武汉轨道交通广虎区间隧道爆破施工方案优化

Optimization of blasting construction scheme of Guang-Hu section subway tunnels in Wuhan

武汉市轨道交通二号线广埠屯站~虎泉站区间隧道顶部分布有多座5层以下民房及厂房,均为天然浅基础,砖混结构。隧道采用矿山法施工,在穿越灰岩、石英砂岩与中风化砂岩段需爆破开挖。在分析区间隧道周围环境、构筑物结构形式以及地形、地质条件基础上,控制钻孔深度（循环进尺）,采用微差爆破技术,并根据爆破监控反馈信息优化最大单段装药量,将爆破振动控制在设计允许范围内,减少了隧道爆破开挖施工对附近房屋的振动影响,保证了周边建筑物的安全,达到了设计预期的效果。

There are a number of brick-concrete houses and plants which are below five floors with natural shallow foundation on the surface of Guangbutun-Huquan subway tunnel line 2 in Wuhan City.The subway tunnels are designed to be constructed with mine tunneling method.The blasting must be adopted in the excavation of the limestone,quartz sandstone and intermediately-weathered sandstone sections.Based on the analysis of the surrounding environment of the tunnel,building structure,topography and geological condition,through the technological measures of controlling drilling depth（cyclical footage）,short-delay blasting and optimizing maximum mono-section powder charge according to feedback information of blasting monitoring data,the blasting vibration was controlled in permissible scope and the vibration influence on the near-by buildings was reduced,which ensure the safety of the surrounding buildings and the design requirement is achieved.