ST-GeoNet: a spatio-temporal attention network for interpretable factor of safety prediction in open-pit oil sands slopes
摘要
Accurate prediction and interpretation of the Factor of Safety (Fs) are critical for making risk-based decisions in open-pit mines. Historical surrogate models have typically treated geotechnical variables in a geospatial sense (2D) and used separate historical monitoring data in a temporal sense (3D). This limits the ability to determine how the instability mechanism changes across different mining phases. To mitigate this issue, we propose ST-GeoNet, the first dual-branch architecture that integrates phase-aware Transformer temporal attention with the Convolutional Block Attention Module (CBAM) spatial refinement for interpretable Factor of Safety prediction in multi-phase open-pit slopes. Unlike prior spatial-only surrogates, ST-GeoNet jointly processes high-resolution 2D geotechnical fields and multi-phase monitoring sequences to capture both spatial heterogeneity and time-dependent kinematic signatures. The proposed architecture employs a Convolutional Backbone (with Convolutional Block Attention Module (CBAM) spatial feature refinement) and a lightweight Transformer Encoder (with temporal attention) for phase-aware sequence modeling. The gated fusion module takes two context vectors and combines them into a single scalar prediction of Fs, while also exporting interpretable attention maps for engineering diagnostics. The model was developed and tested on a physics-based data set of 8,000 scenarios, including geomechanical properties calibrated to published experimental results for oil sands. Results from multiple randomly seeded evaluations demonstrate that ST-GeoNet has a mean test RMSE of 0.119 and