On the applicability of viscosity-based capillary bundle concepts to predict the penetration behaviour of polymer solutions into sand

Abstract The increasing use of polymer solutions as support fluids in pile drilling, diaphragm walling or tunnelling applications demands a more detailed discussion their penetration behaviour and prediction thereof. In this context, the capillary bundle approach can be useful tool. However, while it is widely discussed oil gas application, subject currently addressed only scarcely with regard to fluid targeting stagnation, where small flow velocities non-cohesive soil environments are relevance. these boundary conditions, applicability approaches not yet sufficiently confirmed substantiated. current paper thus reviews models based on Hagen–Poiseuille combination power-law rheological model discusses respect application context experimental permeation tests for gradients ( $$i\le 10$$ i ≤ 10 ). Two granular materials similar grain size, but different angularity (glass beads sand), four varying chain length concentration investigated, impact assumptions bulk material input variables systematically discussed. results show that theoretical generally able predict filter velocity qualitatively values above $${\bar{v}}=5\times 10^{-7}$$ v ¯ = 5 × - 7 m/s also quantitatively, when an empirical shift factor $$\alpha ^*$$ α ∗ introduced water permeability determined experimentally. With influence parameters, was found particle roughness decreases solution despite hydraulic conductivity water. Polymer were observed control degree possible dilution ^*<1$$ < 1 ) porous system compared characteristics. It therefore concluded indeed applied targeted fields even though they unable complete stagnation $$i>0$$ > 0 . rather than specific tortuosity, taking into account soil-polymer interaction has shown primary importance ensure no under- over-prediction solely rheology.