Unraveling the shear behaviors of bonding interface for post-grouted sandstones considering the temperature and confining pressure effects

作者：Lei Weng, Haoliang Zhang, Zhijun Wu, Jingyu Wang, Longji Wu, Junjie Shi, Zhaofei Chu, Quansheng Liu, Shaokun Ma, Jiabing Zhang · 发表于：Journal of Materials Research and Technology · 年份：2024 · DOI：10.1016/j.jmrt.2024.04.155 · 被引用次数：15 · 研究领域：Grouting, Rheology, and Soil Mechanics、Rock Mechanics and Modeling、Microbial Applications in Construction Materials

The flow and diffusion of grout within rock fractures, as well as the shear behavior of the grout-rock interface, are notably influenced by grouting conditions, encompassing grouting parameters and geological considerations. Regrettably, owing to constraints imposed by prevailing testing techniques, there exists a scarcity of reports investigating the shear mechanical properties of the grout-rock interface across diverse grouting conditions. This study used a low-field nuclear magnetic resonance (LF-NMR) testing system to conduct permeation grouting tests on fractured sandstones under various grouting conditions, followed by direct shear mechanical tests on the post-grouted samples. The influences of grouting pressure, temperature and confining pressure on the shear mechanical properties of the bonding interface were analyzed. Results showed that higher grouting pressure and temperature conditions led to ductile shear failures due to shear-friction action. An increase in grouting pressure (from 0.5 MPa to 1.3 MPa) increased the peak shear strength and residual shear strength of the post-grouted sample. However, increasing the temperature (from 20°C to 50°C) and confining pressure (from 5 MPa to 15 MPa) decreased the peak shear strength and residual shear strength. Meanwhile, with increasing the temperature, both the internal friction angle and cohesion linearly decline, while an increase in confining pressure decreased the internal friction angle but increased cohesion. A she...