JP2567990B2 - Reverse construction method for underground construction - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a reverse construction method for underground construction, and particularly to a ready-made pile configured by connecting a concrete pile with an outer shell steel pipe or a steel pipe pile to a high-strength pile. Regarding the reverse construction method used for underground construction.

<< Conventional Technology >> Generally, when constructing a building having a basement, after root cutting to the bottom of the foundation of the entire building in advance and placing the foundation concrete of the basement that is the lowest layer, for example, 4 basement floors, 3 basement floors.
Construction is being done by placing concrete from the lower layer to the upper layer, such as the first floor, the second floor, the first floor, and the ground floor.

However, in such a progressive construction method, the construction period must be constructed after the construction of the underground portion and the construction period becomes long, so in recent years, the reverse construction method has been widely used. In the reverse driving method, a foundation pile is struck in advance at a predetermined position on the ground where the pillar of the building is to be erected, and at the same time as the above-mentioned ground construction on the top of the true pillar built on the foundation pile, the reverse of the conventional method is applied. It is a construction method in which root cutting and concrete placement are performed from the upper layer of the basement to the lower layer. For example, if the underground part where concrete is placed is a pure reinforced concrete structure (RC structure) and the aboveground part is a steel frame / reinforced concrete structure (SRC structure), first a vertical hole is excavated from the ground surface to the position of a pillar, and concrete piles are used to stake the foundation pile. make. Foundation piles constructed in this way are usually called cast-in-place piles. On this foundation pile, a temporary pillar, which is a temporary pillar, is erected, and an upper steel frame is erected from the top of this pillar to construct the above-ground portion. At the same time, root cutting of the underground portion is performed, and from the upper floors. The underground part is gradually poured into concrete toward the lower floors for construction.

According to such a reverse driving method, since the above-ground portion and the underground portion can be simultaneously constructed, the construction period can be effectively shortened.

<< Problems to be Solved by the Invention >> By the way, in the conventional reverse driving method, cast-in-place piles are used as foundation piles, and structure columns are built in this cast-in-place pile. Even in the case of direct foundations, cast-in-place piles were temporarily placed.

However, there is room for further shortening the construction period and lowering the cost because the construction period of the cast-in-place pile itself also requires a certain construction period and costs.

The present invention has been made in view of such circumstances,
It is an object of the present invention to provide a reverse construction method for underground construction, which can further shorten the construction period and reduce the cost as compared with the conventional one.

<< Means for Solving the Problem >> The present invention, when constructing an underground structure of a building having a basement, strikes a foundation pile in advance at a predetermined position on the ground where the pillar of the building is to be erected, and builds on the foundation pile. In the reverse construction method for underground construction in which the ground construction and the concrete placement from the upper to lower layers of the basement are performed at the same time as the above-ground construction on the top of the true pillar, the above-mentioned foundation pile is a ready-made pile in which a steel pipe pile is connected to a high-strength pile. Use
After driving the prefabricated pile into the ground, the structure pillar is reached on the prefabricated pile.

Further, the present invention, in the underground construction of a building having a basement,
A foundation pile is struck at a predetermined position on the ground where the pillar of the building is to be erected in advance, and at the same time as the above ground construction at the upper part of the structure pillar built on the foundation pile, the root cutting and the basement from the upper layer to the lower layer In the reverse construction method for underground construction where concrete is placed, as the foundation pile, a ready-made pile in which a concrete pile with an outer shell steel pipe is connected to a high-strength pile is used, and after driving the ready-made pile into the ground, The feature is that the true columns are built on the ready-made piles.

Further, it is characterized in that a rooting fixative is poured into the ready-made piles to fix the structure injection.

<< Working >> According to the above-described construction method of the present invention, a ready-made pile in which a concrete pile with an outer shell steel pipe or a steel pipe pile is connected to a high strength pile,
Since it is used as a foundation pile, the construction period can be further shortened and the cost can be reduced as compared with the case of using a cast-in-place pile that involves a relatively large underground excavation.

As high-strength piles that make up ready-made piles, various piles such as PC piles, PHC piles and concrete piles with outer shell steel pipes can be adopted as long as they have sufficient strength, and they can be formed. As the method, it is possible to adopt various molding methods such as centrifugal molding.

Moreover, since the true-columns built on the ready-made piles are fixed and installed by injecting the fixing solution into the ready-made piles, the positioning and holding of the true-fixture columns are sure.

<< Embodiment >> Hereinafter, an embodiment of the present invention will be described with reference to FIG.

In the present embodiment, basically, when constructing an underground structure of a building having a basement, a foundation pile is struck in advance at a predetermined position on the ground where the pillar of the building is to be erected, and the upper part of the true pillar constructed on the foundation pile. At the same time as above-ground construction at the same time, in the reverse construction method for underground construction, which performs root cutting and concrete placement from the upper layer to the lower layer of the basement,
As the foundation pile, the ready-made pile 4 in which the steel pipe pile 5 is connected to the high-strength pile 3 is used, and after driving the ready-made pile 4 into the ground, the structure pillar 6 is built on the ready-made pile 4. In addition, ready-made pile 4
Then, the fixing column 6 is fixedly installed by injecting the root fixing solution b into the inside.

In the case of a pile foundation in a building, it is often designed with ready-made piles 4 in consideration of the condition of the stratum, workability, cost, construction period, and the like. In addition, the diameter of the ready-made pile 4 has been increased to the latest, Φ800.
~ Piles 4 such as Φ1000 may be used.

Therefore, it is sufficiently possible to use the ready-made pile 4 as it is and adopt the reverse driving method.

In addition, in this embodiment, the construction of a building having an SRC structure on the first basement floor and above and an RC structure on the second basement floor and below is described.

First, normal root cutting is performed up to the first basement floor. Then, the holes 2 for installing the piles are excavated from the ground surface 1 at various positions where the building columns should be erected by various bending methods. A stabilizing solution a such as bentonite is injected into the hole 2 so that the hole 2 does not collapse.

A ready-made pile 4 is driven into this hole 2 as a foundation pile, and necessary centering is performed. In this embodiment, the ready-made pile 4 is configured by using a concrete column with an outer shell steel pipe coated with a steel pipe as the high-strength pile 3 and connecting a steel pipe pile 5 to the concrete column.
As the high-strength pile 3, various piles such as a PC pile and a PHC pile can be adopted as long as they have sufficient strength.
As the forming method, various molding methods such as centrifugal molding can be adopted. In addition, 7 is a reinforcing plate.

Then, after driving the ready-made piles 4 configured in this way into the ground, the true columns 6 are built on the ready-made piles 4. Prior to this, a pipe, a hose, or the like is inserted into the steel pipe pile 5 portion, and the root-fixing liquid b is filled near the bottom of the steel pipe pile 5. Then, the true columns 6 are installed in the steel pipe pile 5 portion.

In this way, by injecting the rooting fixative liquid b into the steel pipe pile 5 and fixing and installing the structural column 6, level accuracy is ensured, and at the same time, the steel pipe pile 5, and thus the ready-made pile 4 and the structural column. 6 and 6 are integrated.

After this, at the same time as the above-ground construction on the upper part of the structural column 6, root cutting and construction from the upper layer of the basement to the lower layer are performed.

According to the above-described present embodiment, if the supporting force required by the reverse driving method is 200t to 300t that can be achieved with the Φ800 to Φ1000 of the ready-made pile 4, it is not necessary to use the conventional cast-in-place pile. It was confirmed that it could be handled at a relatively low cost.

Further, according to the present embodiment, since the ready-made pile 4 in which the steel pipe pile 5 is connected to the high-strength pile 3 is used as the foundation pile, compared to the case of using the cast-in-place pile that involves relatively large-scale underground excavation. Moreover, the work period can be further shortened and the cost can be further reduced.

Further, since the true-structured columns 6 built on the ready-made piles 4 are fixedly installed by injecting the root-fixing fixing liquid b into the steel pipe piles 5, the true-positioned columns 6 are surely positioned and held.

In addition, although the thing which connected the steel pipe pile 5 to the high strength pile 3 was applied as the ready-made pile 4 in the said Example, this invention is not restricted to this, The concrete pile with an outer shell steel pipe was connected to the high strength pile 3. Needless to say, various ready-made piles such as ones can be applied, and similar effects are exhibited in such a case.

<< Effects of the Invention >> As described above, according to the present invention, since a high-strength pile is used as a foundation pile, a concrete pile with an outer shell steel pipe or a ready-made pile in which a steel pipe pile is connected, a relatively large-scale underground excavation is involved. Compared with the case of using cast-in-place piles, excellent effects such as further shortening of construction period and cost reduction can be achieved.

Further, since the true pillars built on the ready-made piles are fixed and installed by hardening the fixing solution into the ready-made piles, the positioning and holding of the true pillars are also reliable.

[Brief description of drawings]

 FIG. 1 is an explanatory view showing an embodiment of the present invention. 3 …… High-strength pile, 4 …… Prepared pile 5 …… Steel pipe pile, 6 …… Structured pillar b …… Root consolidation fixative

Claims (3)

(57) [Claims] 1. When constructing an underground structure of a building having a basement, a foundation pile is previously struck at a predetermined position on the ground where the pillar of the building is to be erected, and at the upper part of the structure pillar installed on the foundation pile. In the reverse construction method for underground construction that performs root cutting and concrete placement from the upper layer to the lower layer at the same time as above-ground construction, a prefabricated pile in which a steel pipe pile is connected to a high-strength pile is used as the foundation pile. A reverse driving method for underground construction, characterized in that the concrete pillar is erected on the ready-made pile after the concrete has been driven into the ground. 2. When constructing an underground structure of a building having a basement, a foundation pile is previously struck at a predetermined position on the ground where the pillar of the building is to be erected, and at the upper part of the true pillar built on the foundation pile. In the reverse construction method for underground construction, which performs root cutting and concrete placement from the upper layer to the lower layer at the same time as the above-ground construction, as the foundation pile, a ready-made pile in which a concrete pile with an outer shell steel pipe is connected to a high-strength pile is used. After driving the ready-made pile into the ground,
A reverse construction method for underground construction, characterized in that a true pillar is built on the ready-made pile. 3. The reverse for underground construction according to any one of claims 1 and 2, characterized in that a rooting fixative is injected into the ready-made piles so that the structural columns are fixedly installed. Driving method.