JPS59118907A - Filling of sand into mat connected with cylindrical sheets - Google Patents

Abstract

PURPOSE:To completely fill sand into a mat with good efficiency by a method in which an aqueous sand slurry of a high sand concentration is mixed with a thickening agent and filled into a mat consisting of connected cylindrical sheets by means of a pump. CONSTITUTION:An aqueous sand slurry containing 30-60% sand is mixed with a thickening agent, e.g., water-soluble cellulose ether, etc., to prepare a sand-rich slurry whose viscosity is 30-1,000cps. The sand-rich slurry is filled into a mat 1 consisting of connected cylindrical sheets 6. Sand can thus be completely filled into the mat 1 because the slurry can be transported through a pipeline without causing the separation of sand and water in the slurry.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of filling sand into a mat made up of connected cylindrical sheets, which is laid for preserving the slope of a river embankment or preventing scouring of the rubble foundation of a breakwater.

Conventionally, in order to fill sand into a mat 1 which is made up of cylindrical sheets connected together as shown in FIG. 1 for the above-mentioned purpose, water is added to sand 3 in a sand reservoir 2 in a cylindrical sheet 6 and mixed as shown in FIG. The resulting sand slurry is sucked up by the sand pump 4 and injected into the cylindrical sheet 6 through the injection hole 5 provided at one end of the cylindrical sheet 6 through the pipe 7f. The sand in the sand slurry is accumulated from the vicinity of the injection hole 5 of the cylindrical sheet 6 to the depths, and excess water begins to seep out through the texture of the cylindrical sheet 6.

However, in the above method, the concentration of sand in the sand slurry is 10cs to 15%, and 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 of the sand slurry is set to 30 g or more, the sand in the sand slurry will quickly precipitate near the injection hole and block the inside of the cylindrical sheet, which will not improve the efficiency of the filling operation. There was the problem of 〇 Therefore, a method of adding a thickening agent made of a polymer substance to the sand slurry and transporting it using a sand pump has been considered. According to this method, sedimentation of sand in the sand slurry can be prevented, so it is possible to fill the car with a sand slurry with a high content of sand to some extent. It was not yet possible to fill the sand slurry with sand slurry, and in order to fill the sand slurry with a gold sand ratio more than double that of the conventional sand slurry, an extremely large sand pump was required, which was uneconomical.

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

The method of filling sand into a mat formed by connecting cylindrical sheets according to the present invention is to use a pump to fill the mat formed by connecting cylindrical sheets with a highly concentrated sand slurry of water and sand mixed with a thickening agent.f: Features.

□ The present invention will be explained in detail below with reference to the drawings.

In the present invention, water is added to the sand to be filled so that the gold sand ratio is 3.
Create a sand slurry with a concentration of 0% to 60%, and add a thickening agent such as water-soluble cellulose ether to increase the viscosity of water (at 25°C) to 30 centiboise (cpII) or more.10
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 separated. Since the sand does not separate and therefore does not settle in the pipe, it can be easily filled with highly concentrated sand slurry of 30 g or more.

Examples of the thickening agent used in the present invention include water-soluble cellulose ethers 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.

Examples Eva methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxyglobilcellulose, carboxymethylcellulose sodium salt (CMC)
, carboxyethyl cellulose sodium salt, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl hydroxyethyl cellulose, sodium alginate, guar gum, hydroxypropyl guar gum, xanthan gum, carboxymethyl starch, hydroxyethyl starch, polyvinyl alcohol,
These include 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 is such that the viscosity of the water containing the thickening agent is 30.
cps or more and 1000 cpa or less, and varies depending on the type and degree of polymerization of the water-soluble polymer used as a thickening agent, but is usually about 0.05 to 10% by weight, preferably 0.1 to 10% by weight based on water. It is sufficient to add about 1.0 weight. If the viscosity of the water containing the thickening agent is less than 30 cps, it will be difficult to transport it by pump; on the other hand, if it exceeds 1000 cps, the power required for the pump will be large, making it necessary to add a large amount of the thickening agent. The necessary economic efficiency is lost.

Since the method of the present invention is consistent with the above, the following effects can be obtained.

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

(2) Especially the gold sand ratio in the sand slurry is 50 to 6
When it is 0%, the filled water is the empty l! of the sand volume after filling. 1 [is satisfied, so no surplus water goes 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 Figure 4, 10 is a river, 11 is its embankment, and 5th
In the figure, 12 is the seabed, 13 is the rubble foundation mound, and 14
is a caisson.

[Brief explanation of drawings]

Figure 1 is a perspective view of a mat with connected cylindrical sheets, Figure 2
The figure is an explanatory diagram of the conventional method for filling this mat with sand, Figure 3 is an explanatory diagram of the method of the present invention, Figure 4 is an explanatory diagram of the above mat used for embankment surface protection, and Figure 5 is an explanatory diagram of the method of the present invention. 2 is an explanatory diagram of the case where the same method is used to prevent scouring of the rubble foundation of a breakwater. 1...mat, 2...sand tank, 3...sand, 4...
・Sand pump, 5... Injection hole, 6... Seat, 7
... Pipe, 8... Mixer, 9... Concrete pot/pipe, 10... River, 11... Embankment, 12... Seabed, 13... Rubble foundation mound, 14... ·caisson. 37-

Claims (1)

[Claims] (1) A mat formed by connecting cylindrical sheets, characterized in that a highly concentrated sand slurry of water and sand mixed with a thickening agent is filled with a pump using a pump. How to fill the mat with sand. (2) The viscosity (25°C) of water containing a thickening agent is 30 centivoise (cps) or more10
The method for filling sand according to claim 1, characterized in that a sand filling method is used that has a sand pressure of 0.00 cps or less. (3) The sand filling method according to claim 1 or 2, wherein the pump is a piston type concrete pump. (4) The sand filling method according to claim 1 or 2, wherein the pump is a snake pump.