Experimental Modeling and Measuring Stresses and Strains during Arching Phenomenon

In the current paper an experimental Modeling for studying the arching effect over a trapdoor in the sand is presented. To simulate this phenomenon, a well instrumented apparatus is used. In this research plain strain behavior and 2D modeling for fine sand has been selected. For this the thickness of apparatus container is 40 cm. The apparatus comprises concentric rectangular trapdoors with different width that can yield downward or upward while the stresses and deformations of the trapdoor are recorded simultaneously. To measure the changes in stress in the sand mass, circular minatory stress gouges with 14mm diameter has been made and used. To calibrate the stress gauges Hg column over a flexible membrane that can transfer the Hg load to the gauge surface is used. To obtain the strain and deformations of the sand mass Particle Image Velocimetry (PIV) method has been used. According to the experiments, during arching effect, four zones in sand mass are obvious.