Victoria Chapter

Groundwater and Deep Excavations

Rob Day

Abstract

Due to popularity and a large number of requests, this talk is a longer format of the AGS Vic symposium keynote talk by Rob Day. The presence of groundwater in deep excavations in soil and rock has the potential to profoundly impact bit the stability of the excavation, and the impacts that the excavation can have on the areas surrounding the excavation. This talk is intended as guidance, based on the presenter’s experience, on some of the key considerations and pitfalls that designers of deep excavations should take into account when designing deep excavations where groundwater is present. The presentation will focus on the influences of Melbourne geology and hydrogeology on the design of deep excavations and will provide a brief summary of some of the important groundwater features of the central Melbourne area. A series of generalised examples will be presented to demonstrate some of the important impacts that groundwater can have on the stability of excavations and structural loads on buried structures as well as some of the impacts that dewatering activities can have on areas surrounding the excavation.

About Rob Dayrobday

Rob Day is a Technical Director of Ground Engineering and Tunnelling with AECOM Australia Pty Ltd. He is a geotechnical engineer with over 30 years’ experience in geotechnical design and site investigation, project management and construction supervision. A large proportion of his career has been spent in the delivery of geotechnical and groundwater solutions for major transport infrastructure projects, as investigator and designer for both conventional Construct Only, and Design and Construct projects, and as reviewer on Public Private Partnership projects.

For most of his career, Rob has been based in Melbourne, giving him an extensive knowledge of the geology and geotechnical issues in Victoria. Rob has also worked on underground road/rail and tunnelling projects across Australia, South East Asia, and the Middle East, giving him an international perspective. Some of the deep excavation projects Rob has worked on where groundwater was a key consideration include; a design or review role on three of Melbourne’s major road tunnel projects (CityLink, Eastlink, and East-West Link), lead geotechnical designer on four separate underground metro rail projects (Perth Metro, Bankok Metro, Delhi Metro, and Riyadh Metro), geotechnical independent reviewer for the Victorian Desalination Project, and tender design of Brisbane’s Inner City Bypass.

Venue location

Engineers Australia members participating in AGS technical sessions can record attendance on their personal CPD logs. Members should refer to Engineers Australia CPD policy for details on CPD types, requirements and auditing guidelines.