ABSTRACT
The paper deals with some fundamental observations gathered by the author from monitoring a large number of Artificial Ground Freezing jobsites, at first as technical director at geotechnical contractors and then as independent expert advisor. Surveying the freezing boreholes and real-time monitoring of temperatures, groundwater pressure and displacements are of the utmost importance for a successful ground freezing job. For all of them some practical recommendations are given from the point of view of both design and construction. The observations deal mainly with three aspects: the influence of the position of thermometric gauges versus freeze-pipes, the estimation of the temperature distribution within and around the frozen body and the evaluation of the transient phase between construction and maintenance of the frozen body, when different coolant fluids are used, with practical reference to one freezing project in Rome and two in Paris.
