When we intend to work heavy wagons such as tractors or bulldozers on the peat ground, we are faced with the problem of the bearing power of the ground. So, at the first stage of this research, the authors intended to investigate the bearing power of peats of different kinds, making use of loading plates of various sizes and shapes, and examined the relations among the load, the required time and the sinking degree. They investgated the penetration resistance of the cone, too. The results of the investigation were reported in Report I. From the results of the above-mentioned investigation, they could conclude as follows :
(1) The shape of the loading plate touching the ground surface dominates the sinking degree of the plate under the same intensity of the load.
(2) In the case of the constant sinking, the following formula introduced by Housel is applicable to the peat soil also. P=mx+n
where P is the intensity of load, x is the ratio of the circumferential length to the area of the plate.
On the basis of the above conclusions, this report explains the results of the experiments on the sinking amount of low-humased and medium-humased peat soils, which are unstripped and 20cm stripped of the surface, under the real static wagons.
Five bulldozers or tractors with track-shoes of different shapes and giving various pressures on the ground surface were used in the experiments. The results are summarized as follows :
As in the case of the loading plate, the intensity of the loading weight for the constant sinking is influenced by the circumferential length and the area of the ground-touching part of the machine, and is-in direct proportion to the ratio of the circumferential length to the area, and when other conditions are the same, is dominated by the shape of the ground touching part of the track-shoe.