Show simple item record

contributor authorMichael G. Gomez
contributor authorCharles M. R. Graddy
contributor authorJason T. DeJong
contributor authorDouglas C. Nelson
contributor authorMichael Tsesarsky
date accessioned2017-12-30T12:55:02Z
date available2017-12-30T12:55:02Z
date issued2018
identifier other%28ASCE%29GT.1943-5606.0001804.pdf
identifier urihttp://138.201.223.254:8080/yetl1/handle/yetl/4243377
description abstractMicrobially induced calcite precipitation (MICP) is a biomediated cementation process that uses natural microbial enzymatic activity to improve the geotechnical properties of granular soils. In this study, two sets of experiments are completed using soil samples obtained from different depths to evaluate the feasibility of stimulating native ureolytic microorganisms for MICP at depths relevant to geotechnical applications. Batch and column experiments completed using five different stimulation solutions demonstrate that stimulation of native microbial ureolysis is improved with an enhanced stimulation solution, which differs from a standard stimulation solution used in previous studies through initial solution pH adjustment to 9.0 and higher concentrations of ammonium chloride and yeast extract of 100 mM and 0.2  g/L, respectively. A sterile sampling and column testing program is completed using soil materials obtained at shallow (2 m), middle (5.9 m), and deep (12 m) depths from a geotechnical boring and treated with both standard and enhanced stimulation solutions. Despite significant differences in stimulated urea degradation between soil depths and stimulation solution types, all tested columns achieved ureolysis rates sufficient to induce MICP, although at different times. Following 14 cementation treatments, soil columns achieved final Vs values as high as 1,020  m/s and unconfined compressive strengths as high as 1.9 MPa. The results of this study suggest that native ureolytic microorganisms may be successfully stimulated in natural soil deposits to induce calcite precipitation at treatment depths up to 12 m for geotechnical ground improvement.
publisherAmerican Society of Civil Engineers
titleStimulation of Native Microorganisms for Biocementation in Samples Recovered from Field-Scale Treatment Depths
typeJournal Paper
journal volume144
journal issue1
journal titleJournal of Geotechnical and Geoenvironmental Engineering
identifier doi10.1061/(ASCE)GT.1943-5606.0001804
page04017098
treeJournal of Geotechnical and Geoenvironmental Engineering:;2018:;Volume ( 144 ):;issue: 001
contenttypeFulltext


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record