JP3718153B2 - Hollow pipe for sand pile construction and rectangular sand pile construction method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sand pile building hollow pipe and a rectangular sand that can efficiently construct a sand pile having a substantially rectangular cross section in a ground such as a loose sand ground or a soft clay ground. It relates to the pile construction method.
[0002]
[Prior art]
There is a ground improvement pile construction method that improves the ground by placing sand piles in soft ground such as sand ground. As this ground improvement pile construction method, for example, after penetrating the hollow tube to a predetermined depth, the process of pulling out the hollow tube to an appropriate length and the process of re-penetrating the hollow pipe are sequentially brought to the ground surface. Repeatedly, in the compacted sand pile construction method to create a compacted sand pile in soft ground, or in the above method, the hollow pipe re-penetration process is omitted and the sand is discharged into the ground while pulling out the hollow tube There is a sand pile construction method that creates sand piles in soft ground.
[0003]
In these construction methods, the substitution rate of the sand pile with respect to the original ground may be 100%, or the sand pile may be formed in a continuous wall shape in a part of the ground. Japanese Patent Application Laid-Open No. 2000-265454 uses a hollow tube having at least a tip formed in a polygonal rectangular tube, and forms a sand pile in a polygonal cross section corresponding to the rectangular tube. A ground improvement pile construction method is disclosed in which each side of the entire cross section is brought into close contact with each side of a plurality of adjacent sand piles in a dense state. When constructing with a sand pile replacement rate of 100%, the conventional cylindrical hollow tube placement creates a gap that is not replaced with a sand pile or wasteful placement where some of the adjacent sand piles overlap. When efficient construction was impossible, according to the construction method, the replacement rate of the sand pile with respect to the original ground can be made 100%, and the high-quality improvement of the ground can be achieved.
[0004]
[Problems to be solved by the invention]
The method of creating a sand pile having a polygonal cross section is a method of creating a sand pile having a cross-sectional shape corresponding to a polygonal rectangular tube formed at the tip of a hollow tube. The hollow tube is penetrated by operating a vibro hammer. However, when a hollow tube is driven using a vibro hammer, vibrations and noise are generated, and problems such as environmental measures are required. On the other hand, in Japanese Patent Laid-Open No. 8-284146, a hollow tube having no outer peripheral surface is used, and the hollow tube is reciprocally rotated to remove friction with the ground. A vibration-free and noise-free compacted sand pile construction method in which a hollow tube is lifted and pulled out by a hollow tube lifting device that sometimes obtains reaction force from a leader is disclosed. However, this sand pile construction method is a method of creating a sand pile with a circular cross-section using a cylindrical hollow tube, and this construction method generates a gap where waste piles and sand piles are not placed as described above. It is difficult to create an efficient and high-quality continuous wall sand pile.
[0005]
Accordingly, an object of the present invention is to create a sand pile that can suppress vibration and noise as much as possible, and can efficiently create a high-quality continuous wall sand pile or a sand pile with a replacement rate close to 100%. The object is to provide a hollow pipe and rectangular sand pile construction method.
[0006]
[Means for Solving the Problems]
In such a situation, the present inventors have intensively studied. As a result, if a hollow tube having a specific tip shape is constructed by a reciprocating rotation operation, vibration and noise can be suppressed as much as possible, and a substantially rectangular cross section can be obtained. The present invention was completed by finding that a high-quality continuous wall-like sand pile and a sand pile having a replacement rate close to 100% can be efficiently created.
[0007]
That is, the present invention (1) includes a hollow tube into which sand pile material is charged and an outer tube attached to the tip of the hollow tube, and the outer cross-sectional shape of the outer tube is Sand that has a shape in which opposite corners on the short axis of the rhombus shape are cut out by a predetermined length, and a sand pile having a substantially rectangular cross section is formed in the ground by a reciprocating rotation operation. A hollow tube for pile construction is provided.
[0008]
Further, the present invention (2) includes a cylindrical hollow tube into which a sand pile material is charged, and a pair of protrusions attached to the left and right sides of the tip of the hollow tube, and the outer periphery of the protrusion The cross-sectional shape of the substantially triangular shape is such that the two sides of the outer periphery of the substantially triangular shape are formed tangential to the cylindrical hollow tube. The present invention provides a sand pile building hollow tube for building a sand pile having a rectangular cross section.
[0009]
Moreover, this invention (3) is each process of the penetration process to the predetermined depth of the hollow pipe for sand pile formation of the said invention, the reciprocating rotation operation process in the predetermined depth position, and the discharge process of the sand pile material by drawing. The sand pile construction method is provided in which the sand pile having a substantially rectangular cross section is created in the ground by sequentially repeating the process up to the ground surface.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, a sand pile building hollow pipe and a rectangular sand pile building method using the same in the embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a plan view of the hollow pipe for sand pile formation of this example, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 4 is a front view showing a part of the hollow pipe reciprocating rotation device in a broken state, FIG. 5 is a schematic view of the sand pile forming apparatus equipped with the sand pile forming hollow tube of this example, and FIG. The figure which shows the substantially rectangular cross-sectional shape of the sand pile constructed | assembled using the hollow pipe of FIG. 2, FIG. 7-9 is the figure compared with the sand pile of a circular section, FIG. 10 is the hollow for another sand pile creation Sectional drawing of a pipe | tube (figure seen along the BB line of FIG. 11), FIG.
[0011]
1 and 2, a sand pile building hollow pipe 1 is attached to a cylindrical hollow pipe 1a into which a sand pile material is charged and a tip of the cylindrical hollow pipe 1a, and is cylindrical in a plan view. An outer tube 1b formed so as to surround the hollow tube 1a, and the cross-sectional shape of the outer periphery of the outer tube 1b is such that the opposite corners 101 on the rhombic short axis 3a have a predetermined length. It is the form which was notched and the corner | angular part 102 which faces on the long axis 3b was rounded. In the present invention, the notch length of the notch 7 on the short shaft 3a is not particularly limited, but the cross-sectional shape of the sand pile formed in the ground by a reciprocating rotation operation described later is closer to a rectangle. Specifically, a notch length of 0.15 to 0.35 of the major axis length of the rhombus shape is preferable. Moreover, although the roundness 6 on the long axis 3b may or may not be provided, in the case of providing the roundness, the smaller the rounded radius, the more preferable is that a rectangular pile with a long long axis portion is formed. Further, the outer tube 1b is connected to the cylindrical hollow tube 1a by installing the top plate 103 to form a hollow tube having a different diameter, and retains the function as a hollow tube. Reference numeral 8 denotes a plate-like reinforcing body that reinforces the joining between the cylindrical hollow tube 1a and the outer tube 1b. The height H of the outer tube 1b is a length corresponding to the drawing stroke, that is, the length of the sand pile by one drawing, and is appropriately determined depending on the soil condition and the purpose of improvement.
[0012]
Further, a reinforcing plate 4 is provided on the outer peripheral surface of the outer tube 1b, and the tip is thickened to prevent damage due to friction with the ground during penetration. Further, on both sides on the long axis of the inner peripheral surface of the distal end of the outer tube 1b, drill bits 5 that protrude downward from the distal end are installed to facilitate the penetration of the hollow pile 1 for sand pile formation into the ground. Yes. In the sand pile forming hollow tube 1 of this example, the shape of the hollow tube 1a is not limited to the above-described cylindrical shape, and a polygonal shape such as a quadrangle, an elliptical shape, and an indefinite shape can also be used.
[0013]
The sand pile building hollow tube 1 of this example is configured to form a sand pile having a substantially rectangular cross section in the ground by a reciprocating rotation operation. The hollow pipe reciprocating rotation device for sand pile formation is not particularly limited, and examples thereof include a mechanical rotation device that uses an electric motor and gears, and a hydraulic rotation device. Examples of the hydraulic rotating device include those shown in FIGS. 3 and 4. That is, the hollow tube reciprocating device 10 reciprocally rotates the hollow tube 1a using a pair of hydraulic cylinders 15 attached so as to sandwich the hollow tube 1a from both sides from the opposite side of the leader 12 (FIG. 3). It is a device that penetrates and pulls out while cutting the friction with the ground.
[0014]
The hollow tube reciprocating rotation device 10 is fixed to a side of the leader guide portion 13 opposite to the leader 12 of the leader guide portion 13 that moves up and down along the leader 12, and is restricted by the reciprocating movement of the hollow tube 1a. The fixed portion 16 and the tip of the piston rod 52 that are not attached are attached to the piston rod shaft support portions 17 attached to both side surfaces of the hollow tube 1a, and the cylinder portion 51 is attached to the cylinder shaft support portion 61 of the fixed portion 16 A pair of hydraulic cylinders 15 are provided so as to sandwich 1a from the side opposite to the leader 12 and to be positioned at the center position in the vertical direction of the leader guide portion 13.
[0015]
The fixed portion 16 is fixed to a pair of upper and lower hollow disk members 18 fixed to the leader guide 13 and an end portion 111 of the pair of hollow disk members 18 on the side opposite to the leader 12. The whole has a substantially U-shape as viewed from the side. The hollow disk member 18 is an intermediate member for integrally fixing the vertical member 62 to the leader guide portion 13. For this reason, the hollow disk member 18 has an inner diameter larger than the outer diameter of the hollow tube 1a, and a bearing 19 is interposed between the hollow tube member 18a and the hollow tube member 1a. It is not regulated. The vertical member 6 is substantially U-shaped, and a vertical axis 55 fixed to the cylinder portion 51 of the hydraulic cylinder is pivotally supported in the horizontal direction at the center in the vertical direction of the left and right side surfaces of the vertical member main body 621. A cylinder shaft support 61 is provided.
[0016]
The hydraulic cylinder 15 includes a cylinder part 51 and a piston rod 52, and is attached to the cylinder part 51 so as to be rotatable in a horizontal direction on a cylinder shaft support part 61 as a fixed part. When the hydraulic cylinder 15 is attached to the hollow tube 1 and the fixed portion 16, the hydraulic cylinder 5 maintains a horizontal position, and when the hydraulic cylinder 15 is located at the center position in the vertical direction of the leader guide 3, the external force is transmitted to the leader 12. Is preferable in that is efficiently performed.
[0017]
Further, as shown in FIG. 5, the hopper 22 and the forced elevating device 21 located above the hollow tube reciprocating device 10 are integrally coupled to the fixed portion 16 of the hollow tube reciprocating device 10. . For this reason, the hopper 22, the forced elevating / lowering device 21 and the hollow tube reciprocating / rotating device 10 are similarly lowered by the descending activation of the forced elevating device 21, and similarly raised by the ascending activation. The hopper 22 is for making it easy to throw sand pile material into the hollow tube 1 and a known one is used. Further, the forcible elevating device 21 is not particularly limited as long as the reaction force from the leader 12 can be obtained at the time of intrusion and withdrawal, for example, by rack and pinion, by chain and sprocket, by towing a wire rope And so on.
[0018]
Next, a method of creating a sand pile having a substantially rectangular cross section in the ground using the sand pile forming hollow tube of this example will be described. First, when the forced elevating device 21 is lowered, the hollow tube reciprocating rotation device 10 is activated, and the sand pile forming hollow tube 1 is pushed and pulled within a predetermined rotation range, and reciprocally rotates to a predetermined depth. Intruded until. Penetration efficiency is improved by rotating the sand pile building hollow tube 1 in the penetration step. When the sand pile building hollow tube 1 is driven to a predetermined depth, the process proceeds to a reciprocating rotation operation process at the predetermined depth position. The rotation range may be the same as the rotation range at the time of penetration, and is selected within a range of less than 90 degrees indicated by Z in FIG. 6, and is 78 degrees in this example. That is, it is rotated in the arrow Y direction from the position 25b where the long axis is on the line A-B, is stopped at the position 25a where the long axis is on the line CD, and is further rotated in the direction of the arrow X. , And stops at a position 25b where the long axis is on the line A-B, and is repeated as necessary to obtain a drawing trace 25 having a rectangular cross section indicated by oblique lines after drawing. By appropriately selecting the rotation range, the cross-sectional shape of the drawn trace becomes close to a rectangle, and the sand pile can be efficiently created without waste in a continuous wall shape. Moreover, if it is not rotated in the reciprocating rotation operation process, it is only possible to leave a trace corresponding to the shape of the outer tube after drawing, and even if the sand pile is formed in a continuous wall shape, it is substantially rectangular. It does not become a cross-section sand pile.
[0019]
Then, after the reciprocating rotation operation process, the process proceeds to a sand pile material discharging process by drawing. The drawing stroke is a height H of the outer tube 1b of the sand pile building hollow tube 1 or less. If the length H is pulled out, the extracted trace surely forms a substantially rectangular cross section, and the shape after the sand pile material is discharged also forms a substantially rectangular cross section. The sand pile material is not particularly limited, and examples thereof include sand, crushed stone, gravel, other sand-like granular materials, and those in which a metal-based reducing material is mixed. Sand containing a metal-based reducing material is applied, for example, to a groundwater purification wall constructed for the purpose of purifying groundwater contaminated with organic volatile compounds. In the case of pulling out, the reciprocating rotation operation is not particularly necessary. After discharging the sand pile material by pulling out, the reciprocating rotation operation process and the sand pile material discharging process by pulling are sequentially performed again at the position after the pulling, and thereafter the same operation is sequentially repeated until the ground surface. As another example, after the sand pile material is discharged to the drawing trace, a re-penetration process may be performed and compaction may be performed. In the case of this re-penetration, it is preferable that the sand pile forming hollow tube 1 is rotated in the same rotation range in that a compacted sand pile closer to a rectangular cross section is formed.
[0020]
Further, the rectangular sand pile creation method of the present invention creates a continuous wall-shaped sand pile by overlapping at least the short side of the sand pile having a substantially rectangular cross section with the short side of another adjacent sand pile or part of the side. To do. The sand pile created by this sand pile creation method will be described with reference to FIGS. FIG. 7 shows a part of a continuous wall-shaped sand pile obtained by taking a relatively large overlap between the short side of a sand pile having a substantially rectangular cross section and the short side of another sand pile adjacent thereto, and FIG. 8 shows a sand pile having a substantially rectangular cross section. FIG. 9 shows another sand adjacent to the short side of the sand pile having a substantially rectangular cross section. Each of the continuous wall-shaped sand piles with the short sides of the piles touching each other is shown, (A) is a substantially rectangular sand pile according to this example, (B) is a conventional circular sand pile for comparison. is there. From Fig. 7, the roughly rectangular sand pile of this example is 4 sand piles, and when the same overlap is taken, it can be built about 1.3 times longer than the circular sand pile. It becomes. Moreover, useless placement portions (black portions at the upper and lower ends of the circular sand pile in the figure) do not occur in the short side direction. From FIG. 8, the substantially rectangular sand pile of this example is 4 sand piles, the same overlap is taken, and the sand pile with the same diameter as the circular sand pile in the length direction (left and right direction) is compared. Then, useless placement portions are not generated in the short side direction. From FIG. 9, the substantially rectangular sand pile of this example has four sand piles in contact with each other and the short side length is the same as the diameter of the circular sand pile. A fourfold increase is possible. In the sand pile creation method of the present invention, the long side of a sand pile having a substantially rectangular cross section may be overlapped with the long side of another adjacent sand pile or a part of the side or the sand pile having a substantially rectangular cross section. The short side may be overlapped with the long side and the adjacent side or part of another adjacent sand pile, and the size of the continuous wall-shaped sand pile can be freely adjusted by combining the short sides described above. .
[0021]
According to the sand pile building hollow tube 1 of this example and the sand pile construction method having a substantially rectangular cross section using the same, vibration and noise can be suppressed as much as possible, and a sand pile having a substantially rectangular cross section can be created. Moreover, a high-quality continuous wall-like sand pile and a sand pile with a replacement rate close to 100% can be efficiently created. Furthermore, in the sand pile forming apparatus provided with the conventional rotation driving means, a rotation driving apparatus such as an electric motor or a swivel apparatus is attached. These facilities have a complicated mechanism and are large-scale, which contributes to an increase in the cost of the apparatus. However, if the hollow pipe for sand pile formation of this invention is used, since a rotational drive apparatus and a swivel apparatus can be abbreviate | omitted, this sand pile formation apparatus can be made simple and the cost reduced.
[0022]
Moreover, the other hollow pipe for sand pile formation which concerns on this invention is demonstrated with reference to FIG.10 and FIG.11. 10 and 11, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, description thereof is omitted, and different points are mainly described. That is, in the sand pile building hollow tube 1A of this example, the difference from the sand pile building hollow tube 1 is that instead of forming the tip outer peripheral shape of the hollow tube with an outer tube, the hollow tube 1A Protrusions are provided, and are formed by hollow tubes and protrusions. That is, the sand pile building hollow tube 1A of this example is provided with a pair of protrusions 1B on the left and right sides of the tip of the cylindrical hollow tube 1a into which the sand pile material is charged, and a cross section of the outer periphery of the protrusion 1B. The shape is a substantially triangular shape, and the two sides 101B on the outer periphery of the substantially triangular shape are formed to be tangential to the cylindrical hollow tube 1a. The roundness 105 at the tip formed by the two sides 101B of the outer periphery of the substantially triangular shape may or may not be present. In the sand pile forming hollow tube 1A having such a configuration, the same effect as that of the sand pile forming hollow tube 1 can be obtained, and the structure can be further simplified. Moreover, in this invention, a substantially rectangular shape is widely interpreted in the range which can achieve the objective of this invention of producing a continuous wall-like sand pile efficiently by high quality.
[0023]
【The invention's effect】
According to the construction method using the sand pile forming hollow pipe of the present invention, vibration and noise can be suppressed as much as possible, and a sand pile having a substantially rectangular cross section can be formed. Sand piles with a replacement rate close to 100% can be efficiently created. In addition, the sand pile building hollow tube has a relatively simple structure and requires a hollow tube reciprocating rotation device, but it is possible to omit a rotational drive device and a swivel device that are more expensive than the device. The cost of the creation device can be reduced.
[Brief description of the drawings]
FIG. 1 is a plan view of a hollow tube for sand pile formation according to the present example.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is a plan view of a hollow tube reciprocating rotation device.
FIG. 4 is a front view of the hollow tube reciprocating device with a part thereof broken away.
FIG. 5 is a schematic view of a sand pile forming apparatus equipped with the sand pile forming hollow pipe of this example.
FIG. 6 is a view showing a cross-sectional shape of a sand pile formed using the sand pile forming hollow tube of this example.
FIG. 7 is a diagram showing a cross-sectional shape of a part of a continuous wall-shaped sand pile formed using the sand pile forming hollow tube of this example.
FIG. 8 is a view showing another cross-sectional shape of a part of a continuous wall-shaped sand pile formed using the sand pile forming hollow tube of this example.
FIG. 9 is a diagram showing another cross-sectional shape of a part of a continuous wall-shaped sand pile formed using the sand pile forming hollow tube of this example.
FIG. 10 is a cross-sectional view of another sand pile building hollow pipe.
FIG. 11 is a front view showing a part thereof broken away.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Sand pile hollow tube 1a Cylindrical hollow tube 1B Projection part 1b Outer tube 3a Rhombus-shaped short shaft 3b Rhombus-shaped long shaft 4 Reinforcement plate 5 Excavation bit 6 Round 7 Notch 8 Plate-shaped reinforcement DESCRIPTION OF SYMBOLS 10 Hollow pipe reciprocating rotation device 12 Leader 13 Leader guide 15 Hydraulic cylinder 16 Fixed part 17 Piston rod shaft support part 18 Hollow disk member 21 Forced raising / lowering device 22 Hopper 25 Sand pile 51 Cylinder part 52 Piston rod 61 Cylinder shaft support part

Claims (5)

A hollow pipe into which sand pile material is charged and an outer cylindrical pipe attached to the tip of the hollow pipe, and the outer circumferential section of the outer cylindrical pipe is opposed to the rhombic short axis During the construction of a sand pile, the corner portions are notched with a predetermined length, and a sand pile having a substantially rectangular cross section is created in the ground by a reciprocating rotation operation. Empty tube. A cylindrical hollow tube into which sand pile material is charged, and a pair of protrusions attached to the left and right sides of the tip of the hollow tube, and the cross-sectional shape of the outer periphery of the protrusion is substantially triangular. Yes, the two sides of the outer periphery of the substantially triangular shape are formed tangential to the cylindrical hollow tube, and a sand pile having a substantially rectangular cross section is formed in the ground by a reciprocating rotation operation. A hollow pipe for sand pile construction characterized by being. Each of the penetration process to the predetermined depth of the hollow pipe for sand pile formation according to claim 1 or 2, the reciprocating rotation operation process at the predetermined depth position, and the discharging process of the sand pile material by drawing is sequentially repeated to the ground surface. A sand pile construction method characterized in that a sand pile having a substantially rectangular cross section is created in the ground. The sand pile construction method according to claim 3, wherein a re-penetration step is performed after the step of discharging the sand pile material by the drawing. 5. The continuous wall-shaped sand pile is formed by overlapping at least a short side of the sand pile having a substantially rectangular cross section with a short side of another adjacent sand pile or a side or a part thereof. The described sand pile construction method.

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