Pore water pressure and liquefaction response of layered fine soils undergoing cementation

Cemented paste backfill (CPB) is fine-grained soil undergoing cementation. It is widely used in underground mining operations for ground support and mine waste (tailings) disposal. In the field, CPB may be placed in one layer (continuous filing), or multiple layers (discontinuous or sequential filling). Till today, no studies have addressed the effect of the different filling strategies on the response of CPB during cyclic events by using the shaking table technique. This manuscript presents new findings of investigating the effect of the different filling strategies of CPB on its geotechnical response to dynamic loading. CPB samples were prepared with different scenarios, including one Layered-CPB (discontinuous filling) sample at which each layer was cured to different curing time, and two unlayered-CPB (continuous filling) that were cured to 2.5 hrs and 4.0 hrs, respectively. All samples were exposed to same cyclic loading conditions using 1-D Shaking table. Geotechnical parameters or characteristics, including pore-water pressure, settlement, volumetric water content and liquefaction susceptibility were monitored or determined before, during, and after shaking. Obtained results indicate that Layered-CPB samples are resistant to liquefaction under the studied loading conditions, while the unlayered-CPB samples are prone to liquefaction under the studied conditions when they are cured to less than 4.0 hrs of curing time.