JP3265061B2 - How to build underground structures - 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 of constructing an underground structure in which underground construction work can be performed in parallel with skeletal construction work by concrete casting on the ground and excavation work underground.

[0002]

2. Description of the Related Art Generally, in the construction of a basement floor,
After excavating the underground, concrete is cast on the skeleton including the foundation. For example, there is a reverse beating method in which concrete is lowered from the upper floor to the lower floor, contrary to the usual case. Further, as one of the foundation methods, there is a caisson method in which a cylindrical or box-shaped caisson is constructed, or the entire basement is constructed on the ground, and the lower part is dug down and sunk.

[0003]

However, in a general underground construction work or a reverse beating method, since the underground is excavated and then concrete is poured, the construction period is long.
In the case of the caisson method, there is an advantage that skeleton work can be performed on the ground, but there is a disadvantage that the work is large-scale and the construction period is long.

Accordingly, an object of the present invention is to provide a method of constructing an underground structure in which an underground excavation work can be performed in parallel with a frame work on the ground, thereby shortening the construction period.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention uses an airtight casing comprising a plurality of cylindrical members having a larger diameter than that of a lower one, which are expanded and contracted. This casing is inserted into a pile hole drilled in the ground in an extended state, and concrete is poured into the casing except for the uppermost tubular member to form a concrete pile, and then the liquid is poured into the uppermost tubular member. Injection and
After forming the concrete foundation by pouring concrete including the upper end of the uppermost cylindrical member on the ground, an ice column is formed by freezing the liquid in the uppermost cylindrical member. In the formed state, excavation of the underground underground space portion and formation of a concrete structure by driving concrete on the concrete foundation on the ground are performed in parallel. Return, and the liquid is gradually discharged from the uppermost cylindrical member, whereby the uppermost cylindrical member is gradually sunk, and the underground structure including the concrete foundation and the concrete structure is provided in the underground space. The method is to sink the objects.

[0006]

The concrete pile casing has an airtight structure in which a plurality of tubular members having diameters larger than those of the lower ones are expanded and contracted, and the casing on the ground including the uppermost tubular member is provided. The concrete foundation can be supported by icicles by forming the concrete foundation and injecting the liquid into the uppermost cylindrical member, and freezing the liquid injected into the uppermost cylindrical member into an icicle. Therefore, the underground space can be excavated. Therefore, the underground structure can be formed on the ground in parallel with the excavation of the underground space.

[0007] Then, the liquid returned by melting the icicle is gradually discharged from the uppermost cylindrical member, and the uppermost cylindrical member gradually sinks under the load of the underground structure. Underground structures can be submerged in the space. Therefore, there is no need to remove equipment for jacking up the underground structure to be constructed on the ground, and the casing can be buried as it is.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for constructing an underground structure according to the present invention will be described below with reference to FIGS.

First, FIG. 1 shows the construction state of a concrete pile as an example to which the present invention is applied, where GL is a ground level, 1 is a pile hole, 2 is a casing used in the present invention, and 7 is a concrete pile. is there. As shown in the figure, a casing 2 is inserted into a pile hole 1 drilled in the ground by, for example, an earth drill, and a concrete pile 7 is driven into a predetermined position in the casing 2.

As shown in FIG. 2, for example, the casing 2 is made of three tubular members 3, 4 and 5 made of steel pipe and is extendable and contractible, and the joint structures of each other are airtight. That is, the middle cylindrical member 4 having a smaller diameter is slidably incorporated into the uppermost cylindrical member 3 having the largest diameter, and the lowermost cylindrical member having the smallest diameter is further added to the cylindrical member 4. By incorporating the member 5 slidably,
The telescopic casing 2 is constituted. The casing 2 may be composed of at least two cylindrical members 3 and 4, or may be composed of four or more cylindrical members.

The joint between at least the uppermost cylindrical member 3 and the lower cylindrical member 4 has an airtight structure as shown in FIG. 3, for example. That is, FIG.
In the example of (a), the lower end of the upper cylindrical member 3 is a small-diameter portion 3a that slides on the outer periphery of the lower cylindrical member 4, and the upper end of the lower cylindrical member 4 slides on the inner periphery of the upper cylindrical member 3. A seal ring 6 is interposed between the large-diameter portions 4a to be in contact therewith. In the example of FIG. 3B, the outer periphery of the lower cylindrical member 4 slides on the inner periphery of the upper cylindrical member 3, and the inner peripheral annular groove 3 b is formed at the lower end of the upper cylindrical member 3. At the same time, an outer peripheral annular groove 4b is formed at the upper end of the lower cylindrical member 4, and a seal ring 6 is provided therebetween. In addition,
A similar airtight structure may be adopted for other joints.

The present invention is characterized by a method for constructing an underground structure using such a telescopic and airtight housing 2. First, in a first step,
The casing 2 is pulled up by a crane in a state where the three cylindrical members 3, 4, and 5 are extended from each other, and the extended casing 2 is inserted into a pile hole 1 drilled in the ground by, for example, an earth drill. Then, concrete is driven into a predetermined position excluding the uppermost cylindrical member 3 in the casing 2, and the concrete pile 7 is constructed.

Next, in the second step, as shown in FIG. 4, the upper end of the cylindrical member 3 protruding above the ground is closed with a hatch 8, a predetermined formwork is performed, and concrete is driven in. A predetermined concrete foundation 9 is constructed. The concrete foundation 9 includes a predetermined footing, an underground beam, and a pressure plate. In this manner, the concrete foundation 9 is constructed by safe work on the ground. At the time of placing the concrete foundation 9, a water pipe 11 which penetrates the hatch 8 and connects the inside of the cylindrical member 3 and the foundation is buried.
The water pipe 11 is provided with a valve 12 at the top.

Then, in the next third step, the water conduit 11
The liquid is injected into the cylindrical member 3 from. That is, as shown in FIG. 5, the water 13 is filled in the cylindrical member 3. In this case, since the connection between the cylindrical members 3 and 4 is kept airtight by the seal ring 6, there is no water leakage. In addition, the surroundings of the cylindrical member 3 in which the water 13 is full are appropriately dug to form a freezing excavation space 14, and the water 13 in the full state is frozen in the cylindrical member 3. The freezing is performed by, for example, covering the periphery of the cylindrical member 3 with a freezing jacket 15.

As shown in FIG. 6, for example, the freezing jacket 15 is made up of jacket halves 16 and 16 formed by connecting a cylindrical shape in half in the longitudinal direction, and is connected to the inside of the jacket halves 16 and 16. Are provided with refrigerant passages 17 and 17. This freezing jacket 15
For example, by connecting a connecting pipe of a freezing device 18 separately placed on the ground and circulating a refrigerant by operating the freezing device 18, an ice column 21 is formed as shown in FIG. The load on the concrete foundation 9 can be supported by the icicles 21. Further, the lateral swing is provided by the cylindrical member 3 made of a steel pipe.

Next, in the fourth step, as shown in FIG. 7, while keeping the state of the icicles 21 by the continuous operation or the intermittent operation of the freezing device 18, it is further widened and deepened below the concrete foundation 9. A predetermined underground space 22 is excavated, and in parallel with the excavation work, a predetermined formwork is performed on the concrete foundation 9 on the ground, and concrete is driven into the concrete base walls 23, 23 and The slab 24 is constructed. Thus, the predetermined underground structure 25 is constructed on the ground.

The parallel underground space 22
After the excavation work and the construction of the underground structure 25 on the ground are completed, in the next fifth step, the operation of the freezing device 18 is stopped, the freezing jacket 15 is removed, and the icicle 2 is removed.
1. Start thawing. The icicle 21 may be thawed at room temperature or may be thawed positively by using an appropriate thawing device or heating device.

In parallel with the thawing of the icicles 21, the valve 12 of the water pipe 11 is opened, so that the cylindrical member 3 is opened.
Drain the melted water within. That is, since the concrete foundation 9 is connected to the cylindrical member 3 and the load of the underground structure 25 is applied, as shown in FIG. Discharge and cylindrical member 3
Is gradually lowered by sliding along the outer periphery of the cylindrical member 4 below. By controlling the opening and closing of the valve 12 using the pressure-resistant valve 12, the amount of discharged water can be controlled, and the speed at which the cylindrical member 3 sinks can be moderately controlled.

In this way, the underground structure 25 is gradually lowered and buried in the underground space 22, as shown in FIG.
Pour in. By the solidification of the grout 26, the concrete pile 7 and the concrete foundation 9 are joined to each other.

As shown in FIG. 9, the first-floor concrete walls 27, 27 are located on the first-floor floor level 1FL.
Ground structures such as are installed. This underground structure 25 may be cast on the slab 24 after the above-described subsurface structure 25 is buried, or may be continuously installed after the underground structure 25 is constructed in the fourth step. May be.

As described above, according to the present invention, the icicles 21 are formed inside the casing 3 to perform the excavation work in the underground space and the skeleton work on the ground, and require a large-scale work like the caisson method. And the construction period can be shortened.

Although the above embodiment has been described with reference to the drawings showing the entire building, if the plane is wide,
That is, in a large building having a plane having many spans, the present invention may be applied to each pillar and a foundation pile. In this case, the thawing and drainage of the entire icicle are controlled so that the entire wide plane is uniformly lowered.

Furthermore, in the embodiment, the building has a basement. However, the present invention is not limited to this. The building may be at least partially buried underground.
Further, the airtight structure of the joint portion of the casing, the configuration of the freezing device, and the like are also arbitrary. For example, a method of turning liquid into an icicle using liquid nitrogen is also conceivable. In addition, the liquid to be injected into the casing may be a liquid other than water, and it goes without saying that the specific detailed structure and the like can be appropriately changed.

[0024]

As described above, according to the method for constructing an underground structure according to the present invention, the concrete pile casing
As a gas-tight seal made by assembling a plurality of cylindrical members with a larger diameter than that of the lower one so that they can expand and contract, in particular, by using an icicle that freezes the liquid injected into the uppermost cylindrical member, The underground structure can be constructed on the ground in parallel with the excavation of the underground space.

Further, when the liquid returned by melting the icicles is gradually discharged from the uppermost cylindrical member, the uppermost cylindrical member gradually sinks under the load of the underground structure, and the underground space enters the underground space. Since the structure can be submerged, there is no need to remove any equipment for jacking up the underground structure to be constructed on the ground, and the casing can be buried as it is.

Accordingly, the construction work on the ground and the excavation work on the underground can be performed in parallel without requiring a large-scale construction like the caisson method, so that the construction period can be shortened.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing a construction state of a concrete pile as an example to which the present invention is applied.

FIG. 2 is a schematic perspective view showing a casing used in the present invention.

FIG. 3 is an enlarged vertical cross-sectional view showing a joint structure portion having the airtightness of a casing, in which both (a) and (b) show the difference in the airtight structure.

FIG. 4 is a schematic longitudinal sectional view showing a construction state of a concrete foundation on the ground according to the present invention.

FIG. 5 is a schematic longitudinal sectional view showing injection of a liquid into the casing.

FIG. 6 is a schematic perspective view showing an example of a freezing device used for freezing.

FIG. 7 is a schematic longitudinal sectional view showing excavation of an underground space by formation of an icicle according to the present invention and construction of an underground structure on the ground.

FIG. 8 is a schematic longitudinal sectional view showing a process in which a casing and an underground structure sink by melting a icicle and discharging a liquid according to the present invention.

FIG. 9 is a schematic vertical sectional view showing a state where the burying of the underground structure is completed.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 pile hole 2 casing 3, 4, 5 cylinder member 6 seal ring 7 concrete pile 8 hatch 9 concrete foundation 11 water guide pipe 12 valve 13 liquid 14 freezing excavation space 15 freezing jacket 16 half jacket 17 refrigerant passage 18 freezing device 19 Connecting pipe 21 icicle 22 underground space 23 concrete wall 24 slab 25 underground structure 26 grout

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E02D 29/045 E21D 13/00

Claims (1)

(57) [Claims] 1. An airtight casing comprising a plurality of cylindrical members having a diameter larger than that of a lower one and having a larger diameter than that of a lower one. The casing is stretched and inserted into a pile hole opened in the ground. Then, after concrete is poured into the casing except for the uppermost tubular member to form a concrete pile, liquid is injected into the uppermost tubular member, and the upper end of the uppermost tubular member on the ground And then forming a concrete foundation by pouring concrete, and then forming an icicle by freezing the liquid in the uppermost tubular member. In a state where the icicle is formed, an underground space portion underground Excavation and the formation of a concrete structure by pouring concrete on the concrete foundation on the ground were performed in parallel, and then the icicles were melted and returned to liquid. By gradually discharging the liquid from inside the uppermost tubular member, the uppermost tubular member is gradually sunk, and an underground structure comprising the concrete foundation and the concrete structure in the underground space A method for constructing an underground structure, comprising: