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Submitted on: 06 March 2014.
Revised on: 27 April 2014.
Accepted on: 11 May 2014.
___________________Journal of the South African Institution of Civil Engineering
Submitted on: 18 March 1999.
Revised on: 17 May 1999.
Accepted on: 30 May 1999.
___________________Journal of the South African Institution of Civil Engineering
Submitted on: 23 November 1999.
Revised on: 04 January 2000.
Accepted on: 01 February 2000.
___________________Journal of the South African Institution of Civil Engineering
Submitted on: 26 May 2007.
Revised on: 27 June 2007.
Accepted on: 07 August 2007.
___________________Journal of the South African Institution of Civil Engineering