微生物诱导碳酸钙沉淀孔隙尺度加固机理及模拟进展

Advances in Mechanism and Simulation of Microbially Induced Calcite Precipitation at Pore Scale

摘要:

微生物诱导碳酸钙沉淀（MICP）是一种新兴的加固技术，具有胶结强度高、环境扰动小等优点，但在实际工程应用中仍存在碳酸钙沉淀分布不均匀、成本较高及现场监测难度大等挑战。为揭示MICP固化机理，系统分析了孔隙尺度MICP加固过程中的关键生化反应与传质过程。MICP加固过程涉及微生物新陈代谢产生脲酶诱导尿素水解，从而产生碳酸钙沉淀以填充多孔介质的颗粒间隙，降低结构的孔隙率与渗透率，显著提升结构强度。结合微流控芯片实验研究，梳理了细菌浓度、脲酶活性、胶结液浓度、温度、灌浆方式和土体性质等因素对沉淀分布均匀性及固化效果的影响规律。同时，结合研究目的，从模型完整性、多物理场耦合度等角度总结孔隙尺度MICP数值模型的研究进展和不足。最后，对潜在的研究方向进行了展望。

Abstract:

Microbially induced calcite precipitation （MICP） is an emerging reinforcement technology known for its high bonding strength and minimal environmental impact. However， its engineering applications still face challenges， such as non-uniform precipitation distribution， high costs， and difficulties in field monitoring. To explore the mechanisms of microbial reinforcement， we investigate the key biochemical reactions and mass transport processes involved in MICP at the pore scale. During MICP， the microbial metabolism produces urease， which catalyzes the hydrolysis of urea， inducing calcite precipitation. The precipitation fills the interparticle voids in porous media， reducing the porosity and permeability， and significantly enhancing the structural strength. Based on microfluidic chip experimental results， we investigate the impact of factors on the precipitation distribution and reinforcement effectiveness， such as bacterial concentration， urease activity， cementation solution concentration， temperature， injection strategies， and soil properties. Furthermore， we review the progress and limitations of pore-scale MICP numerical models， focusing on model completeness and multi-physics coupling. Finally， we discuss potential research directions.