JP2002275879A - Construction for stabilizing banking on soft ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make greatly easier connection between piles than usual, offer good constructiveness and further improve the stability of a banking in a one- layer soft structure, without giving the influences of the inclination of the piles due to the strike slip of a ground on other piles as they are and causing the tear-off or breakage of pile head portions during the strike slip of the ground. SOLUTION: After a number of wood piles 1 are driven into a soft ground in spaced relation as required while leaving their pile head portions 1a, used tires 2 as joint rings are loosely applied on the pile head portions 1a of the wood piles, the old tires are connected to each other with ropes 3 in a meshed form, the pile head portions, the used tires and the ropes are buried with a sand mat and then soil is filled thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an embankment stabilization method for stabilizing an embankment on soft ground.

[0002]

2. Description of the Related Art Japanese Patent Publication No. Sho 60-55648 discloses a method in which a plurality of wooden piles, reinforced concrete piles, prestressed concrete piles, steel pipe piles, or the like, or cast-in-place piles made of reinforced concrete piles are used. After the heads are left and cast at a predetermined interval, the pile heads are connected to each other in a net-like manner with a flexible connecting member such as a reinforcing bar while the connecting member is bent downward. A method of embedding the heads and the connecting member with a sand mat, laying a civil engineering sheet thereon, laying sand thereon, and then embankment is disclosed.

[0003]

This construction method is called "pile net construction method" and has achieved great results in various places under the technical guidance of the present inventors. Such a destruction problem has arisen.

Conventionally, a reinforcing bar is wound around a pile head of a wooden pile, and the wooden piles are connected to each other with a reinforcing bar in a mesh shape. Due to the lateral displacement, the wooden piles inclining from the first row are greatly inclined, and other wooden piles connected with reinforcing bars are also pulled in a chain and inclined, so that the reinforcing bars bite into the pile head and the pile head is It was torn or broken, leading to destruction. FIG. 1 is a schematic view showing a state in which a wooden pile a connected in a net shape by a reinforcing bar b has moved from a position indicated by a solid line to a position indicated by a broken line due to lateral displacement of the ground in the direction of the arrow.

[0005] The reason for this is that when the bearing capacity of the pile is large, the pile load is not transmitted to the ground between the piles because the pile does not sink, and the pile load and the ground are not transferred to the connecting members connecting the piles and the piles. When some of the piles are inclined due to the lateral displacement, the other piles connected to the pile by the connecting member
Since a wooden pile is pulled while being concentrated while receiving a large stress such as an overlaid load and a lateral shift, the pile head is torn or broken.

[0006] In the conventional pile net method, when connecting the pile heads, a reinforcing bar is wound around the pile head of the pile after casting. It took time and effort.

The inventor of the present invention has analyzed the above-mentioned fracture phenomena, and has conducted intensive studies on the countermeasures. As a result, the inclination of the pile due to the lateral displacement of the ground does not directly spread to other piles, and the lateral displacement of the ground has occurred. In addition, the pile head is not torn or broken, and the connection between the piles is much easier than in the conventional pile net method, and the workability is good. The present invention has been devised which can further enhance the stability.

[0008]

SUMMARY OF THE INVENTION According to the present invention, a plurality of piles are cast at a required interval in soft ground while leaving the pile heads, and then a connecting ring is attached to each pile. Loosely, and connect the connecting rings to each other with a connecting member
The pile head, the connecting ring, and the connecting member are embedded in a sand mat, and embankment is laid thereon.

In the present invention, the connection between the piles is performed by connecting the connection rings loosely covered on the pile heads with the connection members without winding the connection members around the pile heads, or After the members are first connected by the connecting member, the connecting ring is loosely put on the pile head, so that the connecting operation is easy and the pile head is not tightened by the connecting member.

Since the connecting ring is loose with respect to the pile head, the connecting ring and the connecting member are free in the vertical direction relative to the pile, and the embankment load (overlaying load) can be widened by the group pile effect. , And at the same time, the pile load is supported by the pile heads, and the embankment load between the piles is determined by the connecting ring and the connecting member connected in a mesh, and the connecting ring is buoy (float). Like a net-shaped raft, it is evenly supported separately from the pile head, so it has a more flexible structure compared to connecting piles by wrapping a connection member around the pile head, further enhancing the stability of the embankment be able to.

On the other hand, when some of the piles are subjected to a load that is greatly inclined with the coupling ring placed on them,
Since the other pile is buffered and pulled via the connecting member connected to the coupling ring, the inclination is suppressed by the other pile.

Since the connecting members are connected to each other through a connecting ring and stretched in a net-like manner, the connecting members can be prevented from being cut by the embankment load and the overlying load, and have a buffering effect on the tensile force of the pile.

[0013] With respect to the four piles arranged in four points of a quadrilateral, the four connecting rings are connected to the four sides of the quadrilateral and the diagonal by connecting members, and the connecting members are connected to each other at the intersection of the diagonal lines. .

It is preferable to use old tires for automobiles as the coupling ring. Rubber tires for automobiles have an inner diameter suitable for loosely covering the pile thickness commonly used in the present invention, and have elasticity and cloth or steel wire embedded therein. Since it is tough, in addition to its original function of joining the connecting members, it also has a buffering effect against an overload and tensile stress, and has good durability because it does not corrode, and is suitable as a connecting ring used in the present invention. Moreover, the use of old tires, which are difficult to dispose or recycle because of their large volume, can contribute to effective use of resources and reduce construction costs.

The connecting member for connecting the old tires as the connecting ring may be a rope such as a nylon rope or a wire rope.

A metal ring can be used as the connecting ring, and the metal rings can be connected to each other by a steel material or a wire rope.

[0017]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

Example 1 Dutch cone penetration test value 1
~3Kg / cm ^2, water content ratio from 400 to 1000%, with respect to soft ground of about peat 9m, as shown in FIG. 2, pile diameter 2
A wooden pile 1 of 0 cm and a pile length of 9 m, and a pile head 1 a of about 30
cm, and piled in a grid shape at an interval of 1.5 m. Then, as a connecting ring on each pile head 1a, loosely cover the old tires 2 having an inner diameter larger than the pile diameter, and connect the old tires 2 to each other as a connecting member. The rope was connected in a net-like manner with a nylon rope 3 having a diameter of about 13 mm in a relaxed state without tension. That is, as shown in FIG. A set of four wooden piles 1 arranged in four points of a quadrilateral is used as a set, and four old tires 2 are connected with the ropes 3 on the four sides of the quadrilateral and diagonally, and the ropes 3 are connected with each other at the intersection of the diagonal lines. Joined.

Thereafter, as shown in FIG. 4, the pile heads 1a,
A sand mat 4 having a cover thickness enough to hide the old tire 2 and the rope 3 was formed. At this time, the pile heads 1a are arranged in a grid at equal intervals, and the old tires 2 loosely covered on the respective pile heads 1a are connected in a mesh manner with the ropes 3 between the pile heads 1a. Since the load on the ground is dispersed evenly and acts on the soft ground, the bulldozer or dump truck should be run immediately without needing a floor plate, etc. while covering the pile head 1a, old tires 2 and ropes 3 with sand. Was completed.

Next, embankment 5 was applied to sand mat 4 without using a sheet for civil engineering. Since the old tires 2 connected in a net shape by the ropes 3 exist between the pile heads 1a, the embankment load does not slip through between the pile heads 1a. Embankment 5 without laying
There was no problem even if it was applied directly.

Example 2 Dutch cone penetration test value 0.5-3 kg / cm ² , water content 500-1000%,
As shown in FIG. 5, a wooden pile 1 having a pile diameter of 20 cm and a pile length of 9 m was placed on a soft ground having a peat layer of about 10 m.
a was driven into a grid at intervals of 1.5 m while leaving about 30 cm. Next, as shown in FIG. 6, a metal ring 8 having an inner diameter larger than the pile diameter is loosely covered as a connecting ring, and a connection fitting 9 which is a U-shaped metal plate as shown in FIG. As shown in FIG. 7, the four wooden piles 1 which are hung as shown in FIG.
As a set, the four rings 8 were connected to the four sides and the diagonal of the quadrilateral using the connection fitting 9 and the connecting wood 10, and the intersections of the connecting wood 10 were connected at the intersections of the diagonal lines. The connection between the connection fitting 9 and the connection wood 10 is as follows.
Tightening was performed with bolts 11 and nuts 12.

Thereafter, although not shown, the pile head 1a,
A sand mat having a cover thickness enough to hide the connection fitting 9 and the connection wood 10 was formed. At this time, the pile heads 1a are arranged in a grid at equal intervals, and the rings 8 loosely covered on the respective pile heads 1a are connected in a mesh manner with the connecting fitting 9 and the connecting wood 10 between the pile heads 1a. Since the overhead load is dispersed on average and acts on the soft ground, a bulldozer or dump truck is mounted on the pile head 1a, the ring 8, the connection fitting 9 and the connecting lumber 10 while covering the sand with sand. The vehicle was able to run immediately without the need for.

Next, embankment was applied to the sand mat without using a civil engineering sheet. Since the ring 8, the connection fitting 9, and the connecting wood 10 are connected in a mesh between the pile heads 1a, the embankment load does not slip through between the pile heads 1a. There was no problem even if the embankment was applied directly without laying a civil engineering sheet.

In the case of the second embodiment, the metal ring 8 is loosely connected to the wooden stake 1 and is connected to the wooden pile 1 in a net-like manner, even though the connecting wood 10 as the connecting member is not flexible. Since the entirety of the connecting lumber 10 can be moved up and down using the pile head 1a of the cast wooden pile 1 as a guide, the embankment load and the overburden load can be obtained as if it were a raft floating on soft ground. Can be flexibly supported.

The two embodiments have been described above.
As the pile, a wooden pile is suitable as described in JP-B-60-55648, but a reinforced concrete pile,
It may be a ready-made pile such as a prestressed concrete pile, a steel pipe pile, or a cast-in-place pile made of a reinforced concrete pile. In the first embodiment, a nylon rope is used as the rope 3 connecting the old tires 2, but a metal wire rope or the like may be used.
Further, the old tires 2 may be connected to each other with a reinforcing bar, and the reinforcing bar may be bent downward between the pile heads so as to flexibly cope with an embankment load, an overlying load, a tensile stress caused by a pile, and the like. Further, in the second embodiment, the metal ring 8 is connected by the connection fitting 9 and the connection wood 10, but may be connected by using a reinforcing bar, a steel material, a wire rope, or the like. When connecting the metal ring 8 with a reinforcing bar or a steel material, the reinforcing bar or the steel material may be bent downward.

[0026]

According to the present invention, after a large number of piles are driven into the soft ground at a required interval while leaving the pile heads, a connecting ring for each pile is loosened to the pile heads. Over
Since the connecting rings are connected in a mesh by the connecting member, the following effects are obtained in addition to the various effects described in JP-B-60-55648.

When the soft ground is largely displaced laterally, such as when a reinforcing bar is wound around a pile head and the wooden piles are connected to each other in a net shape by the reinforcing bar, the reinforcing bar bites into the pile head and the pile head is torn. It does not break and break.

Since the connection ring loosely connected to the pile head is connected without winding the reinforcing bar around the pile head, the connection work becomes easy and the workability is improved, so that the construction period is shortened and the construction cost is reduced. I can do it.

Since the connection rings loosely covered on the pile heads are connected without directly connecting the pile heads, the pile heads have a more flexible structure, and have enhanced absorbability against the embankment load and the overlying load. The occurrence of plastic flow and the influence on the surrounding ground can be more reliably prevented.

If an old tire is used as the connecting ring, it is tough and has an original function of connecting the connecting members, and also has a buffering action against an overload and a tensile stress, and has good durability because it does not corrode. Moreover, by utilizing old tires that are troubled with disposal and reprocessing,
It can contribute to effective use of resources and reduce construction costs.

[0031] Not only is the civil engineering sheet unnecessary, but also
Since the sand amount of the sand mat is reduced, the workability is further improved and the construction cost can be further reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a state in which a wooden pile connected in a mesh by a reinforcing bar moves due to a lateral displacement of soft ground in a conventional “pile net method”.

FIG. 2 is a perspective view of Example 1 of the present invention using an old tire as a coupling ring.

FIG. 3 is a plan view of the same example.

FIG. 4 is a sectional view of the same example.

FIG. 5 is a side view of Embodiment 2 of the present invention using a metal ring as a coupling ring.

FIG. 6 is a plan view of the same example.

FIG. 7 is a perspective view showing a connection configuration between a metal ring and connection wood in the same example.

FIG. 8 is a perspective view of a connection fitting used for the connection.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 wooden pile 1 a pile head 2 old tire 3 rope 4 sand mat 5 embankment 8 metal ring 9 connection fitting 10 connecting wood 11 bolt 12 nut

Claims (5)

[Claims] 1. After a number of piles are cast at a required interval in soft ground while leaving the pile heads, a connecting ring is loosely put on the pile head for each pile, and the connecting rings are connected to each other. Characterized in that the pile head, the connecting ring and the connecting member are buried in a sand mat, and the embankment is laid on the pile head, the connecting ring and the connecting member. 2. The four stakes arranged in four points of a quadrilateral are connected by connecting members at four connecting rings with respect to the four sides of the quadrilateral and diagonally, and the connecting members are connected at the intersection of the diagonal lines. 2. The method according to claim 1, wherein the connection is performed.
The embankment stabilization method on soft ground described in 4. 3. The method for stabilizing embankment on soft ground according to claim 1, wherein an old tire for an automobile is used as the coupling ring. 4. A method for stabilizing embankment on soft ground according to claim 3, wherein a rope is used as the connecting member, and the connecting rings are connected in a mesh form with the rope. 5. The embankment stabilization method on soft ground according to claim 1, wherein a metal ring is used as the connecting ring, and the metal rings are connected to each other by a steel material or a wire rope.