Development of an axisymmetric field simulator for cone penetration tests in sand

An experimental system capable of simulating axisymmetric field conditions has been developed. This system, as an improvement over conventional calibr ation chambers, enables cone penetration tests (CPT) to be calibrated under minimal boundary effects. The new simulator consists of a stack of 20 ring s to house the sand specimen. These rings are lined with an inflatable sili cone rubber membrane on the inside. The boundary expansion and stress are m easured and individually controlled, respectively, at each ring level durin g the CPT. The soil from physical boundary to infinity is simulated using a nonlinear cavity expansion curve derived from a lateral compression test o n the specimen. Results from a series of CPTs show that at relative densiti es of approximately 80%, the cone tip resistance values agree within 4% as the diameter ratio of the physical specimen over cone varies from 18 to 22. This paper describes unique features of this field simulator, presents ava ilable CPT data performed in the simulator, and discusses its implications on future calibration tests.