Ground freezing around chilled gas pipelines

This paper describes the monitoring of the soil pipe interactions associated with pipelines transporting gas at temperatures below 0°C. Two particular types of ground distress are being investigated, frost heave and ground cracking. The magnitude and extent of these distress modes are influenced by three factors — pipeline operating conditions, soil characteristics and environmental conditions. It is, therefore, essential to monitor all these factors to understand the mechanisms of the possible distress modes. A field study has been commenced and the in-situ monitoring techniques are summarised in this paper. The particular parameters being studied include soil stress, moisture fluctuations and temperature distribution, together with pipeline operation and environmental factors.