This paper demonstrates how numerical modeling can inform the design of a large rockfill dump intended to function as a clay retention structure over a low permeability, saturated clay layer. The objective is to study the stability of the rockfill
dump as construction progresses, while optimizing rock usage and circumventing the need for wick drains to manage pore pressure buildup. These aspects are crucial in large mine projects where the installation of wick drains can become cost prohibitive.
A two-dimensional numerical model was developed based on a proposed dump cross-section and construction sequence. The Hardening Soil with small strain stiffness constitutive model (HSS) and the Plaxis computational platform were used to perform deformation analyses. Following the base case scenario, a sensitivity analysis was conducted to assess the impact of hydraulic conductivity, rate of rise, and clay foundation thickness on dump stability.
The results reveal that numerical modeling can assist owners and practitioners in establishing key monitoring locations for the construction sequence of rockfill dumps on soft clay.
