摘要
微生物固化技术是近年来岩土工程领域兴起的一种新型环保地基处理技术,该技术通过向待固化土体内注入细菌,利用细菌水解尿素,并在引入钙源的条件下,诱导产生碳酸钙晶体以胶结松散土颗粒。在微生物固化过程中,碳酸钙晶体分布的均匀性是目前该技术研究的热点之一。文中尝试通过在纯菌液中引入0.05 mol/L氯化钙溶液(称为混合菌液)对细菌分布进行人为干预,并基于动三轴试验及扫描电镜测试,对比分析了纯/混菌液、混合菌液及传统纯菌液等注射方式对微生物固化砂土动力特性的影响。试验结果表明:纯/混菌液注射方式能有效提高微生物固化砂土中碳酸钙晶体分布的均匀性,从而获得碳酸钙含量较高、动弹性模量较大及耗能能力较强的微生物固化砂土。
Microbial-induced calcite precipitation（MICP） is an emerging ground treatment technique in geotechnical engineering. This technique is performed through injecting bacteria into the soil and then hydrolyzing urea into carbanion to induce the calcite crystals at the presence of calcium ions. Accordingly, the precipitated calcite crystals are used to bond loose soil particles together. Distribution uniformity of calcite crystals is a key point for this technique. In this study, calcium chloride solution with a concentration of 0.05 mol/L is introduced into the pure bacteria solution to intervene in the distribution of bacteria, the effects of biological injection methods, i.e. the pure/mixed bacteria solution, the mixed bacteria solution and the traditional pure bacteria solution on the dynamic behavior of bio-cemented sand are analyzed by dynamic triaxial test and scanning electron microscope（SEM） test. The test results indicate that the pure/mixed bacteria solution can effectively improve the distribution uniformity of calcite crystals in bio-cemented sand, obtaining bio-cemented sand with higher content of calcite, greater dynamic modulus and energy-dissipating capacity.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2017年第11期3173-3178,共6页
Rock and Soil Mechanics
基金
国家自然科学基金(No.51478201
No.51278216
No.51308241)
中国博士后科学基金(No.2016M600595)
华中科技大学研究生创新创业项目(No.2015650011)~~
关键词
微生物固化砂土
菌液注射方式
动三轴试验
扫描电镜测试
bio-cemented sand
biological injection method
dynamic triaxial test
scanning electron microscope test
