Structural Reliability Of Retaining Walls Designed To AS 4678 For Permanent, Imposed And Seismic Loads

Part 1 – External Stability

AS 4678-2002 Earth retaining structures may be used to design gravity retaining walls (including reinforced soils, segmental gravity retaining walls and cantilever retaining walls). This paper compares the structural reliability of retaining walls designed to AS 4678, to those designed using other codes, British Code of Practice CP2 and the National Concrete Masonry Association (USA) method of designing reinforced soils.

Part 2 – Earthquake

AS 4678 Appendix I sets out the options for designing retaining walls for earthquake, based on a classification method consistent with AS 1170.4-1993 (which is now superseded) and simplified rules. Some combinations lead to non-conservative design, but only where “failure would result in not more than moderate damage and not more than minimal loss of access”, or “failure would result in moderate damage and loss of services” with low or medium seismicity.