JP2001214427A - Method of water penetration test for ground - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of water penetration test for the ground which can measure correct water permeability at a construction site, without any damage to the ground where measurement is objected. SOLUTION: The method of water penetration test for ground uses a device 10 equipped with a cylinder 15 of which one end is closed with a lid 15a and another end is open, and a pipe 11 which is connected to the lid so as to communicate into the cylinder. The open end 15b of the pipe is laid on the ground surface without forcing into the ground 40, the peripheral ground surface of the open end of the pipe is paved with membranous stuff 16 consisting of not permeable agents, and the method examines the water permeability of the ground by measuring volume of water penetrated into the ground after filling the cylinder and the pipe with water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for testing the permeability of ground, and more particularly to a method for testing the permeability of an in situ low-permeability ground such as clayey soil.

[0002]

2. Description of the Related Art The disposal sites for general and industrial wastes are constructed by laying low-permeability clay on the bottom, and the permeability of this clayey soil is determined by the conventional test method shown in FIG. It is measured at the construction site by the equipment.

[0003] In FIG. 3, a test apparatus 30 includes a cylinder 32 having one end closed by a lid 32a and the other end formed in an open state.
And a tube 31 attached to the lid 32a so as to communicate with the inside of the cylinder 32. And the test apparatus 30
The open end 33 of the cylinder 32 is pressed into the ground 40 and the pipe 31
Then, water is injected into the cylinder 32. This water permeates the ground 40 as indicated by the arrow in the figure, and the pipe 31
, The water level gradually decreases, and the amount of change over time of this water is measured to determine the water permeability of the ground.

[0004]

However, in the conventional test method described above, when the cylinder 32 is pressed into the ground 40 and the test apparatus 30 is installed, the ground may be damaged.
In this case, since water leaks along the surface of the cylinder 32, there is a disadvantage that accurate water permeability of the ground cannot be measured.
Therefore, an object of the present invention is to provide a method for testing the permeability of ground, which can accurately measure water permeability at a construction site without damaging the ground to be measured.

[0005]

According to the present invention, a cylinder having one end closed by a lid and the other end being open, and a tube connected to the lid so as to communicate with the inside of the cylinder. A method for testing the permeability of ground using an apparatus provided with the apparatus, wherein the open end of the cylinder is placed on the ground surface without being pressed into the ground, and a membrane made of a water-impermeable material is formed on the ground surface around the open end of the cylinder. A method is provided for testing the soil permeability by laying a material, filling the cylinder and the tube with water, and measuring the amount of water permeating into the ground.

In the present invention, it is preferable that the film material is laid in a concentric shape with the cylinder. Further, the film material made of the water-impermeable material is, for example, a sheet made of rubber or synthetic resin or the like is previously bonded to the open end of the cylinder,
Alternatively, after the open end of the cylinder is placed on the ground surface, it can be formed of a liquid or gel curable material, for example, a synthetic resin such as paraffin or araldite. The film material is provided so as to closely contact the outer peripheral surface of the open end of the cylinder without any gap.

[0007] The pipe connected to the lid is used for measuring the amount of water permeating into the ground. That is, the tube is formed from a transparent material, the surface is provided with graduations,
Thereby, the inside water level is formed so that it can be measured visually from the outside. Therefore, as the water filled in the cylinder or the tube penetrates into the ground, the water level in the tube decreases, and the amount of decrease in the water level is measured visually to measure the amount of water permeating the ground. Therefore, in order to accurately measure the amount of water that has penetrated, the pipe must be about 3 to 7 mm.
It is preferable that the inner diameter is formed to be extremely small. Although it is possible to supply water into the cylinder from this extremely thin tube, the water supply time tends to be long because this tube has a small diameter. Therefore, in addition to this pipe, it is preferable that a pipe for water injection, that is, a water supply pipe is connected to the cylindrical lid, and an open / close valve is provided at a predetermined position of the water supply pipe. In addition, a water supply pipe having a relatively large inner diameter is used so that water can be easily supplied.

[0008]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of a test apparatus 10 used in the present invention, and FIG. 2 is a plan view seen from the II-II direction in FIG. In FIG.
The test apparatus 10 has an upper end closed by a lid 15a and a lower end 15b
And a membrane material 1 made of a water-impermeable material laid on the ground surface around the opening of the cylinder 15
6, 22 and a lid 15a so as to communicate with the inside of the cylinder 15.
And a water supply pipe 13 connected to the water supply pipe.

An on-off valve 14 is provided in the middle of the water supply pipe 13, and a funnel-shaped water supply port 12 is provided at the upper end. When water is supplied into the cylinder 15, the water supply port 12 is preferably supported near the upper end of the thin tube 11, and for this purpose, a support member (not shown) such as a column may be provided.

The thin tube 11 is formed of a transparent material, has a scale on the surface, and is formed so that the internal water level can be visually measured from the outside. Therefore,
When the water inside the cylinder 15 permeates into the ground, the water level in the thin tube 11 also decreases, so that the amount of water permeating into the ground can be measured.

The film materials 16 and 22 are formed as shown in FIG.
It can be formed by any one of the modes (b).
2A, a sheet made of rubber, synthetic resin, or the like is punched out to form a donut-shaped sheet concentric with the cylinder 15, which is bonded to the lower end 15b of the cylinder 15 in advance. On the other hand, in FIG. 2B, a ring 21 having a diameter larger than the cylinder 15 is placed on the ground surface so as to be concentric with the cylinder 1, and a liquid state is formed on the ground surface surrounded by the ring 21 and the cylinder 15. Alternatively, the film material 22 is formed at a test site or a construction site by pouring a gel-like curable material.

Next, a method for testing the water permeability of the ground using the test apparatus 10 of the embodiment shown in FIGS. 1 and 2A will be described. First, the test apparatus 1 is placed on the ground 40 to be tested.
Set 0. At this time, the cylinder 15 has its lower end 15b
Is placed on the ground surface without being pressed into the ground. Then, the membrane material 16 is laid on the ground surface, and a weight (not shown) is placed on the membrane material 16 to prevent water leakage from between the membrane material 16 and the ground surface. To eliminate the gap.

Next, when the on-off valve 14 is opened and water 18 is supplied to the water supply port 12, the water reaches the inside of the cylinder 15 through the water supply pipe 13, and when the inside is filled with water, the water is further discharged. It rises inside the thin tube 11. When water reaches a predetermined height in the thin tube 11, the on-off valve 14 is closed to stop water supply. The water in the cylinder 15 penetrates into the ground and flows out from the ground surface as shown by a plurality of arrows, and the water level in the thin tube 11 gradually decreases. The amount of decrease in the water level is visually measured at predetermined time intervals, and by analyzing the actual measurement result, the water permeability of the test target ground can be obtained.

[0014]

According to the water permeability test method of the present invention, unlike the conventional test method, the open end of the cylinder is not pressed into the ground, but only the open end of the cylinder is placed on the ground surface. The defects caused by the test method, that is, damage to the ground at the time of press-fitting of the cylinder can be prevented.Furthermore, since a membrane made of water-impermeable material is laid on the ground surface around the open end of the cylinder, Water from the ground surface can be prevented. Therefore, the water from the cylinder or the pipe penetrates only into the ground to be measured, so that accurate ground water permeability can be measured at an experimental site or a construction site.

[Brief description of the drawings]

FIG. 1 is a sectional view of a test apparatus used in the present invention.

FIG. 2 is a plan view seen from the II-II direction in FIG.

FIG. 3 is a cross-sectional view of a conventional water permeability test device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Permeability test apparatus 11 Tube 15 Cylindrical 15a Lid 15b Open end 16 Membrane material 22 Membrane material 40 Ground

Claims (2)

[Claims] 1. A ground water permeability test method using a device having a cylinder closed at one end with a lid open at the other end and a pipe connected to the lid so as to communicate with the cylinder. Then, the open end of the cylinder is placed on the ground surface without being pressed into the ground, and a membrane made of a water-impermeable material is laid on the ground surface around the open end of the cylinder, and the cylinder and the pipe A method of testing the water permeability of the ground by filling the body with water and measuring the amount of water that penetrates into the ground. 2. The water permeability test method according to claim 1, wherein the membrane material is laid in a concentric shape with the cylinder.