Measurement of Suction in a Marine Clay as an Indicator of Sample Disturbance

摘要

This paper describes a test program that investigated the potential of residualrnporewater pressure, or suction, to be a quick and nondestructive measure of samplerndisturbance. A portable 35 mm diameter suction probe, consisting of a high air-entryrnporous ceramic stone and pressure transducer capable of direct suction measurementsrnon soil samples, was developed for this study. The suction probe was used at a testrnsite located in Newbury, Massachusetts where a layer of low to medium plasticityrnBoston Blue Clay (BBC) exists. Six Sherbrooke block samples and several 76 mmrnsplit spoon samples were collected. Consolidation tests were conducted on allrnsamples to assess sample quality based on volumetric strain methods. The highrnquality Sherbrooke block samples had much higher suctions than the poor qualityrnsplit spoon samples. The results suggest that the suction probe could be a practicalrntool for making assessments of sample quality in the field immediately after samplerncollection and during selection for laboratory consolidation and strength testing.