基于隧道超欠挖控制的周边孔装药结构优化研究OA

The Weicheng Tunnel was taken as the engineering background.In order to ensure the smooth blasting construction effect,an optimization plan for the charge structure of the surrounding holes of the tunnel was proposed.This plan aimed to improve blasting efficiency and reduce unnecessary disturbance and damage to the surrounding rock mass by finely adjusting the charging parameters.To verify the effectiveness of the optimization plan,the blast-ing numerical models of the initial blasting plan and the optimized blasting plan were established.The rock damage distribution,control effect of the tunnel overbreak and underbreak and effective stress of the surrounding rock of the two models were compared and analyzed.The optimized blasting plan was applied to on-site construction.The re-search results indicate that the charging structure of the surrounding holes has a significant impact on the control of overbreak and underbreak in tunnels;By adjusting the charge structure,the effective stress of the tunnel surround-ing rock can be adjusted to accurately control the overbreak and underbreak of the tunnel.Among them,the blasting effects of the two-stage with uniform charge structure were the best,which can not only meet the requirements of overbreak and underbreak control standards,but also better break the rock mass.After applying the optimized blasting plan on site,there was no underbreak on the tunnel face,and the maximum overbreak occurred at the top of arch and the numerical control was within the allowable range of the specifications.This blasting optimization scheme not only reduces the disturbance and damage to the surrounding rock,reduces the consumption of concrete backfill,but also ensures the safe and efficient construction of tunnel engineering.