Sources of Geotechnical Risk
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Dr. Fred Baynes discusses sources of geotechnical risk in construction projects. He notes that cost or time overruns occur on 20-50% of projects. While ground conditions can pose risks, he argues that project staff are likely a greater source of risk if they do not properly understand the ground conditions. Different types of geotechnical risks include poor project management, contractual issues, unreasonable analytical models or design values, and unforeseen geological details. However, risks can be systematically managed through techniques like comprehensive site investigations and ensuring project staff have proper training and education to understand the site's geotechnical challenges.
Sources of Geotechnical Risk
- 1. SOURCES OF GEOTECHNICAL RISK A talk by Dr Fred Baynes, President of IAEG Point 1: Cost or time over-runs occur on ~20 to 50% of projects. Point 2: Project staff are probably a greater source of risk than the ground conditions www.baynesgeologic.com.au
- 2. A “dry dock” under construction www.baynesgeologic.com.au
- 3. A foundation “problem” www.baynesgeologic.com.au
- 4. Landslides affecting housing and infrastructure www.baynesgeologic.com.au
- 5. Teton Dam - 5 June 1976 - about 4 hours after leak appeared - 11 people were killed www.baynesgeologic.com.au
- 6. West Driefontein Mine – December 1962 – a 3 story crusher disappeared – 29 lives lost www.baynesgeologic.com.au
- 7. ABERFAN • Debris flow of colliery spoil • 3rd slide on 21 October 1966 • 140,000 yd3 hit a primary school • 144 killed including 116 kids under 10 www.baynesgeologic.com.au
- 8. OUR PERFORMANCE? • Geo-engineering risks: –Cost or time over-run ~20 to 50% of projects –Physical failure ~ 1 to 2% for civil, ~ up to 20% for mining projects www.baynesgeologic.com.au
- 9. Geotechnical Risk “the risk to building and construction work created by the site ground conditions (Clayton 2001)” Risk = Hazard x Consequence www.baynesgeologic.com.au
- 10. Is the risk created by the site ground conditions or by the work practices permitted by people? www.baynesgeologic.com.au
- 11. Different sources of risk within the organization PROJECT MANAGEMENT PROJECT RISKS GEOTECHNICAL RISKS TECHNICAL CONTRACTUAL GEOLOGICAL ANALYTICAL PROPERTIES www.baynesgeologic.com.au
- 12. Type of Geotechnical Risk Hazard Poor management of Project management entire geo-engineering process Poor management of site investigation and Contractual contract documentation Analytical Unreasonable analytical model chosen Unreasonable design Properties values chosen Technical Unforeseeable geological details Geological Inherently hazardous ground conditions Unforeseen ground conditions www.baynesgeologic.com.au
- 13. Unforeseen vs unforeseeable – karst cavities www.baynesgeologic.com.au
- 14. “Unforeseen” vs “contractually unforeseen” Remember that Saint Thomas More described lawyers as “a sort of people whose profession it is to disguise matters” www.baynesgeologic.com.au
- 15. Green - people are the source Pink – the ground is the source www.baynesgeologic.com.au
- 16. Geotechnical Risk “the risk to building and construction work created by the site ground conditions (Clayton 2001)” but probably more often created by the project staff not understanding the ground conditions! www.baynesgeologic.com.au
- 17. People are the main source of geotechnical risk – what kind are on your project? www.baynesgeologic.com.au
- 18. Geotechnical risk management techniques www.baynesgeologic.com.au
- 19. CONCLUSIONS • Cost or time over-run ~20 to 50% • Physical failure ~ 1 to 2% for civil, ~ up to 20% for mining projects • Risks can be systematically considered • Project staff are probably a greater source of risk than ground conditions • Established techniques exist and a team of engineering geologists & geotechnical engineers can contribute • Challenge is to manage all the sources of risk • Training and education is a key requirement www.baynesgeologic.com.au