JPS6330443B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of filling sand into a pine in which cylindrical sheets are connected, which is laid to protect the slope of a river embankment or prevent scouring of rubble foundations of breakwaters.

Conventionally, to fill sand into a mat 1 in which cylindrical sheets are connected together as shown in FIG. 1 for the above purpose, water is added to sand 3 in a sand reservoir 2 in a cylindrical sheet 6 and mixed as shown in FIG. A sand slurry is sucked up by a sand pump 4 and injected into the cylindrical sheet 6 through a pipe 7 through an injection hole 5 provided at one end of the cylindrical sheet 6. The sand in the slurry gradually accumulates from the vicinity of the injection hole 5 of the cylindrical sheet 6 toward the back, and excess water begins to seep out from the texture of the cylindrical sheet 6.

However, in the above method, the concentration of sand in the sand slurry is 10% to 15%, and there is a problem that a large amount of surplus water is generated compared to the sand being filled, and this surplus water damages the surrounding environment. Furthermore, if the concentration in the sand slurry is increased to 30% or more, the sand in the sand slurry will quickly precipitate near the injection hole and block the inside of the cylindrical sheet, resulting in problems such as not improving the efficiency of the filling operation. There was a problem.

Therefore, a method can be considered in which a thickening agent made of a polymer substance is added to the sand slurry and the slurry is transported by a sand pump. This method prevents the sand from settling in the sand slurry, so it is possible to fill the sand slurry with a somewhat high sand content. It has not yet been possible to fill sand slurry with a sand content of more than twice that of the conventional method, and an extremely large sand pump is required, which is uneconomical.

The present invention solves the conventional problems by providing a method of filling sand slurry at high concentrations.

When filling sand into the mat made by connecting the cylindrical sheets of the present invention using a pump, water is added to the sand to create a highly concentrated sand slurry with a sand content of 30% to 60%, and a thickening agent is added. The viscosity (at 25℃) is 30
It is characterized by using centipoise (cps) or more and 1000 cps or less.

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

In the present invention, water is added to the sand to be filled to make a sand slurry with a sand content of 30% to 60%, and a thickening agent such as water-soluble cellulose ether is added to increase the viscosity of water (25°C ) is 30 centipoise (cps) or more and 1000 cps or less, and as shown in FIG. .

In the present invention, by adding a polymer thickening agent to the sand slurry, the viscosity of the water in the sand slurry increases, and as a result, the apparent hydraulic conductivity of the sand in the sand slurry decreases, so that water and sand are Since sand does not separate and therefore does not settle in the pipe, it can be easily filled even with sand slurry with a high concentration of 30% or more.

Thickening agents used in the present invention include water-soluble cellulose esters such as alkyl cellulose, hydroxyalkyl cellulose, carboxyalkyl cellulose, and mixed cellulose ethers, natural gums, modified natural gums, and water-soluble synthetic polymers. It will be done.

For example, methylcellulose, ethylcellulose,
Hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose sodium salt (CMC), carboxyethylcellulose sodium salt, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, carboxymethylhydroxyethylcellulose, sodium alginate, guar gum, hydroxypropylguar gum, xanthan gum, carboxymethyl starch, hydroxyethyl These include starch, polyvinyl alcohol, polyacrylic acid, sodium polyacrylate, polyacrylamide, and polyethylene oxide. These may be used alone or in combination of two or more.

The amount of the thickening agent added should be selected so that the viscosity of the water containing the thickening agent is 30 cps or more and 1000 cps or less, and it varies depending on the type and degree of polymerization of the water-soluble polymer used as the thickening agent. 0.05-10 for normal water
It may be added in an amount of about 0.1 to 1.0% by weight, preferably about 0.1 to 1.0% by weight. The viscosity of water containing a thinner is 30cps
In the following cases, it becomes difficult to transport by pump; on the other hand, if it exceeds 1000 cps, the power required for the pump becomes large, and it becomes necessary to add a large amount of thickening agent, resulting in a loss of economic efficiency.

Since the method of the present invention is as described above, the following effects can be obtained.

(1) Dehydration of the water in the sand slurry is prevented, and therefore the sedimentation phenomenon of the sand is prevented, making it possible to fill with highly concentrated slurry.

(2) Especially reduce the sand content in the sand slurry to 50% to 60%.
In this case, the filled water fills the voids in the sand volume after filling, so that no excess water flows out to the outside.

As the piston-type concrete pump, for example, "Niigata-Thomsen Concrete Pump" (trademark) manufactured by Niigata Tekko Co., Ltd., a rotary displacement type uniaxial eccentric screw pump, such as Mono Pump (trademark), or a snake pump may be used.

In addition, in FIG. 4, 10 is a river, 11 is its embankment, in FIG. 5, 12 is the seabed, 13 is a rubble foundation mound, and 14 is a caisson.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a mat in which cylindrical sheets are connected, FIG. 2 is an explanatory diagram of a conventional method for filling this mat with sand, and FIG. 3 is an explanatory diagram of the method of the present invention.
FIG. 4 is an explanatory diagram of the case where the above-mentioned pine is used to protect the embankment surface, and FIG. 5 is an explanatory diagram of the case where the pine is similarly used to prevent scouring of the rubble foundation of a breakwater. 1...Matsuto, 2...Sand tank, 3...Sand, 4...
...Sand pump, 5...Injection hole, 6...Seat,
7... Pipe, 8... Mixer, 9... Concrete pump, 10... River, 11... Embankment, 12...
Seabed, 13... rubble foundation mound, 14... caisson.

Claims (1)

[Claims] 1. When filling sand into a mat formed by connecting cylindrical sheets using a pump, water is added to the sand to create a highly concentrated sand slurry with a sand content of 30% to 60%, and A method for filling sand into a mat made of connected cylindrical sheets, characterized by using a thickening agent that has a viscosity (at 25°C) of 30 centipoise (cps) or more and 1000 cps or less. 2. The sand filling method according to claim 1, wherein the pump is a piston type concrete pump. 3. The sand filling method according to claim 1, wherein the pump is a snake pump.