VPRS 19412 City of Melbourne Underground Railway Test Bore Logs

This series contains bore logs recording exploratory drilling in relation to the development of the Melbourne Underground Rail Loop. Early planning for the Rail Loop began in 1929, when Melbourne’s Metropolitan Town Planning Commission released a report recommending an underground city bypass from Richmond to North Melbourne stations. In 1960, the ‘City of Melbourne Underground Railway Construction Act' was passed, and shortly afterwards test boreholes were drilled by the Mines Department (VA 612) in preparation for the development. Boreholes are used during geotechnical investigation of proposed building sites in the early stages of construction, aiding in determining suitability of the chosen location and final design. Soil samples are collected through drilling in various sites within the proposed location for analysis on earth formation and strata. A borehole chart may show the different layers of soil at different depths and their properties. This data is necessary to determine appropriate foundation type for the build and may also be used to determine piling lengths as suitable for structural standards. The records in this series are illustrative charts showing the depth of the drilling and material struck. Information recorded includes the ‘peg’ number of each borehole, rock type and degree of weathering, geological structures and average joint spacing. The logs were drawn by W.E. Bramford over the period of 1962-1963. One page is marked as revised by J.L. Neilson in 1977. This series may relate to VPRS 18051 Reports, Planning and Building of Melbourne Underground Rail Loop (1958 – 1987), which includes reports by the Mines Department, geological surveys, and geotechnical investigations.