Case Study Of 9m High Geogrid Reinforced Segmental Block Wall In Southeast Queensland

A 9.0m high geogrid reinforced segmental block wall was designed and constructed in Bethania, southeast of Queensland in 2012. It is currently the highest geogrid reinforced segmental block wall in Australia using the Stone Strong® system. In-situ highly to moderately weathered meta-siltstone and meta-sandstone were adopted as reinforced fill of the wall. Due to the significant depth of residual fill beneath the wall, the wall was designed to be founded on a continuous raft footing supported by drilled concrete piers. At critical sections over the wall length, differential height tiered walls supporting a heavily loaded access ramp were designed. This paper describes the design methodology based on large scale pull-out test results and AS4678:2002 guideline is adopted to assess the stability and deflection of the wall. Finite element and limit equilibrium analyses were performed to verify critical design sections, including sensitivity check on key design parameters from in-situ materials. Construction procedures and methodology to meet the design criteria in achieving the project requirements will be discussed.