分离式隧道扩建成小净距隧道群爆破震动控制研究

Study on Blasting Vibration Control in Small Clear Distance Tunnel Group Extended by Separated Tunnel

双洞分离式隧道扩建成四洞小净距隧道群的施工必须保证原隧道衬砌结构和新建隧道与原隧道之间中夹岩的稳定。运用三维有限元动力分析方法,对分离式隧道扩建成小净距隧道群的施工过程中原隧道衬砌结构爆破动力响应特性进行分析。根据原隧道衬砌结构最大平均有效应力特征得到了Ⅳ级、V级围岩隧道在不同施工方式条件下的原隧道衬砌结构的最大爆破震动控制速度和控制药量,为隧道扩建设计和安全施工提供了依据。

In the construction that double track separated tunnels extends to four track tunnels group with small clear distance, the stability of the original tunnel lining structure and the interlaid rock between the new and the original tunnel should be must guaranteed. Using three-di- mensional finite element method, the blasting dynamic characterstic of the original tunnel lining structure in the construction process that the separated tunnel extends to the small clear distance tunnel group is analyzed. According to the original tunnel liniing structure characteristic of the maximum average effective stress,the biggest blasting vibration control speed and＇dose of class 1V and V surrounding rock tunnel un- der the condition of different construction mode are given. The basis for entension design and the safety construction of the tunnel are provid- ed.