Mitigation of Liquefaction Hazard using Biotechnologies

J. Chu

In the proceedings of: GeoVancouver 2016: 69th Canadian Geotechnical Conference

Session: CASE HISTORIES - II Seismic Design Aspects

ABSTRACT: Liquefaction of granular materials has long been identified as one of the major geohazards. An experimental study to establish a more cost-effective approach for mitigation of liquefaction hazard through a biological process is presented in this paper. This so-called biogas desaturation method generates tiny inert gas bubbles within liquefaction prone ground to increase the resistance to liquefaction. In order to stabilize the gas bubbles in various groundwater flow conditions and develop a reliable long term solution, a microbial induced calcium carbonate precipitation (MICP) process is also applied. A series of model tests have demonstrated that this combined biodesaturation and bioclogging method is effective for maintaining the long term stability of gas bubbles in sand and reducing pore pressure generation during cyclic loading. Results show that as the degree of saturation of the soil is controlled to be less than 90%, the generation of pore pressure in sand and potential for liquefaction is largely contained.

RÉSUMÉ: économique quant à la Cette méthode dite de désaturation à la liquéfaction. De manière à stabiliser les bulles de gaz dans diverses conditions de nappe, et ainsi développer une solution pérenne sur le long terme, un processus de précipitation microbienne du carbonate de calcium (MICP) est également mis en oeuvre pour stabiliser les bulles de gaz dans le sol. Les essais ont demontré que cette méthode consistant à combiner la bio-désaturation et le bio-colmatage est efficasse pour maintenir durablement la stabilité des bulles de gaz dans le sable ainsi que pour réduire la pression interstitielle induite lors de sollicitations cycliques. Les résultats montrent que lorsque le degré de saturation du sol est controllé pour être inférieur à 90%, la génération de pressions interstitielles dans le sable et le risque de liquéfaction sont largement contenus.

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Cite this article:
J. Chu (2016) Mitigation of Liquefaction Hazard using Biotechnologies in GEO2016. Ottawa, Ontario: Canadian Geotechnical Society.

@article{4140_0721032513,author = J. Chu,title = Mitigation of Liquefaction Hazard using Biotechnologies,year = 2016}