Intact Rock Strength Of Neranleigh-Fernvale Strata

The Neranleigh-Fernvale strata outcrop and underlie much of the Brisbane CBD and surrounding city areas. Many high-rise buildings and significant sections of recently constructed tunnels in the city are founded in these rocks. This paper reviews some key factors impacting on intact rock strength. Indicative strength values are provided as a guide for the conceptual design of engineering structures constructed in these strata. Strength estimates may be confounded because laboratory tests are often limited to a narrow range of foliation dips (25˚ to 45˚) relative to the direction of compressive loading of the test samples. There is a convincing correlation between weathering and strength.