An instrumented full-scale trial of the remediation technique of lime piling was carried out on a Gault Clay embankment slope on the M1 which has a history of shallow failures. Lime piles were installed in each of two 20m long test areas of embankment, in one case the lime piles were unlined and in the other they were lined with waterwell screen. Results from earlier laboratory trials had indicated that, when using pure quicklime, there was much advantage in using plastic waterwell screen pipe to line piles because of the higher undrained shear strengths obtained. The field performance in both cases was compared with that of a control area where no remedial work was undertaken. Site measurements of pore water pressure and ground movements enabled a systematic comparison of behaviour using the different approaches. The construction procedure, cost implications and an evaluation of slope performance during the twenty-six months following construction are described in the report. (A)

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