ANCHORED WALL DESIGN: COMPARING THE GLOBAL AND PARTIAL FACTORS OF SAFETY INCORPORATING THE AUSTRALIAN STANDARDS
Keywords:
Anchored walls, Global Factor of Safety (GFS), Partial Factor of Safety (PFS)Abstract
A versatile and user-friendly model has been developed for evaluating the factor of safety of anchored
sheet-pile structures, using both global factors of safety (GFS) and partial factors of safety (PFS) methods, abiding
AS 4678 standard, an Australian standard for retaining wall design. The developed model is aimed to determine the
following features: (i) depth of embedment, (ii) total wall height for determining the amount of material required,
(iii) the length of anchor, (iv) the anchor force and (v) the maximum moment acting on the sheet-pile wall. Key
findings are highlighted based on the design calculations. Thisstudy incorporates different design scenarios including
layered soil, line loads and uniformly distributed surcharge loads to draw comparisons between the GFS and PFS
methods. Many examples are used to validate the outputs of the program. The results indicate that the PFS method
is preferred for design strength and safety aspects, whereas the GFS method is adopted for cost effectiveness and
simplicity of design calculations. The limitations of the Australian standard AS 4678-2002 are discussed in order to
identify the superiority of one method over another.