JPH083512Y2 - Impermeable packer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a water blocking packer in a measuring device for measuring pore water pressure in the ground.

(Prior art) In dam foundations, landslides, stability of cut slopes, etc., it is extremely important to know the properties related to the strength and deformation of the ground, as well as the distribution of underground pore water pressure and its change over time. is there.

Conventionally, the distribution of pore water pressure in deep ground in the latter,
The measurement of the change with time had a problem that a lot of boring holes having different depths were excavated and a high-precision pore water pressure gauge was embedded in each of the boring holes for measurement, which required a lot of time and cost. .

Therefore, in recent years, in order to solve these problems,
A measuring tube 1'on which a measuring jig 4'as shown in the figure and a water blocking packer 3'made of a flexible material are alternately attached is inserted into one measuring hole H '. The water pressure of each layer in the ground is measured.

This is to measure the water pressure of each layer by injecting water, nitrogen gas, or the like into the water-proof packer 3'by pressure from the ground and expanding the water, thereby blocking the inside of the measurement hole H'in multiple steps.

(Problems to be solved by the invention) However, in the measuring method as described above, since the water-impervious packer is formed of flexible rubber or the like having elasticity, which expands with water, nitrogen gas, or the like, In relatively soft ground, if the pressure in the water shield packer acts on the ground,
There was a problem that the ground was creep-deformed, and if it was left for a long time, the impermeable property could not be perfected.

Therefore, in order to solve such a problem, a pressure device for periodically filling water or nitrogen gas, or for always maintaining the water shield packer in a predetermined expanded state has been required.

The present invention has been made in view of the above problems, and an object thereof is to provide a water-impervious packer capable of performing perfect impermeability by always maintaining a predetermined expansion state with a simple device.

(Means for Achieving the Object) The structure as means of the present invention for achieving the above object is a water-impervious packer attached to a pore water pressure measuring pipe, and the water-impervious packer is a cloth inner skin. A water-impervious packer is characterized in that it is formed into an annular shape having a penetrating portion in the central portion by an outer skin and an upper and lower portions thereof, and an insertion port communicating with the water-impervious packer is provided respectively.

(Operation) According to the above configuration, since the measuring pipe is inserted into the penetrating portion of the central portion, the water-impervious packer and the water pressure gauge are alternately mounted, and the upper injection port is grounded. An injection tube connected to the device is connected, and a plurality of injection tubes connected to the upper insertion openings of the lower water-impervious packers are inserted into the lower insertion openings through the water-impermeable packer. There is.

(Embodiment) An embodiment of the present invention will be described below in detail with reference to the drawings.

1 to 3 are cross-sectional views showing a state of use of a pore water pressure measuring device A (hereinafter, simply referred to as a measuring device).
Is formed by alternately mounting the filter material 2 and the water blocking packer 3 on the measuring tube 1.

As shown in FIGS. 2 to 4, the measurement tube 1 has a plurality of tube bodies 1a of appropriate lengths connected to each other and has the same length as the depth of the measurement hole H,
For example, it is formed with a length of 80 m or 100 m. Then, a water pressure measuring pipe 1b having a built-in water pressure gauge 4 and electrically connected to a measuring device S on the ground via a cord 9 is attached to the connecting portion of the pipe body 1a, and the water pressure measuring pipe 1b The entire outer circumference is covered with the filter material 2.

As shown in the enlarged cross-sectional view of FIG. 5, the water pressure measuring pipe 1b is provided with a through hole 10 at the water pressure measuring portion, and a water pressure gauge 4 is installed at the upper end of the water pressure gauge 4 such as a porous stone. The elastic material 4a is provided. Also, this water pressure measuring tube 1b
Since the upper and lower parts of the inside are filled with epoxy resin m,
Water is prevented from entering the inside of the tubular body 1a, and the cord 9 is always kept dry.

The filter material 2 has excellent water permeability in order to protect the water pressure gauge 4 and prevent clogging.
It is attached with an adhesive material or an adhesive tape so as to cover the entire surface of 1b and the tubular bodies 1a above and below it.

In addition, the water blocking packer 3 is provided on the upper and lower ends of the filter material 2.
An absorbing part 8 may be provided for absorbing the sealing material 5 oozing out of the water, and the absorbing part 8 having a finer mesh than the filter material 2 covering the water pressure measuring tube 1b is used. It is attached at a position where the part and the upper end contact each other.

The water shield packer 3 is attached so as to cover the entire surface of the measuring pipe 1 between the adjacent filter materials 2.
When the sealing material 5 is filled in the inside 3c, the sealing material 5 expands and comes into close contact with the measurement hole wall to prevent water from entering the measurement depth layers n in which the water pressure gauges 4 are installed.

Further, as shown in FIGS. 6 and 7, the water-impervious packer 3 is formed in an annular shape by a cloth inner skin 3a and an outer skin 3b, and a penetrating portion 3d into which the measuring tube 1 is inserted is provided in a central portion, Similar to the filter material 2, the upper and lower parts are attached to the outer surface of the measuring tube 1 with an adhesive material or an adhesive tape.

And, the upper insertion port 6a is provided at the upper and lower parts of the impermeable packer 3.
And a lower insertion port 6b are provided respectively, and a plurality of injection tubes 7 connected to the ground injection device P are inserted into the upper insertion port 6a. The injection tube 7 seals the sealing material 5 in each water shield packer 3c. Is filled.

Further, a plurality of injection tubes 7 connected to the upper insertion opening 6a of the lower water-impervious packer 3 are inserted into the lower insertion opening 6b through the water-impermeable packer 3c.

Therefore, these injection tubes 7 are connected to the other water shield packers 3 from the ground injection device P through the inside of each filter material 2 and each water shield packer 3c.

As described above, according to the present invention, since the water-impervious packer 3 is made of cloth, the sealing material filled in the water-impervious packer 3 is appropriately exuded from the cloth surface, so that the water-impervious packer 3 is filled without rupturing. Can be filled.

Further, since the sealing material 5 oozing from the water blocking packer 3 adheres to the wall of the measurement hole, perfect water blocking can be achieved.

The sealing material 5 is clay (usually commercially available as a construction material), water and hydrophilic urethane resin 20 to 40%: 40
-60%: A mixture of 10 to 30% is used, but in the present example, shielding clay, water, and hydrophilic urethane resin are used in a ratio of 30%: 49%: 21%. The mixture is injected by the injection device P into each water shield packer 3 through the injection tube 7. Further, the sealing material 5 is hardened into a gel having high elasticity in a state where it slightly exudes to the outer surface of the water shield packer 3 with the passage of time.

Thus, as shown in FIGS. 8 and 9, the sealing material 5 has excellent elastic deformation and expandability, so that the sealing material 5 adheres to the measurement hole wall in a state of leaching from the water shield packer 3 and has a sealing effect. It is possible to manufacture it at a low cost as well as having a high followability of being deformed along with the deformation of the ground.

Further, even if a gap is formed between the measurement hole wall and the water shield packer 3 after the sealing material 5 has expanded, there is an advantage that it absorbs ambient water and expands again to seal the gap. .

Therefore, the conventional rubber water-impervious packer 3 '
However, the pressure in the water-permeable packer 3'acts on the ground to cause creep deformation of the ground, and if it is left for a long time, the water cannot be perfectly impermeable. Once the packer 3 is filled with the sealing material 5, it is not necessary to fill the sealer 5 until the measurement of the water pressure is completed or to constantly apply the pressure.

The sealing material 5 is not limited to a mixture of the above-mentioned clay, water and a hydrophilic urethane resin, but may be an ordinary cement milk.

Next, a method of measuring the pore water pressure in the ground using the measuring device A will be described.

First, a measurement pipe 1b in which a water pressure measuring pipe 1b having a built-in water pressure gauge 4 is connected for each measurement depth, and a filter material 2 and an impervious packer 3 are alternately attached, are excavated to a predetermined depth. Insert into hole H.

At this time, the injection tube 7 connected to each water shield packer 3 is connected to the ground injection device P, and the water pressure gauge 4 is connected to the measurement device S via the cord 9 passing through the measurement pipe 1.

Next, the sealing material 5 made of clay, water, and hydrophilic urethane resin is injected by the injection device P into each water shield packer 3c of the measuring pipe 1.

This injection is performed by sequentially filling each of the impermeable packers 3 located at a deep position, and the amount thereof is determined in advance by taking into consideration the amount of seepage from the impermeable packers 3 to the outside.

Further, since the sealing material 5 oozing out from the water-impervious packer 3 is completely absorbed by the absorbing portion 8 directly below, it does not soak into the filter material 2 on the outer surface of the water pressure gauge 4.

Further, the water-impervious packer 3 filled with the sealing material 5 expands with the lapse of time to strengthen the adhesion to the measurement hole wall, thereby forming the multi-step measurement depth layer n in the measurement hole H. And, by these expanded water shield packer 3,
Since each measurement depth layer n is completely sealed, it is possible to prevent intrusion of the water under pressure and measure the water pressure accurately.

(Effects of the Invention) The present invention has the following effects by adopting the above configuration.

By making the water impermeable packer made of cloth, the sealing material mixed with clay, water and hydrophilic urethane resin was injected into each water impermeable packer, and the sealing material bleeds on the outer surface of the water impermeable packer over time. As it emerges, it hardens into a highly elastic gel and adheres the water shield packer to the measurement hole wall, so that the water shield of each measurement depth layer formed in the measurement hole can be perfected.

By injecting an elastic gel-like sealant having water-swelling expandability into the water shield packer, it is possible to prevent the sealing effect from being lowered due to creep deformation of the ground.

By connecting the injection tube that injects the sealing material to the upper insertion port of the lower water-blocking packer through the inside of the water-blocking packer, each injection tube can be used as a water pipe, so that the measurement depth layer mutual Water can be prevented from entering.

Even if there is water pressure or the groundwater flow is fast, the sealing material can be prevented from escaping by injecting it into the cloth packer.

[Brief description of drawings]

1 to are cross-sectional views of a state in which a pore water pressure measuring device is used, FIG. 2 is an enlarged cross-sectional view of a main part of the pore water pressure measuring device, and FIG. 3 is a cross-sectional view taken along line AA of FIG. Fig. 4 shows the same B-
B line sectional view, FIG. 5 is an enlarged sectional view of a water pressure measuring pipe, FIG. 6 is a perspective view of a water-impervious packer, FIG. 7 is the same enlarged sectional view, and FIG.
FIG. 10 is a stress-strain relationship diagram showing elastic deformation of the sealing material, FIG. 9 is a time-dependent diagram showing expansion coefficient of the sealing material, and FIG. 10 is a sectional view of a conventional pore water pressure measuring device. In the figure, A: Measuring device for pore water pressure 1: Measuring pipe, 2: Filter material 3: Impermeable packer, 3a: Inner skin 3b: Outer skin, 3d: Penetration part 4: Water pressure gauge, 6a, 6b: Insertion port respectively .

Front page continuation (72) Inventor Hiroshi Umeda 1-7-1 Kyobashi, Chuo-ku, Tokyo Toda Construction Company (72) Inventor Ichiro Sekine 1-7-1 Kyobashi, Chuo-ku, Tokyo Toda Construction Company (72) Inventor Hiroshi Nonome Inside Toda Construction Co., Ltd. 1-7-1 Kyobashi, Chuo-ku, Tokyo (72) Inventor Toshiaki Hara 1-7-1 Toyo Construction Co., Ltd., Kyobashi, Chuo-ku, Tokyo (56) Reference Documents JP-A-2-292493 (JP, A) JP-A-1-150830 (JP, A) JP-B-58-33359 (JP, B2)

Claims (1)

[Scope of utility model registration request] 1. A water shield packer attached to a pore water pressure measuring pipe, wherein the water shield packer is constituted by a cloth inner skin and an outer skin in an annular shape having a penetrating portion at the center thereof, and the water shield packer. An impervious packer, characterized in that each of the upper and lower parts of the impeller packer has an insertion port that communicates with the impermeable packer.