JP3608175B2 - Yamadome method - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a mountain retaining method used in the construction of an underground part of a structure, an underground structure, or the like.
[0002]
[Prior art]
In the conventional mountain retaining method, as shown in FIG. 12, the retaining wall a is constructed around the ground to be excavated, and after excavating between these retaining walls a, the earth pressure P ₁ from the outside of the retaining wall a In order to receive this, a beam member b is provided between the mountain retaining walls a and is supported.
Then, excavation between the retaining walls a is performed at a predetermined depth while repeating the excavation process and the support process.
[0003]
[Problems to be solved by the invention]
The above-mentioned Yamadome method has the following problems.
For partitioning the <b> ground in the mountains Tomekabe a, subject to earth pressure P ₂ from the ground also outside between YamaTomekabe a.
Therefore, there is a possibility that YamaTomekabe a is destroyed by soil pressure P _2.
If <b> YamaTomekabe a surrounding ground is soft, the slip is YamaTomekabe a outer ground, wraps around the lower part of the mountain Tomekabe a push excavation face c as a soil pressure P ₃ (Heaving).
Therefore, measures against such heaving must be taken.
[0004]
[Object of the present invention]
The present invention has been made to solve the above problems, and an object of the present invention is to provide a mountain retaining method capable of preventing deformation or destruction of a retaining wall and dealing with heaving.
[0005]
[Means for solving problems]
That is, the present invention provides a structure in which the underground wall is continuously constructed between the mountain walls built in the ground, and the mountain wall is supported by the underground wall. It is a mountain retaining method that is excavated together with the underground wall, and before the underground wall hardens, by inserting a soft material by inserting an injection tube from above into the underground wall to a predetermined position, It is a mountain retaining method characterized by providing an edge cut portion in the horizontal direction in the underground wall. Further, the present invention is the mountain method according to the above-described mountain method, wherein the underground wall forms a diverging haunch portion and is connected to the mountain wall. Further, the present invention is the mountain retaining method according to the above-described mountain retaining method, wherein the underground wall is provided with water passage means for allowing water passage in the penetrating direction. Further, the present invention is the mountain retaining method according to the above-described mountain retaining method, wherein the underground wall is formed of soil cement.
[0006]
[Example 1]
Hereinafter, an embodiment of a mountain retaining method according to the present invention will be described in the order of work steps with reference to the drawings.
[0007]
<I> Construction of the Yamato wall (Fig. 1)
The mountain retaining wall 10 is constructed at a predetermined depth in a predetermined ground according to the structure to be constructed. This mountain retaining wall 10 is a wall body that holds earth and sand outside thereof in order to secure an underground space, and may be constructed by a known method such as an underground continuous wall.
For example, a groove is opened at the building position of the mountain retaining wall 10 and a reinforcing bar is built in the groove, and then concrete is placed and hardened. And the mountain retaining wall 10 of a predetermined shape is constructed by repeating these steps.
The construction shape of the mountain retaining wall 10 has a rectangular cross section in FIG. 1, but may have any shape as long as it has opposing surfaces.
The “facing surface” of the mountain retaining wall 10 referred to here does not only indicate parallel wall surfaces, but the wall surfaces of the mountain retaining walls 10 and 10 that are not parallel or the corners of the bent mountain retaining wall 10. It includes two wall surfaces on both sides. Even if it is such a wall surface, the underground wall 10 can be constructed in the meantime and they can be supported.
[0008]
<B> Construction of underground wall (Figs. 1-5)
In order to prevent the mountain wall 10 from being damaged by the earth pressure from the outside, the underground wall 20 is continuously constructed in the ground between the mountain walls 10 and 10 facing each other.
The underground wall 20 is preferably in a state where both ends are in contact with the mountain retaining wall 10 and in a direction substantially perpendicular to the mountain retaining wall 10.
When both ends of the underground wall 20 abut the mountain retaining walls 10, 10, the earth pressure P associated with each mountain retaining wall 10 is transmitted to the underground wall 20 as shown in FIG. 2.
For this reason, since the earth pressure concerning each mountain retaining wall 10 acts on the underground wall 20 from the opposite direction, those earth pressures P will be mutually offset by the underground wall 20.
Therefore, since the earth pressure P can be suppressed by the underground wall 20, it is possible to prevent the mountain wall 10 from creeping and being damaged.
In addition, the underground wall 20 continuous to the mountain retaining wall 10 referred to here is not only in a state where the mountain retaining wall 10 and the underground wall 20 are completely in contact with each other, but if earth pressure can be transmitted through the ground, The state may not be completely abutted.
[0009]
Moreover, in order to transmit the earth pressure from the mountain retaining wall 10 to the underground wall 20 efficiently, it is preferable to arrange the underground wall 20 orthogonal to the mountain retaining wall 10.
However, the arrangement direction of the underground wall 20 is not limited to the direction completely orthogonal to the mountain retaining wall 10, and may be other arrangement directions as long as the earth pressure can be transmitted. Furthermore, the arrangement position and the number of arrangement of the underground wall 20 may be arbitrarily set depending on the surrounding ground conditions.
[0010]
Thus, the underground wall 20 must have a predetermined compressive strength to transmit earth pressure, but is excavated together with the ground in the mountain retaining wall 10 and thus is easily broken. There is a need to.
For example, the underground wall 20 can be formed of soil cement.
That is, the ground where the underground wall 20 is to be constructed is excavated and stirred with an auger or the like and cement is mixed to form the soil column 21, and the soil column 21 is continued side by side as shown in FIG. 3 to construct the underground wall 20. To do.
At that time, as shown in FIG. 4, if a diverging haunch portion 22 is provided at the end of the underground wall 20 and abuts against the mountain retaining wall 10, the force due to earth pressure is dispersed and the mountain retaining wall 10 becomes underground. It is transmitted to the wall 20 and from the underground wall 20 to the mountain retaining wall 10.
For this reason, it is possible to prevent the mountain retaining wall 10 from being locally broken due to the concentrated load and to prevent the underground wall 20 from being easily buckled at the end thereof.
The material for forming the underground wall 20 is not limited to soil cement, and any other material may be used as long as it has a predetermined compressive strength and is easily broken.
[0011]
On the other hand, a plurality of underground walls 20 are arranged so as to intersect each other so as to subdivide the ground deeper than the excavation bottom surface surrounded by the mountain retaining wall 10.
Thereby, as shown in FIG. 5, since the soft ground which is going to wrap around from the bottom of the mountain retaining wall 10 can be suppressed by the underground wall 20 facing the intrusion direction, The slip 40 can be prevented.
[0012]
<C> Excavation and support in the retaining wall (Figs. 1 and 5)
After the underground wall 20 is constructed, the ground in the mountain retaining wall 10 is excavated together with the underground wall 20 by a known method.
At that time, the excavation work may be performed by digging the ground and the underground wall 20 simultaneously, or by digging only the ground to some extent and then breaking the underground wall 20. Then, a support beam is provided by a known method, such as by providing a cut beam 30 in the dug portion, and the mountain retaining method is completed.
The excavation process and the support process may be repeated alternately or may be performed simultaneously.
[0013]
[Example 2]
The mountain retaining wall 20 is not limited to the shape surrounding the predetermined ground, and may have other shapes as long as it has opposing wall surfaces.
For example, if the two mountain retaining walls 20 and 20 are constructed in parallel to the ground, and the underground wall 10 is constructed between them, the same mountain retaining method as in Example 1 can be performed, and the same effect can be obtained. .
[0014]
[Example 3]
In some cases, the underground wall 20 is constructed first, and then the mountain retaining wall 10 is constructed.
In this case, since the underground wall 20 is formed of a material that is easily broken, the underground wall 20 is constructed in advance in a large size as shown in FIG. Is easy.
Even if the mountain retaining wall 10 is constructed after constructing the underground wall 20 in this manner, the same effects as those of the first embodiment can be obtained.
[0015]
[Example 4]
The edge cut portion 24 may be formed in the underground wall 20 in the horizontal direction.
That is, when the excavation process is repeated several times, excavation work can be facilitated by forming a low-strength edge notch 24 in the excavated portion of the underground wall 20 in advance as shown in FIG. Can do.
As an example of the method for forming the edge cut portion 24, as shown in FIG. 8, before the underground wall 20 is hardened, an injection tube 50 is inserted into the underground wall 20 from above to a predetermined position to inject a soft material. To do.
The soft material is injected so as to be formed in order from the lower edge cut portion 24.
It is preferable that the injection pipe 50 has its jet outlet 51 opened sideways in order to allow the soft material to flow out in the horizontal direction within the underground wall 20.
The material of the soft material may be any material that can secure the edge cut portion 24 having low strength.
[0016]
[Example 5]
You may arrange | position the water flow means which accept | permits the water flow in the penetration direction in the underground wall 20.
When there is a soft soil layer in the ground around Yamato wall 10 and there is an influence of groundwater during construction, it is necessary to install a deep well 80 etc. in the ground and forcibly drain it to lower the pressure level There is.
However, since the ground is partitioned in the vertical direction by the construction of the underground wall 20, a decrease in the pressurized water level is prevented.
Thus, as shown in FIG. 9, if the water passing means 60 is provided at a predetermined position in the underground wall 20, such a problem can be solved.
This water flow means 60 may be appropriately installed at an arbitrary position in an arbitrary underground wall 20 according to the surrounding ground conditions and the like.
[0017]
As the water flow means 60, for example, a water flow pipe 70 as shown in FIG. 10 can be adopted. The water pipe 70 has a structure in which a thin water pipe 72 and a drain pipe 73 are communicated with the outer peripheral surface of the main pipe 71.
The main pipe 71 is a high-rigidity pipe having a length that is about the thickness of the underground wall 20 and open at both ends.
Since the main pipe 71 is a member that remains in the underground wall 20, it is necessary to have rigidity that can withstand earth pressure acting in the underground wall 20. For example, a steel pipe or the like can be adopted.
Inside the main pipe 71, two water-permeable members 711 made of ice, gravel, or the like filled with ice or gravel are disposed so as to be slidable in the axial direction of the main pipe 71 so as to close the openings on both sides. Yes.
When the water passage member 711 is filled with ice or when the water passage member is an ice block, the water does not melt after the water passage pipe 70 is installed, so the water permeability of the water passage 70 becomes very good. On the other hand, a rod 74 having a jack part 741 formed at the tip is inserted into the water supply pipe 72, and the jack part 741 reaches the main pipe 71 and is located between the water passing members 711.
The jack portion 741 has a structure in which the lateral width expands and contracts in a pantograph shape by the rotation of the rod 74.
In addition, the jack part 741 may use other well-known things, such as a hydraulic jack.
The drain pipe 73 communicates with the peripheral surface of the lower part of the main pipe 71 so that drainage in the main pipe 71 can be performed.
[0018]
Next, a method for installing the water pipe 70 will be described.
After the soil cement or the like forming the underground wall 20 is placed, it is inserted into the underground wall 20 in such a manner that the main pipe 71 is pushed into the underground wall 20 from the top with the water supply pipe 72 or the water distribution pipe 73 before being hardened.
At that time, the main pipe 71 is set to face the thickness direction of the underground wall 20.
When the main pipe 71 reaches a predetermined position, the insertion operation is stopped, and the rod 74 is rotated to expand the jack portion 741 in the horizontal direction as shown in FIG.
Then, it is pushed by the jack part 741 and the water-permeable members 711 and 711 are pressed against the ground.
Next, water is pumped from the water pipe 72 through which the rod 74 is inserted, and the soil cement or the like in the water passage member 711 is discharged to prevent clogging.
Then, the rod 74 is reversely rotated to contract the jack portion 741 and lift it from the water supply pipe 72, thereby completing the installation of the water flow pipe 70.
[0019]
If the water pipe 70 as described above is employed, the water passage means can be reliably and economically and efficiently installed on the underground wall 20.
Further, the water pipe 70 can pump up the groundwater through the drain pipe 73.
In addition, the water flow means 60 is not limited to the said water flow pipe 70, You may employ | adopt other well-known water flow materials.
[0020]
【The invention's effect】
Since the present invention is as described above, the following effects can be obtained.
<I> The underground wall is constructed between the opposing mountain retaining walls, and the underground wall is excavated together with the ground between the mountain retaining walls.
For this reason, the earth pressure applied from the outside of the retaining wall can be received by the underground wall, and the earth pressure applied from both sides can be offset.
Therefore, it is possible to avoid deformation of the retaining wall before excavating between the retaining walls, and to prevent breakage associated therewith.
<B> By constructing underground walls between the retaining walls, the ground between the retaining walls is subdivided.
For this reason, it can reduce that a soft ground turns around from the lower part of a mountain retaining wall.
Therefore, excavation of the excavated surface due to slip failure of the ground on the rear side of the mountain retaining wall, that is, heaving can be prevented.
<C> Heaving can be more effectively reduced by constructing a plurality of underground walls intersecting the mountain walls.
<D> If a diverging haunch is provided at the end of the underground wall, stress can be transmitted between the retaining wall and the underground wall without stress concentration on the retaining wall and part of the underground wall. It can be done reliably.
<E> By constructing the mountain retaining wall behind the underground wall, unnecessary portions of the soft underground wall can be scraped off and the retaining wall in contact with the underground wall can be reliably constructed.
<F> By providing the edge cut portion in the underground wall, excavation work between the mountain retaining walls can be performed efficiently.
<G> By providing a water pipe in the underground wall, a water passing function can be imparted to the ground partitioned by the underground wall.
<H> If the underground wall is formed of soil cement, it becomes soft while having a predetermined compressive strength, so that excavation work becomes easy.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a mountain retaining method in Example 1. FIG. 2 is an explanatory diagram of earth pressure acting on a mountain retaining wall and an underground wall. FIG. 3 is an illustration of earth pressure acting on a mountain retaining wall and an underground wall. Explanatory drawing [FIG. 4] Explanatory drawing of the haunch part of the underground wall [FIG. 5] Explanatory drawing of the heaving suppression function [FIG. 6] An explanatory drawing of the mountain retaining method in Example 3. [FIG. FIG. 8 is an explanatory diagram of a mountain retaining method in Example 4. FIG. 9 is an explanatory diagram of a mountain retaining method in Example 5. FIG. 10 is a perspective view of a water conduit. Explanatory drawing [Fig. 12] Explanatory drawing of prior art

Claims (4)

The underground wall is continuously constructed between the mountain walls built in the ground, and the ground wall between the mountain walls together with the underground wall is supported by the underground wall. It is a mountain method that is excavated,
Before the underground wall is hardened, by inserting an injection tube from above into the underground wall to a predetermined position and injecting a soft material, an edge cutout is provided in the horizontal direction in the underground wall. A feature of the Yamadome method. In the mountain retaining method according to claim 1,
The underground wall method is characterized in that the underground wall forms a diverging haunch and is connected to the mountain wall. In the mountain retaining method according to claim 1 or 2,
The underground wall method, wherein the underground wall is provided with water passage means that allows water to pass therethrough. In the mountain retaining method according to any one of claims 1 to 3,
The underground method is characterized in that the underground wall is formed of soil cement.

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