Blasting scheme and vibration characterization analysis of hard rock tunnel underpass expressway
Based on the working condition of Shancha Tunnel underpass expressway,the heading method is used for excavation,and a detailed blasting and monitoring scheme is formulated.Moreover,the test results are analyzed.It is concluded that the heading method excavation can effectively control the blasting vibration energy and improve the efficiency of single cycle footage.Three vibration velocity components are Vz>Vx>Vy,and the z-direction vibration velocity is used as the criterion for the safety allowable vibration velocity of the underpass section of the expressway.The peak velocity of the particle is proportional to the charge quantity and inversely proportional to the distance of the measuring point.The main vibration frequency domain is distributed in 50-250 Hz,which belongs to the middle and high frequency band.When the peripheral holes are detonated at the same time and the number of holes is large,the instantaneous energy will be sharply increased.The detonation section of the peripheral holes can be appropriately increased to avoid the hazards caused by energy superposition.
万方数据
维普
