JPH093869A - Surface grout method and surface grout device - Google Patents

Abstract

(57) [Summary] [Objective] To provide a surface grout method capable of efficiently injecting grout material into a finished excavated surface and a surface layer portion thereof, and a surface grout device used for this method. [Structure] A surface grouting apparatus including a substantially cup-shaped chamber provided with a grout injection hole, an air bleeding hole, and a peripheral end portion which defines a bottom portion to be opened, and which has a predetermined strength, A method of injecting grout material into the surface layer portion of the finish excavation surface, wherein the chamber is pressure-bonded to the finish excavation surface from the peripheral end portion, and the grout material is introduced into the chamber through the grout injection hole. Continuously pressure-feeding, in this initial stage, the air inside the chamber is bleeded from the air bleeding hole to prevent the grout material from leaking to the outside of the chamber through the gap between the peripheral end portion and the finishing surface. The grout material filling the inside of the chamber is pressed against the finish excavation surface and injected into the surface layer portion, and at the same time, the surface grout device. Characterized in that adding a negative pressure to the borehole provided in advance in the vicinity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface grouting method and a surface grouting apparatus, and more particularly to a surface grouting method mainly used for rock processing such as dam foundations and tunnel foundations, and a surface grouting apparatus used for this method.

[0002]

2. Description of the Related Art The following grout injection method has been conventionally used as a bedrock treatment for increasing the strength and water impermeability of dam foundations.

(A) Cover lock As shown schematically in FIG. 5 (a), this construction method is a mode in which the grout material is injected while being pressurized through the boring hole 52. By suspending the excavation at 3 m above, the unexcavated rock is secured as a part to set the packer 53 for preventing the grout material from leaking from the boring hole 52 to the surface during pressurization and pouring.
Undigged rock is excavated after grout injection.

(B) Cover concrete This construction method is also a mode in which the grout material is pressed and injected through the boring hole 52 as in (a). In particular, if there is a large amount of grout material leaking from the rock surface on the finished excavation surface such as a cover lock, as shown in Fig. 5 (b), concrete 54 is placed on the rock surface to prevent leakage from the rock surface by placing about 50 cm. However, the portion to which the packer 53 is applied is secured, and the unexcavated rock is excavated after the grout injection.

(C) Slash grouting This method is a mode in which the grout material permeates the rock in a natural state without pressurizing it through the boring hole 52. Therefore, no packer is required (see FIG. 5 (c)). .

[0006]

However, the above conventional method has the following problems.

(A) Cover rock Since excavation is carried out again after grout injection, new cracks and the like occur in the rock mass, and the strength and water impermeability of the finished excavated surface and its surface layer are insufficient.

(B) Cover concrete As in the case of (a), since excavation is carried out again after grouting, new cracks and the like occur in the rock mass, and the strength and water impermeability of the finished excavated surface and its surface layer are insufficient.

Further, although the grout effect can be expected more than in (a) and (c), the cost is increased and the construction period is prolonged because the concrete is placed.

(C) Slash grouting Since grout injection does not involve pressurization, sufficient grout material cannot be injected, and air remains as voids in unsaturated areas, etc., to obtain desired strength and water impermeability. I can't.

The present invention has been made in view of the above problems, and an object thereof is a surface grout method capable of efficiently injecting a grout material into a finish excavated surface and a surface layer portion thereof, and It is to provide a surface grout device used in the construction method.

[0012]

A surface grout method according to the present invention is a method for injecting grout material from a finish excavation surface to a surface layer portion of the finish excavation surface using a surface grout device. , Grout injection hole,
The chamber includes a substantially cup-shaped chamber provided with an air bleeding hole and a peripheral end portion defining a bottom portion to be opened and having a predetermined strength.

The finish excavation surface is the surface of the rock that is exposed after the predetermined excavation and cutting in the dam foundation, tunnel foundation, etc., and the finish excavation surface is used for the grout injection from the finish excavation surface to the surface layer portion. Improvements are also included.

As the grout material, various kinds of cement milk prepared according to various conditions of the bedrock are used, but clay grout or chemical grout may be used in some cases.

In the method of the present invention, the chamber in the surface grout device is pressure-bonded to the finish excavation surface from the peripheral end portion. This is by pressing the surface grout device against the finish excavation surface using known devices such as power shovels and boring machines having suitable pressing capabilities.

The predetermined strength imparted to the chamber is the strength that can withstand the above-mentioned pressing, and can be obtained by the material of the chamber itself or by attaching another reinforcing member.

Further, in the present invention, the grout material is continuously fed into the chamber through the grout injection hole. This is to connect a general grout kneading / pressurizing device to the grout injection hole to utilize the pressurizing ability of the pressurizing device for pressurizing the grout material against the finish excavated surface.

Further, in the initial stage of the continuous pressure-feeding of the grout material into the chamber, the air inside the chamber is evacuated from the air vent hole, and thereafter,
The air vent hole is manually closed.

Further, the grout is filled inside the chamber while preventing leakage of the grout material to the outside of the chamber through the space between the peripheral end portion and the finished surface by providing a packing in the surface grout device or the like. The material is pressed against the finish excavated surface and injected into the surface layer portion.

Further, simultaneously, a negative pressure is applied to a boring hole previously provided in the vicinity of the surface grout device. This is because the vacuum pump is connected to the packer set in the boring hole.

The boring holes are formed in advance on the finish excavation surface in a predetermined pitch pattern, but they may be formed successively in parallel with the grout injection.

[0022]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 and 2 are a side view and a plan view schematically showing a surface grout device 10 used in the surface grout method according to the present invention, and a cross section taken along line S--S of FIG. 1 is shown in FIG.
Indicated by.

The surface grout device 10 includes a bottom portion 12 (see FIG. 3).
The chamber 11 has a substantially cup-shaped opening (see FIG. 2) and a packing 17 provided so as to surround the peripheral end 13 of the chamber 11 defining the bottom 12 from the outside of the chamber 11.

The chamber 11 has a grout injection hole 14
2 and two air vent holes 15 are provided, and the compensating plate 16 is arranged in a cross shape from above.

FIG. 4 is an explanatory view showing a usage state of the surface grout device 10. The surface grout device 10 is provided on the finishing excavation surface 1 of the dam foundation after the predetermined excavation, and between the boring holes 3 having a depth of about 5 m provided in the finishing surface 1 in a pitch pattern of about 2 to 3 m. It is located approximately in the center.

Further, the chamber 11 is provided with a grout injection hole 1
4 through a general grout kneading / pressurizing device (not shown), and further pressed from above the compensating plate 16 with a well-known device (not shown) having an appropriate pressing ability such as a power shovel. The peripheral end portion 13 is crimped to the finished excavation surface 1. The compensating plate 16 imparts strength to the chamber 11 that can withstand the pressing.

From this state, the grout material is continuously pumped into the chamber 11 by the grout kneading and pumping device, and a negative pressure is simultaneously applied to the boring hole 2 located near the surface grout device 10. This negative pressure is
By a vacuum pump (not shown) through the packer 3 set in the boring hole 2.

On the other hand, in the initial stage of the pressure-feeding of the grout material, the air inside the chamber 11 is blown out by the air vent hole 15.
After that, the air vent hole 15 is closed. Therefore, the grout material fills the inside of the chamber 11, and then the surface layer portion 1 ′ is pressed through the rock cut while pressing the finishing excavation surface 1 corresponding to the bottom portion 12 of the chamber 11.
Is injected into. At this time, the packing 17 is
The grout material is prevented from leaking to the outside of the chamber 11 through the gap between the finishing excavation surface 1 and the finishing excavation surface 1.

Further, by reducing the pressure in the boring hole 2, air in the cuts or voids in the surface layer portion 1'below the surface grout device 10 is easily discharged from the boring hole 2, so that the effect of injecting grout into the surface layer portion 1'is remarkable. Increase.

The above steps are performed on the entire area of the finish excavation surface 1 while changing the position of the surface grout device 10. The boring hole 2 is filled with grout material.

[0032]

As described above, according to the present invention, the grout material is directly pressurized / injected into the finish excavation surface through the chamber of the surface grout device.
It is possible to efficiently increase the strength and water impermeability of the surface and surface layer not only around the boring hole but over the entire area of the finished excavation surface as in the conventional method, and by using negative pressure for the boring hole together. Since the air in the cracks on the surface layer is discharged from the boring hole, the grout injection effect can be significantly improved.

[Brief description of drawings]

FIG. 1 is a side view of a surface grout device according to the present invention.

FIG. 2 is a plan view of a surface grout device according to the present invention.

FIG. 3 is a cross-sectional view of the surface grout device taken along line S-S of FIG.

FIG. 4 is an explanatory diagram of the present invention showing a usage state of the surface grout device.

FIG. 5 is an explanatory view (a) schematically showing a conventional grout injection method, an explanatory view (b) of another conventional method and an explanatory view (c) of still another conventional method.

[Explanation of symbols]

 1 Finished excavation surface 1'Surface layer part 2 Boring hole 3,53 Packer 10 Surface grout device 11 Chamber 12 Bottom part 13 Circumferential end part 14 Grout injection hole 15 Air vent hole 16 Complement plate 17 Packing

Claims (2)

[Claims] 1. A surface grout device including a substantially cup-shaped chamber provided with a grout injection hole, an air bleeding hole, and a peripheral end portion defining an opening bottom portion, and having a predetermined strength. 2. A method for injecting grout material from a finish excavation surface to a surface layer portion of the finish excavation surface by using the surface grout device according to claim 1, wherein the chamber is subjected to the finishing from the peripheral end portion. Pressure is applied to the excavated surface, the grout material is continuously pressure-fed into the chamber through the grout injection hole, and air in the chamber is evacuated from the air bleed hole at the initial stage, and the peripheral end and the At the same time as injecting the grout material filling the inside of the chamber into the surface layer portion by pressurizing it against the finish excavation surface while preventing leakage of the grout material to the outside of the chamber through between the surface and the finish surface, A surface grout method characterized by applying a negative pressure to a boring hole provided in advance in the vicinity of the grout device.