Comprehensive evaluation of high-steep slope stability and optimal high-steep slope design by 3D physical modeling

摘要

High-steep slope stability and its optimal excavation design in Shuichang open pit iron mine were analyzed based on a large 3D physical simulation technique.An optimal excavation scheme with a relatively steeper slope angle was successfully implemented at the northwest wall between Nos.4 and 5 exploration lines of Shuichang Iron Mine,taking into account the 3D scale effect.The physico-mechanical properties of rock materials were obtained by laboratory tests conducted on sample cores from exploration drilling directly from the iron mine.A porous rock-like composite material was formed for the model,and the mechanical parameters of the material were assessed experimentally;specifically,the effect of water on the sample was quantitatively determined.We adopted an experimental setup using stiff modular applied static loading to carry out a visual excavation of the slope at a random depth.The setup was equipped with acoustic emission(AE) sensors,and the experiments were monitored by crack optical acquirement,ground penetrating radar,and close-field photogrammetry to investigate the mechanisms of rock-mass destabilization in the high-steep slope.For the complex study area,the model results indicated a clear correlation between the model's destabilization resulting from slope excavation and the collected monitoring information.During the model simulation,the overall angle of the slope increased by 1-6 degrees in different sections.Dramatically,the modeled excavation scheme saved over 80 million tons of rock from extraction,generating enormous economic and ecological benefits.