# Research on Grouting Dynamic Monitoring Based on Borehole-Tunnel Joint Resistivity Method
## 5 Conclusions  
In the field of coal mine grouting engineering, we have innovatively developed a tunnel-borehole 3D cross-line monitoring system to achieve precise, comprehensive oversight of grouting processes. By strategically deploying survey lines in tunnels and boreholes, this system constructs a multi-layered, spatially integrated observation network. Coupled with real-time 3D resistivity inversion technology, it dynamically visualizes grout diffusion patterns and trajectories in subsurface spaces. This combination breaks through the temporal and spatial limitations of traditional grouting detection, successfully achieving full-dimensional transparent monitoring of the coal mine grouting process. The transition from 2D profiles to 3D datasets enhances vertical resolution, allowing accurate delineation of grout spatial distribution. When suitable horizontal directional drilling survey lines are unavailable, the vertical accuracy may decrease. Meanwhile, integrating this technology with microseismic monitoring to enhance inter-borehole resolution represents a promising future research direction.  
Real-time dynamic monitoring shows that during the grouting of the F1 fault, the grout diffused along the principal stress axis, forming a \"Y\"-shaped low-resistivity anomaly zone and breaking through the fault structural block to create a continuous water-resisting barrier. The spatial displacement of grout expansion monitored by this technology, combined with parameters, such as grouting pressure and grout injection volume, provides a quantitative basis for dynamic regulation of grouting pressure. After more than 30 days of continuous monitoring, it was captured that water gradually separated from the grout,  
Figure 7: Resistivity profile of grout diffusion distribution.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Stage** & **Resistivity** & **Percentage** & **Planar Diffusion** & **Vertical Diffusion** \\  & **(\(\Omega\)-m)** & **Change** & **Range (m)** & **Range (m)** & **Error Source** \\ \hline Before Grouting & 200 \(\pm\) 5 & — & — & — & Background noise \(\pm\)3\% \\ Diffusion Stage & 180 \(\pm\) 8 & \(-\)10\% & 100 (along 15\({}^{\circ}\) and \(-\)20\({}^{\circ}\) azimuths) & 40 (upward) & Inversion grid error \(\pm\)5\% \\ After Solidification & 220 \(\pm\) 5 & +22\% & — & — & Inversion grid error \(\pm\)5\% \\ \hline \hline \end{tabular}
\end{table}
Table 3: Changes in resistivity and diffusion range during grouting monitoring.  
cement hydration products formed a dense structure, conductive pathways were disrupted, and resistivity increased. No new low-resistivity anomaly zones were detected, providing a basis for grouting evaluation.  
This technology provides a novel solution for evaluating grouting reinforcement effectiveness and preventing water inrush disasters under complex geological conditions. Additionally, it can be applied to the monitoring of roof and floor strata failure during coal mining, as well as grouting monitoring in engineering projects, such as highways and railways.  
Conceptualization, methodology, C.W.; writing--review and editing, L.Z.; project administration, L.Y.; software, B.L. All authors have read and agreed to the published version of the manuscript.  
This study was funded by the National Natural Science Foundation of China (42274103).  
Not applicable.  
The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.  
Authors [PERSON] and [PERSON] were employed by the company CCTEG Xi'an Research Institute (Group) Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.