Abstract:This paper focuses on the Qitou Mountain mining project in Sanmen County, Taizhou City, employing Plaxis2d for the simulation of the excavation process from small to large section adits. The results indicate that for large and small section adits, the crown settlement amount during sidewall pilot tunnel climbing excavation method is approximately 8.0% and 5.0% higher than that of the middle pilot tunnel, respectively. Considering the low construction efficiency caused by too small single-round advance and the poor safety associated with too large single-round advance, for small section adits, the single-round advance should be controlled at 2.5m, with the number of daily blasts during sidewall/middle pilot tunnel excavation not exceeding two times; for large section adits, the single-round advance should be controlled at 3.0m, with the number of daily blasts during sidewall/middle pilot tunnel excavation not exceeding three and two times, respectively.
