Evaluation of a toroid for model pipeline testing of very soft offshore box core samples

摘要

The paper describes a new model pipeline test apparatus that uses a toroid to measure soilresponse during simulated pipeline embedment and axial movement in very soft clays. The portable apparatususes a 20mm diameter, 40mm lever arm, toroid coupled to a computer controlled load frame that can controlvertical displacement, vertical stress and rate of rotation. It mounts directly on a 0.5m square box core sampleso that testing can be performed offshore immediately after collection of an intact sample. The system wasevaluated in the laboratory using kaolin samples with undrained shear strengths between 2 to 5 kPa. Variousloading conditions typically encountered during the service life of a pipeline were examined including pipeweight, embedment depth, consolidation, shearing rate, and episodic loading events. The results show that toroidtesting of box core samples is a feasible method of performing model pipeline testing.