Performance Studies of Microbial Induced Calcite Precipitation to Prevent the Erosion of Internally Unstable Granular Soils

2018 ◽  
pp. 37-49
Author(s):  
Fatima-Zahra Haouzi ◽  
Annette Esnault-Filet ◽  
Benoît Courcelles
Keyword(s):  
Performance Studies ◽  
Granular Soils ◽  
Calcite Precipitation

scholarly journals Unsaturated Fluid Flow through Granular Soils Treated with Microbial Induced Desaturation and Precipitation

2020 ◽  
Vol 195 ◽  
pp. 05003
Author(s):  
Elizabeth G. Stallings Young ◽  
Claudia E. Zapata ◽  
Leon van Paassen
Keyword(s):  
Degree Of Saturation ◽  
Granular Soils ◽  
Calcite Precipitation ◽  
Gas Generation ◽  
Soil Matrix ◽  
Carbon Dioxide Gas ◽  
Liquefaction Hazard ◽  
Flow Through ◽  
The Impact ◽  
Precipitation Phase

The use of microorganisms to induce desaturation of granular soils via denitrification results in nitrogen and carbon dioxide gas generation, which in turn lowers the degree of saturation of the soil matrix. Given sufficient substrates, the stimulated bacteria will produce enough gas to develop a continuous gas phase. Introducing gas into the soil to reduce the degree of saturation is shown to increase the soil resistance to dynamic loading and helps to mitigate liquefaction. The impact of desaturation on liquefaction hazard mitigation has comparative value to the calcite precipitation phase of the process. Meso-scale tests have been performed on a relatively thin tank of soil to simulate planar flow through a granular soil treated with MIDP.

Effect of bio-cementation on geophysical and cone penetration measurements in sands

2018 ◽  
Vol 55 (11) ◽  
pp. 1632-1646 ◽  
Author(s):  
Michael G. Gomez ◽  
Jason T. DeJong ◽  
Collin M. Anderson
Keyword(s):  
Ground Improvement ◽  
Engineering Properties ◽  
Granular Soils ◽  
Soil Behavior ◽  
Cone Penetration ◽  
Calcite Precipitation ◽  
Environmentally Conscious ◽  
Empirical Parameter ◽  
Improvement Method ◽  
Limited Sensitivity

Microbially induced calcite precipitation (MICP) is a potentially environmentally conscious ground improvement method that can improve the engineering properties of granular soils through the precipitation of calcite. In this study, an experiment involving two 1.7 m diameter tank specimens was completed to investigate the effect of bio-cementation on cone penetrometer and geophysical measurements in sands. Following nonuniform bio-cementation treatments, specimens achieved calcite contents ranging from 0.5% to 5.3% by mass, shear wave velocity (Vs) values between 131 and 967 m/s, and mid-depth cone penetration resistances (qc) ranging between 3.6 and 32.1 MPa. At calcite contents exceeding 5.0%, qcand Vsimprovements were as high as 527% and 686%, respectively. Although cone penetration resistance, sleeve friction, and friction ratio measurements exhibited limited sensitivity to bio-cementation at calcite contents of less than 3.0%, Vsmeasurements successfully detected bio-cementation at calcite contents near 1.0%. When qcand Vsmeasurements were compared at similar locations, increases in an empirical parameter (KG) enabled improved detection of bio-cementation at calcite contents near 0.5%. Large increases in normalized tip resistances (Qtn) and small decreases in normalized friction ratios (Fr) with increasing bio-cementation resulted in cemented materials plotting near and within the gravelly sand and sand-like dilative soil behavioral type regions using two soil behavior type (SBT) charts.

Effect of Microbial-Induced Calcite Precipitation on Surface Erosion and Scour of Granular Soils

2017 ◽  
Vol 2657 (1) ◽  
pp. 10-18 ◽  
Author(s):  
Ruotian Bao ◽  
Junhong Li ◽  
Lin Li ◽  
Teresa J. Cutright ◽  
Long Chen ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Natural Phenomenon ◽  
Granular Soils ◽  
Surface Erosion ◽  
Bridge Scour ◽  
Calcite Precipitation ◽  
Practical Applications ◽  
Full Contact ◽  
Porous Sediments ◽  
Treatment Procedures

Erosion is relevant to a variety of infrastructure problems such as bridge scour, roadway shoulder erosion, coastal erosion, and riverbank and slope stability. This research investigated the feasibility of using microbial-induced calcite precipitation (MICP) as an erosion countermeasure. MICP is a natural phenomenon in which calcite precipitation occurs as a consequence of microbial metabolic activity. The precipitated calcite modifies the soil fabric and provides an additional bonding force between soil particles. In this paper, a preliminary experimental study on the erosional behavior of MICP-treated sand is presented. A standard soil, Ottawa graded sand, was treated with a bacterium (Sporosarcina pasteurii) in a full-contact reactor-one in which the soil in a fabric mold was fully immersed in the bacteria and cementation solution. The morphologies and crystalline structures of the precipitated calcite in porous sediments were characterized using microscopic imaging techniques. The treated soil samples were tested in a flume to investigate the erosional behavior; both surface erosion and bridge scour tests were conducted. Although the untreated soil is highly erodible, the erosion of the treated sand was found to be negligible under the circumstances of the test; however, some concerns were raised regarding practical applications. Efforts will be made in the future to identify alternative treatment procedures that are more applicable to the field.

We Listen Together

2017 ◽  
Vol 6 (2) ◽  
pp. 92-97
Author(s):  
Craig Gingrich-Philbrook
Keyword(s):  
Performance Studies ◽  
Ways Of Knowing

In this brief essay, the author responds to a performative panel of essays by students of Devika Chawla. He situates his reading of the event betwixt and between typical modes of performance studies research, demonstrating how the panelists reveal narrative's power to reflect on the layering of time, power and privilege, and ways of knowing.

A Performative Memoric Investigation of YoungGiftedandFat

2016 ◽  
Vol 5 (1) ◽  
pp. 51-62
Author(s):  
Sharrell D. Luckett ◽  
Audrey Edwards ◽  
Megan J. Stewart
Keyword(s):  
African American ◽  
Performance Studies ◽  
African American Females ◽  
Stage Manager ◽  
The Arts ◽  
Assistant Director ◽  
Power Negotiations ◽  
Research Collective

In 2013, Sharrell D. Luckett formed the Performance Studies & Arts Research Collective, which encourages members to explore their identities through the arts. Around this time, Audrey Edwards and Megan J. Stewart—both African American females and Collective members—became interested in autoethnography, and Luckett invited them to study closely with her. In this performative essay, Luckett, Edwards, and Stewart implicitly highlight various power negotiations enacted as professor/student, actress/stage manager, actress/assistant director, and mentor/mentee, while all working on their own autoethnographies, and while working collectively on Luckett's autoethnographic performance: YoungGiftedandFat.

The Category Is . . . Opulence!

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Joseph Plaster
Keyword(s):  
Performance Studies ◽  
Knowledge Creation ◽  
People Of Color ◽  
Gender Nonconforming ◽  
Johns Hopkins University ◽  
The Cross ◽  
And Gender ◽  
A Performance

In recent years there has been a strong “public turn” within universities that is renewing interest in collaborative approaches to knowledge creation. This article draws on performance studies literature to explore the cross-disciplinary collaborations made possible when the academy broadens our scope of inquiry to include knowledge produced through performance. It takes as a case study the “Peabody Ballroom Experience,” an ongoing collaboration between the Johns Hopkins University Sheridan Libraries, the Peabody Institute BFA Dance program, and Baltimore’s ballroom community—a performance-based arts culture comprising gay, lesbian, queer, transgender, and gender-nonconforming people of color.

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