Characterising and Dealing with Reactive Soils – A Linear Infrastructure Focus
Graeme Jardine
Black soils, or highly reactive soils, underlie significant amounts of transport infrastructure especially in southern and eastern Australia and to a lesser extent in WA. Several technical papers have considered the effects of black soils on transport infrastructure and there is also extensive literature on their identification by surface expression, as well as their related potential behavioural characteristics. However, there has been less emphasis on the systematic characterisation of black soil in relation to depth, and especially the effects of differing soil moisture profiles. A consistent method for logging physical characteristics of black soil would augment standard logging to AS1726. This presentation looks at potential optimum methods for identifying black soil extents in the field (utilizing more recent technology), a brief review of historical black soil characterisation and suggests a more detailed approach linking physical attributes to possible process thereby defining possible design and construction approaches to minimize their reactivity. Taking this assessment the presentation then explores the potential best methods of ground engineering investigations to define such soil reactivity, the possible adverse effects on long linear infrastructure of these soils and the potential methods which could apply to nullify or minimize this geohazard.
Graeme Jardine Technical Director, Global Subject Matter Expert Engineering Geology Jacobs
Graeme has over 35 years’ experience in geotechnical engineering / engineering geology, natural terrain hazard and slope stability assessment, onshore and offshore construction supervision, dredging, site investigation on land and overwater, and ground conditions evaluation in a diverse range of both soil and rock environments, both within Australia and internationally. Projects he has worked on include roads, railways, tunnels, dams, mining operations, water and gas pipelines, bridges/viaducts, airports, reclamations, dredging and drainage projects, power stations, building structures, landslide assessments, construction material sourcing, and nuclear. Graeme has lead geotechnical / engineering geological design teams including JV’s and Alliances, undertaken technical advisory roles, Resident Engineer, SME roles, Superintendent’s Representative, checking engineer, as well as part of a team for tender evaluation and claims assessments for a number of major infrastructure projects. Graeme is Jacobs Global Subject Matter Expert in Engineering Geology and is responsible for the technical quality of works, mentoring, training & development of the Company’s staff. He is called upon by the Company internationally to provide key technical support for a huge portfolio of projects including infrastructure, water, power & resources industries. Graeme’s experience with reactive soils covers a number of years of working on both long linear infrastructure and major buildings around Australia, from identifying their extents, to detailed descriptions in the field, relating their site characteristics with probable behaviour and coping with their reactivity in terms of design and construction advice.
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