Research
Dr Guijie Sang investigates new biocementation techniques for applications in coastal and geotechnical engineering, rock mechanics, and subsurface infrastructure. His work develops microbial and biochemical approaches for improving hydromechanical properties of soil/rock/concrete, addressing challenges such as coastal erosion, slope instability, pile scouring, and subsurface (wellbore/formation) leakage.
Microbially induced carbonate precipitation (MICP)
Guijie’s research develops low-carbon MICP techniques to enhance soil strength and resistance to erosion. His work began with studying the transport and attachment of S. pasteurii in sand, monitoring and modelling hydraulic flow, and delivering MICP fluids to target zones by injection or spraying. These methods successfully transformed loose sand into “sandstone” with an unconfined compressive strength of ~8 MPa. He scaled the process from centimetre-scale column experiments to metre-scale laboratory trials, and later supervised a field project with BAM Ritchies applying MICP to natural soil deposits. Guijie has also worked with industrial and public partners on (1) spray-drying storage of S. pasteurii for MICP applications (EPSRC IAA project: PI); (2) optimising bacterial growth (IBioIC project), and (3) in situ bio-stimulation to protect coastal assets from hydraulic erosion (iPACT project).
His research focuses on:
• Microbial metabolisms for bio-cementation (ureolytic, oxidation of organic compound, microbial CO2 capture)
• Multi-scale bio-cementation tests (in-situ X-CT under compression, lab to field trials on soil/rock improvement)
• Finite Element/Volume Modelling (reactive transport of microbes and chemicals)
• Geotechnical, coastal and subsurface applications
Rock Mechanics; Coupled Hydro-Mechanical-(Bio)Chemical Processes
Throughout Guijie's PhD at Pennsylvania State University, Guijie studied hydro-mechanical properties of subsurface rocks (e.g. shale) by investigating water transport and condensation in shale through analysis of sorption isotherms, transport modelling, and in situ small angle neutron scattering (SANS); detecting mechanical damage and failure of shale under cyclic uniaxial loading using in situ acoustic monitoring and coda wave interferometry; characterizing gas-sorption-induced rock swelling under reservoir condition; and quantifying rock-brine-CO2 interactions using SANS, and synchrotron X-ray computed tomography (CT). Guijie's research interests include:
• Rock Mechanics and Permeability
• Rock-fluid Interactions
• Geophysical Monitoring