Abstract
A type of soil improvement works, referred to as soil dressing, is commonly executed in Japan. By this procedure soil is brought from other places and mixed with top soil at the rate of 200 to 600 m3 per ha. In large scale execution, soil is commonly carried by dumptrucks or locomotives. If the ground surface is suitably sloped soil may conveniently be led along irrigation canals into paddy field. Transportation cost is high in the former case of transportation. The latter method, being influenced by topography, cannot be applied to any project site indiscriminately. Consequently introduction of new transportation methods bas been expected.
A new procedure, in which soil is mixed with water and crushed into dense muddy water, which is carried to the spot by pumps through pipes, was recently developed and already applied to several areas. The author is planning to report successively the results of his studies, with stress on practical side, on problems to overcome in the practical execution of the new technique.
In the present paper theoretical formulas are introduced for computing soil content of muddy water for soil dressing through pipes and it is shown that experimental values contentedly con-formed to the values computed from the formulas.
In equations (I-1) - (I-4)
Cv volume % of granules in muddy water, Cv′ : apparent volume % of natural deposit soil, assuming that the shape are kept in muddy water, Cw : weight % of dry soil in muddy water, G : specific gravity of granules, p : specific gravity of muddy water, γd : dry apparent specific gravity of natural deposit soil, e : void ratio, n : porosity, Ws′ : we ight of wet soil supplied to the mud plant in unit time, Ww : weight of mixing water supplied to the mud plant in unit time, w : water content.
