Tank Foundation Construction in Sub Zero Temperatures: Two Case Studies

This paper presents and compares two case studies in which gravel foundations for steel oil tanks were built in early winter. The subzero weather presented challenges in the preparation of the site and the compaction of the gravel due to water freezing in the gravel and frozen subgrades. This conference paper will be useful to the pipeline industry in planning future tank foundations constructed in subzero temperatures. The first case studies a project — Tank 46 at Hardisty — that used aluminum coils running hot water to keep the overlying sand and gravel warm prior to placement and compaction. The second case studies a dual project — Tanks 301 and 302 at Kirby Lake — that used a heated tent to cover the tank foundation work as well as “tiger torch”-heated culverts to warm the overlying gravel stockpiles. The goal was to maintain water content in the gravel unfrozen until the design compaction levels were achieved. The two cases are compared on the effectiveness of compaction, ease of workflow and costs.