Method for Forming Long-Earth Heart Pattern by Using the Depilation Effect of Inclined and Parallel Holes

摘要

PURPOSE: A long cut design method in underground excavation is provided to minimize the residual hole and improve digging efficiency by simultaneously blasting angle and parallel holes. CONSTITUTION: A long cut design method in underground excavation comprises the steps of: arranging horizontal center hole rows(130) along the central line of a tunnel cut section, arranging horizontal parallel hole rows(150) and angle hole rows at regular intervals symmetrically about the horizontal-center hole rows, symmetrically arranging baby cut rows(110) adjacent to the tunnel center line inside the angle hole rows, and completing charge in the angle hole rows and baby cut rows.