TEM inspecting of goaf treatment effect with grouting super high water material

In order to study the feasibility of TEM inspecting the effect of goaf treatment with grouting super high water material, 1D forward modeling was used to obtain the TEM response data before and after grouting, then the data was inversed. The result showed that there were obvious differences between before and after, a fter grouting the max amplification of secondary field induced voltage would be about 40% or100% depending on whether goaf had been water-accumulating or not befo re, the corresponding apparent resistivity would decrease more than 20% after inversion. The practice at a coalmine of North China showed that the change features of apparent resistivity between before and after grouting coincided with the theoretical result, the effective grouted area inferred by the boundary whose apparent resistivit y had decreased more than 20% was basically accurate, this method was feasible and effective.