JPS58187485A - Method for improving earth and sand - Google Patents

Abstract

PURPOSE:To reduce the free water content of earth and sand, improve the handleability such as transportability, etc. and prevent the pollution of working environment and staining of road, etc., by mixing the earth and sand having high water-content with resin powder which swells by water-absorption, thereby absorbing the water from the earth and sand. CONSTITUTION:Dredged earth, sludge, etc. having high water-content is mixed uniformly with resin powder which has an average particle diameter of about 0.05-1.0mm. and swells and gels by water-absorption (e.g. starch acrylonitrile copolymer). When an aqueous solution of electrolyte is added to the earth mixed with the above resin powder, the absorbed water can be released and the earth can be dehydrated to dryness.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a soil improvement method for reducing free moisture in excavated soil such as dredged soil and sludge containing a large amount of water. The aim is to improve the ease of handling townships.

In general, sludge-like soil with a high moisture content is difficult to shake, especially when transported using a belt conveyor or dump truck.
Sediment is scattered around the area, reducing transportation efficiency and deteriorating the working environment.
This invention, which has caused problems such as road surface accidents, was developed in view of the above-mentioned problems.The gist of the invention is to: It is mixed with the earth and sand and absorbs the moisture in the earth and sand,
This is a soil improvement method characterized by reducing free moisture in the soil.

The resin that absorbs water and swells to be used in this invention is one that does not dissolve in water but absorbs water and swells from several times to nearly 1,000 times its volume. For example, starch-acrylonitrile or starch-methacrylate graft copolymers, partial hydrolysates of vinyl ester-ethylenically unsaturated carboxylic acid copolymers in polyacrylonitrile, polymers with hydrophilic groups introduced such as sulfonated styrene, polyethylene oxide , polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid salt, polyacrylamide, carboxymethylcellulose, polyacrylic acid polyacrylic acid copolymer, radiation-irradiated products of hydrophilic polymers such as pullulan, methylene bisacrylamide, dichloroacetic acid , epichlorohydrin, crosslinked products using crosslinking agents such as aldehydes, hydrophilic groups partially substituted with lipophilic groups, copolymers of isobutylene and luic anhydride, and the like.

When these resin powders are added to sand and sand with a moderate moisture content, the resin powder absorbs water and swells, reducing the amount of free water in the sand within a few minutes. Therefore, the ease of handling earth and sand is improved, and problems such as ease of transportation, working environment, and road surface pollution can be improved.

Resin powder usually has an average particle size of 0.05M to 1.0++as
It is of Q degree, and its particle size is too large so that it mixes uniformly with the earth and sand, and it takes a long time to absorb water, which is undesirable.

9. These resin powders generally lose their ability to absorb water when they come into contact with an electrolyte aqueous solution such as calcium chloride, so after reducing the free water content of soil with a bird's content content and treating it, Adding an electrolyte aqueous solution to the escape sediment,
It is also possible to absorb water, return the resin powder to its original state, release moisture, and dry the earth and sand.

Example water content W = 120%, wet density PL = 1.4 l/
9 was added to and mixed with resin powder (acrylic acid polymer trade name: Aqua Keep) 2, which has the property of absorbing water and becoming J1-toned when 1.7 cm of sludge is treated. Sludge is 2~
After 3 minutes, the product has a slump of 0 to 5cILfIA and has a round shape, making it easy to transport by belt conveyor or dump truck, and improving workability, work environment, and road surface pollution problems.

A comparison with the conventional transportation cost of unprocessed sludge is shown in Table F.

Claims (1)

[Claims] (1) A soil improvement method characterized by mixing resin powder that absorbs water and swells with soil and sand having a high moisture content to absorb water in the soil and reduce free moisture in the soil, J