Reliability model test of resistivity sounding for detecting grouting quality of the high-speed railway karst roadbed

According to the realistic difficulty of the quality test of karst roadbed of the highspeed railway, based on the field typical geological section, it has built the indoor model of stenopeic limestone and carried out series analysis of resistivity sounding test data on multiple sections before and after grouting, and also compared it with the real diffusion area in the model. It dedicates that after the cement flow injection, apparent resistivity has decreased obviously than before grouting. When the decreased extent is equal to or above 15% after grouting, its effect is good. The rational test time is 7 days after grouting. However the field test basically verifies the model test´s results, it is significantly controlled by underground water level, and this would cause partial fault judgments.