JPH02269294A - Batholith forming engineering method for vertical shaft - Google Patents

Abstract

PURPOSE:To obtain a good batholith by grounding a concrete bag on a bottom hole, supplying ready-mixed concrete to the concrete bag to be closely stuck to the inner wall of the vertical shaft, and solidifying the concrete to form a batholith. CONSTITUTION:A casing cleaner 4 is inserted in the interior of a vertical shaft 1 to shave off sediment and level a bottom hole. Next, a bag-like concrete bag 5 to which a concrete supply pipe is connected is lowered with an air vent pipe 7 to the bottom hole to fill the concrete bag 5 with concrete C through the concrete supply pipe 6. The concrete bag 5 is made closely stuck to a casing 2 to be watertight, whereby a water stop concrete 10 is formed. Thus, the tissue of ready-mixed concrete C after hardening can be kept in tight solidity while the property can not be deteriorated by water and mud.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a construction method for constructing a bottom plate for water stoppage in a starting shaft and a reaching shaft in a propulsion construction method.

[Conventional technology]

Conventionally, water stoppage work performed after excavating a shaft has been carried out by supplying water stoppage cement to the bottom of the shaft to form a bottom plate. For example, the construction method proposed in Japanese Patent Application No. 191798/1988 filed by the applicant is one example.

Figure 4 shows the conventional construction method, in which the shaft 1 is constructed by press-fitting the casing 2 and simultaneously excavating its inside.
is formed in the casing 2, and then the remaining soil adhering to the side wall of the casing 2 is removed and the bottom of the pit is leveled from the ground (FIG. 2(a)). Work such as removing the remaining soil and leveling the ground at the bottom of the mine is performed manually using a shovel S with a long handle, a water jet, etc. After this work, concrete is sent in to form a bottom plate at the bottom of the shaft 1, and water in the shaft 1 is stopped.

[Problem to be solved by the invention]

After excavating the shaft 1, groundwater 3 infiltrates into the shaft 1, so that the bottom level is submerged in water. Therefore, while submerged in water, use a toremi tube T, etc. to make a chemical container U -) C
When concrete is poured (Fig. 4 (b)), it becomes concrete! J-) Water gets mixed into C. For this reason, the ready-mixed concrete (C) tends to deteriorate, causing problems in terms of water-stopping ability. In addition, if the groundwater 3 contains soil 3a from the bottom of the mine, raw concrete! J-)
Contamination with C deteriorates the quality of the finished bottom board.

Furthermore, the degree of occurrence of laitance 3b, in which fine substances float and precipitate on the surface of the raw concrete IJ-C due to breathing (floating ice phenomenon), is also large. This poses problems such as impeding the proper construction of the bottom plate and requiring construction work such as removal of the laitance 3b and measures against flooding.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a water-stop cement construction method in which a good base plate construction can be obtained by pouring water-stop cement without contaminating groundwater.

[Means to solve the problem]

In order to achieve the above object, the present invention allows a bag-shaped concrete bag to which a concrete supply pipe is connected to be brought to the bottom of a shaft, and supplies fresh concrete from the concrete supply pipe to the concrete bag. The method is characterized in that the concrete bag is brought into close contact with the inner wall of the shaft by expansion of the concrete bag due to filling, and the filled concrete is solidified to form a water-stop bottom plate at the bottom of the shaft.

〔Example〕

Hereinafter, features of the present invention will be specifically explained with reference to embodiments shown in the drawings.

FIG. 1 shows the process of the construction method of the present invention, and FIG. 2 shows an outline of the concrete bag used in this construction method.

The concrete bag 5 used in the present invention is a bag-like material having a predetermined strength so that it will not break when filled with concrete. That is, the concrete bag 5 includes a flat bottom plate 5a at its lower end, and a peripheral wall 5b made of a foldable bag-shaped material. Peripheral wall 5
b is made of a material that can be water-sealed to prevent groundwater from entering the inside, and can be tightly attached to the inner wall of the casing 2 to prevent groundwater from entering into the bottom side of the pit. Such a material is preferably, for example, a cloth-filled rubber sheet or a plastic sheet, which has a strength that can withstand filling with concrete as described above.

The concrete bag 5 is made to have a capacity such that the peripheral wall 5b can be brought into close contact with the inner wall of the casing 2 after the inside thereof is filled with concrete. In other words, when filled with concrete, the peripheral wall 5b expands and has a size that allows it to strongly (adhere) to the inner wall of the casing 2. Also, to ensure a predetermined thickness of the bottom concrete, the peripheral wall 5b should be sufficiently deep in the vertical direction. It goes without saying that the capacity should be large enough to be filled with concrete.

Furthermore, the bottom plate 5a of the concrete parag 5 is a plate-shaped body made of metal or wood, for example, and is inserted into the shaft 1 and landed on the bottom of the shaft, or the concrete bag 5 is placed on top of muddy water near the bottom of the shaft. It plays a role in making it float. On the other hand, the peripheral wall 5b
are fastened by bolts and nuts 5c as shown in FIG. 2(C) (an enlarged sectional view of the portion surrounded by the dashed line in FIG. 2(a)). Therefore, the peripheral wall can be folded up and down with respect to the bottom plate 5a, and even if underground water accumulates in the shaft 1, the bottom plate 5a can be placed on the bottom of the shaft or floated on top of muddy water, and the peripheral wall 5b portion can be folded up or down. It can be set so that it always faces upward. Note that instead of using the bolts and nuts 5c, the bottom plate 5a and the peripheral wall 5b may be integrated using rivets, adhesives, stitching, or the like.

Further, in the center of the upper end of the concrete bag 5, a connection port 5d for concrete injection and an exhaust port 5 for air venting are provided.
e is provided. A concrete supply pipe 6 is connected to the connection port 5d.
is connected to the exhaust port 5e, and an air vent pipe 7 is connected to the exhaust port 5e. The lower end of the concrete supply pipe 6 is inserted into the connection port 5d as shown in FIG. . On the other hand, air vent pipe 7
A hose or the like is used, and a vibrator is provided at the lower end of the vibrator, which is inserted into the exhaust port 5e, and is tightened using a tool. Note that the concrete supply pipe 6 and the air vent pipe 7 are connected to the concrete bag 5 in advance on the ground 8 and inserted into the shaft 1 as a unit.

Here, the unnecessary air inside the concrete bag 5 that is generated as the concrete is filled must be sufficiently discharged because if it gets mixed into the concrete and hardens as it is, it may cause cavities in the concrete later. be. On the other hand, since the air vent pipe 7 is provided, even if air is mixed in during filling with concrete, it can be evacuated, and problems such as cavitation of the concrete do not occur. In addition, 5 concrete bags were added to 3 underground water.
Since the surrounding wall 5b is crushed by the water pressure, air is unlikely to accumulate in the concrete bag 5. For this reason, the air vent pipe 7 is not necessarily required if there is no air mixing from the concrete supply source.

Next, the construction method of this embodiment will be sequentially explained step by step.

FIG. 1(a) shows a state in which earth and sand 9 remain on the inner wall of the casing 2 and the bottom of the shaft after a shaft 1 is excavated by a method similar to that described in the section of the prior art. Then, groundwater 3 intrudes into the casing 2 and the bottom of the mine is submerged.

1 and 2) show the operation of inserting a casing cleaner 4 into the shaft 1 to scrape off earth and sand adhering to the inner wall of the casing 2 and to level the bottom of the shaft.

FIG. 1(C) shows that after cleaning the inner wall and bottom of the shaft 1, the concrete bag 5 is lowered to the bottom of the shaft together with the concrete supply pipe 6 and the air vent pipe 7, and fresh concrete C is poured from the concrete supply pipe 6 into the concrete bag 5. Indicates the filling operation.

Furthermore, FIG. 1 (6) shows that the concrete bag 5 is filled with ready-mixed concrete C, and the concrete bag 5 is brought into close contact with the casing 2 to make it watertight and to form a water-stop concrete IJ-).
10 is shown.

As described above, in the construction method of the present invention, after removing the remaining soil in the casing 1 and leveling the unevenness of the pit bottom, the concrete bag 5 is placed at the bottom of the pit, and the concrete bag 5 is inserted from the ground 8 into the concrete bag 5. It is possible to fill the concrete bag 5 with fresh concrete C, inflate the concrete bag 5, and bring it into close contact with the pit wall to create a watertight state.

Therefore, since the fresh concrete C is isolated from the outside world by the concrete bag 5, the properties of the concrete are not inhibited by water or mud. Further, since there is no separation from aggregate particles, the structure of the concrete after hardening can maintain its solidity, and the effectiveness of the water-stopping concrete 10 can be enhanced. After the bottom plate is completed, there is no need to make any repairs to prevent flooding or leakage, so water stoppage construction can be completed at low cost and with simple work.

FIG. 3 shows another embodiment, in which the concrete bag 5 is bag-shaped and does not include the bottom plate 5a of the previous embodiment. The function of the concrete bag 5 is to be able to fill it with fresh concrete C and to seal it tightly against the inner periphery of the casing 2 through expansion, so even if it is shaped like a bag, there is no problem in forming the bottom plate. You can use it.

As shown in the figure, a concrete supply pipe 6 and an air vent pipe 7 are connected to the concrete bag 5, and the bag 5 is inserted into the shaft 1 in a deflated state as shown in FIG. If the concrete bag 5 is bag-shaped like this, there will be no interference such as interference with the inner wall of the casing 2, and the work will be easier than when the concrete bag 5 is provided with the bottom plate 5a. In addition, after the concrete bag 5 has landed on the bottom of the pit as shown in FIG. 10 can be formed as a bottom plate. in this case,
Since the concrete bag 5 is bag-shaped, it can be placed on the floor following the bottom of the pit, and a better bottom plate can be obtained than in the case where the bottom plate 5a is provided.

Moreover, if the concrete bag 5 is simply made into a bag-like object, it will be easier to manufacture than the case where the bottom plate 5a is provided, and it will be advantageous in terms of cost. Furthermore, since the weight is reduced, the burden on the operator is also reduced.

〔Effect of the invention〕

In the present invention, water-stop cement is formed by press-fitting fresh concrete into a concrete bag, so the cement paste is not affected by groundwater, so there is no separation from aggregate particles, and the structure of the hardened cement can maintain confidentiality.

In addition, the performance of concrete is not inhibited by mixing with groundwater, so the function of water-stopping concrete is fully demonstrated. In addition, there is little laitance and there is no need to inject chemicals for ground improvement, making the work easier and cheaper, and shortening the construction period.

[Brief explanation of drawings]

Figure 1 is a diagram showing each process of the construction method of the present invention, Figure 2 is a schematic diagram of a concrete bag used in the construction method of the present invention, and Figure 3 is a diagram showing another example of forming a base using a concrete bag. 4 are diagrams showing an outline of the conventional construction method. 1: Vertical shaft 2: Casing 3: Groundwater
4 Casing cleaner 5: Concrete bag 5a: Bottom plate 5b Two peripheral walls 5c: Bolts
Nut 5d: Connection port 5e: Exhaust port 6: Concrete supply pipe 6a: Tightening tool 7: Air vent pipe: Above ground: Earth and sand: Water-stop concrete C: Ready-mixed concrete

Claims (1)

[Claims] 1. A sack-shaped concrete bag connected to a concrete supply pipe is brought to the bottom of a shaft, fresh concrete is supplied from the concrete supply pipe to the concrete bag, and the concrete is expanded by expansion of the concrete bag as it is filled with concrete. A method for forming a bottom plate for a shaft, which is characterized by forming a water-stop bottom plate at the bottom of the shaft by attaching a bag to the inner wall of the shaft and solidifying the filled concrete.