TECHNICAL ACTIVITIES TECHNICAL ACTIVITIES MANAGER MARY ELLEN BRUCE Geothermal Energy Foundations Workshop Researchers and practitioners gathered in École Polytechnique Fédérale de Lausanne (EPFL) in Lausanne, Switzerland, to discuss using thermo-active geotechnical systems for near-surface geothermal energy, also known as geothermal energy foundations or piles. The March workshop focused on applications, best practices for design and construction methods, research needs and market barriers to the sustainable use of energy foundations. Over 70 participants from universities, design and construction companies, and owners from all over the world joined the 2.5-day workshop, which was organized by Professors Guney Olgun (Virginia Tech), John McCartney (University of Colorado at Boulder), Lyesse Lalouie (EPFL) and Kenichi Soga (Cambridge University). DFI was represented by Trustee Gianfranco Di Cicco, DFI Past President Tracy Brettmann, DFI ACIP Piles Committee Chair Mike Moran, and DFI Technical Activities Manager Mary Ellen Bruce. Specialists delivered four plenary lectures including: • Advances in the analysis of thermo-active foundations and underground structures (Lyesse Laloui, EPFL) • Future European Union strategic research priorities in the field of geothermal energy and applications to civil engineering (Burkhard Sanner, European Geothermal Energy Council [EGEC]) • Advanced testing of thermo-active foundations and vision for enhanced design (Prof. Kenichi Soga, Cambridge University) • Historical development of energy foundations (Duncan Nicholson, ARUP) Six breakout sessions covered the topics listed below. Summary reports of these breakout sessions are being prepared by the session leaders and will be available on the workshop website at http://www.olgun.cee.vt.edu/workshop/. • Identification of best practices, installation, testing, field testing (led by Tony Amis, Geothermal International) • Building codes, green certification, and implementation issues, market challenges (led by Kenichi Soga) • New technologies and applications: materials and equipment (led by Rolf Katzenbach, Technische Universität Darmstadt) • Issues involved with a.) characterization of thermo-mechanical soil behavior, and b.) soil-structure interaction in energy foundations (led by Lyesse Lalouie) • Validation of design tools (led by Peter Bourne-Webb, Instituto Superior Tecníco, Lisboa) • Environmental aspects and life cycle costs (led by Duncan Nicholson) In addition, DFI will publish a dedicated issue of the DFI Journal on geothermal energy foundations/piles. It is intended that practice- oriented summary reports will be published in this November 2013 special issue. Additional papers for this issue are welcome on any topic related to the design, research, installation and application of energy foundations, piles, and other geothermal heat transfer systems in foundation applications, including: • Best practices for installation, laboratory testing, field testing • Design procedures and tools • Sustainability aspects and benefits • Building codes, “Green” certification and implementation issues • New technologies, applications, materials and equipment • Characterization of thermo-mechanical soil behavior • Soil-structure interaction in energy foundations • Market challenges For more information, or to submit a paper for the special issue, go to www.dfi.org/dfijournal.asp. Amis presented an overview of the design and construction guidelines for energy foundations published in October 2012 by the Ground Source Heat Pump Association (GSHPA). Amis and Nicholson were contributing authors to this guideline document. This docu- ment is available to download free of charge through at http://www.gshp.org.uk/pdf/GSHPA_Thermal_Pile_Standard.pdf. The GSHPA is dedicated to “promoting the efficient and sustainable use of ground source heat pumps, raising awareness of the benefits of ground source heat pumps, developing ground source instal- lation standards, encouraging high standards of training for the industry, providing a forum for information interchange, liaising with related organizations to benefit the ground source industry, and lobbying for Ground Source Energy industry in matters of local, national and international interest to members.” Information on their activities and products are at http://www.gshp.org.uk. Discussions on sustainability and life cycle costing highlighted a need for education on sustainability programs and tools. The group expressed great interest in the EFFC-DFI Carbon Calculator for deep foundations techniques. This user-friendly, spreadsheet- based calculator tool and associated database of standardized carbon factors allow for standardized comparison between different foundation technologies and variations of quantities and materials for specific foundation solutions. The calculator is available through www.geotechcarboncalculator.com. The calculator currently addresses foundation solutions using bored piles (drilled shafts), micropiles, diaphragm walls, slurry walls, sheet pile walls, anchors, grouting and soil mixing. New techniques to be added in 2013 include stone columns, displacement piles, bored pile walls, vibro compaction, jet grouting, soil nails, soldier pile walls, dynamic compaction, dewatering, underpinning, and horizontal drilling. (See article on p. 33) DEEP FOUNDATIONS • JULY/AUG 2013 • 63
