Abstract: Due to the difficulty of quality test of karst roadbed,based on typical field geological sections,a model of stenopeic limestone is established,and analysis of the results of resistivity sounding test on many sections before and after grouting is carried out,and comparison with the real diffusion area in the model is also performed.The results suggest that after the cement flow is injected into the model,the apparent resistivity decrease more obviously than before grouting.When the decreased ext...