Research on the Technology for Monitoring and Controlling Blasting
Vibration During Shallow Tunnel Excavation
(1 College of Architecture Engineering, Beijing University of Technology, Beijing 100124; 2 Beijing Municipal Road Engineering Quality Supervision Office, Beijing 100068)
Abstract：
Based on the blasting excavation of the Xisiduhe tunnel of the Huaichang Road reconstruction project, the technology for monitoring and controlling blasting-induced vibration during tunnel construction is addressed in this paper. By monitoring the particle vibration velocities on the ground surface and in the structure, the transmission law of the blasting vibration wave is studied and a spectral analysis is conducted. Finally, a rational controlling technology is presented. The results of monitoring analysis show that: (1) the magnitude of the particle blasting vibration velocity is closely related to the maximum explosive charge of each blasting and the distance between the monitoring points and the blasting center; (2) for left- and right-part blasting excavations on the lower bench, the larger the clamping force of the first blasting on the rocks, the bigger the blasting vibration response and the higher the vibration velocity. Because the first blasting offers a new free face to the second blasting, it can mitigate the blasting vibration effects and decrease the vibration velocity; (3) since the high-frequency components of the particle vibration velocity are not abundant, the dominant frequency of the vibration velocity is mainly distributed in low-frequency band; (4) because the air vents laid on the covered arch at the cut-and-cover section generate the reflecting action of a stress wave, the blasting vibration has a significant influence on the reinforced concrete covered-arch structure.
CHEN Gui-1,
GAO Wen-Xue-1,
LIU Dong-1 etc
.Research on the Technology for Monitoring and Controlling Blasting
Vibration During Shallow Tunnel Excavation[J] MODERN TUNNELLING TECHNOLOGY, 2014,V51(5): 195-198
2014, Vol. 51 