said about the case.

  The present invention is not limited to this, and it is also possible to form a rounded shape by dropping the edge of the side where the lower bottom surface 20 and the peripheral side surface 24 are in contact, as in the partition material 112 shown in FIG.

  In this case, the partition material 112 put into the rotation transmission cylinder portion 38 is less likely to be caught by the inner wall surface of the rotation transmission cylinder portion 38 when falling, compared to the partition material 12, and the fluidization treated soil 14 is more reliably secured. Can reach the surface.

  Further, if the edge of the side where the lower bottom surface 20 and the peripheral side surface 24 are in contact with each other is dropped too much, when the backfill 15 collides and the partition material 112 is about to rotate, the lower bottom surface 20 and the peripheral side surface 24 will be rotated. There is a possibility that the side in contact with the inner wall surface of the rotation transmission cylinder portion 38 is not sufficiently in contact with the inner wall surface of the rotation transmission cylinder portion 38, but the side in contact with the upper bottom surface 22 and the peripheral side surface 24 is formed in an edge shape like the partition material 12. For this reason, the upper end portion of the peripheral side surface 24 abuts against the inner wall surface of the rotation transmission cylinder portion 38, thereby suppressing the rotation of the partition member 112.

  The partition member may have a slightly smaller diameter on the lower bottom surface than on the upper bottom surface, and may have a tapered shape as a whole. Also in this case, the partition material is less likely to be caught on the inner wall surface of the rotation transmission cylinder portion 38 when falling, and can reach the surface of the fluidized soil 14 more reliably.

  Furthermore, in the above-mentioned embodiment, the case where the partition material 12 was formed by the expanded polystyrene was described.

  The present invention is not limited to this, for example, the partition material may be formed of various materials such as a solid columnar synthetic resin or a hollow cylindrical rubber, and in short, it can be formed with a thickness. Any material may be used as long as it does not deform greatly even when an impact is applied when the backfilling soil 15 is added and does not integrate with the fluidized soil 14 and the backfilling soil 15 over the years.

  Furthermore, in the above-described embodiment, the case where the partitioning member 12 has a cylindrical shape has been described. However, the present invention is not limited thereto, and may be various shapes such as an octagonal prism, and has a thickness. The fluidized soil 14 may be a shape that can be physically separated from the backfill soil 15 and that does not catch on the inner wall surface of the rotation transmission cylinder portion 38 when it is introduced.

  Further, in the above-described embodiment, the case where the lower layer portion 11 is configured by the fluidized soil 14 and the upper layer portion 13 is configured by the backfill soil 15 has been described. However, the present invention is not limited thereto, and for example, the solidified material. The upper layer portion 13 and the lower layer portion 11 are composed of various soils, such as the lower layer portion 11 is composed of the fluidized soil having a large mixing ratio and the upper layer portion 13 is composed of the fluidized soil having a small mixing ratio of the solidified material. In short, the upper layer portion 13 and the lower layer portion 11 may be formed of soil having different characteristics.

  Furthermore, in the above-described embodiment, when the rotation transmission cylinder portion 38 is stood on the ground 3, the fluidized soil 14, the partition material 12, and the backfill soil 15 are put inside the rotation transmission cylinder portion 38. Said.

  The present invention is not limited to this, and in the state where the excavation hole 10 is formed by pulling out the rotation transmission cylinder portion 38 and the tip blade tip portion 36, the fluidized soil 14, the partition material 12, and the buried material are placed inside the excavation hole 10. The return soil 15 may be thrown in.

  In this case, when the backfill soil 15 collides and tries to rotate, the partition member 12 comes into contact with the inner wall surface of the excavation hole 10 serving as a cylindrical portion and rotation is suppressed.

  DESCRIPTION OF SYMBOLS 1 ... Underground structure, 2 ... Ground surface, 3 ... Ground, 10 ... Excavation hole, 11 ... Lower layer part, 12 ... Partition material, 13 ... Upper layer part, 14 ... Fluidized soil, 15 …… Backfill, 20 …… Lower bottom surface, 22 …… Upper bottom surface, 24 …… Surrounding side surface, 30 …… Crawler crane, 31 …… Mixer truck, 32 …… Backfill machine, 34 …… Rotation drive machine, 36... Tip edge portion 38... Rotation transmission cylinder portion 40. Excavation tool 42. Placing device 50.

Claims (2)

In the manufacturing method of the underground structure extending in the vertical direction in a substantially cylindrical shape in the ground,
A lower layer part forming step of forming a lower layer part by throwing the first soil having predetermined characteristics into the inside of the cylindrical part extending in a substantially cylindrical shape in the ground;
A partition material that is formed in a substantially cylindrical shape and is formed of polystyrene foam , and that rotates on the inner side of the cylindrical portion around a rotation axis that extends substantially in the horizontal direction, and that prevents rotation by contacting the inner wall surface of the cylindrical portion. , A partition material placement step to be placed on top of the lower layer,
An upper layer portion forming step of forming an upper layer portion by introducing a second soil having a characteristic different from that of the first soil into the upper portion of the partition material. The method for manufacturing an underground structure according to claim 1, wherein the cylindrical portion is a cylindrical rotation transmission portion provided with a cutting edge for excavating the ground at a lower end portion and rotated by a rotary driving machine.

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