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SUMMARY:Sustainable Biogeotechnics: An Overview and Recent Technical Advan
 ces - Professor Jason DeJong (UC Davis)
DTSTART:20160427T183000Z
DTEND:20160427T193000Z
UID:TALK65696@talks.cam.ac.uk
CONTACT:Stefan Ritter
DESCRIPTION:Description: Arguably the next advent for the geotechnical eng
 ineering profession is to recognize that soil itself is a living ecosystem
 .  For example\, more than 106 bacteria are typically present in 1 cm3 of 
 poorly graded quarry sand typically used as backfill or roadway subgrade m
 aterials in engineering works. The living nature of soil can involve biolo
 gical and chemical changes that challenge our traditional understanding/as
 sumptions regarding the time-dependent stability in soils. Over the past 1
 5 years\, geotechnical researchers have formed interdisciplinary teams wit
 h microbiologists and geochemists to merge their knowledge and identify bi
 o-mediated processes that may be accelerated in time to induce changes in 
 soil that result in significant improvements in engineering soil propertie
 s.  More recently\, researchers have started to study biological systems\,
  which have optimized their functions over the millennia within their loca
 l ecological constraints\, to identify the forms\, functions\, and princip
 les of these systems that may lead to bio-inspired engineering solutions t
 hat are more efficient and sustainable than those currently used in engine
 ering practice.\nThis presentation will first present an overview of the e
 merging field of sustainable biogeotechnics by describing frameworks for e
 xploring bio-mediated and bio-inspired technologies\, complimented with se
 veral examples.  Recent technical advances in the bio-mediated processes o
 f biocementation and biofilm formation will then be presented in detail.  
 Biocementation technology\, enabled by microbially induced calcite precipi
 tation at particles contacts in granular soils\, is developing rapidly as 
 it can induce step changes in soil strength\, stiffness\, permeability\, m
 odulus\, etc. Upscaling from the laboratory to full scale implementation o
 n industry projects requires overcoming challenges regarding biostimulatio
 n of native bacteria\, improving treatment uniformity\, and developing met
 rics to verify successful treatment.  Results from recent prototype tests 
 are used to present advances in these issues.  Biofilm formation\, enabled
  by the formation of EPS in the granular pore space\, is promising as it c
 an temporarily reduce the permeability of sands by 500+ times.  Results fr
 om recent laboratory tests are presented to explore the treatment effectiv
 eness\, treatment permanence\, and use of native bacteria in applying the 
 treatment. \n\nShort biography: Jason T. DeJong is a Professor at the Univ
 ersity of California\, Davis.  He received a B.S.C.E. from UC Davis and an
  M.S.C.E. and Ph.D. at the Georgia Institute of Technology.  After working
  at the Centre for Offshore Foundation Systems at the University of Wester
 n Australia and the University of Massachusetts Amherst\, Jason moved back
  to his hometown of Davis\, CA in 2005.\nThrough the Soil Interactions Lab
 oratory he directs research in the areas of bio-mediated soils processes\,
  advanced site characterization\, behavior of intermediate and gravelly so
 ils\, sustainable geotechnical practice\, and deep foundation performance.
 \nHis work has been funded through grants totaling more than $5 million an
 d results have been disseminated through more than 100 publications.  His 
 work has been recognized through the ASTM International Hogentogler Award\
 , the ASCE Huber Research Prize and the Casagrande Professional Developmen
 t Award\, and the Prakash Research Award\, among others.\n
LOCATION:OCR\, St. Catharine's College
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