Miniature Gauges for Soil, Grains and Powders

The authers developed miniature gauges for soil, grains and powders mentioned below:(a) Pressure cell: measuring the normal stress between grains and wall. (b) Friction cell: measuring the tangential stress between grains and wall. (c) Internal stress cell: measuring the magnitude and direction of principal stress in grains. (d) Gradient cell: measuring the angle of revolution in grains. (e) Strain cell: measuring the strain in grains. In these gages, (a)(d) are made up of electrical strain gauges, and (e) is made up of electrical coil. Then, using these gauges, the experiment of compression of sand in a cylinder was carried out. In this experiment, the accuracy of gauges was confirmed. And the distributions of resultant stress of wall, and internal stress and strain in sand were revealed.