부산대학교 도서관

Drilled shafts have been applied to withstand the axial uplift load for transmission towers in Gobi, a common geological formation in Northwest China. This study elucidated the uplift behavior of drilled shafts in the Gobi gravel. Nineteen full-scale drilled shafts were installed at six sites, and pullout load testing was conducted for each drilled shaft. The load test results were interpreted using four representative uplift capacity interpretation criteria to define various elastic, inelastic, and “failure” states for each drilled shaft. The results were interrelated to establish a generalized correlation among these states using a mean uplift load-displacement curve for drilled shafts in the Gobi gravel, which was compared with parallel studies in gravelly and cohesive soils. Using the hyperbolic fitting method, normalized curves were developed by approximating the load-displacement curves for all load tests. Explicit hyperbolic curve-fitting constants were suggested at different confidence levels, and normalized load-displacement curves were presented by considering the uncertainty in the prediction. The slope tangent and Chin methods represented the lower and upper bounds, respectively. The L1–L2 method was found to be appropriate for interpreting the uplift capacity. Normalizing the load-displacement curves reduced scattering in the curves. The normalized load-displacement curves can be used in a drilled shaft design that considers capacity and displacement together.