ABSTRACT
Subsea pipelines have been used to carry oil or gas produced from fields that lie under the sea to shore. It consumes less energy comparing with other ways of transportations, e.g. tanks (Palmer & King 2008). Due to budget constraints or harsh seabed conditions, most pipelines are just lowered from the lay barge to sea bottom without being buried. In such cases, free spans may form due to the irregularities of sea bed or the scouring of underlying soil.
