Electrical resistivity method to appraise static segregation of gangue-cemented paste backfill in the pipeline

For effective prevention of pipe blockage caused by segregation, a real-time electrical resistivity monitoring method is proposed. The cross-sectional horizontal electrical resistivity (HER) at different depths and diametrical electrical resistivity (DER) with different orientations of gangue-cemented paste backfill (GCPB) under different mass concentrations in pipe were investigated. The results show that HER can capture the real-time segregation characteristics. Under the action of segregation, the HER decline rate in the upper region is greater than that in the lower region at the early stage, and the derived segregation index (SI) gradually decreases. The HER difference in the stable HER change stage between layers decreases with an increase in the mass concentration. DER is less sensitive than HER, and can only distinguish the difference of the static stability between the GCPBs with lower mass concentrations (78% and 79%). Finally, the relationship between ER and aggregate distribution determined by image analysis was established.

Automated summary

The use of horizontal electrical resistivity can effectively monitor the segregation characteristics in pipes, with decreasing differences in resistivity between layers as mass concentration increases. Diametrical electrical resistivity is less sensitive to segregation and can only distinguish the stability differences in GCPBs with lower mass concentrations.