1. Lecturer, College of Engineering and Informatics, National Univ. of Ireland, Galway H91 HX31, Ireland (corresponding author).
2. Geotechnical Engineer, Arup, Ringsend Road, Dublin D04 T6X0, Ireland; formerly, Research Student, College of Engineering and Informatics, National Univ. of Ireland, Galway H91 HX31, Ireland.