An Improved Rotating Soak Method for MICP-Treated Fine Sand in Specimen Preparation

摘要

An improved preparation method for microbial-induced carbonate precipitation (MICP)-treated fine sand was studied in this article. By improving the test apparatus and adding some additives, the specimens had more comprehensive contact with calcium source solution. Unconfined compression strength (UCS) and triaxial shear strength (TSS) were tested on the specimens prepared through this improved experimental method. Three different bacteria concentrations, two additives with six addition amounts, and a nonadditive were prepared in the process of UCS and TSS testing. The results indicate that the UCS increased 2.7 times and the precipitated calcium carbonate in the core increased 1.6 times through this improved experimental method. The uniformity of specimens was also significantly promoted through this method. The optional bacteria concentration and the best amount of additive addition were proposed in consideration of mechanical performance and environment friendliness. Moreover, the improved preparation method presents a meaningful experiment exploration applying MICP technology to more extensive soil.