微生物改性水泥土的制备与力学特性研究

花岗岩残积土在我国华南地区广泛分布,由于其具有明显的遇水崩解特性,往往带来山体滑坡等地质灾害.基于微生物诱导碳酸钙沉淀技术(MICP)采用巴氏芽孢杆菌对水泥加固花岗岩残积土的工程性质、工程技术进行改良研究,探究以水泥掺入量、钙离子浓度和钙源等因素为变量时,MICP技术对水泥土强度、应力应变关系等力学性能的影响.通过无侧...

Preparation and Mechanical Properties of Cement Soil Modified by Sporosarcina pasteurii

Widely distributed in south China, granite residual soil often brings about landslide and other geological disasters as it disintegrates obviously when confronted with water. In this research, the engineering properties and engineering techniques of cemented granite residual soil were improved by adding bacillus pasteurii using microbial induced calcite precipitation (MICP) technology. The influence of MICP technology on the mechanical properties of cemented-soil such as strength and stress-strain relationship was examined when factors such as cement mixing ratio, calcium ion concentration and calcium source were taken as variables. Unconfined compressive strength (UCS) test was conducted to analyze the mechanical strength of cemented-soil strengthened by MICP, and conclusions were obtained as follows: 1) MICP technology significantly enhanced the engineering properties inclusive of strength, stiffness and toughness of cemented granite residual soil; 2) compared with the control group, the maximum growth rate of strength in the test group amounted to 87.5%, and the most economical cement mixing ratio was 15%; 3) calcium chloride and calcium acetate could both improve the toughness of test specimens, and the effect of calcium acetate was superior; compared with the control group, the maximum growth rate of the toughness of the test group reached 69.67% when the calcium ion concentration was 0.5 mol/L.