This year’s theme ‘Expanding Underground’ will focus on the knowledge and passion the tunnelling industry offers to make a positive impact on the world. Highlighting the multiple advantages and solutions that the underground space can provide with a whole new era of smart technology, where sophisticated digital tools are rapidly changing investigation, design, construction and operation methods and strategies.
SMEC’s technical specialists Alexandre Gomes (Chief Technical Principal), Helen Baxter-Crawford (Principal Engineering Geologist), Leonardo Rosas Sanchez (Principal Engineer), Ivan Ching (Principal Engineer), Ali Keneti (Senior Associate Engineer), Dante Tsang (Principal Engineer) and Sam Azari (Associate Engineer- Tunnels) thought-provoking technical papers have been accepted.
Our Technical Papers
Conceptual Framework of the Snowy 2.0 Pumped Storage Project (PSP) Geotechnical Baseline Report (GBR) for Underground Works
Alexandre Gomes (Chief Technical Principal – Tunnels and Underground), Ben Chapman (Tunnel Engineer and GBR Lead), M.S.Diederichs (Professor Geological Engineering), Ivan Ching (Principal Engineer – Tunnels)
The Snowy 2.0 pumped hydro project in Australia is situated within a complex alpine geological and hydrogeological setting which entails significant geotechnical uncertainties for sub-surface construction. To address this condition, a Geotechnical Baseline Report (GBR) has been incorporated in the construction contract of underground works to stipulate the allocation of geotechnical risks. This paper outlines the conceptual framework used in the preparation and development of this GBR and associated risk-sharing mechanisms.
Numerical analysis of a shallow underground mined cavern and ancillary tunnels in Sydney using PLAXIS 3D
Sam Azari (Associate Engineer – Tunnels), Dante Tsang (Principal Engineer – Tunnels), Alexandre Gomes (Chief Technical Principal -Tunnels and Underground), Arjun Shivasami (Principal Tunnel Engineer)
Development of metropolitan areas requires the implementation of modern infrastructure projects and the use of underground space to provide efficient transportation, conveyance of water, and installation of services. This paper presents the methodology and challenges associated with the preliminary modelling of an unprecedented large-span shallow underground mixed metro station cavern and ancillary tunnels in Sydney’s Central Business District.
Televiewer defect aperture logging for detailed model development – A case study from the M8, Sydney, Australia
Helen Baxter – Crawford (Principal Engineering Geologist), Aaron Lippett (Senior Tunnel Engineer)
The M8 is part of Sydney’s WestConnex road tunnel network, comprising twin road tunnels connecting the M5 South-West to extensions of the M4 and M8 to the north. A three-phase drilling program was designed with grout-holes to be drilled by percussion methods and logged with a televiewer probe to facilitate targeted grouting of unfavourable features. This paper discusses the processes involved in the data collection, the 3D modelling that eventuated from the assessment and the coincidental benefits gained by the project by completing the grouting program.
A 3D numerical study of sprayed concrete lined junctions
Ali Keneti (Senior Associate Engineer – Tunnels)
In this study, advanced three-dimensional numerical simulations investigate the structural-ground interaction during the sequential excavation of an adit off a vertical shaft. Real case study data from the Heathrow Airport Terminal 5 project is used to validate the results of the numerical analysis. The results highlight the key influences at an underground junction and thereby can provide a design basis to improve the efficiency of design at junctions and associated tunnels.
Fair Risk Allocation in Tunnelling: A Game Modelling Approach
Leonardo Rosas Sanchez (Principal Engineer – Tunnels)
Tunnelling involves risks that are unique. In order to manage risks, the tunnelling industry has supported risk sharing approach. In this paper, Game Modelling Theory is used as an analysis tool of risk allocation in a tunnel construction contract. Game Theory is a branch of applied mathematics devoted to the logic of decision making in social interactions. The unfair allocation of risk is affecting the reputation of the tunnelling industry, Game Modelling can be utilised as an effective educational tool.