大断面小净距隧道施工对地表变电站的保护措施研究

贵阳市北京东路道路工程#1隧道为大断面小净距隧道,K0+500～+580暗挖段下穿贵乌变电站,埋深浅,地质条件复杂。通过采用洞外对变电站进行加固、洞内CRD六步法开挖、高精度数码电子雷管逐孔起爆的措施,同时加强变电站场坪内地表沉降观测和爆破振速监测,成功穿越了贵乌变电站,地表沉降得到了有效的控制,爆破振速控制在0.4cm/s以内,保证了变电站的结构安全和正常运行。

Research on Protective Measures for Ground Substation by Construction of Tunnel with Large Section and Small Spacing

No. 1 tunnel of Beijing East Road Project, Guiyang City, is a tunnel with large section and small spacing, the underground excavation section of K0 ＋ 500 ~ ＋ 580 is under the Guiwu Substation, the buried depth is shallow, and geological conditions are complex. Through reinforcement of the substation outside the cave, excavation by CRD six steps, hole by hole blasting of the high precision digital electronic detonator inside the cave, and strengthening the observation of the surface settlement and the velocity of blasting vibration on the ground of the substation, the underground section under the Guiwu Substation is successfully excavated, the ground surface settlement is controlled effectively, and the velocity of blasting vibration is controlled within 0. 4cm/s, so that the structure safety and normal operation of the substation is ensured.