Pressuremeter Testing for Foundation Design

Over a period of 35 years, the author has used pressuremeter test data to predict bearing capacity and settlement of foundations supported on various types of deposits. It was observed that in cohesive soil deposits the bearing capacity predictions using the pressuremeter frequently did not agree with the predictions based upon conventionally obtained soil properties. Some of this difference can be attributed to obtaining in-situ versus laboratory test parameters. Based primarily on interpretation of the pressuremeter test data rather than solely on theory, a correlation has been developed for prediction of the undrained shear strength of cohesive soils. Using this empirically derived shear strength, the prediction of bearing capacity for high rise buildings supported on overconsolidated cohesive soils by the pressuremeter formula and conventional soil procedures were found to be in close agreement. In soft clay soils, the empirically derived shear strength agrees reasonably well with the measured shear strength based upon vane shear tests