抄録
In chapter 1, the peculiarity of powder (soil) mechanics is considered and it is concluded that the stress in powder mass is, if possible, to be measured without inserting any probe. A photoelastic method using no probe is proposed.
In chapter 2, outline of the procedures of this method is explained and the following are made known: (1) Isoclinics can be observed in the same way as in ordinary photoelastic experiment; (2) Distribution of brightness caused by the photoelastic effect in less than one fringe is observed, the equibrightness lines corresponding to ordinary isochromatics; (3) A sort of striped pattern resulted from fibrous structure in powder mass is observed by a circular polariscope, the direction of the stripes coinciding with that of the major principal stress in powder mass; (4) Measurements by Babinet Compensator and Tank's method are also possible.
In the next report, the following will be given; (1) Photoelastic properties of glass powder mass; (2) Technical problems in experimental procedure; (3) Utility of this method in engineer ing field.
