Design methods of the "Terrasafe" loricate sheet pile

The paper deals with the design procedure of a new prefabricated structure (a "loricate" sheet pile named Terrasafe) for the support of unstable soil. Because of the difficulties in interpreting the complex interaction between soil and structure during installation and during the working life, an experimental in situ campaign was performed, aimed at evaluating the internal forces in the steel frame and understanding the global behavior of the entire structure under service loads, whose results were presented in a previous paper. On the basis of those results, a specific design procedure has been developed. Starting from the assumption that active earth pressure acts on the support elements, the proposed approach, assessing both internal and external (or global) safety conditions, is presented and discussed.