Upper-bound solutions for the soil thrust of clay under a track system in 3D conditions.

• Soil thrust allows remotely operated vehicles to move forward. • Three failure modes are geometrically possible at the soil-track interface. • Upper-bound solutions for soil thrust are mathematically derived. • Resultant soil thrust is determined as the least upper-bound solution. • Proposed solution efficiently and accurately predicts the soil thrust. This study proposes a quick and reliable method for estimating the soil thrust in clay ground for a tracked vehicle based on limit analysis in three-dimensional conditions. With respect to the shape and location of failure surfaces in clayey ground, block, triangular wedge, and trapezoidal wedge failure modes were considered. Between the upper-bound solutions from the different failure modes, the least upper-bound solution was proposed as the soil thrust. To verify the proposed solution, it was compared to the model test and numerical simulations for a track system over model clay ground. The proposed upper-bound solution is expected to produce a reliable soil thrust quickly in real time, especially for submerged heavy-weight remotely operated vehicles (ROVs). [ABSTRACT FROM AUTHOR]