Work

Biogrouting for seepage control in rock fractures using on-site bioslurry formation method

Year: 2025

Type: article

Abstract: Biogrout produced via microbially induced carbonate precipitation (MICP) has emerged as a promising solution for seepage control in fractured rock. However, achieving effective underground seepage reduction remains challenging due to the complex interactions among multiple influencing factors. In particular, balancing the rapid formation of calcium carbonate (CaCO 3 ) with the need to avoid clogging during biogrout injection is critical but not yet fully understood. This study investigates the key parameters affecting biogrouting performance, including the urease activity of the bacterial solution (BS), the concentration of the cementation solution (CS), and the flow rate of the grout. A novel on-site bioslurry formation method is proposed to enhance the efficiency of biogrouting within the fracture. To evaluate these factors, four small-scale and one large-scale model tests were conducted using transparent rock fracture models. The spatiotemporal evolution of CaCO 3 precipitates during biogrouting was monitored using three-dimensional (3D) scanning and image analysis. The results show that permeability in the large-scale model decreased by up to three orders of magnitude after 9 h of biogrouting. High urease activity (20 U) and elevated CS concentration (1.0 M) significantly shortened the biogrouting duration, while a higher flow rate (3 mL/min) led to faster and more uniform CaCO 3 distribution. Furthermore, the proposed on-site bioslurry formation method improved the calcium conversion efficiency and facilitated faster CaCO 3 formation. These findings provide important insights into the mechanisms of MICP-based biogrouting and offer practical guidance for its application in rock fracture seepage control.

Source: Journal of Rock Mechanics and Geotechnical Engineering

DOI: 10.1016/j.jrmge.2025.08.040

Authors: Bo Liu, Jian Chu, Kangda Wang, Shifan Wu, Kok Pang Lam

Institutions: Nanyang Technological University, JTC Corporation

Language: English

Topic: Microbial Applications in Construction Materials

Subfield: Environmental Engineering

Field: Environmental Science

Domain: Physical Sciences

SDG: Industry, innovation and infrastructure

Open Access status: diamond

Funders: National Research Foundation, Nanyang Technological University, Centre for Urban Solutions, Nanyang Technological University