The interaction of biological materials with geotechnical processes has long been ignored by geotechnical engineering, and its importance is just beginning to be realized. In the 2006 report from the National Academy of Sciences entitled “Geological and Geotechnical Engineering in the New Millennium: Opportunities for Research and Technological Innovation” the role of biological processes in soil behavior is identified as a technical area that has not been accounted for and is cited as a critical research thrust and opportunity for the future. Biological materials are unique by their innate characteristics of being self-active and re-growing within geotechnical soil matrices. The biological alteration of the mechanical behavior of soils is thus a potential novel path for directed manipulation and improvement of soils.
The soil environment is known to be exceptionally complex and heterogeneous in structure. Such complexity is essential to support plant and animal life by providing an intricate particle-pore matrix that consists of solid, liquid and gas phases for the effective cycling and storage of nutrients. This same complex soil matrix is also the fundamental “building block” for geotechnical engineering. With our increased understanding of soil microbial life this biological activity and its products can be harnessed to provide new innovative solutions for geotechnical problems as well as provide explanation for observed geosystem performance. To address and explore this opportunity, integration of the sciences and engineering is necessary. The complexity of the processes cannot be sufficiently addressed within a single discipline.
The goal of this workshop was to bring together experts from a spectrum of traditional disciplines (e.g. geotechnical engineering, environmental engineering, geosciences, microbiology, soil science, biology) that are leaders in their field, are creative and innovative, and have a personal interest in exploring this new interdisciplinary field. This was accomplished by holding a workshop with about 50 participants, about 50% US and 50% International participants, which was jointly funded by multiple NSF programs and by the EPSRC in the United Kingdom.
The workshop was organized in a manner that gradually progressed build from developing a mutual foundation of understanding of different disciplines, to sharing current research and brainstorming about new opportunities, to identifying the necessary “action items”, or developmental steps, required to mature this field. An informal environment and activities that fostered discussion, brainstorming, and free sharing of ideas was incorporated into the agenda.
The primary research outcomes of the workshop were significant and far-reaching. The primary “state variables” controlling bio-soil processes within each respective traditional discipline were identified and their maturity level assessed. This resulted in identification of substantial research needs in the following overarching interdisciplinary engineering and hard science areas: spatial heterogeneity, soil fabric and pore space architecture, fluid movement and transport, upscaling of biological processes, biological community composition and distribution among others. Further, interdisciplinary participant groups identified significant scientific merit and potential broader impacts in bio-soil controlled applications for mechanical property control, hydraulic flow control, subsurface remediation and waste treatment, energy and carbon sequestration, and agricultural soil-plant interactions.
The emergence of this new interdisciplinary field also necessitates education pedagogical change. Training of students and academicians for interdisciplinary research requires a significant departure from the predominant current education approach wherein an individual becomes highly specialized in scientific/engineering niche. Instead, a “renaissance” education, wherein an individual can speak the technical language of multiple disciplines but is specialized in a specific area, is necessary. Several ideas of education reform to meet this need were discussed and identified.
At the workshop’s conclusion there was overwhelming consensus that a new interdisciplinary field at the cross-roads of biological and soil processes is emerging and it will have a substantial impact on society. In effect, the workshop itself has enabled the primary “chapters”, or topics, of this “book” to be identified and outlined. Hard science and engineering research over the next several decades in the research and education areas identified herein is necessary to begin maturing this new field.