隧道扩挖既有衬砌的爆破拆除

以浙江温岭楼山隧道扩挖工程为背景,采用ANSYS数值模拟软件对两种工法下隧道拱顶既有衬砌的爆破拆除方案进行对比,研究不同的爆破开挖方案对隧道周边岩土体及既有隧道产生的影响。其中,工法一对隧道I部分衬砌及上方I部分岩土体同时进行开挖;工法二则对上述两部分进行分部开挖。通过对两种工法下监测点的振动速度进行研究分析,并参考GB 6722—2014《爆破安全规程》,对比选出合适的爆破拆除方法。结果表明:两种工法左侧未开挖隧道的振动速度均低于安全标准;工法一的爆破振动速度相对较大,隧道右洞质点振动速度大于安全允许值;采用Matlab对右洞监测点的振动速度进行拟合,获得了爆破振动衰减规律。

Blasting Demolition of Existing Lining in Tunnel Expansion Excavation

Based on the project of expanding and digging Wenling Loushan Tunnel in Zhejiang, the blasting demolition schemes of existing lining of tunnel arch roof under two engineering options were compared by ANSYS numerical simulation software, and the influences of different blasting excavation schemes on surrounding rock and soil mass and existing tunnels were studied. In construction method 1, the lining of part I of the tunnel and the rock and soil mass of part I above the tunnel are excavated at the same time. In construction method 2, the above two parts are excavated by segments. Vibration velocity of monitoring points under the two construction methods were analyzed. According to Safty Regulations for Blasting (GB 6722—2014), it was concluded that blasting vibration velocities in the two construction methods meet the standard. Vibration velocity in construction method 1 is relatively large, and that of the particle point in the right hole of the tunnel using engineering method 1 is greater than the safety allowable value. Matlab was used to fit the vibration velocity of the monitoring point in the right hole, and the blasting vibration attenuation tendency was obtained.