ABSTRACT
"Rocks of Silurian age form the basement or 'bedrock' of the entire Melbourne area. The widespread distribution and great thickness of the Silurian age sedimentary rocks, and the very similar lower Devonian and Ordovician age sedimentary rocks, in the Melbourne region, makes them the ultimate supporting or host rock for all engineering works in this area. Engineering works of interest generally consist of structures founded on the mudstone, excavations into the mudstone, and use of the mudstone as a construction material. A weathering classification for Melbourne mudstone as presented by J. L Neilson, was based on earlier classifications and has been used as the basis for subsequent classifications. The methods of evaluating foundation conditions in Melbourne mudstone, particularly the strength and deformation properties of the rock mass, range from indirect to direct. The geotechnical design of footings founded in Melbourne mudstone requires an assessment of the strength and deformation properties of the rock mass.
