Field observations of soft clay response to slurry trench excavations

A field trial was carried out to determine the response of soft clays to excavation of slurry trenches of length 2.8m and 6.4m excavated to 56.6m deep. Inclinometers, piezometers, water standpipes and settlement markers were installed to monitor the effects of the excavation. The trial programme included a study of the influence zone of the excavation, sensitivity of the trench stability to variations in slurry heads and effects of concreting pressure on the surrounding ground. The data obtained from the field instrumentation is presented and analyzed. The interpretation of observations made is discussed.