五沟煤矿饱水砂层注浆过程中地电场响应规律OA

Objective:To address the unclear grout diffusion mechanism and the insufficient understanding of geoelectrical response characteristics during grouting in saturated sand strata,indoor grouting simulation experi-ments were conducted to investigate the grout diffusion behavior and its geoelectrical response characteristics in saturated sand layers,so as to provide a theoretical basis for real-time monitoring and performance evaluation of grouting-based water control and strata reinforcement in underground engineering.Methods:A saturated sand layer was constructed in a three-dimensional physical model with dimensions of 82 cm×82 cm×82 cm,and grouting experiments were carried out under a grouting pressure of 0.3 MPa.Based on the indoor three-dimen-sional model and a parallel electrical monitoring system,the exciting current,self-potential,primary field poten-tial,and apparent resistivity were dynamically monitored throughout the entire grouting process.The spatiotem-poral evolution characteristics of these electrical parameters during grout diffusion and consolidation were then systematically analyzed.Results:The experimental results showed that the exciting current was a sensitive elec-trical parameter for characterizing the grout diffusion and consolidation processes,effectively reflecting the ad-vance of the grout front and the evolution of conductive pathways.At the initial stage of grouting,the exciting current decreased from approximately 0.75 mA to 0.65 mA.Subsequently,with the displacement and mixing of grout and pore water,the electrical conductivity increased,and the exciting current rose to approximately 0.80 mA before gradually stabilizing.Both the self-potential and primary field potential exhibited pronounced fluctu-ations and increasing trends during grouting,which effectively revealed the migration pathways and diffusion range of grout at different strata levels.Owing to the heterogeneity of the weathered zone,the variations in elec-trical parameters were more complex,with stronger spatial differences and instability,whereas the responses in the saturated sand layer were relatively consistent.The three-dimensional inversion results of apparent resistivi-ty indicated that the resistivity generally decreased first and then increased during the grouting process.During the grouting stage,grout entered the formation and mixed with pore water,forming a low-resistivity zone of ap-proximately 50 Ω·m.During the consolidation stage,as cement hydration intensified and pore spaces were pro-gressively filled,the free water content decreased and the conductive pathways within the pores were weakened,resulting in a gradual increase in resistivity to above 150 Ω·m.Conclusions:Grout diffusion and consolidation in saturated sand strata induce significant geoelectrical responses during the grouting process.Among the moni-tored parameters,the exciting current is the most sensitive to the advancing grout front and consolidation evolu-tion,while the self-potential,primary field potential,and apparent resistivity can characterize grout migration and consolidation features from different perspectives.Grout consolidation in saturated sand strata exerts a pro-nounced weakening effect on conductive pathways,leading to significant electrical property variations.The re-sults of this study can provide a reference for the real-time monitoring,dynamic identification,and engineering evaluation of grouting-based water control and reinforcement effects in underground engineering such as coal mines.