Effects of Carbonate Distribution Inhomogeneity on the Improvement Level of Bio-cemented Sands: A DEM Study

Aoxi Zhang*, Anne Catherine Dieudonné

*Corresponding author for this work

Research output: Chapter in Book/Conference proceedings/Edited volumeConference contributionScientificpeer-review

Abstract

Microbially induced carbonate precipitation (MICP) involves bacteria to drive calcite precipitation and naturally cement soils, thereby improving soils performance. Experimental studies have shown that bio-cemented specimen can suffer from severe spatial inhomogeneity of the calcite content, leading to large uncertainty in treatment efficiency prediction. To evaluate the effect of inhomogeneity on the mechanical behaviour of bio-cemented soils, the discrete element method (DEM) is used to model bio-cemented samples with a single carbonate distribution pattern (i.e. either bridging or contact cementing) but different characteristics of inhomogeneity. Both drained triaxial compression and triaxial extension simulations are carried out to evaluate the impact of inhomogeneity along different loading paths. The results indicate that inhomogeneity has different effects on bio-cemented samples depending on the carbonate distribution patterns and the loading path. Specifically, the shear strength in compression of samples exhibiting bridging cementation is largely affected by inhomogeneity, while the effect on shear strength in extension is negligible. On the other hand, samples with contact cementing show limited sensitivity to the variation of inhomogeneity under both triaxial compression and triaxial extension tests.

Original languageEnglish
Title of host publicationChallenges and Innovations in Geomechanics
Subtitle of host publicationProceedings of the 16th International Conference of IACMAG
EditorsMarco Barla, Alessandra Insana, Alice Di Donna, Donatella Sterpi
PublisherSpringer Science
Pages554-561
Number of pages8
Volume3
ISBN (Print)9783031128509
DOIs
Publication statusPublished - 2023
Event6th International Conference of the International Association for Computer Methods and Advances in Geomechanics, IACMAG 2022 - Turin, Italy
Duration: 30 Aug 20222 Sep 2022

Publication series

NameLecture Notes in Civil Engineering
Volume288 LNCE
ISSN (Print)2366-2557
ISSN (Electronic)2366-2565

Conference

Conference6th International Conference of the International Association for Computer Methods and Advances in Geomechanics, IACMAG 2022
Country/TerritoryItaly
CityTurin
Period30/08/222/09/22

Keywords

  • Bio-cemented soil
  • DEM
  • Inhomogeneity
  • MICP
  • Shear strength

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