JP3208729B2 - Blistering prevention method and construction method of underground building - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing swelling and a method for constructing an underground building.

[0002]

2. Description of the Related Art Bulging can occur when there is an impermeable ground between the bottom of the root cutting and the vicinity of the tip of the retaining wall, and there is a pressurized aquifer underneath. It is said that there is a risk of causing an accident.However, in the past, the methods for preventing swelling were to reduce the pressure with a deep well, to lower the retaining wall to an impermeable layer and close it, and to improve the bottom plate And a method of dividing the basement and constructing it.

[0003]

However, the method of reducing the pressure by the deep well has the drawback that the treatment capacity of the public sewerage system due to drainage becomes a problem, or that the surrounding ground may be compacted and settled due to a decrease in water level. The method of lowering the earth retaining wall to the impermeable layer ground and closing it has the drawback that the impermeable layer ground is accurately assumed, and it is technically difficult to securely close the ground and the construction cost increases. The method of closing off by improving the bottom plate has the disadvantages that the reliability of the injection of the chemical solution for improving the bottom plate is not always high and the cost is high. The method of dividing the basement and constructing it has the drawback that there is a limit to the operation of deep excavation, the construction period is long, and the joint of the skeleton is increased.

[0004] The inventors of the present invention have intensively studied to develop a method for preventing swelling which has improved these disadvantages and a method for constructing an underground building using the same, and completed the present invention. It is relatively simple, yet effective and economical to prevent.

[0005]

SUMMARY OF THE INVENTION The present invention provides a method for preventing board bulge.
Is as follows. (1) Permeable layer ground 2 above difficult / impermeable layer ground 1
・ Soil where there is a confined aquifer ground 3 below impermeable layer ground 1
In the soil, the tip reaches the difficult / impermeable layer ground 1
Retained walls 4 and 5 are constructed and established on the permeable ground 2
The object construction area b is surrounded. (2) In the building construction area b, an auger screw
From the surface of the permeable layer ground 2 using
Drilling to the required depth of the ground 3 is performed. (3) At least the hard and impermeable ground 1
And mortar or concrete
The auger screw while pressing and filling the plate c.
Head separates from mortar or concrete c
Pull out while maintaining the inserted state without inserting. (4) Immediately thereafter, the upper part is the surface of the permeable ground 2
It is located in the vicinity and the lower part is the above-mentioned difficult / impermeable layer ground 1
And penetrates to the required depth of the confined aquifer ground 3
A steel pile material d having a length of
The concrete or c is hardened. (5) With this, the upper part is provided with the surface of the permeable ground 2
Located near, the lower part penetrates the above-mentioned hard / impermeable layer ground 1
Along with the required depth of the confined aquifer ground 3
The stake prevention pile a is built.

[006] As the steel pilings d, H-type steel or steel
Is preferred. In addition, as the swelling prevention pile a, an expanded pile
To penetrate the pressurized aquifer ground 3 by adopting
There is an advantage that the end side length can be shortened .

The construction method of the underground building of the present invention is as follows.
It is a cage. (1 ') The required number of piles a for preventing swelling a is driven in a predetermined arrangement by the above-mentioned swelling prevention method to perform required swelling prevention . (2 ') repeatedly performs the installation of the excavation and支保Engineering 6 in building construction region b where Retaining walls 4, 5 are surrounded, board department
It is located near the surface of the permeable layer ground 2 of the stake prevention pile a.
A lining plate 7 is constructed on the upper part, and a bottom slab concrete 8 is constructed on the root bottom . (3 ') Construct the frame 9 of the target building . (4 ') Thereafter, the pile-prevention pile a is cut at the root bottom surface to remove the pile-prevention pile a located in the excavation space b', and the excavation space b 'is removed. Backfill soil will be constructed for

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. 1 is a poorly permeable or impermeable ground made of cohesive soil or the like, that is, a poorly / impermeable ground.
Is a permeable ground above the difficult / impermeable ground 1, 3 is a pressurized aquifer ground such as sandy soil below the hard / impermeable ground 1, 4,
Reference numeral 5 denotes a retaining wall constructed and established at a required interval necessary for surrounding and forming the building construction area b in the permeable ground 2, each end of which is formed on the hard / impermeable permeable ground 1. Has been reached.

Reference numeral a denotes a slab prevention pile which is cast in the above-mentioned building construction area b surrounded by the retaining walls 4 and 5, and the required length of the tip side penetrates the pressurized aquifer ground 3. ing. This swelling prevention pile a is constructed as follows. Set the pile driver in place and use the auger screw to
The required depth of the confined aquifer ground 3 from the ground surface (for example, at least 9
drilling up to m).

After confirming that the drilling has reached the predetermined depth, the mortar or concrete, which has been previously kneaded and mixed, is pumped by a grout pump through an auger shaft hollow shaft, and injected from the tip of the auger, thereby covering the hole. The portion of the confined aquifer ground 3 and the hard / impermeable aquifer ground 1 is filled. In this case, the auger head is pulled up while being kept inserted at about 1 m without being separated from the mortar surface, pulled out while rotating the auger screw forward, and discharged.

After the auger has been pulled out, the required length and space are poured into the mortar or concrete c which is being filled .
That is, the upper part is located near the surface of the permeable ground 2.
At the same time, the lower part penetrates through the difficult / impermeable
H having a length that penetrates to the required depth of the aquifer ground 3
Immediately build a steel pile material d such as a mold steel or a steel pipe and let it stand until the mortar or concrete c hardens.
Thereby, the upper part is located near the surface of the permeable ground 2.
And the lower part penetrates the above-mentioned difficult / impermeable ground 1
Prevention of blistering that penetrates into the required depth of confined aquifer ground 3
The pile a is built.

Injecting and filling the mortar or concrete c seals the gap between the steel pile material d and the surrounding ground in the hard / impermeable layer ground 1 and the pressurized aquifer layer 3 to reduce the groundwater to be pressed. It is possible to prevent water from leaking above the hard / impermeable layer ground 1 through the hole. In other words, building a steel pile d only by drilling or driving a steel pile d directly into the ground creates an air gap between the ground and the steel pile d, thereby reducing the pressure of groundwater. It is not appropriate because it causes water to leak above the hard / impermeable layer ground 1 and cannot obtain the desired frictional force with the surrounding ground.

The swelling prevention pile a constructed as described above has a steel stake d and a mortar or concrete c firmly adhered and integrated, and the outer peripheral surface of the mortar or the concrete c is covered. The compressed water layer 3 and the hard / impermeable layer ground 1 are pressed against the wall surface of the hole.

The pile a for preventing swelling penetrates through the hard / impermeable layer ground 1 and penetrates into the pressurized aquifer layer 3.
The peripheral frictional force between the outer peripheral surface (pile peripheral surface) of the mortar or concrete c in the pressurized aquifer ground 3 and the peripheral ground is set as a reaction force, and the outer periphery of the mortar or concrete c in the hard / impermeable aquifer ground 1 By setting the frictional force between the surface (pile peripheral surface) and the surrounding ground as the resistance to the lifting pressure acting on the difficult / impermeable layer ground 1, the floor bulging can be prevented.

According to the experiment, the adhesive force between the steel pile material d and the mortar or concrete c is larger than the peripheral friction resistance of the mortar or concrete c with the surrounding ground. The above-mentioned adhesive force does not break before breaking.

After the required number of the piles for pile-up prevention a has been set and set, and the construction for the pile-up prevention has been performed, the building construction area surrounded by the retaining walls 4 and 5 is obtained. The excavation in b and the installation of the shoring 6 such as cutting beams and erection are repeated, and the permeable layer of the pile a
A lining plate 7 is constructed on the upper part located near the surface of the ground 2 ,
The upper opening of the excavation space b 'is temporarily closed (FIG. 4).

As described above, in addition to preventing the swelling, the swelling prevention pile a is located near the surface of the permeable ground 2.
It can be used as a support pile for supporting the lining plate 7 at the section, and this greatly contributes to a reduction in construction cost.

Then, the bottom concrete 8
(FIG. 5), and furthermore, a frame 9 of a target building (tunnel, subway station building, etc.) is constructed (FIG. 6). Further, the swelling prevention pile a is cut at the root bottom surface to remove the steel pile material d located in the excavation space b ', and the excavation space b' is backfilled with soil ( (FIG. 7).

The swelling prevention pile a is formed as an expanded bottom pile, that is, a widened portion a 'is formed at the tip, so that the penetration length of the pile 3 into the pressurized aquifer ground 3 is improved. Thus, it is also clear that the overall length can be shortened (FIG. 8).

[0020]

As is apparent from the above description,
The following effects can be obtained by the method of the present invention. The anti-blurring pile penetrates through the impervious / impermeable layer ground and penetrates into the confined aquifer ground below it. The friction force between the peripheral surface (pile peripheral surface) and the surrounding ground is defined as the reaction force between the peripheral surface (pile peripheral surface) and the surrounding ground as the reaction force. By making the resistance to the lifting pressure acting on the layered ground, the swelling can be prevented very effectively.Moreover, compared with the conventional swelling prevention method, the construction can be performed easily and reliably. There is an advantage that the construction period can be shortened.

In addition, the swelling prevention pile is prepared by injecting and filling mortar or concrete into at least a portion of the borehole in the pressurized aquifer layer and the hard / impervious layer ground, and embedding a steel pile into it. Mortar or concrete is difficult to inject and fill, making it difficult to seal the gap between the steel pile and the surrounding ground in the impervious and impregnated aquifer ground, and to make the pressurized groundwater through boreholes.・ The expected construction can be performed while preventing water from leaking above the impermeable layer ground.Steel piles can be built only by drilling, or steel piles can be driven directly into the ground. a gap between a steel pilings, that can not <br/> to obtain the desired frictional force between the surrounding ground causes the leakage of artesian water above the flame-impermeable layer ground There is no fear.

In addition, the pile for preventing swelling constructed in the above-described manner has a steel pile material and mortar or concrete firmly adhered and integrated, and the outer peripheral surface of the mortar or concrete is pressurized and confined. It is pressed against the hole wall surface of the water layer ground and the impervious / impermeable layer ground, and the peripheral friction force between the outer peripheral surface (pile peripheral surface) of mortar or concrete and the surrounding ground in the pressurized aquifer layer is regarded as the reaction force. Also, difficult
By making the frictional force between the outer peripheral surface (pile peripheral surface) of mortar or concrete c and the surrounding ground in the impermeable layer ground, the resistance to the lifting pressure acting on the difficult / impermeable layer ground,
The function of preventing the bulging becomes more certain.

The method for constructing an underground building according to the present invention
The board blisters prevention method, which performs construction of the intended precursor while reliably prevented me board department, in which case, the board department
The upper part of the stake prevention pile located near the surface of the permeable ground
In other words, the swelling prevention pile can literally prevent swelling and can also be used as a supporting pile, and it is clear that the construction advantage is extremely large.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, in which a retaining wall for surrounding a building construction area is constructed and established in a permeable ground.

FIG. 2 is a cross-sectional view showing a state where a slab prevention pile is cast in a building construction area.

FIG. 3 is an enlarged cross-sectional view of a main part of a swelling prevention pile.

FIG. 4 is a cross-sectional view of a state where excavation and support of a building construction area are performed.

FIG. 5 is a cross-sectional view showing a state in which bottom slab concrete is laid and laid in the above excavation space.

FIG. 6 is a cross-sectional view of a state in which a building body of the building is constructed in the above-described excavation space.

FIG. 7 is a cross-sectional view showing a state in which the swelling prevention pile is cut and backfilled.

FIG. 8 is a cross-sectional view of a state in which an expanded pile is cast as a pile for preventing swelling.

[Explanation of symbols]

 a Piling preventing pile a 'Widening part b Building construction area b' Excavation space c Mortar or concrete d Steel pile material 1 Difficult / impermeable layer 2 Permeable layer 3 Pressurized aquifer layer 4,5 Soil Retaining wall 6 Shoring 7 Lining plate 8 Bottom concrete 9 Frame

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Tanaka 2- 14-2 Nagatacho, Chiyoda-ku, Tokyo Japan Railway Construction Public Corporation (72) Inventor Hiroshi Chikyu 2nd Sanbancho, Chiyoda-ku, Tokyo Tobishima Construction Co., Ltd. In-company (72) Inventor Kaoru Kobayashi No. 2 Sanbancho, Chiyoda-ku, Tokyo Tobishima Construction Co., Ltd. (72) Inventor Hiroshi Matsushima No. 2 Sanbancho, Chiyoda-ku, Tokyo Tobishima Construction Co., Ltd. (72) Inventor Abe Yukio No.2 Sanbancho, Chiyoda-ku, Tokyo Tobishima Construction Co., Ltd. (56) References JP-A-4-174134 (JP, A) JP-A-4-30019 (JP, A) JP-A-50-91113 (JP) JP-A-5-9945 (JP, A) JP-A-6-158671 (JP, A) JP-A-10-121465 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) E02D 29/045 E02D 27/34 E21D 13/00

Claims (4)

(57) [Claims] (1) a permeable layer ground above a difficult / impermeable layer ground;
In the ground where there is a pressurized aquifer under the hard / impermeable layer
And the earth retaining point where the tip reaches the above-mentioned impervious and impermeable ground
Establish a wall and establish a building construction area on the permeable ground
Surround and use auger screws within the building construction area.
From the surface of the permeable ground
While drilling to the depth , at least the above-mentioned impervious and impervious
Pumping mortar or concrete to aquifer ground
While filling, the auger screw is
Insert without separation from rutar or concrete
Pull out while maintaining the proper state, and then immediately place the upper part near the surface of the permeable ground.
And the lower part penetrates the above-mentioned impervious and impervious layer ground
Steel pile with a length that penetrates to the required depth of the pressurized aquifer ground
The mortar or concrete
Leave to rest until the REIT hardens, so that the upper part is located near the surface of the permeable ground.
And the lower part penetrates
Construction of piles for preventing blisters that penetrate the required depth of consolidation aquifer ground
Blending prevention method characterized by building. 2. The steel pile material is an H-section steel or a steel pipe.
2. The method for preventing swelling of a board according to claim 1. 3. The method according to claim 1 or 2, wherein the pile for preventing swelling is an expanded pile. 4. The method according to claim 1, 2 or 3, wherein after the required number of piles for pile-prevention is driven in a predetermined arrangement and the required pile-prevention construction is performed, In the building construction area surrounded by the retaining wall, the excavation and the installation of the shoring are repeated, and
Install a lining plate on the upper part located near the surface of the aquifer ground ,
Bottom slab concrete is constructed on the bottom of the root cutting, the skeleton of the target building is constructed, and then the above-mentioned pile-prevention pile is cut at the bottom of the root-cut to prevent the pile from being located in the excavation space. A method of constructing an underground building, comprising removing a pile portion and performing backfill soil construction in the excavated space.