This award supports a 2.5 day international workshop in Lausanne, Switzerland, January 10-12, 2013 for the purpose of exploring and advancing the use of Thermo-active Geotechnical Systems for Near-surface Geothermal Energy as a sustainable geotechnical engineering practice. Thermo-active geotechnical systems are a novel approach to exploit the heat storage capacity of the ground for efficient heating and cooling of structures. The venue of the workshop is École Polytechnique Fédérale de Lausanne in Switzerland. The workshop will be held in a discussion forum format rather than in a conference style setting dominated by presentations. About one-fifth of the event will consist of overview presentations and rest of the time will be devoted to breakout sessions and discussions on resolving contentious issues and exploring future applications of this technology. The main motivation for this international workshop is to discuss and identify the technical and non-technical barriers involved in the implementation of thermo-active geotechnical systems. This workshop will serve as a synergistic discussion platform to bring together researchers from the academia, practitioners, and industry and public agencies representatives, to identify and address the pressing issues. Participants will come from the US, EU, Switzerland and Japan. The diverse mix of attendees from different backgrounds will ensure that communication will be cross-disciplinary and multi-dimensional, while the attendees from different parts of the world will help in transferring practical experience from other countries which have successfully implemented this technology. The technical issues to be addressed in the workshop will include 1) Soil-structure interaction issues related to the design of thermo-active foundation systems, 2) Testing, evaluation and non-destructive verification of these systems, 3) Use of near-surface geothermal energy in dense urban environments with congested and closely spaced foundations, and 4) Future applications of thermo-active foundations; bridge-deck deicing, thermal treatment etc. The non-technical issues that are critical for the wider implementations of these systems are 1) Building code and green-certification issues 2) Environmental impact calculations, 3) Cost-benefit analysis, life-cycle cost analysis, long-term savings. Collectively, these discussion themes will help develop a synergistic dialogue between the workshop participants and create a platform for the discussion and synthesis of ideas for the future direction of research in this field. The main outcome of this workshop will be a series of technical papers along with a synthesis document summarizing the results of the discussion sessions, and a workshop website.
This workshop focuses on this renewable energy technology. This has far reaching impacts than geotechnical engineering through reductions in energy use with wider implementation of this innovative technology. Utilizing energy foundations can ultimately provide a more secure and stable energy source than conventional energy sources, higher energy security for the electric power system, and reduce harmful CO2 emissions. The results of this workshop will have broad impact on the geotechnical engineering profession related to the use of foundation systems for heating and cooling of structures. The workshop has the potential to result in increased use of energy foundations on a broad scale in the United States and globally.
Thermo-active foundations are a novel approach to exploit the heat storage capacity of the ground for efficient heating and cooling of structures. In this approach the deep foundation system of the building is used in conjunction with a heat pump system and geothermal loops, where heat energy is withdrawn or fed into the ground. Researchers from around the world are currently evaluating the feasibility of using geotechnical foundation systems (i.e. piles, foundation rafts, tunnel linings etc.) as heat exchangers for a variety of applications. A schematic of a geothermal foundation system is shown in Figure 1. The technical and non-technical barriers involved in the implementation of thermo-active geotechnical systems were discussed during this workshop. This workshop served as a synergistic discussion platform to bring together researchers from the academia, practitioners, members from the industry and public agency representatives, to identify and address the pressing issues. The diverse mix of attendees from different backgrounds ensured that communication were cross-disciplinary and multi-dimensional, while the attendees from different parts of the world helped in transferring practical experience from other countries which have successfully implemented this technology (Switzerland, Austria, UK, Japan). The technical issues addressed in the workshop included; 1) Soil-structure interaction issues related to the design of thermo-active foundation systems, 2) Testing, evaluation and non-destructive verification of these systems, 3) Use of near-surface geothermal energy in dense urban environments with congested and closely spaced foundations, and 4) Future applications of thermo-active foundations; bridge-deck deicing, thermal treatment etc. The non-technical issues addressed in the workshop included 1) Building code and green-certification issues 2) Environmental impact calculations, 3) Cost-benefit analysis, life-cycle cost analysis, long-term savings. The workshop included six breakout sessions, each with a lead presentation by the session chair and additional short presentations by the participants followed by a group discussion. The discussions took a majority of the session. Session chair facilitated the discussions, which were scribed by a session reporter assisted by a graduate student scribe. The session reporter prepared a synthesis/summary presentation and presented these to the participants. This follow-up session also included additional discussions. The breakout sessions are listed below. Two plenary sessions were run concurrently so that participants would go to the topic of their choosing and the number of participants at each session was kept at a number for better discussion. Breakout Session 1: Identification of the best practices, installation, testing, field testing - Session leader: Tony Amis Breakout Session 2: Building codes, green certification and implementation issues, market challenges - Session leader: Kenichi Soga Breakout Session 3: New technologies and applications; materials and equipment in near surface geothermal systems - Session leader: Rolf Katzenbach Breakout Session 4: Issues involved with thermo-active geotechnical systems: a. Characterization of thermo-mechanical soil behaviour; b. Soil-structure interaction in energy foundations - Session leader: Lyesse Laloui Breakout Session 5: Validation of design tools for thermo-active geotechnical systems - Session leader: Peter Bourne-Webb Breakout Session 6: Environmental impact calculations, life-cycle cost analysis - Session leader: Duncan Nicholson Overall, this workshop served as an important opportunity for training and education activities on energy geostructures. The discussions brought together participants from academic and industry backgrounds. Collectively, these discussion themes helped in the development of a synergistic dialogue between the workshop participants and created a platform for the discussion and synthesis of ideas for the future direction of research in this field.
