A PROPOSAL OF THE NEW METHOD CONTROLLED A PEAK PARTICLE VELOCITY BY BLASTING ON THE SECONDARY TUNNEL OF TWIN TUNNEL

Abstract

In this study, we have proposed the method to control blast vibrations due to secondary tunnel excavation in the twin tunnel constructions. Generally, it is difficult to keep the closest distance between the face of construction tunnel and the vibration monitoring points along pre-existing serviced tunnel. In the pro-posed method, a peak particle velocity (PPV) is controlled on the basis of the attenuation curve between the distance and monitored PPV, which has been compiled and updated based on the vibration monitoring measurements. Moreover, the practicability and utilization of the attenuation curve have been studied in the view of the factors for measured PPV.