岩土工程学报2018，Vol.40Issue(1)：38-45,8.DOI:10.11779/CJGE201801002
MICP胶结钙质砂动力特性试验研究
Dynamic behaviors of MICP-treated calcareous sand in cyclic tests
摘要
Abstract
The calcareous sands from an island of the South China Sea are cemented by the microbially induced calcite precipitation (MICP) method. A series of cyclic tests and SEM tests are carried out to investigate the evolutions of the dynamic strength, dynamic deformation, dynamic pore pressure and effective stress path under different degrees of bio-cement as well as the micromechanism of the MICP-treated calcareous sands. The results show that the cyclic stress ratio and resistance to deformation of the calcareous sands are obviously improved due to the MICP method, implying that the MICP method can significantly improve the dynamic properties of calcareous sands. The evolution of the dynamic pore pressure can be divided into four stages: initial phase, stable development phase, rapid development phase and complete liquid phase. The sample begins to collapse when the pore pressure is developed at the later period of the rapid development phase, and the groove appears in the pore pressure curve. In the whole phase, the soil deformation and the change in soil strength are closely related to the development trend of the effective stress path and dynamic pore pressure, and then, the effective stress path exhibits cyclic mobility. The particles of the MICP-improved calcareous sands are wrapped or filled by the calcite precipitation, leading to the changed properties of calcareous sands, which increases the cohesion and internal friction angle of soils.关键词
MICP胶结钙质砂/动强度/动应变/动孔隙水压力/有效应力路径/SEMKey words
MICP-treated calcareous sand/dynamic strength/dynamic deformation/dynamic pore pressure/effective stress path/SEM分类
建筑与水利引用本文复制引用
刘汉龙,肖鹏,肖杨,王建平,陈育民,楚剑..MICP胶结钙质砂动力特性试验研究[J].岩土工程学报,2018,40(1):38-45,8.基金项目
国家自然科学基金项目(51578096) （51578096）
高等学校学科创新引智计划项目(B13024)) （B13024）
