JP2881639B2 - Soil liquefaction prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for preventing liquefaction of a ground that can be prevented from liquefaction occurring on a sandy ground during an earthquake, thereby preventing liquefaction damage of various structures.

[0002]

2. Description of the Related Art Various measures have been proposed to prevent liquefaction of sandy ground.
There is an invention described in Japanese Patent Publication No. 0 (hereinafter referred to as prior art 1). The present invention relates to a process of driving a casing into a sandy ground by using vibration while compacting the sandy ground, and a method of permeating a pipe having a pressure resistance against a predetermined pressure of the ground and having a hole for water permeation formed in a peripheral wall. Inserting a drain pipe covered with a porous filter into a casing, and removing the casing from the sandy ground to leave the drain pipe in the sandy ground.The drain pipe removes excess pore water pressure in the sandy ground. The present invention relates to a method for preventing liquefaction of sandy ground which is reduced by using the method.

Further, the invention disclosed in Japanese Patent Application Laid-Open No. Hei 2-225712 (hereinafter referred to as "prior art 2") has a large number of openings and a ground from the openings in a predetermined section along the longitudinal direction of the sheet pile body. One or more drainage members provided with a filter for preventing intrusion are provided on at least one surface of the sheet pile main body.

[0004]

The invention of the prior art 1 is as follows.
Since the drain pipe and sheet pile must be constructed separately, it is difficult to cope if there are restrictions on the construction time,
There is a problem in workability. Further, the invention of the prior art 2 is capable of shortening the construction time because the steel sheet pile to which the drainage member is previously attached is cast, but the drainage member can be reduced more than the effect of shortening the construction time. Processing and mounting on steel sheet piles are costly and have problems in terms of economy.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and provides an apparatus for preventing liquefaction of a ground which can reduce the construction time by adding a drainage function to a sheet pile, and which is inexpensive and easy to construct. It is intended for that purpose.

[0006]

[Means for Solving the Problems]

(1) The apparatus for preventing liquefaction of the ground according to the present invention is characterized in that a tubular member or a substantially U-shaped casing is attached to a sheet pile, and a drain member is provided in the casing or in a tubular portion formed between the sheet pile and the casing. After loading, driving the sheet pile into the ground, and then removing the casing with the drain member remaining in the ground, an end face protection for detachably connecting the tip of the casing to the sheet pile. A member is provided.

In the above-mentioned (1) ground liquefaction prevention apparatus, (2) one or more end face protection members are fixed to the side surface of the sheet pile by welding or detachably attached by screws. Furthermore, in the ground liquefaction prevention device of the above (1) or (2), (3) the end surface protection member is an inner surface fitting portion fitted to the inner surface of the casing or an outer surface fitting portion fitted to the outer surface of the casing. , Or both.

[0008] In the apparatus for preventing liquefaction of the ground according to the above (1), (4) the sheet pile is a steel sheet pile, an H-section steel, an H with sheet pile.
(5) the casing is any of a steel pipe, a substantially U-shaped or substantially V-shaped shaped steel, and (6) the drain member is a shaped steel, a steel pipe, a steel pipe with a sheet pile, or a concrete pile. A perforated pressure-resistant tube made of synthetic resin or metal, which has a function of reducing excessive pore water pressure which causes liquefaction in the ground.

[0009]

1A and 1B show an embodiment of the present invention. FIG. 1A is a front view, FIG.
FIG. 2 is an exploded perspective view of FIG. FIG. 3 shows FIG.
(A) BB enlarged sectional view, CC enlarged sectional view, and D-
It is a D expanded sectional view. In the drawing, 1 is a steel sheet pile, 2 is a casing made of a square steel pipe 21 and shorter than the steel sheet pile 1, 3 is fixed to a lower inner surface of the steel sheet pile 1, and an end face protection member to which the lower part of the casing 2 is connected, 4, 4 are Mounting members fixed to the upper part of the inner surface of the steel sheet pile 1 and holding the casing 2,
Is a drain member made of, for example, a polyethylene pressure-resistant tube. Hereinafter, each of the above members will be described in detail.

1 to 3 show the case where the steel sheet pile 1 having a substantially U-shaped cross section is used, for example, an H-section steel 11 shown in FIG. 6 and FIG. 7 (a). H-section steel 1 with sheet pile
2, a steel pipe 13 as shown in FIG. 2 (b), a steel pipe with sheet pile 14 as shown in FIG.
Concrete piles, ready-made reinforced concrete piles, prestressed concrete piles, steel pipe concrete piles, and the like (hereinafter collectively referred to as “concrete piles”) may be used.
Hereinafter, in the present specification, the above-described various sheet piles, steel pipes, piles, and the like are collectively referred to as sheet piles.

The casing 2 uses a steel pipe 21 having a rectangular cross section in the figure, but a steel plate may be welded to form a rectangular cross section or a substantially U-shaped or V-shaped cross section. Alternatively, a member having an appropriate cross-sectional shape may be used, such as using a channel steel 22 having a substantially U-shaped cross section as shown in FIG. 4, a steel section having a substantially V-shaped cross section, or a steel pipe 23 having a circular cross section as shown in FIG. Can be used.

As shown in FIG. 2 and FIGS. 3 to 5, (c), the inner shape of the end face protection member 3 is substantially equal to the outer shape of the casing 2, and the outer face of the casing 2 can be fitted inside. And has an outer surface fitting portion 31 having a substantially U-shaped flat surface with an open upper portion (outer bag type), and a sharp portion 32 having a triangular or triangular pyramid shape formed at the lower portion like a bow of a ship. Have been. As shown in FIG. 8, the end face protection member 3 may be provided with a flange 33 for attachment to the sheet pile 1 at the opening end of the outer surface fitting portion 31 and the sharp portion 32.

As shown in FIG. 9, the outer surface of the end face protection member 3 is substantially equal to the inner shape of the casing 2.
The inner surface of the casing 2 is large enough to be fitted to the outside and has an inner surface fitting portion 34 having a substantially U-shaped cross section (inner bag type). For example, a round bar is welded below both side walls thereof. Contact portions 35, 35, or furthermore, L
The casing 2 is welded to the front wall by welding the V-shaped holding plate 36.
If the lower end portion of the casing 2 is formed so as to be fitted to the outside thereof, for example, by forming the fitting portion 37 and the contact portion 35, it is possible to prevent the casing 2 fitted thereto from swinging in the front-rear direction. Can be.

As shown in FIG. 10A, the bottom surface of the inner surface fitting portion 34 is formed flat, and a holding plate 36 is provided on the front surface, and the fitting portion 37 of the casing 2 is provided between the inner wall and the front wall. The contact portion 35 may be formed, or, as shown in FIG. 10B, a triangular prism 32 a or a triangular pyramid whose upper surface is substantially equal to the outer shape of the casing 2 is attached below the inner surface fitting portion 34. The contact portions 35 may be formed on both sides of the fitting portion 34, and a round bar or the like may be welded to the upper portion of the front wall of the triangular prism 32a to form the contact portions 35 of the casing 2. Further, the inner surface fitting portion 34
A round bar 35a or the like may be attached vertically on both side walls of the casing 2 to prevent swinging when the casing 2 is fitted. In this case, a groove into which the round bar 35a or the like 35a fits at the tip of the casing 2 It is necessary to provide.

Further, when the end surface protection member 3 is formed in a cylindrical shape, a smooth outer surface fitting portion 31 or inner surface fitting portion 34 may be provided as described above, or the outer surface fitting portion 31 may be provided.
A female screw may be provided on the inner circumference or a screw may be provided on the outer circumference of the inner surface fitting portion 34, and a corresponding male screw or female screw may be provided on the lower portion of the casing 2 and screwed together. In the above description, except for the case of FIG.
Although the case where the lower part of the end face protection member 3 is formed sharp is shown, it may be formed flat.

Such an end face protection member 3 is fixed by welding by making the U-shaped opening contact the lower inner surface of the sheet pile 1.
Alternatively, it is detachably attached by bolts and nuts. In the case of the cylindrical end face protection member 3, it is fixed to the sheet pile 1 by welding directly or via an attachment arm, or is detachably attached to the sheet pile 1 by bolts and nuts.

As shown in FIGS. 2 to 4, the mounting members 4 and 4 are formed of substantially L-shaped fittings.
The bolt 6 inserted into the screw insertion hole 43 provided in the sheet pile is inserted into the screw insertion hole 11 provided in the sheet pile 1, the casing 2 is sandwiched between the other pieces 42, 42 and detachably fixed with the nut 61, The casing 2 is held firmly. In this case, one of the pieces 41, 41 of the mounting members 4, 4 may be fixed to the sheet pile 1 by welding, or the other pieces 42, 42 and the casing 2 may be fixed with bolts and nuts. . Further, if the screw insertion holes 43, 43 provided in the one pieces 41, 41 are formed as long holes, the casing 2 can be easily clamped.

When the steel pipe 23 is used for the casing 2, as shown in FIG. 5, the mounting member 4 is formed in a substantially Ω shape, and the outer periphery of the casing 2 is surrounded by holding members 45, 45. The arms 44 may be detachably fixed to the sheet pile 1 with bolts 6 and nuts 61. In addition, the mounting member 4 is not limited to the above structure, and can be appropriately changed according to the shape of the casing 2.

The drain member 5 is, for example, a water-absorbing or water-permeable rod-shaped or tubular-shaped member having a large number of holes 51 formed in a peripheral wall of a pressure-resistant tube made of a synthetic resin such as polyethylene. To prevent intrusion of earth and sand from 51,
For example, as shown in FIG. 9, the filter 52 may be covered with a filter 52 made of synthetic fiber, synthetic resin, stainless steel, or the like having water absorbency or water permeability and corrosion resistance. The drain member 5 is not limited to a synthetic resin, but may be formed of a corrosion-resistant metal tube such as stainless steel.

In the present invention comprising the above members, as shown in FIGS. 1 to 3, an end face protection member 3 is attached to a lower portion of the inner surface of the sheet pile 1 by welding, screwing, or the like, and the casing 2 is attached to the sheet pile 1 by a screw. It is arranged along the inner surface of
It is fitted into the outer surface fitting portion 31 of the end surface protection member 3 until it hits the inner wall of the sharp portion 32. Next, the upper part of the casing 2 is fixed substantially parallel to the sheet pile 1 by the attaching members 4 and 4 attached to the sheet pile 1. Finally, if the drain members 5 and 5 are inserted into the casing 2, the respective members are integrated. be able to.

As shown in FIG. 4, when a channel steel 22 or a V-shaped cross-section steel is used as the casing 2, the opening side is brought into contact with the sheet pile 1 and the lower part is an end face protection member. 3 and the upper part is fixed by a mounting member 4, and the drain members 5 and 5 are inserted into a tubular portion formed between the sheet pile 1 and the casing 2. Further, in the case of the end face protection member 3 having the inner surface fitting portion 34, the casing 2 may be fitted until the lower end of the casing 2 comes into contact with the contact portion 35, and a screw is attached to the end face protection member 3 and the lower end of the casing 2. If provided,
What is necessary is just to screw this screw and to connect both.

In integrating each member,
The edge protection member 3 is attached to the sheet pile 1 and the casing 2 in which the drain member 5 is previously mounted is attached thereto, or the drain member 5 is charged to the casing 2 to which the edge protection member 3 is attached, and this is attached to the sheet pile 1. The end face protection member 3 may be attached to the casing 2 in which the drain member 5 has been previously loaded, and the end face protection member 3 may be attached to the sheet pile 1.

The sheet pile 1, the casing 2, the end face protection member 3, the mounting members 4, 4 and the drain members 5, 5 integrated as described above are integrated into the ground by driving the sheet pile 1 into the ground. Buried in When the driving is completed, the mounting members 4 and 4 are removed or loosened, and the casing 2 is pulled out with the sheet pile 1, the end face protection member 3 and the drain members 5 and 5 remaining in the ground. In this case, the casing 2 may be detached from the sheet pile 1, or the casing 2 may be pulled up halfway and held at that position. The sheet pile 1 may be driven in a state where the casing 2 is mounted, and after the driving is completed, the drain members 5 and 5 may be inserted into the casing 2 and then the casing 2 may be pulled out.

By the way, when the casing 2 is pulled out, the drain members 5 and 5 may move up (up). Therefore, in the present invention, the following countermeasures are taken. That is, as shown in FIG. 9, the inner surface fitting portion 34 is formed on the end surface protection member 3, and a cap 38 having a hook 39 is attached to the upper end thereof. And
Synthetic fiber filter 5 covering drain members 5
The lower end portions 2 and 52 were wound around the hook 39 and fixed. As a result, even if the casing 2 is pulled out, the drain members 5 and 5 are held by the end face protection member 3 and do not go up.

Also, a cap with a hook may be attached to the lower end of the drain members 5 and 5, and the hook may be engaged with a stopper provided on the end face protection member 3, or the casing 2 may be, for example, as shown in FIG. As shown in FIG. 4, in the case of an open section made of the channel steel 22, a holding member projecting toward the drain members 5, 5 is attached to the sheet pile 1 at a position corresponding to the top of the drain members 5, 5, and the drain member 5 , 5 may be blocked.

When the lower ends of the drain members 5 and 5 are closed with a cap or the like, for example, the drain members 5 and 5 are made of a steel bar having a diameter smaller than the inner diameter of the drain members 5 and 5. 5 and 5, the tip is settled down, and when the casing 2 is pulled out, it acts as a reaction force to prevent lifting. When the casing 2 is pulled out, the weight is pulled up. Is also good. Also,
If the lower ends of the drain members 5, 5 are not closed, a plate material larger than the outer shape of the drain members 5, 5 is attached to the upper portion of the weight directly or via a wire, and the weight is inserted into the drain members 5, 5. Then, an appropriate means can be used, such as placing the plate material on the top and acting as a reaction force.

In the apparatus of the present invention configured as described above, the drain member 5 is provided near the sheet pile 1 and both are driven into the ground at the same time, so that the construction is easy and the construction period is shortened. Can be. Further, when the sheet pile 1 is driven, the surrounding soil is stopped, closed, and compacted by the sheet pile 1, the casing 2, and the end face protection member 3 in parallel, so that the strength of the ground against liquefaction may be increased. it can. Furthermore, groundwater flows into the drain member 5 to dissipate the excess pore water pressure generated in the ground, and the high strength sheet pile 1 is provided in close proximity to this to prevent liquefaction damage of various structures. Can be.

In the above embodiment, the casing 2, the end face protection member 3, and the mounting member 4 are provided on the inner side of the sheet pile 1,
Although the case where one or two drain members 5 are inserted into the casing 2 has been described, these members may be provided on the outer surface side of the sheet pile 1 or may be provided on both the inner surface side and the outer surface side. . Further, the number of the drain members 5 can be appropriately increased or decreased. Further, as shown by broken lines in FIGS. 6 and 7,
An appropriate number of drain members 5 can be provided at appropriate locations according to the type and shape of the sheet pile 1.

[0029]

The ground liquefaction prevention device according to the present invention is:
A cylindrical member or a substantially U-shaped casing is attached to the sheet pile, and a drain member is inserted into the casing or a cylindrical portion formed between the sheet pile and the casing. The casing is removed with the member remaining in the ground, and the sheet pile is provided with an end face protection member that detachably couples the tip of the casing, so that the casing can be securely mounted along the sheet pile. Also, after the sheet pile is driven, the casing can be easily pulled out of the ground. Also, when driving the sheet pile, the ground near the sheet pile can be compacted by the end face protection member.

[Brief description of the drawings]

FIG. 1 is a front view of an embodiment of the present invention and a sectional view taken along line AA of FIG.

FIG. 2 is an exploded perspective view of FIG.

FIG. 3 is an enlarged sectional view of BB, CC, and DD in FIG. 1;

FIG. 4 is an enlarged sectional view corresponding to FIG. 3 of another example of the present invention.

FIG. 5 is an enlarged sectional view corresponding to FIG. 3 of another example of the present invention.

FIG. 6 is a schematic view of another example of the sheet pile of FIG. 1;

FIG. 7 is a schematic view of another example of the sheet pile of FIG. 1;

FIG. 8 is a perspective view of another example of the end face protection member of FIG. 1;

FIG. 9 is a front view and a side view of another example of the end surface protection member and the drain member of FIG. 1;

FIG. 10 is a perspective view of another example of the end face protection member of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sheet pile 2 Casing 3 End surface protection member 31 Outer surface fitting part 32 Sharp part 34 Inner surface fitting part 35 Contact part 36 Holding plate 4 Mounting member 5 Drain member 51 Hole 52 Filter

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mitsugu Fuzen 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. (72) Inventor Takayoshi Morikawa 2-3-2 Uchisaiwaicho, Chiyoda-ku, Tokyo Kawasaki (72) Inventor Yugo Oka 2-3-2 Uchisaiwaicho, Chiyoda-ku, Tokyo Kawasaki Steel Corporation (56) References JP-A-2-225712 (JP, A) JP-A-62-146315 (JP, A) JP-A-7-3804 (JP, A) JP-B-6-11990 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) E02D 3/10 103 E02D 3 / 08

Claims (6)

(57) [Claims] 1. A sheet-like casing having a tubular or substantially U-shaped cross section is attached to a sheet pile, and a drain member is inserted into the casing or a tubular portion formed between the sheet pile and the casing. After being cast into the ground, the drain member is left in the ground so that the casing is pulled out, and the sheet pile is provided with an end face protection member for detachably connecting the tip of the casing. To prevent liquefaction of the ground. 2. An apparatus for preventing liquefaction of a ground according to claim 1, wherein one or more end face protecting members are fixed to the side faces of the sheet pile by welding or detachably attached by screws. 3. The end face protection member includes one or both of an inner surface fitting portion fitted on the inner surface of the casing and an outer surface fitting portion fitted on the outer surface of the casing. The liquefaction prevention device for a ground according to the above. 4. The soil liquefaction prevention device according to claim 1, wherein the sheet pile is any one of a steel sheet pile, an H-section steel, an H-section steel with a sheet pile, a steel pipe, a steel pipe with a sheet pile, and a concrete pile. 5. The apparatus for preventing liquefaction of a ground according to claim 1, wherein the casing is one of a steel pipe and a substantially U-shaped or substantially V-shaped shaped steel. 6. The ground according to claim 1, wherein the drain member is a perforated pressure-resistant tube made of synthetic resin or metal, and has a function of reducing excessive pore water pressure that causes a liquefaction phenomenon in the ground. Liquefaction prevention device.