Blue in Sherpa: Author's Pre-print: archiving status unclear Author's Post-print: author can archive post-print (ie final draft post-refereeing) blue in Sherpa: Publisher's Version/PDF: archiving status unclear General Conditions: •Publisher's version/PDF cannot be used, except on Intranet •Internet website or institutional repository •Must link to publisher version at ASCE Civil Engineering Database(http://cedb.asce.org) •Publisher copyright and source must be acknowledged LL 30.6.14. Requested (Perera) Accepted v. & Permission, 31.7.14-MMM. Received permission 7.8.14-MMM, File received 11.8.14-MMM. Supporting documentation added to dark upload - HD 31/5/18