Vibration effect analysis of backward tunnel blasting on antecedent tunnel of small-distance tunnel engineering
In order to study and analyze the influence of the blasting construction of the trailing hole on the leading hole,taking the large-section small clear distance tunnel as the research object,relying on the Mongolia Road Tunnel,conduct numerical simulation.HHT analysis is performed on the vibration test signals after blasting on site,and then the vibration frequency is mainly analyzed,the time-frequency characteristics of the blasting vibration influence signal areconfirmed.The research results show that:when the blasting construction is carried out in the trailing hole,the vertical and tangential vibration velocities of the initial support of the leading hole are obviously smaller than the radial vibration velocity;The radial vibration velocity on the blast-facing side of the rear-going hole is significantly higher than that on the back blasting side,The frequency corresponding to the maximum vibration speed of the back hole blasting is mainly concentrated in the range of 20 Hz to 80 Hz;tensile stress appears at the arch foot of the blasting side of the tunnel lining with small clear distance,which is easy to lead to tensile damage of the tunnel lining.It is suggested to spray steel fiber concreteat this part to strengthen it.
tunnel engineeringblasting vibrationsmall clearancenumerical simulationanalysis of HHT
万方数据
维普
