Characteristics of the Packing on the Peaty Soils

Studies on the farm land improvement of peaty bog in low area (III)

Abstract

Studies were made on the characteristics of compaction in peaty soils so as to obtain fundamental data on the use of low area. The results obtained are summurized as follows:
(1) In an unrepeated drying process, the dry density (γ_d) of the peat soil increased with a decrease in the moisture ratio (w) attaining a maximum (γ_dmax) under a air-dry condition (Fig. 1).
(2) In the wetting process of peat soil, a peak was found on the compaction curve obtained by the repeat method, but no peak on the compaction curve could be found by the unrepeat method (Figs. 2, 3).
(3) The compaction curve for the non-fiber part of peat soil passed through the No.150 sieve (105μ) under water and showed a peak value of dry density, but no peak was recognized on the compaction curve for the fiber part (the residue on the sieve) (Fig. 4).
(4) In regard to the drying process of peat soil in compaction test by the unrepeat method, the smaller the initial moisture content of the peat soil, the higher was its dry density (Fig. 6).
(5) In peat and muck soils, the larger the content of sand, the higher was the maximum dry density and the smaller the optimum moisture content (w_opt) (Figs. 7, 8).