This　paper　presents　an　update　for　the　reliability-based　robust　geotechnical　design　(RGD)　method　in　the　design　of　a　soil-foundation　system　by　systematically　considering　four　different　potential　failure　modes　including:　bearing　resistance　failure　of　subsoil,　excessive　foundation　settlement,　punching　and　bending　failure　of　the　spread　foundation.　Given　the　uncertainties　in　the　critical　geotechnical　and　structural　parameters,　a　comprehensive　investigation　of　the　reliability　and　robustness　of　the　soil-foundation　system　considering　both　single　failure　mode　and　multiple　failure　modes　were　conducted　in　this　study.　Moreover,　the　optimal　designs　of　the　soil-foundation　system　with　respect　to　robustness　and　cost　efficiency　are　found　on　the　premise　of　satisfying　the　safety　requirements.　The　results　from　this　study　indicate　that　both　the　uncertainties　of　the　geotechnical　and　structural　parameters　should　be　taken　into　account　in　the　RGD　of　soil-foundation　system　considering　multiple　failure　modes.　Without　properly　accounting　for　the　width-to-height　ratio　of　the　foundation,　increase　of　the　footing　geometries　and　the　construction　cost　will　not　always　lead　to　a　safer　and　robust　design.　Besides,　bearing　resistance　failure　of　subsoil　has　most　significant　influence　on　the　reliability　and　robustness　of　the　soil-foundation　system　and　is　identified　as　the　control　failure　mode.