密闭条件下洞口爆破安全防护措施

Measures for Safety Protection in Blasting Construction of Tunnel Entrance Under Closed Conditions

隧道洞口属于工程项目施工的重点,也是较为困难泊地段,尤其是对于采取爆破作业的隧道工程,在洞口爆破过程中会产生强湫的振动、冲击波以及飞石等,具有较大的安全威胁,为了减少洞口爆破的有害效应,需要加强爆破技术控制以及对隧道爆破的安全防护措施等。以厦门轨道交通2号线2标东渡路站~建业路站区间某一暗挖工作面爆破开挖进洞为背景,洞门位于既有车站结构内,在此条件下实施爆破进洞,属于密闭条件洞口爆破作业,结合合理爆破设计,要求达到爆破效果的同时又不对车站结构造成任何损伤,则爆破安全防护措施尤为关键。本文对爆破造成结构的危害原因进行分析,针对性选择切实有效的防护措施,并对爆破防护措施进行试验和总结,为爆破进洞施工进展顺利提供有力支持,也为今后类似条件下爆破安全防护提供宝贵经验。

Tunnel entrance is the key point of engineering project construction, and it is also a relatively difficult area. Especially for tunnel project with blasting operation, strong vibration, shock wave and flying rocks will occur in the process of tunnel entrance blasting, which has a greater security threat. In order to reduce the harmful effect of tunnel entrance blasting, it is necessary to strengthen blasting technology control and safety protection measures for tunnel blasting. Taking the blasting excavation of a certain underground excavation face in the section between Dongdu Road Station and Jianye Road Station of Xiamen Rail Transit Line 2 as the background, the tunnel gate is located in the existing station structure and belongs to the blasting operation under the closed condition. Under this condition, the blasting excavation is carried out. Combining with reasonable blasting design, the blasting effect is required to be achieved and the station is not affected at the same time. The blasting safety protection measures are particularly important for any damage caused by the structure. The reasons of the damage caused by the blasting are analyzed, and the blasting protection measures are tested and summarized, which provides strong support for the smooth construction of the project and valuable experience for the blasting safety protection under similar conditions in the future.