Numerical Simulation and Stability Investigation on the Excavation Process of Multistage High Steep Slope

Abstract

Using UDEC discrete-element method (DEM) and field monitoring method, the influence rules of slope height, slope angle, and excavation stage on the stress field, displacement field, and stability safety factor of high steep slopes during the excavation process were investigated. Research shows that: (1) the slope displacement and maximum principal stress gradually decrease from the face (top) to the bottom of the slope and increase from the middle (lower) part of the final excavation face to both sides of slope, and the maximum displacement increase and stress decrease with the increase of slope height (angle) (decrease and basically remain unchanged with the increase of excavation stages respectively). (2) The curve of the slope shoulder (top) displacement versus excavation times can be roughly divided into three development stages, i.e., the early stage of steep increase, the middle stage of gradual increase, and the later stage of gentle decline (slope shoulder), gentle decline–steep increase, or steep drop–slow increase (slope top). (3) Under the same slope height (angle) or excavation stages, the safety factor of slope stability first increases and then decreases with the increase of excavation times, and it decreases with the increase of slope height (angle) under the same excavation times (increases with the increase of excavation stages). (4) The results of the numerical simulation reveal the real-time stress and deformation state of high steep slope in the process of multistage excavation, which is in good agreement with the field monitoring results. It is suggested that dynamic information design, construction, and monitoring should be adopted for multistage high steep slope excavation engineering.