Triaxial Shear Behavior And Microstructure Of Microbially Treated Sand Specimens

Authors : Ayşe Özdoğan Dölçek

Pages : 1675-1682

Doi:10.2339/politeknik.986565

View : 202 | Download : 691

Publication Date : 2023-12-01

Article Type : Research Paper

Abstract :The use of bacteria induced calcite cementation for ground improvement presents a relatively new option for geotechnical engineers, one that has the potential to revolutionize the way that we improve soils to prevent liquefaction-induced damage. This technique uses non-pathogenic organisms which are found naturally in the soil environment to cement sand particles together at their particle-to-particle contacts. There is significant potential for a reduction in environmental concerns on various types of projects; in the long-term, this technique may also prove to be an extremely sustainable form of ground improvement. Consequently, the goal of the research described herein is to enhance the state-of-the-art with respect to our understanding of controlling biological cementation processes in soil. Bio-treatment of sand specimens was performed using a commonly encountered urea-producing soil microorganism called Sporosarcina Pasteurii (ATCC-6453). Microorganisms that were suspended in solution were introduced to the soil, and over time the microorganisms were supplied with necessary nutrients via cycling with a peristaltic pump. After bio-treatment, the specimens were back pressure saturated, isotropically consolidated, and sheared under undrained conditions. Scanning electron microscope (SEM) imaging was performed to examine the soil microstructure over a range of specimen curing periods to assess the nature of any cementitious bonds that may have formed.
Keywords : biocementation, shear strength of sand, ground improvement

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