神岡鉱山における鉱柱内の応力の測定

抄録

In Kamioka Mine of Mitsui Mining and Smelting Co., several efforts have been made to get the maximum extraction percentage safely in pillar working.
As one of attempts for this purpose, the stress in pillars has been measured by means of the photo-elastic apparatus which was contrived at those days. It has been noticed from this measurement that the stress in pillars varies closely as the progress of mining, and that also the direction of the maximum principal stress which is easily detected by the apparatus gives a useful indication about the state of rock pressure. After five years' investigation, the photo-elastic stress measurement is proved to be one of the powerful methods for the rock pressure control in an elastic ground.