微生物灌注加固饱和钙质砂地基的均匀性及抗液化特性

钙质砂常作为人工吹填岛礁地基材料。微生物诱导碳酸钙沉淀（MICP）是加固饱和钙质砂的有效方法。开展微流控芯片试验，监测填充型、裹附型及胶结型碳酸钙沉淀的时空演化过程，揭示不同类型沉淀的生成规律，推导MICP灌注加固钙质砂的对流-扩散-反应控制方程并进行可靠性验证；开展注浆管灌注加固钙质砂地基模型试验，研究加固体微观结构量化指标，建立其与加固体宏观力学参数的经验关系，提出MICP加固地基均匀性定量评价方法；研究灌注参数、浆液参数对加固钙质砂地基均匀性的影响规律，采用响应面法搜索均匀性最优的加固参数组合，提出改善加固均匀性的实用方法；引入加固体宏微观参数间的经验关系，构建考虑加固不均匀性的饱和钙质砂地基抗液化数值模拟方法；开展MICP加固饱和钙质砂地基振动台模型试验并进行对比分析，揭示饱和钙质砂加固不均匀对地基抗液化性能的影响规律，为MCIP技术在饱和钙质砂地基加固中的应用提供理论依据及技术。

Calcareous sand is the main material for artificial hydraulic fill islands. Microbially induced calcite precipitation (MICP) treatment is an effective method to treated saturated calcareous sand.. In this project, The temporal and spatial evolution of three different types (filling, binding, and cementation) of precipitation will be analyzed by the microfluidic chip experiments. The formation rules of different types of precipitation will be revealed. The reactive transport governing equations of MICP grouting will be established. The quantitative index of solid microstructure will be studied. The empirical relationship between the mechanical parameters and the macroscopic parameters of treated soil will be established. A quantitative evaluation method for the uniformity of MICP treated foundation will be proposed. The effect of grouting parameters and slurry parameters on the uniformity of treated calcareous sandy foundation will be studied. Response surface method (RSM) will be used to find out the optimal combination of treatment parameter, and a practical method to improve the uniformity of reinforcement will be proposed. A numerical simulation method of liquefaction resistance of saturated calcareous sandy foundation considering the non-uniformity of reinforcement will be established by introducing the empirical relationship between macroscopic and microscopic parameters of treated foundation. Shake table model tests of saturated calcareous sandy foundation treated by MICP will be carried out to reveal the influence rule of non-uniform reinforcement on the liquefaction resistance performance of foundation. The research results will provide a theoretical basis and technical support for the application of MCIP technology in the liquefaction treatment of saturated calcareous sandy foundation.