JPS6290439A - Construction of cutout wall - Google Patents

Abstract

PURPOSE:To construct a wall having a certain strength and a certain flexibility by a method in which a cement-asphalt milk prepared by mixing specific amounts of the asphalt of an asphalt emulsion and a cement is mixed with the soil of construction site. CONSTITUTION:100pts.wt. asphalt in an asphalt emulsion is mixed with 20-100 pts.wt. cement to form a cement-asphalt milk. The cement-asphalt milk is mixed with the soil of a construction site to construct a cutoff wall. The water- stopping property of the cutoff wall can be raised and the cutoff wall can also be used as an underground wall having a sufficient strength. Therefore, the cutoff wall can be utilized for structures having great deforming amount on the surrounding ground of the cutoff wall, e.g. dam foundation, levee, and underground dam.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method of constructing a water-stop wall using an asphalt-based soil conditioner.

<Prior Art> Conventionally, as a method of improving water-permeable soil and improving water-stopping properties, there is a method of providing a water-stopping wall underground.

Such water-stop walls are generally required to have the following characteristics:

1) Must have sufficient water-tightness 2) Ensure the reliability of the joint 3) Be capable of deformation behavior close to the physical properties of the field foundation 4) Have strength equal to or greater than the field foundation 5) Construction 6) The cost is low; most of the improvers used in conventional water-stop walls are cement-based.

Problems to be Solved by the Present Invention> As described above, since conventional water-stop walls use cement-based materials, the resulting water-stop walls tend to have high rigidity and lack flexibility.

Therefore, as shown in Figure 2, the dam foundation does not sink together with the surrounding ground, and only the wall W is left behind from the sinking, resulting in the destruction of the surrounding dam body. .

As a construction method that improves this point, the slurry wall construction method,
Asphalt mastic construction methods are used.

Although the slurry wall construction method has excellent flexibility, it has the disadvantage that the amount of consolidation settlement after construction is large and the settlement continues for a long period of time.

On the other hand, the asphalt mastic construction method has excellent flexibility and the amount of consolidation settlement is small.

However, construction requires excavating a trench and pouring asphalt mastic at a temperature of over 200 degrees Celsius, which poses many problems in terms of workability and economy.

In addition, although the injection method has the effect of lowering the hydraulic conductivity, its water-stopping performance is inferior to that of underground continuous walls.

As described above, although many construction methods exist, the current situation is that there is no construction method that is superior in flexibility, water-stopping properties, workability, economic efficiency, etc.

Furthermore, among the underground continuous wall construction methods, there is also a construction method in which cement milk and asphalt emulsion are injected into the ground and stirred.

The purpose of this construction method is to improve the water-stopping effect of the entire ground, and the amount of asphalt emulsion used is only about 5 to 10 kg per cubic meter of soil.

Therefore, unlike the construction method of the present invention, it is not intended to construct a flexible wall underground.

OBJECTS OF THE INVENTION The present invention has been made to improve the above-mentioned drawbacks, and an object of the present invention is to provide the following method of constructing a water-stop wall.

<B> A method of constructing a water-stop wall that allows the construction of a wall with a certain level of strength and flexibility in the ground, rather than improving the entire ground. If the surrounding earth and sand settles, it will settle in a similar manner,
A method of constructing a water-stop wall that does not settle excessively or be left behind by surrounding subsidence (C) There is no need to use special equipment to handle high-temperature asphalt (in terms of ease of construction and economy) Excellent water-stop wall construction method = 3 - <Configuration of the present invention> Next, examples of the present invention will be described.

<Example 1> Cement Asphalt Milk The asphalt emulsion used in the present invention is a liquid in which fine particles of straight asphalt or the like are dispersed in water containing an emulsifier and a stabilizer.

In the present invention, the above-mentioned additives are added as necessary to improve workability and quality of the cement as described below.

<mouth> Mixing ratio with earth and sand In the present invention, the proportion of soil and sand is as follows: It was injected or added and mixed.

Example of cement asphalt milk Cement asphalt milk having the composition shown in the image was used. As a result, the following uniaxial test results were obtained.

The stress-strain ratio for each sample is as shown in FIG.

That is, sample No. 1 cracked at the peak load.

In No. 2, cracks appeared when the load was slightly lower than the peak load.

No. 003 is similar to No. 2, but has greater deformability than No. 2, and has greater ability to respond to deformation.

Blend No. 4 did not have a clear peak, deformation continued slowly, and therefore no cracks were generated.

In other words, even if a large deformation occurs in the surrounding area, it can be adequately coped with.

No cracks occur even with compositions No. 5, but the strength is N.
It is significantly smaller than 004 and lacks practicality.

The above results show that when the cement asphalt of the present invention is used within the above range, a material having sufficiently high strength and a deformation coefficient close to that of soil (approximately 100 kg/cat) can be obtained.

<Example 2> <Example of mixing ratio with earth and sand> (1) Against Silty Sand, Mixing was carried out in the following proportions.

As a result, No. 1 indicates that the amount of cement milk is insufficient to obtain a good mixing condition.

It was found that 150 kg/nr or more of 2 is required.

The results of the uniaxial compression test of the above sample are as follows.

(2) Standard sand was mixed at the following ratio.

The results of the uniaxial compression test of the above sample are as follows.

From the above results, it can be seen that good effects can be obtained when 150 kg or more of the cement asphalt milk of the present invention is mixed with 1 cubic meter of earth and sand.

On the other hand, in the case of mixing 1000 kg or more of cement asphalt milk, it is difficult to use it practically from the economic point of view.

Effects of the Present Invention> Since the present invention is as described above, the following effects can be expected.

B) Not only does it improve water-stopping properties, but it can also be used as an underground wall with sufficient strength.

Therefore, for example, a cutoff wall at the foundation of a dam, a cutoff wall on a dam,
It can be used for structures where the ground around the water stop wall is subject to large deformation, such as the water stop wall of an underground dam.

<Exposure> Materials with a modulus of elasticity close to that of the ground can be easily designed by adjusting the composition.

Therefore, it is possible to construct an underground wall that blends in perfectly with the surrounding structures without causing the inconvenience of settling excessively compared to the surrounding earth and sand or remaining behind even though the surrounding area has settled. can.

[Brief explanation of drawings]

Figure 1. 2 Stress-strain curve diagram from uniaxial test on test piece using the Senmendo Asphalt Milk of the present invention.

Claims (1)

[Claims] Asphalt in asphalt emulsion: 100 (parts by weight) Cement: 2
A method for constructing a water stop wall, characterized by mixing cement asphalt milk mixed in a ratio of 0 to 100 (parts by weight) or more with locally generated soil.