【摘要】 基于复线隧道施工爆破对既有隧道稳定性冲击问题,结合沪蓉线庙垭分岔隧道工程实例,研究了其小间距段施工爆破的振动监测方法、爆破动力特性及其减振控制技术。通过对隧道爆破围岩和衬砌质点振动速度波的频谱分析及其振速预测数学模型的改进研究,分析了隧道振速峰值纵向衰减规律、衬砌振速主频、横断面振速分布规律及爆破掌子面附近振动情况,并以小间距既有隧道中墙迎爆侧破坏为基准,从循环进尺、微振起爆、掏槽结构等方面提出了相邻隧道爆破减振技术措施。研究结论可为类似工程的爆破设计、施工及监测提供参考。更多还原

【Abstract】 Based on the engineering background of the selected bifurcation tunnel,the monitoring way,dynamic behavior and controlling technology of blasting vibration wave induced by close-spaced tunnel excavation were studied for the bifurcation tunnel.By regression analysis of the testing data,a new revised mathematical model of spread of blasting seismic wave was established according to the blasting condition.Through the results of monitoring on blasting vibration,especially the testing data of the particle velocity wave and main frequency of concrete lining tunnel,the longitudinal attenuation of maximal vibration velocity,the dominating vibration frequency of lining,vibration velocity distribution of cross section and vibration near the excavation face were presented.In order to reduce the adjacent blasting vibration of rock masses of close-spaced tunnel,the vibration reduction measures of close-spaced tunnel based on middle rock wall were put forward from circle footage,millisecond vibration,undermine pattern and so on.The study will play an important role in guiding the excavation blasting construction of the tunnel project and assuring the safety of underground structure.更多还原