Performance of a Full-Height Panel MSE Wall with Pond Ash Backfill: Sensitivity Analysis and Design Recommendations

Mechanically stabilized earth (MSE) walls have become an inseparable part of the modern transportation infrastructure network. Granular materials best serve the MSE wall backfills. However, their utilization involves economic and logistic constraints, and environmental concerns. Industry byproducts, such as pond ash offer a viable alternative. There have been feasibility studies on the use of pond ash as backfill, but there are still concerns about its use on an industrial scale due to large variations in the material properties of Indian pond ashes and the absence of specific recommendations and design guidelines. The current study attempts to address these concerns with the aid of numerical simulations and sensitivity analysis performed using a robust finite-element (FE) model. These simulations require careful selection of constitutive model and precise determination of model parameters to simulate the stress–strain behaviour and interface interaction of pond ash. It is observed that the maximum lateral displacement of the wall, connection loads, and reinforcement strains are lower for the pond ash backfill case when compared with sand backfill. The sensitivity analysis reveals that the wall displacements, connection loads, and reinforcement strains are fairly sensitive to the variation in angle of internal friction ( \(\phi\) $\varphi$ ), unit weight ( \(\gamma _s\) ${\gamma }_s$ ), elastic modulus number ( \(k_e\) $k_e$ ), and elastic modulus exponent (n) of the pond ash. Based on the sensitivity analysis, limiting values of model parameters for specified design requirements are computed.