EVALUATION OF STRESS CELL PERFORMANCE

Described in this paper are the design and construction of a series of low compliance total stress cells and their performance in the laboratory and in the field. Experimental data from laboratory calibration tests are evaluated by means of several different finite element models, and the results indicate that, within the limits investigated, neither the thickness-to-diameter ratio of these cells nor the relative stiffness of the soil and the cell had much influence on the measured response, but regions of loose or dense soil in the immediate vicinity of the cells do affect their output. Limited evidence suggests that these cells can also measure horizontal stresses quite reliably. The qualitative field performance of 35 cells within two soil-pipe installations and the quantitative field performance of three free field cells suggest rather convincingly that these cells are relatively insensitive to temperature variations and are capable of measuring accurately the static stresses acting normal to their faces.