JPH09195267A - Liquefaction preventing device for ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preventing device in which the constructing time can be shortened, and the construction is facilitated at low cost by adding draining function to a sheet pile. SOLUTION: This device is formed of a sheet pile 1 to be driven into the ground; an end surface protecting member 3 mounted on the sheet pile 1; a casing 2 formed into a cylinder or substnatially U-shape the top end part of which is attachably and detachably connected to the end surface protecting member 3, a wear plate 4 bonded to the upper part of the casing 2; a locking members 42a, 42b provided on the wear plate 4 and engagingly locked by the sheet pile 1 to arrange the casing 2 fitted to the end surface protecting member 3 substantially in parallel to the sheet pile 1; and a water absorptive or water permeable bar-like or cylindrical drain member 5 inserted into a cylindrical part formed within the casing 2 or between the casing 2 and the sheet pile 1. These are integrated and driven into the ground, and the wear plate 4 and the casing 2 is pulled out in the state where the sheet pile 1, the end surface protecting member 3 and the drain member are left in the ground.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground liquefaction prevention apparatus capable of preventing liquefaction generated in sandy ground during an earthquake and 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 the casing, and withdrawing the casing from the sandy ground to leave the drain pipe in the sandy ground, and draining 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.

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

[0004]

DISCLOSURE OF THE INVENTION The invention of the prior art 1 is
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.

The present invention has been made to solve the above-mentioned problems, and by adding a drainage function to the sheet pile, the construction time can be shortened, and a liquefaction prevention device for the ground which is inexpensive and easy to construct is obtained. This is the purpose.

[0006]

[Means for Solving the Problems]

(1) A ground liquefaction prevention apparatus according to the present invention is a sheet pile that is driven into the ground, an end face protection member that is attached to the sheet pile, and is formed in a tubular shape or a substantially U shape, and the tip portion is the end surface. A casing removably connected to the protective member, a backing plate to which the upper portion of the casing is joined, and a casing provided on the corresponding plate and locked to the sheet pile and connected to the end face protection member, the sheet pile. A locking member arranged substantially in parallel,
It is water-absorbent or water-permeable, and comprises a rod-shaped or tubular drain member that is inserted into the casing or a tubular portion formed between the casing and the sheet pile.

Further, in the ground liquefaction prevention device of (1) above, (2) the sheet pile is a steel sheet pile, an H-shaped steel, or a sheet pile H
It is either a shaped steel, a steel pipe, a steel pipe with a sheet pile, or a concrete pile, and either (3) the end face protection member is an inner face fitting part fitted to the inner face of the casing or an outer face fitting part fitted to the outer face of the casing. One or both are provided.

Further, (4) the casing is a steel pipe, or a substantially U-shaped or V-shaped steel, and (5) the drain member is a perforated pressure resistant pipe made of synthetic resin or metal. It has a function of lowering the excessive pore water pressure that causes a liquefaction phenomenon in the ground.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention. (A) is a front view, (b) is a sectional view taken along line AA,
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 figure, 1 is a steel sheet pile, 2 is a casing made of square steel pipes 21 and shorter than the steel sheet pile 1, 3 is an end face protection member that is fixed to the lower portion of the inner surface of the web of the steel sheet pile 1, and the lower portion of the casing 2 is connected. A patch plate 5 having a width equal to or smaller than the width of the web of the steel sheet pile 1 and a short length is a drain member made of, for example, a perforated pressure resistant pipe made of polyethylene. Hereinafter, each of the above members will be described in detail.

The steel sheet pile 1 shown in FIGS. 1 to 3 is a case where the steel sheet pile 1 having a substantially U-shaped cross section is used. For example, the H section steel 11 shown in FIG. 6 and FIG. 7 (a) are shown. H-section steel with sheet pile 1
2, a steel pipe 13 as shown in FIG. 2 (b), a steel pipe 14 with a sheet pile as shown in FIG. 2 (c), etc. may be used.
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 is shown in the drawing using a rectangular steel tube 21 having a rectangular cross section. However, 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 sectional shape, such as a channel steel 22 having a substantially U-shaped cross section as shown in FIG. 4, a shaped steel 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 FIGS. 2 and 3 to 5C, the end surface protection member 3 has an inner shape substantially equal to the outer shape of the casing 2, and a size such that the outer surface of the casing 2 can be fitted inside. In addition, it has an outer surface fitting portion 31 having a substantially U-shape in plan view with an open upper portion (outer bag type), and a sharp portion 31a is formed in the lower portion by a triangular shape or a triangular pyramid shape like a bow of a ship. Has been done. A cushioning material with which the casing 2 and the tip of the drain member 5 abut may be provided inside the end face protection member 3.

As shown in FIG. 8, the end face protecting member 3 has an outer shape substantially equal to the inner shape of the casing 2,
The inner surface of the casing 2 has an inner surface fitting portion 32 having a substantially U-shaped cross section and having a size capable of fitting to the outer side (inner bag type). For example, a round bar or the like is welded below both side walls thereof. Abutment parts 33, 33 are provided, or L
The holding plate 34 in the shape of a letter is welded to form the casing 2 between it and the front wall.
The lower end portion of the casing 2 may be formed so that it can be fitted to the outside thereof, for example, by forming the fitting portion 35 of FIG.

Further, when the end face protecting member 3 is formed in a cylindrical shape, a smooth outer surface fitting portion 31 or inner surface fitting portion 32 may be provided as described above, or the outer surface fitting portion 31.
A female thread may be provided on the inner periphery of the casing 2, or a screw may be provided on the outer periphery of the inner surface fitting portion 32, and a male screw or a female screw corresponding to the female screw may be provided on the lower portion of the casing 2 for screw connection. In the above description, the case where the lower portion of the end face protection member 3 is formed to be sharp is shown, but it may be formed to be flat.

The end face protecting member 3 as described above is attached to the inner surface of the lower portion of the web of the sheet pile 1 by abutting the U-shaped opening to fix the end face protecting member 3 by welding, or 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 through the mounting arm,
Alternatively, it is detachably attached to the sheet pile 1 with bolts and nuts.

The backing plate 4 is plate-shaped, and has a hole 41 for passing through a wire or the like at the time of pulling it up.
In addition, substantially U-shaped locking members 42 are provided on both side edges of the upper portion.
One of the legs of a and 42b is attached by welding. The lower part of the contact plate 4 is integrally joined to the upper part of the casing 2 by welding. When the casing 2 is composed of the steel pipe 23, as shown in FIG. 5, brackets 43a and 43b are welded to both sides of the casing 2 to secure the connection with the contact plate 4, and this is applied to the contact plate 4. Four
It may be welded to.

As described above, the locking members 42a and 42b are attached to the backing plate 4 and locked to the sheet pile 1 to hold the casing 2 substantially parallel to the sheet pile 1. For example, FIG. As shown in (a), the locking members 42a, 42b
May be attached to the front surface of the backing plate 4 so as to be locked to the upper end portion of the sheet pile 1, or as shown in FIG. Member 42a,
The shape and mounting position of 42b can be changed as appropriate, such as by mounting 42b and locking it at the upper end of arrow 1.

The drain member 5 is, for example, a water-absorbing or water-permeable rod-shaped or tubular member having a large number of holes 51 formed in the peripheral wall of a pressure-resistant tube made of synthetic resin such as polyethylene. In order to prevent the infiltration of earth and sand from 51,
For example, as shown in FIG. 8, the filter 52 may be covered with a filter 52 made of synthetic fiber, synthetic resin, stainless steel, or the like having water absorption or water permeability and corrosion resistance. The drain member 5 is not limited to the synthetic resin, and may be a metal tube having corrosion resistance such as stainless steel.

In the present invention composed of the above-mentioned members, as shown in FIG. 10A, the end face protecting member 3 is attached to the lower inner surface of the sheet pile 1 by welding, screwing or the like. Then, the backing plate 4 joined to the casing 2 is arranged along the inner surface of the web of the sheet pile 1, the locking members 42a and 42b are locked to the upper end portion of the sheet pile 1, and the lower end portion of the casing 2 is connected to the end surface. In the outer fitting portion 31 of the protection member 3, the sharp portion 31
Insert until it hits the inner wall of a. Then, the backing plate 4 joined to the sheet pile 1 and the casing 2 is grasped by a bi-blow hammer 7 as shown in FIG. Finally, as shown in FIG. 10B, the drain member 5 is inserted into the casing 2. In FIG. 11,
(A) is the case where the casing 2 is provided on the inner surface side of the web of the sheet pile 1, (b) is the case where the casing 2 is provided on the outer surface side of the web of the sheet pile 1, (c) is the casing 2 of the web of the sheet pile 1. The case where it is provided on both the inner surface side and the outer surface side is shown.

Further, as shown in FIG. 4, when a grooved steel 22 or a V-shaped section steel is used as the casing 2, the opening side is brought into contact with the backing plate 4 to join them by welding.
The lower part is fitted to the end face protection member 3 and the locking member 4
It suffices to lock 2a and 42b on the sheet pile 1 and insert the drain members 5 and 5 into a tubular portion formed between the sheet pile 1 (abutting plate 4) and the casing 2. Further, in the case of the end surface protection member 3 having the inner surface fitting portion 32, the casing 2 may be fitted until the lower end portion of the end surface comes into contact with the contact portion 33 or the like, and a screw is attached to the end surface protection member 3 and the lower end portion of the casing 2. If provided,
These screws may be screwed together to connect the two.

Incidentally, in integrating each member,
The end face protection member 3 is attached to the sheet pile 1, and the backing plate 4 joined to the casing 2 in which the drain member 5 is inserted in advance is locked to the sheet pile 1 or is drained to the casing 2 to which the end face protection member 3 is attached. The member 5 may be loaded and attached to the sheet pile 1 via the backing plate 4, and further, the casing 2 in which the drain member 5 is loaded in advance.
Attach the end face protection member 3 to the end face protection member 3
The cover plate 4 attached to the casing 2 and joined to the casing 2
It can be changed as appropriate, for example, by locking it to the sheet pile 1.

As shown in FIG. 12A, the sheet pile 1, the casing 2 and the abutting plate 4, the end face protecting member 3 and the drain members 5 and 5 which are integrated in this way together with the abutting plate 4, the sheet pile 1. It is embedded in the ground integrally by driving it into the ground. Then, when the placement is completed, FIG.
As shown in (b), the contact plate 4 and the casing 2 are pulled out with the sheet pile 1, the end face protection member 3, and the drain members 5 and 5 left in the ground. At this time, if the backing plate 4 is projected upward from the upper end portion of the sheet pile 1, this protruding portion can be directly grasped and pulled out. Further, by providing the contact plate 4 with the through hole 41 for the wire or the like and the locking metal fitting for the wire or the like, the pulling out work can be facilitated.

In this case, the backing plate 4 and the sheet pile 1 joined to the casing 2 are simultaneously gripped and driven into the ground, and the sheet pile 1
Since the casing 2 and the casing 2 are integrated with each other, processing and components for the integration are not required, and a removing work for separating the sheet pile 1 and the casing 2 after driving is also unnecessary. Furthermore, since the processing marks for integrating the sheet pile 1 and the casing 2 (for example, bolt holes when they are integrated with bolts) do not remain on the sheet pile 1, it is possible to maintain the appearance after the sheet pile construction.

By the way, when the casing 2 is pulled out together with the contact plate 4, the drain members 5 and 5 may also go up (up). Therefore, in the present invention,
The following supply prevention measures were taken. That is, as shown in FIG. 8, the inner surface fitting portion 32 is formed on the end surface protecting member 3, and the cap 36 having the hook 37 is attached to the upper end portion thereof. Then, the lower ends of the synthetic fiber filters 52, 52 coated on the drain members 5, 5 are wound around and fixed to the hook 37. 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 come up.

Further, a cap with a hook may be attached to the lower ends 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 the open cross section made of the channel steel 22, a holding member projecting to the drain member 5, 5 side is attached at a position corresponding to the top of the drain member 5, 5 of the sheet pile 1. , 5 may be blocked.

Further, when the lower end portions of the drain members 5 and 5 are closed by a cap or the like, for example, a weight made of steel bar having a diameter smaller than the inner diameter of the drain members 5 and 5 and having a wire or the like attached to the upper portion thereof is used as the drain member. Insert the inside of the casing 5 and 5 to set the tip to the bottom, and act as a reaction force when pulling out the casing 2 to prevent it from rising, and pull up the weight when the casing 2 is pulled out. Good. Also,
When the lower ends of the drain members 5 and 5 are not closed, a plate material larger than the outer shape of the drain members 5 and 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 and 5. Then, an appropriate means such as placing the plate member on the top of the plate member and acting it as a reaction force can be used.

In the apparatus of the present invention constructed as described above, the drain member 5 is provided close to the sheet pile 1 and both of them are simultaneously driven into the ground, so that the construction is easy and the construction period is shortened. You can In addition, when the sheet pile 1 is driven, the sheet pile 1, the casing 2 and the end face protection member 3 simultaneously perform soil stopping, closing and compaction of the surrounding ground, so that the strength against liquefaction of the ground can be increased. it can. In addition, groundwater flows into the drain member 5 to dissipate excess pore water pressure generated in the ground, and a strong sheet pile 1 is provided close to it to prevent liquefaction damage of various structures. You can

In the above embodiment, the casing 2 and the end face protection member 3 to which the contact plate 4 is joined are provided on the inner surface side of the web of the sheet pile 1, and one or two drain members 5 are inserted into the casing 2. Although such a case is shown, these members may be provided on the outer surface side of the web of the sheet pile 1, or may be provided on both the inner surface side and the outer surface side of the web. Further, the number of drain members 5 can be appropriately increased or decreased. further,
As shown by the broken lines in FIGS. 6 and 7, an appropriate number of drain members 5 can be provided at an appropriate location depending on the type and shape of the sheet pile 1.

In the embodiment, in the case of the apparatus shown in FIG. 1, the sheet pile 1 has a length of 10.5 m, the casing 2 has a length of about 10 m, the drain member 5 has a length of about 10 m, and the outer diameter thereof is 55 mm. Further, as shown in FIG. 5, when the steel pipe 23 is used as the casing 2, the outer diameter of the steel pipe 23 is about 140 mm,
The outer diameter of the drain member 5 was 100 mm.

[0030]

The ground liquefaction prevention apparatus according to the present invention comprises:
A sheet pile that is driven into the ground, an end face protection member that is attached to the sheet pile, a casing that is formed in a tubular shape or a substantially U shape, and has a tip end portion detachably connected to the end face protection member, and an upper portion of the casing. A backing plate to be joined, a locking member that is provided on the backing plate and that locks to the sheet pile and that arranges the casing fitted to the end face protection member substantially parallel to the sheet pile, has water absorption or water permeability, and It consists of a rod-shaped or cylindrical drain member that is inserted into the casing or a cylindrical portion formed between the casing and the sheet pile, and these are integrated and driven into the ground, and the drain member is left in the ground. Since the backing plate and the casing are pulled out in this state, the construction is inexpensive, the construction is easy, and the construction period can be shortened.

In addition, when the sheet pile is driven, the sheet pile, the caul plate, the casing, and the end face protection member simultaneously perform soil stopping, closing, and compaction of the surrounding ground, thereby improving the liquefaction resistance of the ground. Can be made. Furthermore, since groundwater is caused to flow into the drain member to dissipate excess pore water pressure generated in the ground and a sheet pile is provided in the vicinity thereof, liquefaction damage to various structures can be prevented.

[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.

3 is an enlarged cross-sectional view of BB, CC, DD of FIG.

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

FIG. 5 is an enlarged cross-sectional view of another example of the present invention, which corresponds to FIG.

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.

FIG. 8 is a front view and a side view of another example of the end face protection member and the drain member of FIG.

9 is a schematic view showing another example of the locking member of FIG.

FIG. 10 is an explanatory diagram of an example of a burying method using the present invention.

FIG. 11 is an explanatory diagram of an example of a burying method using the present invention.

FIG. 12 is an explanatory diagram of an example of a burying method using the present invention.

[Explanation of symbols]

 1 Sheet Pile 2 Casing 3 End Face Protecting Member 31 Outer Surface Fitting Part 32 Inner Surface Fitting Part 33 Abutting Part 34 Holding Plate 36 Cap 37 Hook 4 Abutting Plate 42a, 42b Locking Member 5 Drain Member 51 Hole 52 Filter

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsugu Fusamae 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Takayoshi Morikawa 2-3-2, Uchisaiwaicho, Chiyoda-ku, Tokyo Kawasaki Steel Works (72) Inventor Yugo Oka 2-3-2 Uchisaiwaicho, Chiyoda-ku, Tokyo Inside Kawasaki Steel Co., Ltd.

Claims (5)

[Claims] 1. A casing formed in the ground, an end face protection member attached to the sheet pile, and a casing formed in a tubular shape or a substantially U shape, and a tip portion of which is detachably connected to the end face protection member. A cover plate joined to the upper part of the casing, and a locking member which is provided on the plate and which locks the casing fitted in the end face protection member by being locked to the sheet pile and arranged substantially parallel to the sheet pile. And a rod-shaped or tubular drain member that is water-absorbent or water-permeable and that is inserted into the casing or a tubular portion formed between the casing and the sheet pile to prevent liquefaction of the ground. 2. The ground liquefaction preventing 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 or a concrete pile. 3. The end surface protection member is provided with either one or both of an inner surface fitting portion fitted to the inner surface of the casing and an outer surface fitting portion fitted to the outer surface of the casing. Ground liquefaction prevention device. 4. The ground liquefaction prevention device according to claim 1, wherein the casing is one of a steel pipe and a substantially U-shaped or V-shaped steel. 5. The ground according to claim 1, wherein the drain member is a perforated pressure resistant pipe made of synthetic resin or metal and has a function of lowering excess pore water pressure which causes a liquefaction phenomenon in the ground. Liquefaction prevention device.