RT - Journal Article T1 - Effect of Biocalcite on some Physical Properties of Sandy Soils JF - JSTNAR YR - 2014 JO - JSTNAR VO - 18 IS - 68 UR - http://jstnar.iut.ac.ir/article-1-2777-en.html SP - 69 EP - 78 K1 - Sporosarcina pasteurii K1 - Sporosarcina ureae K1 - Biocementation K1 - Bioclogging K1 - Soil strength K1 - Saturated hydraulic conductivity. AB - Biocalcite infilling and bridging in a sandy soil was studied in the present research. Effects of 2 bacterial species (Sporosarcina pasteurii and Sporosarcina ureae), 3 reactant concentrations (0.5, 1.0, and 1.5 M of urea and CaCl2 mixture), and 6 reaction times (12, 24, 48, 96, 192, and 288 hr) on saturated hydraulic conductivity and mechanical strength of a sandy soil were studied as a factorial experiment. Soil samples were selected from sand dunes of Joopar area, Kerman Province. Bacterial inoculums and reactant solutions were daily added to soil columns. Results of the study showed that S. pasteuriihad had a higher effect on decreasing hydraulic conductivity of the treated samples (11.57 cm/h) compared to the blank (41.61 cm/h) than S. ureae. Increasing reaction times (from 12 to 288 hrs) and reactant concentrations (from 0.5 to 1.5 M) decreased hydraulic conductivity by 49 and 16 %, respectively. S. pasteurii increased strength of treated samples up to 2.6 Mpa pressure compared to S. ureae. Reactant concentrations and reaction times increased soil strength significantly (2.13 and 4.1 Mpa, respectively). Micromorphological observation showed calcite crystals bridging soil particles and filling pore spaces. LA eng UL http://jstnar.iut.ac.ir/article-1-2777-en.html M3 ER -