JPH0988059A - Underground buffer wall and buffer board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to prevent vibration of horizontal displacement from spreading to a neighboring structure by connecting a plurality of buffer boards with a buffer bag to a recessed area of a steel sheet pile in the horizontal direction and driving the buffer boards into the ground and forming the buffer bags positioned in the same direction. SOLUTION: A plurality of buffer bags 4 are mounted on a recessed part of a steel sheet pile along the horizontal direction, thereby forming a buffer board 1 where air is injected into the buffer bags 4. Then, water is sprayed from a jet water pipe 5 while a ground 18 is being excavated, and the buffer boards 1 are driven one by one. At the same time, the horizontal direction of each buffer board 1 is connected with a joint hardware 19, thereby constructing a buffer wall provided with the buffer bags 4 on the whole surface on one side. In the case when vibration is generated in a ground 18a on the buffer bag side 4, the vibration is cut down in an air layer in the buffer bag 4, which does not affect a ground 18b on the opposite side. In the case when a horizontal displacement is produced on the ground 18a on the buffer bag 4 side, the air is vented from an automatic control valve in conformity with the horizontal displacement, which reduces the cross section area of the buffer bags 4 so that the horizontal displacement may be absorbed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an underground buffer wall and a buffer plate.

[0002]

2. Description of the Related Art Generally, pile construction work is performed when constructing a structure on soft ground, and ground improvement work is performed when embankment work is performed.

In the case of the pile driving work, depending on the construction method, vibrations at the time of driving the pile adversely affect the adjacent structures and the like. Further, in the case of ground improvement work, for example, in a deep mixing method and a sand compaction method, horizontal displacement due to a horizontal force of 5 to 10 tf / m ² acting on the surrounding ground adversely affects adjacent structures and the like.

Therefore, in pile driving work, a groove as a blocking wall has been constructed in order to prevent an adverse effect due to vibration.

Further, in the ground improvement work, in order to prevent the adjacent structures from being adversely affected by horizontal displacement, a wall body using U-shaped steel sheet piles and a continuous underground wall made of reinforced concrete have been constructed.

[0006]

However, the groove as a barrier wall for preventing vibration is limited to a depth of about 2 m in the state of a bare moat, and if it is deeper than this, earth retaining will be necessary, which is unsatisfactory. It was an economy.

On the other hand, a wall body using a U-shaped steel sheet pile has a limit in preventing horizontal displacement only by its rigidity, so that horizontal displacement of 10 to 20 cm inevitably occurs in the surrounding ground.

The continuous underground wall made of reinforced concrete is
There is a problem in that it takes a great cost to reduce the horizontal displacement, but it is costly.

The present invention has been made in view of the above problems, and an object thereof is to prevent vibration and horizontal displacement generated in pile driving work or ground improvement work from being propagated to adjacent structures. .

[0010]

In the underground buffer wall for solving the above problems, a plurality of buffer plates, each having a buffer bag provided in a recess of a steel sheet pile, are connected in the horizontal direction and placed in the ground. And that the buffer bag is formed in the same direction, and the buffer bag shrinks according to the horizontal displacement generated in the ground. Further, the cushioning plate is provided with a plurality of cushioning bags detachably along the horizontal direction in the concave portion of the steel sheet pile, the insides of each cushioning bag are connected to each other by an air injection valve, and the lower end portion of the cushioning bag at the bottom is It was covered with a tapered tip cap.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example of an embodiment of a buffer wall and a buffer plate underground will be described in detail with reference to the drawings. 1 is a perspective view of the cushioning plate of the present invention, FIG. 2 is a rear view of the same,
3 is a partially omitted sectional view of the buffer plate, FIG. 4 is a rear view thereof, and FIG.
Is a perspective view of the buffer bag, FIG. 6 is a front view of the same, and FIG. 7 is a perspective view of the uppermost buffer bag.

FIG. 1 shows a buffer plate 1, which has a plurality of buffer bags 4 along a horizontal direction in a recess 3 of a U-shaped steel sheet pile 2.
Are detachably attached with fixing bolts 7.

Each buffer bag 4 is provided with an upper belt 8 and a lower belt 9, and the upper belt 8 and the lower belt 9 of the adjacent buffer bag 4 are connected to each other,
The buffer bags 4 are integrally joined in the longitudinal direction. In this way, since each buffer bag 4 is independent of the appropriate length, it can be easily attached to the steel sheet pile 2.

The air injection valve 10 on the upper surface of each buffer bag 4
However, the inside of each buffer bag 4 is integrally communicated by being fitted into the connection recess 11 on the lower surface of the adjacent buffer bag 4. Therefore, each buffer bag 4 is inflated uniformly by pressurizing air from the air injection valve 10 in the uppermost buffer bag 4.

The lowermost buffer bag 4 is covered with a tapered tip cap 12 at the tip of the steel sheet pile 2. The tip cap 12 is composed of a fixed plate 13 and an inclined plate 14, which is tapered when the buffer plate 1 is placed.
When pulling out the buffer plate 1, the support plate 15 is pulled out by pulling resistance.
The slanted plate 14 rotates around the hinge 16 as a result of being separated.

A water spray pipe 5 for injecting water is attached by a fixing band 6 to the back surface of the steel sheet pile opposite to the buffer bags 4. The water spray pipe 5 is for injecting water to excavate the driving hole of the buffer plate 1. The water spray pipe 5 is not limited to one as described above, and a plurality of water spray pipes 5 can be provided on both sides.

FIG. 10 shows a buffer wall 17 constructed by using the buffer plate 1, which is constructed by joining a plurality of buffer plates 1 mounted on the ground 18 with the buffer bag 4 in the same direction by the joint plate 19. The buffer bag 4 is held at a predetermined air pressure.

In this state, the ground 18a on the buffer bag 4 side
When the vibration occurs in the buffer bag 4, as shown in (1) of FIG. 10, the vibration is blocked by the air layer in the buffer bag 4 having a low density, so that the ground 18b on the side opposite to the buffer bag 4 is affected. Absent. This utilizes the property that the vibration is blocked when the density of the object changes greatly when the vibration is propagated.

On the other hand, when the ground 18a on the buffer bag 4 side is horizontally displaced, as shown in (2) of FIG. 10, air is evacuated from the automatic pressure control valve 20 according to the horizontal displacement,
If the pressure is set to 1 to ² kgf / cm ² , the cross-sectional area of the buffer bag 4 is reduced, so that the horizontal displacement is absorbed. Further, when horizontal displacement above the above pressure occurs, air is automatically discharged from the automatic pressure control valve 20 to the atmosphere in response to the horizontal displacement. Therefore, the ground 18b on the side opposite to the buffer bag 4 is not affected by the horizontal displacement.

That is, the buffer bag 4 is not used to counter the horizontal displacement due to the rigidity of the wall body such as the U-shaped steel sheet pile as in the conventional case.
By absorbing the displacement inside the ground, the ground 18b on the side opposite to the buffer bag 4 is not affected.

Next, the construction method of the above buffer wall will be described. First, a plurality of buffer bags 4 are attached to the recess 3 of the steel sheet pile 2 along the horizontal direction to form the buffer plate 1, and
Air is press-fitted from the air injection valve 10 of the buffer bag 4 at the uppermost portion to a pressure of 1 to 2 kgf or more. The buffer bag 4 may be attached to the steel sheet pile 2 in advance at a factory so as to have a predetermined pressure.

Next, as shown in FIG. 11, the buffer plates 1 are laid out one by one while the water is sprayed from the water spray pipe 5 to excavate the ground 18, and the horizontal direction of each buffer plate 1 is a metal fitting. By connecting at 19, the buffer wall 17 having the buffer bag 4 on the entire surface on one side is constructed.

Then, the buffer bag 4 of the buffer wall 17 absorbs vibration or horizontal displacement caused by the foundation work 21 and the adjacent structure 2
Prevent transmission to 2. As described above, after the foundation work 21 is completed while preventing the adjacent structure 22 from being adversely affected, the buffer bag 4 is evacuated and the buffer plate 1 is pulled out. At this time, the inclined plate 14 of the tip cap 12 is pulled out. It can be pulled out easily by rotating with.

Further, in the present embodiment, the buffer plate 1 is placed by the water jet method, but the method is not limited to this method, and it may be placed by preceding excavation.

[0025]

EFFECTS OF THE INVENTION Since a plurality of shock absorbing plates, each having a shock absorbing bag provided in a recess of a steel sheet pile, are horizontally connected and driven into the ground, and the shock absorbing bags are formed in the same direction. Since the vibration generated in the ground is blocked by the air layer in the buffer bag having a low density, it does not affect the ground on the side opposite to the buffer bag.

A plurality of shock absorbing plates, each having a shock absorbing bag provided in the recess of the steel sheet pile, are horizontally connected and placed in the ground, and the shock absorbing bags are positioned in the same direction to construct a shock absorbing wall. By contracting the buffer bag according to the horizontal displacement generated in the ground, the horizontal displacement generated in the ground can be effectively absorbed, so that the ground on the side opposite to the buffer bag is not affected.

It is possible to economically and easily construct a buffer wall capable of effectively absorbing horizontal displacement, vibration, etc. generated in soft ground and the like.

Since the buffer plate can be easily pulled out, it can be diverted to another.

By connecting a plurality of buffer plates in the long side direction, a buffer wall having an arbitrary depth can be constructed.

By providing the cushioning bag along the recess side of the steel sheet pile, it is possible to form the cushioning sheet using the steel sheet pile of any shape.

Since the lower end of the buffer bag is covered with the tapered tip cap, the buffer plate can be easily placed.

[Brief description of drawings]

FIG. 1 is a perspective view of a buffer plate.

FIG. 2 is a rear view of a buffer plate.

FIG. 3 is a partially omitted sectional view of a buffer plate.

FIG. 4 is a rear view of the buffer plate.

FIG. 5 is a perspective view of a buffer bag.

FIG. 6 is a front view of a buffer bag.

FIG. 7 is a perspective view of the uppermost buffer bag.

8 (1) is a front view of the tip cap, and FIG. 8 (2) is a sectional view of the same.

9 (1) is a front view of a tip cap with a tilted plate rotated, and FIG. 9 (2) is a sectional view of the same.

10 (1) is a cross-sectional view of a buffer wall in which the buffer bag is filled with air, and FIG. 10 (2) is a cross-sectional view of the buffer wall in which the buffer bag is contracted.

FIG. 11 is a cross-sectional view in which a buffer wall is installed.

[Explanation of symbols]

 1 Buffer Plate 2 Steel Sheet Pile 3 Recess 4 Buffer Bag 5 Water Spray Pipe 6 Fixing Band 7 Fixing Bolt 8 Upper Belt 9 Lower Belt 10 Air Injection Valve 11 Recessed Connection 12 Tip Cap 17 Buffer Wall 20 Automatic Pressure Control Valve

Claims (3)

[Claims] 1. A plurality of shock-absorbing plates, each having a shock-absorbing bag provided in a recess of a steel sheet pile, are horizontally connected and driven into the ground, and the shock-absorbing bags are formed in the same direction. Characteristic underground buffer wall. 2. The underground buffer wall according to claim 1, wherein the buffer bag contracts according to a horizontal displacement generated in the ground. 3. A plurality of cushioning bags are detachably provided in the recess of the steel sheet pile along the horizontal direction, the interiors of the cushioning bags are connected to each other by an air injection valve, and the lower end portion of the cushioning bag at the lowermost portion is A buffer plate characterized by being covered with a tapered tip cap.