新建隧道下穿运营隧道爆破减振方案与实施

Blasting Vibration Reduction Scheme and Implementation for New Tunnel Passing Through the Operating Tunnel

以福厦客专厦门北进岛联络线新大帽山1、2号隧道下穿运营高铁新刘塘1号隧道为背景,开展硬质岩地层条件下新建隧道下穿运营隧道爆破减震技术应用研究。通过在试验段选取与交叉点岩性相似处打设仿真试验井,开展爆破振动监测试验,研究几种方案的爆破减震效果并应用于现场施工。研究表明:微差爆破原理产生的应力波相互叠加抵消,可以减小爆破振速;预设减震孔+控制爆破方案的平均减震效率随与试验井距离的减小呈现增大的趋势,而绳锯掏槽+控制爆破方案减震效果优于预设减震孔+控制爆破方案;当爆破振速在6~7 cm/s时,可采用预设减震孔+控制爆破的减震措施,在7~9 cm/s时,可采用绳锯掏槽+控制爆破的减震措施,将振速降低至弱影响区;依托工程采用预设减震孔+控制爆破方案的振速满足控制标准,可为类似工程提供借鉴。

Taking the New Damaoshan No.1 and No.2 Tunnels of Xiamen North Station Island Entry Connecting Line of Fuzhou-Xiamen Passenger Dedicated Railway passing through the New Liutang No.1 Tunnel of the operating high-speed railway as the background, the application research on blasting vibration reduction technology of the new tunnel passing through the operating tunnel under the condition of hard rock stratum was carried out. By drilling simulation test wells in the test section where the lithology was similar to the intersection, the blasting vibration monitoring test was conducted to study the blasting vibration reduction effect of several construction methods and apply them to the site construction. The results show that the stress wave generated by millisecond blasting can reduce the blasting vibration velocity by superposition and cancellation;the average damping efficiency of the preset damping hole+controlled blasting method increases with the decrease of the distance from the test well, while the damping effect of the rope saw cutting+controlled blasting method is better than that of the preset damping hole+controlled blasting method;when the blasting vibration speed is between 6 cm/s and 7 cm/s, the damping measures of preset damping holes+controlled blasting can be adopted;when the blasting vibration speed is between 7 cm/s and 9 cm/s, the damping measures of rope saw cutting+controlled blasting can be adopted to reduce the vibration speed to the weak influence area;the vibration velocity of the preset damping hole+controlled blasting method applied in the project meets the control standard, which can provide reference for similar projects.