Effect of microbial on the engineering properties of cement/lime treated clays

2014 Fiscal Year Final Research Report

• Project/Area Number: 24656288
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Geotechnical engineering
• Research Institution: Saga University
• Principal Investigator: CHAI Jinchun 佐賀大学, 工学(系)研究科(研究院), 教授 (20284614)
• Co-Investigator(Kenkyū-buntansha): HINO Takenori 佐賀大学, 低平地沿岸海域研究センター, 教授 (20295033)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: ウレアーゼ / 炭酸カルシウム / 粘性土 / せん断強度

Outline of Final Research Achievements

The effect of urease (from the powder of sword bean) induced precipitation of CaCO3 and therefore, the increase of undrained shear strength (su) of clayey soils has been investigated experimentally. Define mixing urease, urea and CaCl2 into distilled water at the same time as Method-1; mixing the urease and urea first, and when the metabolic activity of the urease animated, then adding CaCl2 as Method-2. The test results indicate that the Method-2 had a higher CaCO3 precipitation ratio (amount of precipitated divided by the theoretical value). However, the CaCO3 crystal of the Method-2 was in powder form, while lumps for the Method-1. As for the value of su of the improved clayey soils, in case of the Method-1, the higher the amount of CaCO3 precipitation, the higher the value of su. While in case of the Method-2 there is no such clear relationship.

Free Research Field

地盤工学