JP4820276B2 - Construction method and structure of mountain retaining support - Google Patents

Description

  The present invention relates to a support structure for supporting the surrounding ground so that the surrounding ground does not collapse when constructing an underground structure or the like. It relates to the construction method and structure of the support.

When constructing underground structures such as basements and underground beams, the ground is excavated, and the surrounding earth and sand surrounding the excavated space is supported by a temporary material called a mountain retaining support.
Before excavation, a sheet pile and a main pile are driven into the ground, and the ground is excavated along the sheet pile and the main pile.
Along with excavation, the load of the surrounding earth and sand acts on the sheet pile and the like, and the construction that supports this earth and sand load is called a mountain retaining support, and there are various methods of construction as the retaining support.

As one of them, the horizontal cutting beam method that hangs the beam between the earth retaining wall and the opposite earth retaining wall and stretches it with a jack, or the central part of the part to be excavated, remains in this center. There is also an island method where a beam is installed between the ground and the retaining wall.
However, in the horizontal beam method, the beams intersect vertically and horizontally in the underground space, so that the construction is troublesome, the construction period is long, and the cost is high.
In the island construction method, crossed beams and the island part left in the center of the space occupy the space, which hinders construction.
JP 2003-166242 A

  The problem to be solved by the present invention is that the supporting work of the retaining wall occupies the construction space, hinders the construction, and the construction period becomes long.

The construction method of the mountain retaining work according to the present invention is as follows:
In the construction method of the mountain retaining support that supports the load of the surrounding ground by sheet piles or parent piles with the lower part buried underground,
Placing an elastic retaining pile on the ground away from the mountain retaining wall,
An extendable beam material is interposed between the protruding portion of the holding pile exposed from the ground and the retaining wall,
Before excavating the ground inside the retaining wall,
The increase in sediment load acting on the retaining wall is given to the beam as a preload.
In the construction method,
The length of the beam material can be expanded and contracted by a jack,
It has a rotating piece at both ends,
With the preload given by the jack, the beam material can cope with the increase in sediment load,
With the rotating piece, it is possible to follow changes in the angle of the beam material caused by the displacement of the pile and the expansion and contraction of the beam material.

Moreover, the structure of the mountain retaining support according to the present invention is as follows:
A retaining wall that supports the load of the excavated ground,
Between the retaining pile with elasticity, which is placed on the ground at an appropriate distance from the retaining wall,
It is a structure of a mountain retaining work that interposes a beam material,
The beam material can be extended and contracted by a jack,
One end of the beam material abuts against the erection material of the retaining wall through the rotating piece,
The other end of the beam is brought into contact with the holding pile through the rotating piece,
With the preload given by the jack, the beam material can cope with the increase in sediment load,
With the rotating piece, it is possible to follow changes in the angle of the beam material caused by the displacement of the pile and the expansion and contraction of the beam material.

The following effects can be obtained by the construction method and the structure of the mountain retaining support according to the present invention.
<a> A pile is placed on the ground at an appropriate distance from the retaining wall, and a beam is placed between the retaining pile and the retaining wall, so that the construction space can be secured without occupying a large amount of excavation space. At the same time, it will not hinder the construction.
<B> Because one end of the beam is subjected to a reaction force by a holding pile placed on the ground at an appropriate distance from the retaining wall, a beam is placed between the retaining wall and the retaining wall as in the horizontal beam method. There is no need to hand it vertically and horizontally, the construction is simplified, the construction period can be significantly shortened, and the construction cost can be reduced.
<C> Preloading the beam with a jack and predicting the amount of earth and sand generated, and holding down the retaining wall, the beam will hold the earth and sand load even if the stake that protrudes greatly from the ground is displaced. Then, the retaining wall can be effectively pressed down and prevented from sticking out.
<D> Since the rotating pieces are attached to both ends of the beam material, it can handle the length and angle of the beam material, and even if the stake pile is displaced, it becomes a stable support structure that flexibly changes its angle following it. .

  First, the structure of the support work according to the present invention will be described.

<A> Mountain retaining wall A plurality of parent piles 1 made of H-shaped steel are placed at appropriate intervals at the excavation boundary position, and as the deep excavation proceeds, the retaining plate 2 is placed between the parent pile 1 and the parent pile 1. Plug in to prevent ground collapse.
As the retaining wall A, various methods can be employed, such as a method in which a sheet pile is continuously driven, a hole in the ground by a hole punching machine, and a cast-in-place concrete column and wall material are constructed and constructed.

<I> Reserve piles After primary excavation, reserve piles 3 are placed at a position appropriately separated from the retaining wall A. (Fig. 7)
In the embodiment, H-shaped steel is used as the reserve pile 3.
In order to secure the construction space and open the pitch of the beam members 5, it is necessary to increase the load applied to one beam member 5.
Therefore, as shown in FIGS. 1 and 3, two or more H-shaped steels are used for one retaining pile 3.
Of course, it is possible to use a single H-shaped steel as the reserve pile 3.
The reserve pile 3 is excavated and buried in the ground, and grout material is injected into the hole and fixed. A part of the reserve pile 3 is projected from the ground.
A belly raising material 8 is attached to the reserve pile 3.

<C> Beam material The beam material 5 is hung between the belly raising material 4 of the retaining wall A and the pile 3.
An H-shaped steel is used as the anti-raised material 4.
Although H-shaped steel is also used for the beam member 5, the length of the beam member 5 can be expanded and contracted by a jack 6 interposed in the vicinity of one end thereof.
As the beam member 5, it is possible to adopt a structure in which the beam member itself is expanded and contracted without using the jack 6.

<D> Jack The jack 6 can be of various types, such as a mechanical type and a hydraulic type.

<E> Rotating piece Rotating pieces 7 that can rotate and change the angle as shown in FIG.
When the rotating piece 7 abuts against the bulging members 4 and 8 and the beam member 5 is extended by the jack 6 or the retaining pile 3 is warped, the length of the beam member 6 changes. In addition, it is possible to follow the change in the angle between the beam member 5 and the raised members 4 and 8.

  Next, the construction method of an underground structure using the above support structure will be described.

<F> Construction of the beam material The jack 6 of the hung beam material 5 is stretched between the erection material 8 on the side of the retaining pile 3 and the erection material 4 on the retaining wall A side. To support the retaining wall A.

<Ki> Preload In this invention, the ground inside the retaining wall A is further excavated to construct an underground structure.
Since a large earth and sand load acts on the reserve pile 3, it is desirable that it is not displaced as much as possible even if it receives a load.
However, if the ground is further excavated, the reserve pile 3 protrudes greatly on the ground surface.
If it protrudes largely on the ground surface, the reserve pile 3 will be displaced so as to warp in the opposite direction due to its elasticity.
When this displacement occurs, the mountain retaining wall A in which the earth and sand load has increased is projected so as to swell inside the underground space.
If the retaining wall A protrudes, it will hinder the construction of the structure in the underground space, so it is necessary to prevent the retaining wall A from protruding.
For this reason, the beam 5 is further extended by the jack 6 to give the preload F. (Fig. 8)

<K> Expected earth and sand load The second preload F predicts and gives an increase in the earth and sand load acting on the retaining wall A by excavating and deepening the bottom of the ground.
Thereafter, secondary excavation is performed to deepen the excavation bottom, and the storage pile 3 protrudes greatly from the ground surface, and the protruding length L becomes longer.
Due to the elasticity of the protruding pile 3 that protrudes greatly, a displacement T occurs so as to warp.
However, since the increase in the earth and sand load is given to the beam member 5 as a preload, the beam member 5 does not protrude from the mountain retaining wall A. (Fig. 9)

<K> Excavation and dismantling The underground beam is constructed as the predetermined underground structure 9, and the retaining wall A is supported by the underground beam.
In this state, the jack 6 of the beam member 5 is shrunk, and the beam member 5 is removed together with the belly raising member 4 on the mountain retaining wall A side from between the mountain retaining wall A and the retaining pile 3.
The reserved pile 3 is cut off from the ground and removed. (Fig. 10)

<Ko> Other Embodiments In the embodiment shown in FIG. 3 and the like, one beam member 5 is passed from one holding pile 3 to the mountain retaining wall A. However, as shown in the embodiment shown in FIG. Two or more beam members 5 can be applied in an inverted V shape from the pile 3.
By doing in this way, a load can be disperse | distributed and the support force of the pile 1 can also be made small.

It is a perspective view of a mountain retaining support construction state. It is sectional drawing of a support work. It is a top view of a support work. It is a top view of other forms. It is a conceptual diagram of the state which gave the preload. It is a side view of a rotation piece. It is sectional drawing of primary excavation. It is sectional drawing of secondary excavation. It is sectional drawing of the last excavation. It is sectional drawing of beam material removal.

Explanation of symbols

A Mountain retaining wall 1 Parent pile 2 Mountain retaining plate 3 Reserving pile 4 Raised material 5 Beam material 6 Jack 7 Rotating piece 8 Raised material 9 Underground beam

Claims (3)

In the construction method of the mountain retaining support that supports the load of the surrounding ground by sheet piles or parent piles with the lower part buried underground,
Placing an elastic retaining pile on the ground away from the mountain retaining wall,
An extendable beam material is interposed between the protruding portion of the holding pile exposed from the ground and the retaining wall,
Before excavating the ground inside the retaining wall,
The increase in the sediment load acting on the retaining wall is given to the beam as a preload,
The construction method of the mountain retaining work. The length of the beam material can be expanded and contracted by a jack,
It has a rotating piece at both ends,
With the preload given by the jack, the beam material can cope with the increase in sediment load,
The construction method of a mountain retaining support according to claim 1, characterized in that the rotating piece can follow the change in the angle of the beam material caused by the displacement of the holding pile and the expansion and contraction of the beam material. A retaining wall that supports the load of the excavated ground,
Between the retaining pile with elasticity, which is placed on the ground at an appropriate distance from the retaining wall,
It is a structure of a mountain retaining work that interposes a beam material,
The beam material can be extended and contracted by a jack,
One end of the beam material abuts against the erection material of the retaining wall through the rotating piece,
The other end of the beam is brought into contact with the holding pile through the rotating piece,
With the preload given by the jack, the beam material can cope with the increase in sediment load,
With the rotating piece, it is possible to follow the change in the angle of the beam material caused by the displacement of the holding pile and the expansion and contraction of the beam material,
The structure of the mountain retaining work.

Images